OECD SIDS

SODIUM NITRITEFOREWORDINTRODUCTION

SODIUM NITRITECAS N°: 7632-00-0

UNEP PUBLICATIONS

1OECD SIDS

SODIUM NITRITESIDS Initial Assessment Report
For
SIAM 20
Paris, France, 19-22 April 2005

1. Chemical Name:

Sodium Nitrite

2. CAS Number:

7632-00-0

3. Sponsor Country:

Japan
Mr. Motohiko Kato
Director
Second International Organisations Div.
Ministry of Foreign Affairs
2-2-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8919 Japan

4. Shared Partnership with:
Ube Industries, Ltd.
Seavans North Bldg.,
1-2-1, Shibaura, Minato-ku,
Tokyo 105-8449 Japan
Contact: Mr. Etsuro Ito
Phone +81-3-5419-6242
Fax +81-3-5419-6242.
Nissan Chemical Industries, Ltd,
Kowa Hitotsubashi Building,
7-1, Kanda-Nishiki-cho 3-chome, Chiyoda-ku,
Tokyo 101-0054 Japan
Contact: Kazuo Nagashima
Phone +81-3- 3296-8265
Fax +81-3-3296-8210
Mitsubishi Chemical Corporation
Dai-ichi Tamachi Building,33-8, Shiba 5-chome, Minato-ku,
Tokyo 108-0014 Japan
Contact: Yasukazu UchidaPhone +81-3-6414-3620
Fax +81-3-6414-3638
Sumitomo Chemical Co., Ltd.
27-1, Shinkawa 2-chome, Chuo-ku,
Tokyo 104-8260 Japan
Contact: Tsuneo Nara
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SODIUM NITRITE
Phone +81-3-5543-5196
Fax +81-3-5543-5909

5. Roles/Responsibilities of
the Partners:•

Name of industry sponsor/consortium

Sodium Nitrite Consortium•

Process used

Industry collected data, prepared the updated the IUCLID
dossier, and drafted versions of the SIAR and SIAP.

6. Sponsorship History
How was the chemical or
category brought into theOECD HPV Chemicals
Programme?

This substance is sponsored by Japan under the ICCA Initiativeand is submitted for first discussion at SIAM 20.

7. Review Process Prior to
the SIAM:

The Japanese government peer-reviewed the documents andaudited selected studies.

8. Quality check process:9. Date of Submission:

The Japanese government peer-review committee performed
spot checks on randomly selected endpoints and comparedoriginal studies with data in the SIDS Dossier.
25 July, 2005

10. Date of last Update:

22 July, 2005

11. Comments:

No•

UNEP PUBLICATIONS

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SODIUM NITRITESIDS INITIAL ASSESSMENT PROFILECAS No.

7632-00-0

Chemical Name

Sodium nitrite

Structural Formula

O

N

O

Na+

Na(NO 2 ) -SUMMARY CONCLUSIONS OF THE SIAR
Human Health
Sodium nitrite has been reviewed by a number of international organizations: JECFA (Joint FAO/WHO Expert
Committee on Food Additives); National Academy of Sciences (NAS); US National Institute of Environmental
Health Sciences (NIEHS); National Institute of Public Health and the Environmental Hygiene, Netherlands; US
National Toxicology Program (NTP); and California EPA (CAL/EPA).
Nitrite in blood is highly reactive with haemoglobin and causes methaemoglobinaemia. Ferrous iron associated withhaemoglobin is oxidized by nitrite to ferric iron, leading to the formation of methaemoglobin. Humans are
considered to be more sensitive than rats in this respect.
The primary acute effect of sodium nitrite in rats and mice is methaemoglobinaemia. Methaemoglobin
concentrations in SD rats increased from 45% to 80% over 1 hour after an oral dose of sodium nitrite at 150 mg/kg
bw and they returned to normal levels within 24 hours in surviving rats.
LD50 values by gavage are 214 mg/kg bw (males) and 216 mg/kg bw (females) in mice. In an acute inhalation study(which could not be validated) methaemoglobin levels in female rats were significantly increased after 4 hours
exposure to 10 mg/m3 sodium nitrite. The increase was judged not to be haematologically significant. No significant
increase was observed in exposed males. There were no toxicologically significant effects on animals maintained for
14 days post exposure. No information on acute dermal toxicity is available.
Based on the available information, sodium nitrite is a moderate eye irritant, but is non-irritant to skin in rabbits. No
studies are available investigating the sensitising potential of sodium nitrite in animals. No cases of sensitisation havebeen reported in humans.
In a repeated dose toxicity study [NTP] male and female F344/N rats were exposed to 0, 375, 750, 1500, 3000 or
5000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 30, 55, 115, 200, or 310 mg/kg
bw/day in males and 0, 40, 80, 130, 225, or 345 mg/kg bw/day in females) in drinking water for 14 weeks.
Methaemoglobin levels were significantly elevated in all treated groups compared to the controls by the end of thetreatment period. For males, mean methaemoglobin levels after 14 weeks were 0.03±0.01, 0.08±0.01, 0.12±0.02,
0.25±0.07, 0.71±0.20 and 3.38±0.80 g/dL at doses of 0, 30, 55, 115, 200, and 310 mg/kg bw/day. For females, mean
methaemoglobin levels after 14 weeks were 0.06±0.02, 0.14±0.02, 0.16±0.02, 0.48±0.05, 0.99±0.20 and 2.27±0.54g/dL at doses of 0, 40, 80, 130, 225 and 345 mg/kg bw/day. The NOAELs were not determined (increased
methaemoglobinaemia). The LOAELs for other endpoints were 115 mg/kg bw/day (decreased sperm motility) inmales and 225 mg/kg bw/day (increased relative weight of the kidney and spleen) in females .
In a second 14-week repeated dose toxicity study [NTP] male and female B6C3F1 mice were exposed to 0, 375, 750,
1500, 3000 or 5000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 90, 190, 345, 750, or
990 mg/kg bw/day in males and 0, 120, 240, 445, 840, or 1230 mg/kg bw/day in females) in drinking water.
Methaemoglobin levels were not reported however there were no clinical signs of toxicity. The LOAELs were 750
mg/kg bw/day (extramedullary haematopoiesis in the spleen, degeneration of the testis) in males and 445 mg/kg
bw/day (extramedullary haematopoiesis in the spleen) in females.
In a two-year chronic toxicity/carcinogenicity study [NTP] male and female F344/N rats were exposed to 0, 750,
1500 or 3000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 35, 70 or 130 mg/kg bw/day
in males and 0, 40, 80 or 150 mg/kg bw/day in females) in drinking water. There were no clinical findings related to
exposure. Methaemoglobin levels were measured at two weeks and three months. At both 2 weeks and three
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months, methaemoglobin levels were high at night when the rats were actively feeding and drinking and low during
the day when the rats were less active. Methaemoglobin levels tended to increase with increasing dosage.
In a second two-year study [NTP] male and female B6C3F1 mice were exposed to 0, 750, 1500 or 3000 ppm sodium
nitrite (equivalent to average daily doses of approximately 0, 60, 120 or 220 mg/kg bw/day for males and 0, 45, 90 or
165 mg/kg bw/day for females) in drinking water. There were no clinical findings related to exposure. At 12 months,
no significant increase in methaemoglobin level was observed in either sex at any dose.
Based on the two-year studies, the NOAELs for rats were 130 mg/kg bw/day in males and 150 mg/kg bw/day infemales. For mice the NOAELs were 220 mg/kg bw/day in males and 165 mg/kg bw/day in females
Sodium nitrite is a direct-acting, base-pair substitution mutagen in organisms ranging from bacteria to mammaliancells in vitro. This substance induced chromosomal aberrations in mammalian cells in vitro. There is evidence ofpotential in vivo genotoxicity. The substance tested positive in a micronucleus test (peripheral blood) when mice were
dosed by gavage at 10 – 20 mg/kg bw ( 4 times at 24 hrs intervals) but was negative in a second study where mice
were dosed via drinking water at dosed up to 900 mg/kg bw/day (females) for 14 weeks. In a chromosomal aberration
test, pregnant rats were dosed with 210 mg/kg bw/day for 13 days. Positive results for the induction of chromosomal
aberrations in bone marrow of the parents and liver cells of embryos were reported.
In a two-year chronic toxicity/carcinogenicity study [NTP] male and female F344/N rats were exposed to 0, 750,
1500 or 3000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 35, 70 or 130 mg/kg bw/day
for males and 0, 40, 80 or 150 mg/kg bw/day for females) in drinking water. The incidences of hyperplasia of theforestomach epithelium in high dose males (44/50) and females (40/50) were significantly greater than those in thecontrol groups (12/50 males, 8/50 females). The incidence of fibroadenoma of the mammary gland was significantly
increased in 80 mg/kg bw/day females, and the incidences of multiple fibroadenoma were increased in 40 and 80
mg/kg bw/day females; however these neoplasms occur with a high background incidence and no increase was seenin the high dose group. The incidences of mononuclear cell leukemia were significantly decreased in 70 and 130
mg/kg bw/day males (7/50 and 3/50, respectively) and 80 and 150 mg/kg bw/day females (1/50 and 1/50,
respectively) compared with controls (17/50 males, 15/50 females). Under the conditions of this study there is noevidence of carcinogenic activity of sodium nitrite in F344/N rats at approximate doses of up to 130 mg/kg bw/day inmales and 150 mg/kg bw/day in females over a two year period.
In another NTP study male and female B6C3F1 mice were exposed to 0, 750, 1500 or 3000 ppm sodium nitrite(equivalent to average daily doses of approximately 0, 60, 120 or 220 mg/kg bw/day for males and 0, 45, 90 or 165
mg/kg bw/day for females) in drinking water for two years. The incidences of squamous cell papilloma or carcinoma(combined) in the forestomach of female mice occurred with a positive trend (1/50, 0/50, 1/50 and 5/50 at doses of 0,45, 90 or 165 mg/kg bw/day, respectively). The incidence of hyperplasia of the glandular stomach epithelium wassignificantly greater in 220 mg/kg bw/day males (10/50) than in the controls (0/50). Under the conditions of thisstudy there is no evidence of carcinogenic activity of sodium nitrite in male B6C3F1 mice at doses up to
approximately 220 mg/kg bw/day over a two year period. There is equivocal evidence of carcinogenic activity infemale mice, based on the positive trend of squamous cell papilloma or carcinoma (combined) in the forestomach.
Various other carcinogenicity studies in rats were negative. Moreover, some even showed a reduction in tumor risk(e.g. lymphoma or leukemia). WHO concluded that there was no evidence of carcinogenic activity of sodium nitrite
in rats and mice based on the findings of NTP carcinogenicity studies.
There is evidence for transfer of sodium nitrite to fetuses in rats and mice. Reproductive success in the F1 generation
was not affected. Increase in mortality of pre- and postnatal offspring and decrease in body weight of preweaning
pups were observed in rat dams given a diet containing sodium nitrite at 0.0125% (10.75 mg/kg bw/day), 0.025%(21.5 mg/kg bw/day) and 0.05% (43 mg/kg bw/day), and the NOAEL is considered to be 10.75 mg/kg bw/day.
Reproductive toxicity by continuous breeding in the mice was conducted with drinking water at doses of 125, 260 and
425 mg/kg bw/day, and no adverse effect on reproductive performance or necropsy endpoint were observed. The
NOAEL is estimated to be 425 mg/kg bw/day. Sodium nitrite caused maternal anemia and the incidence of abortionand fetal mortality increased when administered to pregnant guinea pigs in drinking water and LOAEL is considered
to be at 60 mg/kg bw/day.
From the weight of evidence, sodium nitrite appears to affect erythropoiesis, haematological parameters and brain
development resulting in mortality and poor growth of offspring.
In humans, sodium nitrite causes smooth muscle relaxation, methaemoglobinaemia, and cyanosis. Infants are
particularly sensitive. A large proportion of haemoglobin in infants is in the foetal haemoglobin form, which is more
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readily oxidised to methaemoglobin than adult haemoglobin. Further, reduced nicotinamide-adenine dinucleotide(NADH)-dependent methaemoglobin reductase, the enzyme responsible for reduction of methaemoglobin back tonormal haemoglobin, has only about half the activity present in adults.
Environment
Sodium nitrite is white or slightly yellow hygroscopic granules, rod or powder, which is very soluble in water (820g/L at 20 °C). Melting point, boiling point, vapour pressure and partition coefficient are 271 °C, >320 °C(decomposes), 9.9E-17 hPa (25°C) and log Kow = -3.7, respectively. Fugacity model Mackay level III calculations
suggest that the substance will distribute mainly to soil if released to the air or soil compartments separately or to all
three compartments simultaneously and almost exclusively to water if released to the water compartment. Estimatedvalue of Henry’s constant is 2.06E-07 atm-m3/mole. This substance dissociates immediately into sodium and nitrite
ions in water. The nitrite ion is a component of the nitrogen cycle. In the environment, bacteria of the genus
Nitrobacter oxidise nitrites to nitrates. Nitrates are reduced to nitrogen by anaerobic bacteria present in soil andsediment. The estimated BCF is 3.162 and hence bioaccumulation is not significant. Indirect photo-oxidation byhydroxy radicals is predicted to occur with a half-life estimated at 82.3 days.
The LC50 values for the acute toxicity of sodium nitrite to fish reported in the literature vary widely between thespecies tested; LC50 (96h) = 0.54 mg NaNO2/L for Oncorhynchus mykiss; LC50 (96h) = 35 mg NaNO2/L for Ictaluruspunctatus; LC50 (96h) = 691.0 mg NaNO2/L for Micropterus salmoides; and LC50 (96h) = 1010.4 mg NaNO2/L for
Anguilla japonica, for example. This difference has been attributed to the ability of certain species, such as eels, bass
and sunfish to prevent nitrite from crossing the gill membrane and entering the blood, whilst other species such as
rainbow trout concentrate nitrite in their blood. The range of toxicity values reported for some species of fish varies
widely and is believed to be dependant on the quality of the water used in the test with pH, chloride and calcium ion
concentration all having an influence. In particular, chloride ion concentration has been shown to be important, withincreasing concentrations leading to a decrease in the toxicity of nitrite. As with fish, there is variation in toxicity
between invertebrate species. Sodium nitrite is toxic to invertebrates such as Cherax quadricarinatus (LC50 (96h) =4.93 mg NaNO2/L and Thamnocephalus platyurus (LC50 (24h) = 3.9 mg NaNO2/L), whereas other species, such as
Procambarus clarkii (LC50 (96h) = 18.7 mg NaNO2/L) and Penaeus paulensis are much less sensitive (LC50 (96h) =539.2 mg NaNO2/L). The presence of chloride ions has been found to mitigate nitrite toxicity in some species. Acutetoxicity to green alga (Desmodesmus subspicatus) is > 100 mg/L (72-h ErC50 and EbC50) [OECD TG 201].
No data is available for chronic toxicity of sodium nitrite in fish. In invertebrates, an 80-day NOEC of 9.86 mg
NaNO2/L for Penaeus monodon has been reported. The NOEC value in green alga (Desmodesmus subspicatus) is
100 mg/L (72-h for growth rate and biomass) [OECD TG 201].
For other aquatic organisms, the EC50 (48h, deformation) and LC50 (48h) for the protozoa Spirostomum ambiguum
were 421 and 533 mg NaNO2/L, respectively; for the microalgae Tetraselmis chuii the EC50 (96h, mobility) andNOEC (96h, mobility) were 7886 and 3740 mg NaNO2/L, respectively.
Exposure
Total production of sodium nitrite in Japan was 10,000 - 50,000 t/year in 2001. Worldwide production of sodium
nitrite is not available.
This substance is used in closed system, for non dispersive use, and also for wide dispersive use. Workers arerecommended to wear protective gear such as a mask, rubber gloves and goggles to prevent exposure. There are noavailable official recommendations or regulations for occupational exposure limits to this substance. This substanceis widely used in various industries in the category including agricultural, basic chemicals, chemical industry, andothers. The use in synthesis includes as raw material for caprolactam and others. This substance is used widely as
food/foodstuff additives, corrosion inhibitor, and so forth.
The nitrite ion is ubiquitous in the environment, where it forms part of the nitrogen cycle. The source of nitrogen isnatural or anthropogenic. Fertilizers are considered to be the main anthropogenic source of nitrogen, althoughanthropogenic nitrogen oxide and dioxide present in the atmosphere from combustion processes are also sources ofnitrite and nitrate in soils and surface waters, delivered via acid rain. Naturally occurring nitrogen oxide and dioxidein the atmosphere are also possible sources of nitrite. It should be noted that although the nitrite ion (NO2-) may
cause a concern when assessing the potential eutrophication hazard including drinking water quality in certain
regions, the use of this substance (NaNO2) as a fertilizer has not been reported. Therefore this substance has apotential of eutrophication, but its influence is lower than that of the fertilizers.

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SODIUM NITRITE

The most common source of exposure of anthropogenic sodium nitrite to consumers is from its use in cured meatproducts. Exposure to nitrite also occurs from vegetables and drinking water. Nitrite can be formed in the bodythrough reduction of nitrate by enteric bacteria and mammalian nitrate reductase. The Joint FAO/WHO Expert
Committee on Food Additives established an acceptable daily nitrite intake of 0 to 0.07 mg/kg bw/day. Various
countries have set limits for nitrite through water quality regulations.

RECOMMENDATION AND RATIONALE FOR THE RECOMMENDATION AND
NATURE OF FURTHER WORK RECOMMENDED
The chemical possesses properties indicating a hazard to human health (acute toxicity, irritation, repeatedtoxicity, mutagenicity, and reproductive toxicity) and the environment (acute toxicity). Given the wide
dispersive use of this substance, member countries are invited to perform an exposure assessment, and if
necessary a risk assessment for these uses. It is acknowledged that some uses (e.g. as a food additive) as well as
the presence in drinking water are already regulated in many member countries. It is recommended that the
information on possible total exposure from regulated and non-regulated use be shared between regulatory
agencies.

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SODIUM NITRITESIDS Initial Assessment Report
1

IDENTITY

1.1

Identification of the Substance

CAS Number:
IUPAC Name:
Molecular Formula:
Structural Formula:
Molecular Weight:
Synonyms:

7632-00-0
Sodium nitrite
NO2Na
Na+(NO2)69.00
Nitrous Acid, Sodium Salt.
Nitrous acid sodium salt (1:1)

1.2

Purity/Impurities/Additives
Moisture: < 0.3 % w/w, water insoluble matter: <0.05 % w/w

1.3

Physico-Chemical properties
Table 1

Summary of physico-chemical properties

Property

Reference

Physical state

White or slightly yellow hygroscopic
granules, rods or powder

Merck Index, 2001

Melting point

271 °C

Merck Index, 2001

Boiling point>320 °C (decomposes)

Merck Index, 2001

2.1 (20 degree)

MERCK MSDS 2004

Vapour pressure

9.9E-17 hPa @ 25°C

UBE Industries, 2005

Water solubility

820 g/L (20 °C)

Density

Partition coefficient noctanol/water (log value)-3.7

Dissociation constant, pKa

3.27

Henry’s law constant

2

Value

ICSC, 2000
ICSC,
2000;
MSDS 2004

MERCK

Takahama et al, 2002
3

2.06E-07 atm-m /mole

UBE Industries, 2005

GENERAL INFORMATION ON EXPOSURE

Environmental and/or exposure to sodium nitrite or the nitrite ion from industrial sources may occur
during production or from use. However, there is also exposure from the nitrite ion that is
distributed ubiquitously in natural water or soils, present in food or generated endogenously.
2.1

Production Volumes and Use Pattern

Total production of sodium nitrite in Japan was 10,000 - 50,000 t/year in 2001. Worldwide
production of sodium nitrite is not available.
Sodium nitrite is widely used in various industries in categories including agricultural, basic
chemicals, chemical industry, electrical/electronic engineering industry, fuel industry, metal
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extraction, refining and processing of metals, paints/lacquers and varnishes industry, polymers
industry, public domain, textile processing industry and others.
Sodium nitrite is used as a raw material for the production of caprolactam polymers andantioxidants for synthetic polymers. It is used as a colour fixative and preservative in meats and fish.
It is also used in: adhesives, binding agents, anti-freezing agents, cleaning/washing agents,
disinfectants, colouring agents, construction materials additives, corrosive inhibitors, cutting fluids,
fillers, food/foodstuff additives, heat transferring agents, intermediates, laboratory chemicals,
lubricants and additives, non agricultural pesticides, oxidizing agents, pesticides, pharmaceuticals,
process regulators, reducing agents, stabilizers, surface-active agents.
2.2

Environmental Exposure and Fate

2.2.1

Sources of Environmental Exposure

The nitrite ion is ubiquitous in the environment, where it forms part of the nitrogen cycle. The
source of nitrogen is natural or anthropogenic. Fertilizers are considered to be the main
anthropogenic source of nitrogen, although anthropogenic nitrogen oxide and dioxide present in theatmosphere from combustion processes are also sources of nitrite and nitrate in soils and surface
waters, delivered via acid rain. Naturally occurring nitrogen oxide and dioxide in the atmosphere
are also possible sources of nitrite. It should be noted that although the nitrite ion (NO2-) may cause
a concern when assessing the potential eutrophication hazard including drinking water quality incertain regions, the use of this substance (NaNO2) as a fertilizer has not been reported. Therefore
this substance has a potential of eutrophication, but its influence is lower than that of the fertilizers.
Various countries have set limits for nitrite through water quality regulations. Limit values
permissible in drinking water are 0.05 mg/L (as nitrite-N, Japan), 0.5 mg/L (as nitrite, EU), 1mg/L(as nitrite-N, US EPA) and 3 mg/L (acute) and 0.2 mg/L (chronic) (as nitrite, WHO).
2.2.2

Photodegradation

Indirect photo-oxidation by hydroxy radicals (1500000 molecule/cm3) is predicted to occur with ahalf-life estimated at 82.3 days (calculated using AOPWIN v1.91 at 25 °C, rate constant, 1.30 x 1013
cm3/molecule/sec, 12-hour day) [UBE Industries, 2005].
2.2.3

Stability in Water

This substance dissociates immediately into sodium and nitrite ions in water.
2.2.4

Transport between Environmental Compartments

Fugacity Model Mackay level III calculations [UBE Industries, 2005] using EPI Suite v3.12
indicate that the substance will distribute mainly to soil if released to the air or soil compartments
separately or to all three compartments simultaneously and almost exclusively to water if released
to the water compartment.
Table 2 Environmental Distribution of Sodium Nitrite Using Fugacity Model
Mackay Level III

In airIn water
In soilIn sediment1000 kg/h emission to thesecompartments separately
Air
Water
Soil
5.0
0
0.3
25.0
99.7
22.3
69.9
0.1
77.4
0.1
0.2
0.0
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Simultaneous 1000 kg/h emission toair, water and soil compartments
1.78
40.2
58.0
0.07
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2.2.5

SODIUM NITRITE

Biodegradation

The nitrite ion is a component of the nitrogen cycle. In the environment, bacteria of the genus
Nitrobacter oxidise nitrites to nitrates. Nitrates are reduced to nitrogen by anaerobic bacteria present
in soil and sediment.
2.2.6

Bioaccumulation

An estimated BCF of 3.162 was calculated by EPI Suite v3.12 using the default Log Pow value of
0.06 [UBE Industries, 2005]. Sodium nitrite is known to be metabolised in fish, hence there is low
potential for bioaccumulation.
2.2.7

Other Information on Environmental Fate

No information available.
2.3

Human Exposure

2.3.1

Occupational Exposure

Occupational exposures at production sites may occur by the inhalation or dermal route.
The atmospheric concentration was measured at two production sites [JISHA, 2004]. Air samples
were collected at a rate of 2.0 L/min through a suction tube placed at the breathing zone of theworker, trapped in a filter in a collection tube and analysed by LC. The monitoring data are shownin Table 3. The concentrations in the operations at site 1 (powder production) were higher thanthose in the operations at site 2 (liquid production).
Workers are recommended to wear protective gear such as a mask, rubber gloves and goggles toprevent exposure. There are no available official recommendations or regulations for occupational
exposure limits to this substance.
Table 3Work Place Monitoring Data For Sodium Nitrite

Operation in site 1(powder production)
Paper bag filling
Sampling (process)Sampling (product)
Analysis work
Operation in site 2(liquid production)
Tank car operation
Sampling (process)Sampling (product)

Monitoring Data
(Maximum Concentration)
mg/m3

Frequency
times/day

Working time
hrs/day

Maximum
EHEinhmg/kg/day

0.110
0.308
0.803
<0.022

1
2
1
2

6.00
0.06
0.03
0.34

1.18 x 10-2
3.30 x 10-4
4.30 x 10-4
1.34 x 10-4

<0.0080.046<0.014

2
2
1

0.60
0.34
0.08

8.57 x 10-5
2.79 x 10-4
2.00 x 10-5

EHEinh: Estimated Human Exposure via inhalation (calculated by using the default value of 1.25
m3/h and 70 kg)

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2.3.2

SODIUM NITRITE

Consumer Exposure

Diet constitutes an important source of exposure to both nitrite and nitrate. The major dietary sourceof nitrate is vegetables. Lettuce, spinach, celery and beetroot commonly contain more than 1g
nitrate/kg fresh weight and may reach 3-4 g/kg [Walker, 1990]. Nitrite occurs in plants at low
concentrations, normally between 1-2 mg/kg fresh weight and rarely over 10 mg/kg, althoughpotatoes have been reported to contain 2-60 mg/kg, with a mean concentration of 19 mg/kg [MAFF,
1992]. Mean estimates of nitrate intake range from 31 – 185 mg/day in various European countries,
with vegetables supplying 80-85% [Gangolli, et al, 1994]. The intake of nitrite is much lower invarious European countries and averages 0.7 – 8.7 mg/day, with both vegetables and cured meats
being the major sources.
As discussed in Section 3.1.1, nitrate can be reduced in the body to nitrite by both enteric bacteria
and mammalian nitrate reductase activity.
The Joint FAO/WHO Expert Committee on Food Additives established an acceptable daily nitrite
intake of 0 to 0.07 mg/kg bw/day. [JECFA, 2003]. This regulation is enforced in OECD countries.
Various countries have set limits for nitrite through water quality regulations (see Section 2.2.1).

3

HUMAN HEALTH HAZARDS

There are several review/evaluation documents on sodium nitrite issued by pertinent international or
national organizations. JECFA (Joint FAO/WHO Expert Committee on Food Additives) has issued
a series of updated evaluation documents [e.g. WHO, 2004]. National Academy of Sciences (NAS,1981), National Institute of Environmental Health Sciences of U.S.A. (NIEHS, 1970), or National
Institute of Public Health and the Environmental Hygiene, Netherlands, (1986) issued a document
regarding drinking water, which included the review/evaluation on human health hazard. National
Toxicology Program document (NTP, 1990, 2001) includes a review on the toxicology publicationsin their reports. With regard to reproductive toxicity California EPA (CAL/EPA, 2000) is anoteworthy review.
3.1

Effects on Human Health

3.1.1

Toxicokinetics, Metabolism and Distribution

Nitrite in blood is highly reactive with haemoglobin and causes methaemoglobinaemia. Ferrous ironassociated with haemoglobin is oxidized by nitrite to ferric iron, leading to the formation of
methaemoglobin. The oxygen-carrying capacity of methaemoglobin is much less than that of
haemoglobin. Humans are considered to be more sensitive than rat in this respect. The primary
acute toxic effects of sodium nitrite in rats and mice are resulted from methaemoglobinaemia.
Reduction of nitrate (NO3-) to nitrite (NO2-) occurs by mammalian nitrate reductase and nitrate
reductase activity of microorganisms in the oral cavity and upper gastrointestinal tract [NAS, 1981;
Walker, 1996; WHO, 1996b]. In particular, oral microorganisms are responsible for significant
levels of nitrate reduction. Salivary nitrate concentrations are considered directly related to an
orally ingested amount of nitrate. Allowing for considerable inter-individual variations it has been
estimated that 25% of nitrate ingested by humans are secreted in the saliva. Of this 25%
approximately 20 % (i.e., about 5 % of the ingested dose) is reduced to nitrite in humans.
The enzyme methaemoglobin reductase catalyzes the reduction of methaemoglobin to haemoglobin
and protects red blood cells against oxidative damage.
The secondary toxic effects of acute sodium nitrite in animals result in vasodilation, relaxation ofsmooth muscle, and lowering of blood pressure.’
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Studies in Animals
In vitro Studies
An in vitro study was conducted using erythrocytes of different species [Klimmek et al., 1988].
After incubation of erythrocytes with sodium nitrite at 2.5 mmol/L, the highest ferrihaemoglobin
formation was observed in dogs followed by cattle and then cats. The degree of ferrihaemoglobin
formation in human erythrocytes was similar to that in cats. The degree of ferrihaemoglobin
formation was lowest in rabbit erythrocytes.
In another in vitro study, Calabrese et al. (1983) showed that 50% methaemoglobin was formed
when 1 mL of human whole blood was mixed with 10 µL of a 3 mmol/L solution of sodium nitrite,
whereas the same concentration of sodium nitrite induced only 14% methaemoglobin formation
with rat blood. The difference in sensitivity is probably due to the fivefold difference in erythrocyte
methaemoglobin reductase activity between humans and rats [Smith and Beutler, 1966].
In vivo Studies
Sodium nitrite at 0.3 mmol/kg bw was given intravenously to rats, rabbits and cats [Klimmek et al.,1988]. Sodium nitrite induced ferrihaemoglobin formation with maxima of 47.7+/-1.3% at 90 min
in cats, 7.5+/-1.0% at 10 min in rabbits and 18.4+/-0.0% at 30 min in rats. Despite the five times
greater ferrihaemoglobin maxima due to treatment with sodium nitrite in cats compared to rabbits,
respiratory rate increased three times less. Total haemoglobin was not influenced by nitrite.
Imaizumi et al (1980) reported that maximum levels of methaemoglobin (45 – 80%) were reached
one hour after dosing Sprague-Dawley rats with 150 mg/kg bw sodium nitrite. The concentration
returned to normal after 24 hours if the animal survived.
In Sprague-Dawley rats receiving a single dose of 30 mg/kg bw of sodium nitrite in aqueous
solution by gavage (10 - 15% of LD50), plasma nitrite and methaemoglobin levels were increased
after 2.8 minutes and maximum effects (plasma nitrite = 15%, methaemoglobin = 12%) wereobserved after 22.5 minutes. After three hours both parameters had returned to normal levels[Hirneth & Classen, 1984].
Friedman et al (1972)investigated the gastric adsorption of sodium nitrite in male Swiss ICR/Ha
mice. The mice were dosed by gavage with 150 µg sodium nitrite in 0.1 mL aqueous solution.
Animals, in groups of 13 – 18, were killed at one, 10, 20 and 30 minutes after dosing. Stomachs,
together with attached 5 mm segments of the esophagus and duodenum, were removed andanalysed separately for sodium nitrite. Sodium nitrite was found to disappear rapidly from themouse stomach, with 85 and 95% losses seen at 10 and 30 minutes, respectively.
In rats, infusion of sodium nitrite at a range of doses up to 1000 µmol/kg bw over 5 minutes,
resulted in a dose-dependent increase in plasma levels of nitrite and a rapid conversion of nitrite
into nitrate. Sodium nitrite decreased mean arterial pressure dose-dependently but no marked effects
on heart rate were observed [Vleeming et al, 1997].
Conclusion
Nitrite in blood is highly reactive with haemoglobin and causes methaemoglobinemia. Ferrous ironassociated with haemoglobin is oxidized by nitrite to ferric iron, leading to the formation of
methaemoglobin. Humans are considered to be more sensitive than rats in this respect.
The primary acute effect of sodium nitrite in rats and mice is methaemoglobinemia.
Methaemoglobin concentrations in SD rats increased from 45% to 80% over 1 hour after an oral

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dose of sodium nitrite at 150 mg/kg bw and they returned to normal levels within 24 hours insurviving rats.
3.1.2

Acute Toxicity

Studies in Animals
Inhalation
One study for acute inhalation toxicity in rats (which could not be validated) is reported in theliterature [ECB,2000]. Rats were exposed to sodium nitrite aerosols generated from the aqueous
solution for four hours. The target exposure concentration was 10 or 100 mg/m3 (achieved; 95.1
mg/m3). Methaemoglobin levels were measured after exposure and the remaining animals
maintained for 14 days. Methaemoglobin was significantly increased above concurrent control
values only in females exposed to 10 mg/m3 only, however this increase was judged not to behaematologically significant as the value was within the range seen for controls animals. There wasno significant methaemoglobin increase in exposed males. There were no toxicologically significant
effects on animals maintained for 14 days post exposure.
DermalNo information is available on acute dermal toxicity.
Oral
Four studies are available for acute oral toxicity, one of which is considered reliable. In this study[Riemann, 1950] male and female mice (10 animals/sex/dose) were dosed by gavage with 100, 150,
200, 250 and 300 mg/kg of a 0.5 – 2% aqueous solution of sodium nitrite. All animals that died
were found to have methaemoglobin in their blood, although the levels are not reported. Micereceiving the larger doses died within a few minutes and all other mice (except one) that died did so
within 24 hours. The LD50 value was 214 mg/kg for males and 216 mg/kg for females.
Similar values were obtained from the other available studies; LD50 values of 77 and 130 mg/kg
were reported for fasted and fed BD rats, respectively [Druckery et al, 1963]; 150 mg/kg for fasted
Sprague-Dawley rats [Imaizumi et al, 1980]; and 124 mg/kg for New Zealand White rabbits[Dollahite and Rowe, 1974].
Other Routes of Exposure
No reliable studies are available.
Studies in Humans
DermalSaito et al (1996) report a case where a four year old boy was treated with two liniment solutions
containing sodium nitrite at 30 g/L (Liniment A) and 140 g/L (Liniment B). Liniment A wasapplied all over the boy’s body, causing listlessness and vomiting. Liniment B was applied all overthe boy’s body a few days later. The boy went into shock and suffered severe cyanosis. He washospitalised immediately, but died after two hours in intensive care. The boy’s blood
methaemoglobin level was found to be 76%. In a study using rats, the authors confirmed
percutaneous absorption of nitrite from both of the liniment formulations [Saito et al, 1997].

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Oral
There are numerous case reports concerning the acute toxicity of sodium nitrite in humans available
in the literature, as illustrated by the following examples: Gowans (1990) reported the fatal case of anurse who probably ingested a 1g tablet of sodium nitrite (670 mg NO2-). Death occurred two hours
after admission to hospital. Post mortem methaemoglobin level was 35%, implying a much higher
level on admission. Serum nitrite level was 13 mg/L. Finan et al (1998) reported a case of
methaemoglobinaemia associated with three previously healthy children (two four year old boys
and a two year old girl). One of the children had mistaken a bag of sodium nitrite crystals for sugar
and added it to cups of tea at concentrations of 5100, 5000 and 4900 mg/L. Methaemoglobin levelsof 77% and 38% were measured for two of the children. Centers for Disease Control (1997) report
two cases of methemoglobinaemia attributable to nitrite contamination of potable water throughboiler fluid additives. In the first of these, 49 schoolchildren were affected after eating soup which
had been diluted with hot water from the tap. The soup was found to contain 459 ppm nitrite.
Methaemoglobinaemia was diagnosed in 59% of the children, with levels between 3 – 47%. In thesecond case, six workers were found to have methaemoglobin levels of between 6 – 16% after
drinking coffee contaminated with 300 ppm nitrite.
Infants under 3 months old are particularly sensitive to nitrite. A large proportion of haemoglobinin these infants is in the foetal haemoglobin form, which is more readily oxidised tomethaemoglobin than adult haemoglobin. Further, reduced nicotinamide-adenine dinucleotide(NADH)-dependent methaemoglobin reductase, the enzyme responsible for reduction of
methaemoglobin back to normal haemoglobin, has only about half the activity present in adults[ATSDR, 2001].
Most clinical case data refer to neonates developing methaemoglobinaemia after drinking water orwater-based formulations with high nitrate or nitrite content. The great majority of cases (wellwater methaemoglobinaemia) occurred when nitrate levels in drinking water exceeded 100 mg NO3/L. It is generally accepted that water nitrate content of 50 mg/L is safe even for neonates.
Assuming normal liquid intake of 150 mL/kg bw/day by neonates, nitrate intake of 7.5 mg NO3-/kg
bw/day is considered safe.
Other review reports are as follows. The lowest acute oral lethal dose of nitrite reported for humans
varied from 27-255 mg/kg bw, in which the lowest figures applied for children and elderly people.
Nitrite is also more toxic to young infants (3 months) than adults giving rise to relatively higher
methaemoglobin levels in the blood. The lowest toxic dose reported was 1 mg NO2/kg bw, whereas
in another study 0.5-5 mg NO2/kg bw did not cause any toxic effect [National Institute of Public
Health and Environmental Hygiene, Netherlands, 1986].
Conclusion
LD50 values by gavage are 214 mg/kg (males) and 216 mg/kg (females) in mice. In an acuteinhalation study (which could not be validated) methaemoglobin levels in female rats weresignificantly increased after 4 hours exposure to 10 mg/m3 sodium nitrite. The increase was judged
not to be haematologically significant. No significant increase was observed in exposed males.
There were no toxicologically significant effects on animals maintained for 14 days post exposure.
No information on acute dermal toxicity is available.
In humans, nitrite causes methaemoglobinaemia and cyanosis. Fatal poisoning cases of infants
resulting from ingestion of nitrates in water or spinach are recorded. Lethal poisonings at doses of
27–255 mg/kg bw from anthropogenic sodium nitrite are also reported.

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3.1.3

SODIUM NITRITE

Irritation

Skin Irritation
Studies in Animals
In a reliable study for skin irritation in rabbits, performed using a method similar to OECD TG 404
but not under GLP, approximately 500 mg of the substance was applied to the shaved backs of 6
male New Zealand White rabbits and covered with a semi-occlusive dressing for four hours. The
animals were examined one hour, one, two and three days after removal of the chemical. Someslight irritation was observed one hour after removal of the substance, but all signs had disappearedby the one day observation and the substance is not considered to be a skin irritant. [Southwood,
1985].
Eye Irritation
Studies in Animals
In a reliable study for eye irritation in rabbits, performed using a method similar to OECD TG 405
but not under GLP, 100 mg of substance was applied into the conjunctival sac of the left eye of six
female New Zealand White Rabbits. The eyes of three of the rabbits were irrigated with water for
two minutes 30 – 60 seconds after application of the substance. Conjunctival effects were seen in
all animals and consisted of moderate redness, mild chemosis and severe discharge. All signs of
irritation had disappeared by twelve days. No corneal effects were observed [Southwood, 1985].
Conclusion
This substance is a moderate eye irritant, but is non-irritant to skin in rabbits.
3.1.4

Sensitisation

No studies are available in animals investigating the sensitising potential of sodium nitrite. As thissubstance is endogenously generated, sensitisation potential is not expected. No evidence ofsensitisation in humans has been reported.
Conclusion
No studies are available in animals investigating the sensitising potential of sodium nitrite. No
cases of sensitisation have been reported in humans.
3.1.5

Repeated Dose Toxicity

Studies in Animals
Oral
Reliable studies are listed in Table 4.
In a NTP study (2001) groups of male and female F344/N rats (10 animals/sex/group) were exposed
to 0, 375, 750, 1,500, 3,000, or 5,000 ppm sodium nitrite (equivalent to average daily doses ofapproximately 0, 30, 55, 115, 200, or 310 mg sodium nitrite/kg bw/day in males and 0, 40, 80, 130,
225, or 345 mg/kg bw/day in females) in drinking water for 14 weeks. Clinical pathology study
groups of 15 male and 15 female rats were exposed to the same concentrations for 70 or 71 days.
One 225 mg/kg bw/day female died before the end of the study. Body weights of 200 and 310
mg/kg bw/day males and 345 mg/kg bw/day females were significantly less than those of thecontrols. Water consumption by 310 mg/kg bw/day males and 225 and 345 mg/kg bw/day females
was less than that by the controls at weeks 2 and 14. Clinical findings related to sodium nitrite
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exposure included brown discoloration in the eyes and cyanosis of the mouth, tongue, ears, and feetof 200 and 310 mg/kg bw/day males and of 130 mg/kg bw/day and higher females. Reticulocyte
counts were increased in 200 and 310 mg/kg bw/day males and 225 and 345 mg/kg bw/day females.
The erythron was decreased on day 19 but increased by week 14 in 310 mg/gk bw/day males and345 mg/kg bw/day females. Methaemoglobin levels were significantly elevated in all treatedgroups compared to the controls by the end of the treatment period. For males, mean
methaemoglobin levels after 14 weeks were 0.03±0.01, 0.08±0.01, 0.12±0.02, 0.25±0.07, 0.71±0.20
and 3.38±0.80 g/dL at doses of 0, 30, 55, 115, 200, and 310 mg/kg bw/day. For females, mean
methaemoglobin levels after 14 weeks were 0.06±0.02, 0.14±0.02, 0.16±0.02, 0.48±0.05, 0.99±0.20
and 2.27±0.54 g/dL at doses of 0, 40, 80, 130, 225 and 345 mg/kg bw/day. The NOAELs were notdetermined. The relative kidney and spleen weights of 200 and 310 mg/kg bw/day males and 225
and 345 mg/kg bw/day females were significantly greater than those of the controls. Sperm motilityin 115 and 310 mg/kg bw/day males was significantly decreased. Increased erythropoietic activity
in the bone marrow of exposed males and females was observed. The incidences of squamous cell
hyperplasia of the forestomach in 310 mg/kg bw/day males and 345 mg/kg bw/day females weresignificantly increased.
In a second 14-week study [NTP, 2001] groups of male and female B6C3F1 mice (10animals/sex/group) were exposed to 0, 375, 750, 1,500, 3,000, or 5,000 ppm sodium nitrite(equivalent to average daily doses of approximately 0, 90, 190, 345, 750, or 990 mg/kg bw/day inmales and 0, 120, 240, 445, 840, or 1,230 mg/kg bw/day in females) in drinking water for 14 weeks.
Body weights of 990 mg/kg bw/day males were significantly less than those of the controls. Water
consumption by males exposed to 1,500 ppm or greater was slightly less than that by the controls atweek 13. Methaemoglobin concentrations were not reported however there were no clinical signsof toxicity. Relative spleen weights of 750 and 990 mg/kg bw/day males and absolute and relative
heart, kidney, liver, and spleen weights of 840 and 1230 mg/kg bw/day females females weregreater than those of the control groups. Sperm motility was decreased in 990 mg/kg bw/day males,
and the estrous cycles of 445 and 1230 mg/kg bw/day females were significantly longer than in thecontrols. There were increased incidences of squamous cell hyperplasia of the forestomach in 990
mg/kg bw/day males and 1230 mg/kg bw/day females, extramedullary hematopoiesis of the spleenin 750 and 990 mg/kg bw/day males and 445 mg/kg bw/day or greater females, and degeneration of
the testis in 750 and 990 mg/kg bw/day males.
In a NTP study (2001) groups of male and female F344/N rats (50 animals/sex/group) were exposed
to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses of approximately 0,35, 70 or 130 mg/kg bw/day for males and 0, 40, 80 or 150 mg/kg bw/day for females) in drinking
water for two years. Survival of exposed groups was similar to that of the controls (29/50, 38/50,
36/50 and 36/50 for males at doses of 0, 35, 70 and 130 mg/kg bw/day, respectively and 33/50,
31/50, 36/50 and 33/50 for females at 0, 40, 80 or 150 mg/kg bw/day, respectively). Mean bodyweights of 130 mg/kg bw/day males and 150 mg/kg bw/day females were less than those of thecontrols throughout the study. Water consumption by high dose males and females was less thanthat by the controls throughout the study and that by the other exposed groups was generally lessafter week 14. Methaemoglobin levels were measured at two weeks and three months. At both 2
weeks and three months, methaemoglobin levels were high at night when the rats were actively
feeding and drinking and low during the day when the rats were less active. Methaemoglobin levels
tended to increase with increasing dosage.
In another NTP study (2001) groups of male and female B6C3F1 mice (50 animals/sex/group) were
exposed to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses ofapproximately 0, 60, 120 or 220 mg/kg bw/day for males and 0, 45, 90 or 165 mg/kg bw/day forfemales) in drinking water for two years. Survival of exposed groups was similar to that of thecontrols (39/50, 45/50, 42/50 and 39/50 for males at doses of 0, 60, 120 or 220 mg/kg bw/day,
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respectively and 40/50, 34/50, 37/50 and 41/50 for females at doses of 0, 45, 90 or 165 mg/kg
bw/day, respectively). Mean body weights of 165 mg/kg bw/day females were less than those of thecontrols throughout the study. Exposed groups generally consumed less water than the control
groups. At 12 months, no significant increase in methaemoglobin level was observed in either sex
at any dose.
In a two year study, groups of male rats (eight animals/group) received drinking water containing 0,100, 1000, 2000 or 3000 mg sodium nitrite/L (equivalent to approximately 0, 10, 100, 250 or 350
mg/kg bw/day, respectively) [Shuval and Gruener, 1972]. There were no significant differences ingrowth, development, mortality or total haemoglobin levels between the control and treated groups.
However, the methaemoglobin levels in the groups receiving 100, 250 and 350 mg/kg bw/day
sodium nitrite were raised significantly throughout the study and averaged 5, 12 and 22% of total
haemoglobin, respectively. The main histopathological changes occurred in the lungs and heart.
Focal degeneration and fibrosis of the heart muscle were observed in animals receiving the highest
dose of nitrite. The coronary arteries were thin and dilated in these aged animals, instead of
thickened and narrow as is usually seen at that age. Changes in the lungs consisted of dilatation of
the bronchi with infiltration of lymphocytes and alveolar hyperinflation. Such changes wereobserved in rats receiving 100, 250 and 350 mg/kg bw/day sodium nitrite.
Table 4

Oral repeated dose toxicity

Species/strain

Dose level

ExposureTime

Effects observed

Rat (male,0, 375, 750, 1,500, 14 weeks
and female), 3,000, 5,000 ppm in
F344
drinking water(0, 30, 55, 115, 200
or 300 mg/kg
bw/day in males; 0,40, 80, 130, 225 or
345 mg/kg bw/day
in females)

Methaemoglobin
formation

NOAEL : not obtained

NTP, 2001

Males: decreased
sperm motility

LOAEL:(all showed methaemoglobin
formation)
Males = 115 mg/kg bw/day
Females = 225 mg/kg bw/day(0, 90, 190, 345,
750 or 990 mg/kg
bw/day in males; 0,120, 240, 445, 840
or 1230 mg/kg
bw/day in females)(0, 35, 70, 130
mg/kg bw/day inmales; 0, 40, 80,
150 mg/kg bw/day
in females)

Reference

Females: increased
weight kidney &spleenMouse (male 0, 375, 750, 1,500, 14 weeks
and female), 3,000, 5,000 ppm in
drinking water
B6C3F10, 750, 1,500, 3,000
Rat (maleand female), ppm in drinking
waterF344/N

LO(A)EL/NO(A)EL/MTD

Males:
extramedullaryhaematopoiesis inspleen,degeneration of
testisLOAEL:

NTP, 2001

Males = 750 mg/kg bw/day
Females = 445 mg/kg bw/day

Females:
extramedullaryhaematopoiesis inspleen2 years

None

NOAEL

NTP, 2001

Males = 130 mg/kg bw/day
Females = 150 mg/kg bw/day

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Species/strain

SODIUM NITRITE

Dose level

Mouse(male 0, 750, 1,500, 3,000
and female), ppm in drinking
B6C3F1
water

ExposureTime

Effects observed

2 years

None

Reference

NOAEL

NTP, 2001

Males = 220 mg/kg bw/day
Females = 165 mg/kg bw/day(0, 60, 120, 220
mg/kg bw/day inmales; 0, 45, 90,
165 mg/kg bw/day
in females)
Rat (male)

LO(A)EL/NO(A)EL/MTD

0, 100, 1,000, 2,000, 24 months
3,000 mg/L in
drinking water

Histologicalchanges in thelung and heart

NOEL : 10 mg/kg bw/day(equivalent to 6.7 mg NO2/kg
bw/day)Shuval andGruener,
1972

0, 500, 1,250, 2,500, 42 days
5,000, 10,000 ppm
in drinking water

Mortality/methae
moglobinformation

MTD: 2,500 ppm

Maekawa
et al., 1982

Rat (male),Sprague
Dawley0, 2,000 ppm in
drinking water

14 months

LOEL: 2000 ppm
Lower body andliver weights andplasma vitamin E
levels, higher GSH
levels and higher
incidence ofpulmonary lesions.
Methaemoglobin
formation

Chow etal., 1980

Rat (male),Sprague
DawleyRat (male),
Wistar(Riv:TOX)

0, 200 ppm in
drinking water

16 weeks

Methaemoglobin
formation(minimal)Hypertrophy ofadrenal zona
glommerulosa

LOEL : 200 ppm

Chow et al.,
1980

LOEL: 12 mmol/L KNO2
(equivalent to 54 mg NO2/kg
bw/day)Boink et al.,
1996

Hypertrophy ofadrenal zona
glommerulosa

LOEL: 100 mg KNO2/L(equivalent to 5.4 mg NO2/kg
bw/day)Til et al.,
1988

(0, 10, 100, 250, or
350 mg/kg bw/day
Rat (maleand female)
F344

Control (36 mmol/L 90 days
KCl), 3.6, 12, 36
mmol/L KNO2 indrinking water
Rat (male0, 100, 300, 1,000, 90 days
and female), 3,000 mg/L KNO2 in
Wistar (Bor; drinking water
WISW)

Studies in Humans
Oral
In U.S.A, 320 cases of infant methaemoglobinaemia have been reported to be associated with theuse of nitrate-containing (converted to nitrite de novo) well water [NIEHS, 1970]. Other cases,
particular in Europe, have been associated with the consumption of high nitrite containing
vegetables, particularly spinach [Sander and Jacobi, 1967; NIEHS, 1970; Hack and Dowes, 1983].
Conclusion
The NOAELs were not determined in the rat 14-week repeated dose toxicity study as all treatedgroups showed elevated methaemoglobin concentrations. The LOAELs for other endpoints were
225 mg/kg bw/day in females (increased relative weight of kidney and spleen) and 115 mg/kg
bw/day in males (decreased sperm motility). The LOAELs in the mouse 14-week repeated dose
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toxicity study were 445 mg/kg bw/day in females (extramedullary haematopoiesis in the spleen)
and 750 mg/kg bw/day in males (extramedullary haematopoiesis in the spleen and degeneration of
the testis). Based on the two-year NTP studies, the NOAELs for rats were 130 mg/kg bw/day inmales and 150 mg/kg bw/day in females. For mice the NOAELs were 220 mg/kg bw/day in males
and 165 mg/kg bw/day in females.
In a two-year study in male rats the NOEL was 10 mg/kg bw/day (Focal degeneration and fibrosisof the heart, dilatation of the bronchi with infiltration of lymphocytes and alveolar hyperinflation inlungs) equivalent to 6.7 mg NO2/kg bw/day. The Joint FAO/WHO Expert Committee on Food
Additives (JECFA) established an acceptable daily nitrite intake of 0 to 0.07 mg NO2/kg bw/day by
applying a safety factor of 100 to this NOEL.
3.1.6

Mutagenicity

A variety of reliable mutagenicity tests on sodium nitrite are available (Table 5, 6). Sodium nitrite ismutagenic and clastogenic in vitro. There are, however, conflicting reports regarding genotoxicity
in vivo. Although the important feature of this substance for genotoxicity is the formation of
nitrosamines or nitrosamides by reaction with secondary amines or amides, repsectively, such issues
are beyond the scope of this document and will be reported elsewhere. Therefore, the results on
mutagenicity of this substance alone in vitro and in vivo are summarized below.
Studies in Animals
In vitro Studies
Positive results have been reported for sodium nitrite, with and without metabolic activation (S9mix), in Salmonella gene mutation studies with strains that revert by base-pair substitution[Ehrenberg et al., 1980; Katz et al., 1980; Ishidate et al., 1984; Brams et al., 1987; Zeiger et al.,
1992; Balimandawa et al., 1994]. Typically, Salmonella Mutagenicity Tests conducted by NTP
showed that there was positive response in TA100 at doses of 6,666, 10,000 ug/plate without
metabolic activation, while negative response in TA98 [Zeiger et al., 1992]. Positive responses
were obtained by using TA100, TA1530 and TA1535 (base-pair substitution) at doses of 1,000,
2,500 and 5,000 mg/plate, whereas TA102 (base-pair substitution), YG1024, DG400 and DJ460(frameshift mutation) were inactive with and without metabolic activation [Balimandawa et al.,1994]. Forward mutation [Kosako and Nishioka, 1982] and DNA damage [De Flora et al., 1984]
were also observed in Escherichia coli tester strains after exposure to sodium nitrite in the presenceof S9 mix. Furthermore, sodium nitrite-induced gene mutations were reported in Saccharomyces
cerevisiae [Fahrig, 1979].
Sodium nitrite was reported to induce gene mutations, chromosomal aberrations and sister
chromatid exchanges in cultured mammalian cells.
Tsuda et al (1973) reported that addition of sodium nitrite (0.05 or 0.1 mol/L) to cell cultures
obtained from newborn Syrian hamsters resulted in transformation after 21 days. Ishidate &Odashima (1977) reported that sodium nitrite induced chromosomal aberrations in Chinese hamsterlung cells (CHL) when tested at doses up to 0.53 mg/mL (the 50% growth inhibition dose) without
exogenous metabolic activation. Tsuda et al (1981) also reported a significant increase in theincidence of chromosomal aberrations in Chinese hamster V79-H3 cells treated with 50 or 100
mmol/L of sodium nitrite without exogenous metabolic activation. Tsuda & Kato (1977) exposed
Syrian hamster embryo cells to sodium nitrite (0, 5, 10, 20, 30, 50 mmol/L) without exogenous
metabolic activation. Significant, dose-dependant increases in chromosomal aberrations wereobserved. Abe & Sasaki (1977) treated Chinese hamster D-6 cells with sodium nitrite (1 or 3
mmol/L) without exogenous metabolic activation. Dose-dependant increases in the number ofchromosomal aberrations and sister chromatid exchanges were observed. Tsuda et al (1981) also
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reported a significant increase in sister chromatid exchanges in Chinese hamster V79-H3 cells
treated with 50 or 100 mmol/L of sodium nitrite without exogenous metabolic activation. HeLa S3cells incubated for 1 to 36 hours had increased levels of unscheduled DNA synthesis (DNA repair)at concentrations above 1 mmol/L sodium nitrite [Lynch et al., 1983].
In vivo Studies
Inui et al (1979b) treated Syrian golden hamster embryos in utero by dosing the pregnant females
by gavage with 0, 125, 250 or 500 mg/kg aqueous sodium nitrite solution on the 11th or 12th day ofpregnancy. The fetuses were excised 24 hours after dosing and cells cultured. Marked dosedependant increases in micronucleus formation, induction of 8-azaguanine- and ouabain-resistantmutations and morphological or neoplastic transformations in the embryo cells were observed.
However, there was no marked increase in the frequency of chromosomal aberrations.
El Nahas et al (1984) reported positive results for the induction of chromosomal aberrations in bonemarrow cells of pregnant female albino rats exposed to 210 mg/kg bw/day in drinking water for 13
days. In this same study, the liver cells of embryos exposed trans- placentally for the first 13 days ofgestation also showed increased numbers of chromosomal aberrations. In another study, SCE
induction increased with increasing dose in bone marrow cells of Swiss albino mice treated with 2.5
to 200 mg/kg bw sodium nitrite by intraperitoneal injection [Giri et al., 1986].
NTP (2001) have performed several in vivo studies. In the first of these, sodium nitrite wasadministered by intraperitoneal injection at 0, 6.25, 12.5, 25, 50, 100 or 200 mg/kg bw to male
F344/N rats three times at 24-hour intervals. 200 mg/kg was found to be the lethal dose. No
significant increase in the frequency of micronucleated polychromatic erythrocytes was observed inany of the dose groups. The initial trial was judged to be positive, based on the trend test (P=0.001);
however, results of a repeat trial, in which doses of 0, 25 or 50 mg/kg bw were tested, were
negative, and the rat bone marrow micronucleus test with sodium nitrite was judged to be negative
overall. A similar study in which male B6C3F1 mice were administered 0, 7.81, 15.63, 31.25, 65.5,
125 or 250 mg/kg bw also gave negative results. In the third in vivo study, a peripheral blood
micronucleus test, male and female mice were administered 0, 375, 750, 1,500, 3,000, or 5,000 ppm
sodium nitrite in drinking water for 14 weeks. The equivalent average daily doses wereapproximately 0, 90, 190, 345, 750, or 990 mg/kg bw/day in males and 0, 120, 240, 445, 840, or
1,230 mg/kg bw/day in females. There was no significant increase in the frequency of
micronucleated normochromatic erythrocytes in either males or females.
Diaz-Barriga Arceo et al (2002) administered 0, 10, 15 or 20 mg/kg of sodium nitrite orally fourtimes at 24-hour intervals and examined peripheral blood samples after 96 hours. The treatedanimals showed a statistically significant increase (p=0.05) in micronucleated polychromaticerythrocytes at all doses compared with the 0h values ( MNPCE/1000 PCE = 1.2+/-0.58 (0h), 4.8+/0.37 (96h) at 10 mg/kg; 0.4+/-0.24 (0h), 5.0+/-0.31 (96h) at 15 mg/kg; and 1.0+/-0.31 (0h), 5.8+/0.85 (96h) at 20 mg/kg). No statistical differences were observed in the PE/NE ratio when theirresults were compared before and after treatment, suggesting that sodium nitrite produced nosignificant influence on normal bone marrow activity in this study.
Conclusion
Sodium nitrite is a direct-acting, base-pair substitution mutagen in organisms ranging from bacteria
to mammalian cells in vitro. This substance induced chromosomal aberrations in mammalian cells
in vitro. There is evidence of potential in vivo genotoxicity.

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Table 5

SODIUM NITRITE
Genotoxicity studies in vitro

Type of test

Test system

Dose

ResultReference

Bacterial test
(reverse mutation)

S.typhymurium TA1535,
TA1537, TA92, TA94,
TA98, TA100

Positive with andwithout metabolic
activation (TA1535,
TA100)

Ishidate et al.,
1984

Bacterial test
(reverse mutation)

S.typhymurium TA1535,
TA1537, TA98, TA100

1,000-10,000ug/plate(TA1535, TA100), 105,000ug/plate(TA1537, TA92,
TA94, TA98)
25-2500ug/plate

Katz et al., 1980

Bacterial test
(reverse mutation)

S.typhymurium
TA1530,TA1535,
TA1538, TA100, TA102,
YG1024, DG400, DJ460
S.typhymurium TA97,
TA98, TA100

Positive with andwithout metabolic
activation (TA1535,
TA100)
Positive with andwithout metabolic
activation (TA1530,
TA1535, TA100)
Positive withmetabolic activation(TA100)
Positive with andwithout metabolic
activation
Positive withmetabolic activation
Positive with andwithout metabolic
activation
Positive with andwithout metabolic
activation

Zeiger et al., 1992

Bacterial test
(reverse mutation)

1-5mg/plate

100-1000ug/plate

Bacterial test
Escherichia coli
(forward mutation) WPuvrA/pKM101

1,000-10,000ug/plate

Bacterial test
(reverse mutation)

S.typhymurium, TA98

23.4-375ug/plate

Bacterial test
(reverse mutation)

S.typhymurium, TA98,
TA100

100-10,000ug/plate

Bacterial test
(DNA repair test)

Escherichia coli WP2,
WP67, CM871

Bacterial test (UV
induced forward
mutation)
Chromosomal
aberration

MIC without S9 mix(ug):
WP2; 2500, WP67;
2500, CM871; 625
MIC with S9 mix (ug):
WP2; 3000, WP67;
3000, CM871; 1250
Saccharomyces cerevisiae 0.058-0.43mM
Positive without(diploid strain MPI)
metabolic activation

Balimandawa etal., 1994

Brams et al., 1987

Kosako &Nishioka, 1982
Ehrenberg et al.,1980

De Flora, et al.,
1984

Fahrig 1979

C3H Mouse mammary
0.001-0.1mol/Lcarcinoma cell line EM3A

Positive without
metabolic activation

Kodama et al.,
1976

Chromosomal
aberration

Chinese hamster lung cellline

0.25-1.0mg/mL

Positive without
metabolic activation

Ishidate et al.,
1977

Chromosomal
aberration

Syrian hamster embryocell

5-50mmol/L

Positive without
metabolic activation

Tsuda & Kato,
1977

Chromosomal
aberration & sister
chromatid
exchange
Chromosomal
aberration & sister
chromatid
exchange

Chinese hamster cell line
V79-H310-100mmol/L

Positive without
metabolic activation

Tsuda et al., 1981

Chinese hamster cell line
D-60.001-0.003M

Positive without
metabolic activation

Abe & Sasaki,
1977

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Type of test

Test system

Dose

ResultReference

Sister chromatid
exchange

Human peripheral blood
lymphocyte

0.003-0.03mol/L

Positive without
metabolic activation

Inoue et al., 1985

DNA repair assay

HelaS3 Carcinoma cell

0.0000001-0.006M

Positive without
metabolic activation

Lynch et al., 1983

Table 6

Genotoxicity studies in vivo

Type of test

Test system

Dose

Micronucleus &chromosomal
aberration test

Syrian golden hamster(embryonic cells)

Chromosomal
aberration test

Albino pregnant rat(bone marrow & liver)

Inui et al., 1979b
125, 250, 500mg/kg Positive:bw (single gavage) micronucleus test
Negative:chromosomal
aberration
El Nahas et al., 1984
Mean 210mg/kg
Positive: pregnant
bw/day for 0-18
adult bone marrow &days (drinking
embryonic liver
water)
2.5-200mg/kg bw
Positive
Giri et al., 1986
(single ip injection)

Sister chromatid
Swiss mouseexchange test(bone marrow)
Heritable
C3H Mouse (male)translocation assay
MN Test (bonemarrow)

F344/N Rat (male)

MN Test (bonemarrow)

B6C3F1 Mouse(male)

MN Test(peripheral blood)

B6C3F1 Mouse(male &female)MN Test(peripheral blood)

Mouse (NIH, male)

8-Azaguanineresistant mutation& neoplastictransformation
assay

Syrian golden hamster(embryonic cells)

3.1.7

60, 120mg/kg bw/
day for 14 days
6.25-200mg/kg bw(three times at 24hour intervals, ip)7.81-250mg/kg bw(three times at 24hour intervals, ip)90-900mg/kg bw(male) 1201,230mg/kg bw(female) (drinking
water, 14-week)
10-20mg/kg bw(four times at 24hour intervals, po)25, 50, 100mg/kg
bw (single gavage)

ResultReference

Negative: noheritable defects in
F1 germ cells
Negative

Alavantic et al., 1988

Negative

NTP, 2001

Negative

NTP, 2001

PositiveDiaz-Barriga Arcero etal., 2002

Positive

Inui et al., 1979a

NTP, 2001

Carcinogenicity

The possibility of carcinogenicity of nitrite and/or nitrate associated with endogenous formation of
N-nitroso compounds has been investigated. It has been shown in several controlled laboratory
studies that, when both nitrite and N-nitrosable compounds are present together at high level, Nnitroso compounds are formed endogenously. The committee of JECFA’s 44th meeting, however,
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noted that quantitative data were available only on N-nitrosocompounds which are readily formed
endogenously, such as N-nitrosoproline, which is not carcinogenic. One long term study of toxicity
and carcinogenicity was recently conducted, where rats were fed with fish meal concomitantly withsodium nitrite [Furukawa et al., 2000]. Dose (fish meal)-related increase in incidences andmultiplicity of atypical renal tubules, adenomas and renal cell carcinomas were found. However thediets used in this study were nutritionally inappropriate and the study does not provide additional
insight for the safety evaluation of sodium nitrite [WHO, 2004]. Therefore, the safety evaluation
should be based on the toxicity study on nitrite.
In vivo Studies in Animals
Reliable studies on carcinogenic potential of sodium nitrite are summarized in Table 7.
In a NTP study (2001) groups of male and female F344/N rats (50 animals/sex/group) were exposed
to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses of approximately 0,35, 70 or 130 mg/kg bw/day for males and 0, 40, 80 or 150 mg/kg bw/day for females) in drinking
water for two years. Survival of exposed groups was similar to that of the controls (29/50, 38/50,
36/50 and 36/50 for males at doses of 0, 35, 70 and 130 mg/kg bw/day, respectively and 33/50,
31/50, 36/50 and 33/50 for females at 0, 40, 80 or 150 mg/kg bw/day, respectively). Mean bodyweights of 130 mg/kg bw/day males and 150 mg/kg bw/day females were less than those of thecontrols throughout the study. Water consumption by high dose males and females was less thanthat by the controls throughout the study and that by the other exposed groups was generally lessafter week 14 The incidences of hyperplasia of the forestomach epithelium in 130 mg/kg bw/day
males (44/50) and 150 mg/kg bw/day females (40/50) were significantly greater than those in thecontrol groups (12/50 males, 8/50 females). The incidence of fibroadenoma of the mammary gland
was significantly increased in 80 mg/kg bw/day females, and the incidences of multiple
fibroadenoma were increased in 40 and 80 mg/kg bw/day females; however these neoplasms occur
with a high background incidence and no increase was seen in the 150 mg/kg bw/day group. The
incidences of mononuclear cell leukemia were significantly decreased in 70 or 130 mg/kg bw/day
males (7/50 and 3/50, respectively) and 80 or 150 mg/kg bw/day females (1/50 and 1/50,
respectively) compared with controls (17/50 males, 15/50 females). Under the conditions of thisstudy there is no evidence of carcinogenic activity of sodium nitrite in F344/N rats exposed at up to3000 ppm (approximately 130 mg/kg bw/day in males and 150 mg/kg bw/day in females) indrinking water over a two year period.
In another NTP study (2001) groups of male and female B6C3F1 mice (50 animals/sex/group) were
exposed to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses ofapproximately 0, 60, 120 or 220 mg/kg bw/day for males and 0, 45, 90 or 165 mg/kg bw/day forfemales) in drinking water for two years. Survival of exposed groups was similar to that of thecontrols (39/50, 45/50, 42/50 and 39/50 for males at doses of 0, 60, 120 or 220 mg/kg bw/day,
respectively and 40/50, 34/50, 37/50 and 41/50 for females at doses of 0, 45, 90 or 165 mg/kg
bw/day, respectively). Mean body weights of 165 mg/kg bw/day females were less than those of thecontrols throughout the study. Exposed groups generally consumed less water than the control
groups. The incidences of squamous cell papilloma or carcinoma (combined) in the forestomach offemale mice occurred with a positive trend (1/50, 0/50, 1/50 and 5/50 at doses of 0, 45, 90 or 165
mg/kg bw/day, respectively). The incidence of hyperplasia of the glandular stomach epithelium wassignificantly greater in 220 mg/kg bw/day males (10/50) than in the controls (0/50). Under theconditions of this study there is no evidence of carcinogenic activity of sodium nitrite in male
B6C3F1 mice exposed at up to 3000 ppm (approximately 220 mg/kg bw/day) in drinking water overa two year period. There is equivocal evidence of carcinogenic activity in female mice, based on
the positive trend of squamous cell papilloma or carcinoma (combined) in the forestomach.
In a third study, groups of male and female F-344 rats (50 animals/sex/group) were given 20 mL of
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SODIUM NITRITE0, 0.125 or 0.250% sodium nitrite/rat/day in their drinking water for two years. There were no
significant differences in the incidence of tumors between control and test groups, apart from alower incidence of mononuclear cell leukaemia amongst the test groups compared with controls.
This was attributed to slight atrophy of the haematopoietic organs [Maekawa et al, 1982].
Although some findings regarded as equivocal, result is conclusively understood as lack ofcarcinogenicity of this substance (the view is consistent with that of WHO, 2004]).
There were a further two studies that employed multiple doses with control groups of both sexes,
equal to or more than 104 week of test period and more than 50 animals per group. These studies
were performed using methods regarded as similar to OECD guidelines. Despite lack of GLP
information, they are subjected to evaluation [Gruener and Shuval. et al., 1973; Taylor and
Lijinsky, 1975]. Neither of these studies showed increased tumor incidences in treated animals
compared to the controls.
Due to the tremendous amount of related information, it would be useful to refer the conclusion of
authoritative review for the studies, except for NTP studies. An expert US Committee [NAS, 1981]
reviewed about 20 studies on nitrite that could be used to evaluate carcinogenic potential. Severalof the studies reviewed, although limited, did involve chronic administration of high levels of nitrite
to large groups of animals. The committee concluded that these studies gave no indication thatnitrite was carcinogenic to rats, mice or guinea pigs.
Table 7

Carcinogenicity Studies

Species/strainRat (maleand female),F344/N

Dose level0, 750, 1,500, 3,000
ppm in drinking
water

ExposureTime
2 years

Results

Reference

Non-neoplastic effects : epithelial
hyperplasia of forestomach (male andfemale)Neoplastic effects : none

NTP, 2001

Non-neoplastic effects : epithelial
hyperplasia of glandular stomach (males)
Neoplastic effects : Positive trend insquamous cell papilloma or carcinoma(combined) in forestomach (females)

NTP, 2001

Mouse(male 0, 750, 1,500, 3,000
and female), ppm in drinking
water
B6C3F1

2 years

Rat (male0, 0.125, 0.25% in
and female), drinking water
F 344/N

104 weeks Lower incidence of mononuclear cell
Maekawa et al.,+ 16 weeks leukaemia amongst the test groups compared 1982
with controls

Studies in Humans
No adequate epidemiology studies of sodium nitrite and human cancer were found in literature.
Conclusion
There is no evidence of carcinogenic activity of sodium nitrite in F344/N rats exposed at up to 3000
ppm (approximately 130 mg/kg bw/day in males and 150 mg/kg bw/day in females) in drinking
water over a two year period. There is no evidence of carcinogenic activity of sodium nitrite inmale B6C3F1 mice exposed at up to 3000 ppm (approximately 220 mg/kg bw/day) in drinking
water over a two year period. There is equivocal evidence of carcinogenic activity in female mice,based on the positive trend of squamous cell papilloma or carcinoma (combined) in theforestomach.
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NTP carcinogenicity studies concluded that there was no evidence of carcinogenic activity of
sodium nitrite in rats or mice except equivocal findings of epitherial hyperplasia, papiloma or
carcinoma of forestomach or glandular stomach. Overall evaluation leads to the conclusion thatnitrite ingestion via drinking water did not show evident carcinogenicity. This NTP view isconsistent with that of the recent view of WHO [WHO, 2004].
3.1.8

Toxicity for Reproduction

There is evidence for transfer of sodium nitrite to foetuses in rats and mice. There were no studies
available for reproductive and developmental toxicity study of sodium nitrite under standard
protocols in rats. There are four studies in mice under the protocol inferable similarity to standard
method. Pre- and postnatal exposure to sodium nitrite had adverse effects on haematologicalparameters, including dose-dependent decreases in Hb content, RBC counts, and MVC value inmice offspring. Guinea pig was used to investigate the maternal effect on offspring, because thoseparameters of the mother guinea pig are susceptible to nitrite administration and eased by coadministration of ascorbic acid.
Studies in Animals
Effects on Reproduction
At a dose of 0.31 g/kg bw in drinking water for the whole gestation period, sodium nitrite did notaffect reproductive parameters of female C57BL/6 mice [Anderson et al., 1985]. Pregnant Swiss
CD-1 mice given sodium nitrite up to 0.24% in drinking water caused reduced maternal water
consumption, but not body weight gain [Chapin and Sloane, 1997]. In the comprehensive
continuous breeding study of sodium nitrite in accordance with NTP protocol, reproductive successin the F1 generation was not affected (0.24 %, approximately 425 mg/kg bw/day). Oral intubationof sodium nitrite on day 13 of gestation up to 120 mg/kg bw/day had no effect on dams [Khera,
1982]. Reproductive performance, such as parental weight gain, food consumption, mortality,
fertility, pregnancy maintenance or gestation length was not affected in male or female rats given
sodium nitrite at 0.0125, 0.025 and 0.05% (10.75, 21.5 and 43 mg/kg bw/day) in feed before andduring breeding [Vorhees et al., 1984]. The NOAEL of reproduction was considered to be 43 mg/kg
bw/day. In general, available studies range over a wide diversity of protocols and endpoints and not
employing standard study designs. This diversity limits the extent to which general comparison canbe made among studies.
Sodium nitrite (60 mg/kg bw/day), in drinking water, administered to pregnant guinea pigs
produced maternal anemia and increase in the incidences of abortion and fetal mortality [Sinha andSleight, 1971]. In guinea pigs, administration of 45 mg sodium nitrite/kg bw/day by s.c. injection
during the last week of gestation resulted in abortion in ascorbic acid-deficient females. Neither
ascorbic acid deficiency alone, nor sodium nitrate in the presence of sufficient ascorbic acid, wasassociated with excess abortions. Authors concluded that maternal anemia was the causative agent
for reproductive toxicity. The LOAEL for reproductive toxicity was considered to be 60 mg/kg
bw/day.
Developmental Toxicity
Sodium nitrite administered by oral intubation to pregnant mice from 0 to 14, 16, or 18 days ofgestation (0.5 mg/mouse per day) did not cause embryonic/fetal mortality, changes in fetal weightor increased incidence of skeletal malformations.
Sodium nitrite caused fetal hepatic
erythropoiesis, probably related to fetal methaemoglobinaemia [Globus and Samuel, 1978]. The
comprehensive and continuous breeding study of sodium nitrite was conducted in accordance with
NTP protocol [Chapin and Sloane, 1997]. The sodium nitrite (0.06, 0.12, 0.24% in drinking water)
did not affect the number of litters per pair, the number of pups per litter, or the viability or weight
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of pups (125, 260, 425 mg/kg bw/day) and no adverse effect on reproductive performance or
necropsy endpoint were observed. The NOAEL is estimated to be 425 mg/kg bw/day.
Increases in fetal and pup mortality and decreases in body weight of preweaning pups wereobserved in rat given, for whole gestation period and 90 days post natal, diet containing sodium
nitrite at 0.025% and 0.05% (21.5, 43 mg/kg bw/day), but not at 0.0125% (10.75 mg/kg bw/day)[Vorhees et al., 1984]. Thus, the NOAEL is considered to be 10.75 mg/kg bw/day.
In addition, oral intubation of sodium nitrite on day 13 of gestation up to 120 mg/kg bw/day had noeffect on dams or pups [Khera, 1982].
No gross abnormalities were noted in any live or aborted fetuses [Kociba and Sleight, 1970]. Coadministration of methylene blue, a MetHb antagonist, exerted a protective effect on maternal
anemia and fetal development.
The following studies are systematic and therefore noteworthy.
Pregnant Wistar rats were given drinking water containing sodium nitrite at 2 g/L from gestation
day 13 until parturition [Nyakas et al., 1990, 1994a, 1994b]. Simple learning in response to either
reward or aversive stimulus was not affected in two-month old male offspring. Discriminatory
learning of both visual and auditory cues, however, was impaired in the treated animals, as of longterm retention of a conditioned passive avoidance response up to 24 month old. The authors related
the observation to higher organ weight of adrenal and prenatal hypoxia, leading to retarded
development of certain neurotransmitter pathways [Nyakas et al., 1994a, 1994b]. These studies
were performed in rats of single dose group and did not show the number of dams or dam
assignment of tested pups. No confirmative or supporting study has appeared thereafter.
Studies in Humans
Effects on Fertility
No studies in humans that evaluated directly the potential for prenatal exposure to sodium nitrite tocause adverse effects on fetal viability, growth, morphology or functional parameters were available.
Conclusion
The NOAEL of reproduction in mice was 425 mg/kg bw/day in drinking water and the NOAEL inrats was 43 mg/kg bw/day in diet. The LOAEL in guinea pigs was 60 mg/kg bw/day in drinking
water. Increase in mortality of pre- and postnatal offspring and decrease in body weight ofpreweaning pups were observed in rat dams given a diet containing sodium nitrite at 0.025% to
0.5%. Sodium nitrite caused maternal anaemia and increase in the incidence of abortion and fetal
mortality when administered to pregnant guinea pigs in drinking water at 60 mg/kg bw/day.
3.2

Initial Assessment for Human Health

Sodium nitrite has been reviewed by a number of international organizations: JECFA (Joint
FAO/WHO Expert Committee on Food Additives); National Academy of Sciences (NAS); US
National Institute of Environmental Health Sciences (NIEHS); National Institute of Public Healthand the Environmental Hygiene, Netherlands; US National Toxicology Program (NTP); andCalifornia EPA (CAL/EPA).
Nitrite in blood is highly reactive with haemoglobin and causes methaemoglobinaemia. Ferrous
iron associated with haemoglobin is oxidized by nitrite to ferric iron, leading to the formation of
methaemoglobin. Humans are considered to be more sensitive than rats in this respect.

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The primary acute effect of sodium nitrite in rats and mice is methaemoglobinaemia.
Methaemoglobin concentrations in SD rats increased to 45% to 80% over 1 hour after an oral doseof sodium nitrite at 150 mg/kg bw, and they returned to normal levels within 24 hours in surviving
rats.
LD50 values by gavage are 214 mg/kg bw (males) and 216 mg/kg bw (females) in mice. In an acuteinhalation study (which could not be validated) methaemoglobin levels in female rats weresignificantly increased after 4 hours exposure to 10 mg/m3 sodium nitrite. The increase was judged
not to be haematologically significant. No significant increase was observed in exposed males.
There were no toxicologically significant effects on animals maintained for 14 days post exposure.
No information on acute dermal toxicity is available.
Sodium nitrite is a moderate eye irritant, but is non-irritant to skin in rabbits. No studies areavailable investigating the sensitising potential of sodium nitrite in animals. No cases ofsensitisation have been reported in humans.
In a repeated dose toxicity study [NTP] male and female F344/N rats were exposed to 0, 375, 750,
1500, 3000 or 5000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 30,
55, 115, 200, or 310 mg/kg bw/day in males and 0, 40, 80, 130, 225, or 345 mg/kg bw/day infemales) in drinking water for 14 weeks. Methaemoglobin levels were significantly elevated in alltreated groups compared to the controls by the end of the treatment period. For males, mean
methaemoglobin levels after 14 weeks were 0.03±0.01, 0.08±0.01, 0.12±0.02, 0.25±0.07, 0.71±0.20
and 3.38±0.80 g/dL at doses of 0, 30, 55, 115, 200, and 310 mg/kg bw/day. For females, mean
methaemoglobin levels after 14 weeks were 0.06±0.02, 0.14±0.02, 0.16±0.02, 0.48±0.05, 0.99±0.20
and 2.27±0.54 g/dL at doses of 0, 40, 80, 130, 225 and 345 mg/kg bw/day. The NOAELs were notdetermined (increased methaemoglobinaemia). The LOAELs for other endpoints were 225 mg/kg
bw/day (increased relative weight of the kidney and spleen) in females and 115 mg/kg bw/day(decreased sperm motility) in males.
In a second 14-week repeated dose toxicity study [NTP] male and female B6C3F1 mice were
exposed to 0, 375, 750, 1500, 3000 or 5000 ppm sodium nitrite (equivalent to average daily dosesof approximately 0, 90, 190, 345, 750, or 990 mg/kg bw/day in males and 0, 120, 240, 445, 840, or
1230 mg/kg bw/day in females) in drinking water. Methaemoglobin levels were not reported
however there were no clinical signs of toxicity. The LOAELs were 445 mg/kg bw/day(extramedullary hematopoiesis in the spleen) in females and 750 mg/kg bw/day (extramedullaryhaematopoiesis in the spleen, degeneration of the testis) in males.
In a two-year chronic toxicity/carcinogenicity study [NTP] male and female F344/N rats were
exposed to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses ofapproximately 0, 35, 70 or 130 mg/kg bw/day in males and 0, 40, 80 or 150 mg/kg bw/day infemales) in drinking water. There were no clinical findings related to exposure. Methaemoglobin
levels were measured at two weeks and three months. At both 2 weeks and three months,
methaemoglobin levels were high at night when the rats were actively feeding and drinking and low
during the day when the rats were less active. Methaemoglobin levels tended to increase withincreasing dosage.
In a second two-year study [NTP] male and female B6C3F1 mice were exposed to 0, 750, 1500 or
3000 ppm sodium nitrite (equivalent to average daily doses of approximately 0, 60, 120 or 220
mg/kg bw/day for males and 0, 45, 90 or 165 mg/kg bw/day for females) in drinking water. There
were no clinical findings related to exposure. At 12 months, no significant increase inmethaemoglobin level was observed in either sex at any dose.

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Based on the NTP two-year studies, the NOAELs for rats were 130 mg/kg bw/day in males and 150
mg/kg bw/day in females. For mice the NOAELs were 220 mg/kg bw/day in males and 165 mg/kg
bw/day in females.
In a two-year study in male rats the NOEL was 10 mg/kg bw/day, equivalent to 6.7 mg NO2/kg
bw/day. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) established an
acceptable daily nitrite intake of 0 to 0.07 mg NO2/kg bw/day by applying a safety factor of 100 tothis NOEL.
Sodium nitrite is a direct-acting, base-pair substitution mutagen in organisms ranging from bacteria
to mammalian cells in vitro. This substance induced chromosomal aberrations in mammalian cells
in vitro. There is evidence of potential in vivo genotoxicity. The substance tested positive in a
micronucleus test (peripheral blood) when mice were dosed by gavage at 10 – 20 mg/kg bw ( 4times at 24 hrs intervals) but was negative in a second study where mice were dosed via drinking
water at dosed up to 900 mg/kg bw/day (females) for 14 weeks. In a chromosomal aberration test,
pregnant rats were dosed with 210 mg/kg bw/day for 13 days. Positive results for the induction ofchromosomal aberrations in bone marrow of the parents and liver cells of embryos were reported.
In a two-year chronic toxicity/carcinogenicity study [NTP] male and female F344/N rats were
exposed to 0, 750, 1500 or 3000 ppm sodium nitrite (equivalent to average daily doses ofapproximately 0, 35, 70 or 130 mg/kg bw/day for males and 0, 40, 80 or 150 mg/kg bw/day forfemales) in drinking water. The incidences of hyperplasia of the forestomach epithelium in highdose males (44/50) and females (40/50) were significantly greater than those in the control groups(12/50 males, 8/50 females). The incidence of fibroadenoma of the mammary gland wassignificantly increased in 80 mg/kg bw/day females, and the incidences of multiple fibroadenoma
were increased in 40 and 80 mg/kg bw/day females; however these neoplasms occur with a highbackground incidence and no increase was seen in the high dose group. The incidences ofmononuclear cell leukemia were significantly decreased in 70 and 130 mg/kg bw/day males (7/50
and 3/50, respectively) and 80 and 150 mg/kg bw/day females (1/50 and 1/50, respectively)
compared with controls (17/50 males, 15/50 females). Under the conditions of this study there is noevidence of carcinogenic activity of sodium nitrite in F344/N rats at approximate doses of up to 130
mg/kg bw/day in males and 150 mg/kg bw/day in females over a two year period.
In another NTP study male and female B6C3F1 mice were exposed to 0, 750, 1500 or 3000 ppm
sodium nitrite (equivalent to average daily doses of approximately 0, 60, 120 or 220 mg/kg bw/day
for males and 0, 45, 90 or 165 mg/kg bw/day for females) in drinking water for two years. The
incidences of squamous cell papilloma or carcinoma (combined) in the forestomach of female miceoccurred with a positive trend (1/50, 0/50, 1/50 and 5/50 at doses of 0, 45, 90 or 165 mg/kg
bw/day, respectively). The incidence of hyperplasia of the glandular stomach epithelium wassignificantly greater in 220 mg/kg bw/day males (10/50) than in the controls (0/50). Under theconditions of this study there is no evidence of carcinogenic activity of sodium nitrite in male
B6C3F1 mice at doses up to approximately 220 mg/kg bw/day over a two year period. There isequivocal evidence of carcinogenic activity in female mice, based on the positive trend of squamouscell papilloma or carcinoma (combined) in the forestomach.
Various other carcinogenicity studies in rats were negative. Moreover, some even showed areduction in tumor risk (e.g. lymphoma or leukemia). WHO concluded that there was no evidenceof carcinogenic activity of sodium nitrite in rats and mice based on the findings of NTP
carcinogenicity studies.
There is evidence for transfer of sodium nitrite to fetuses in rats and mice. Reproductive success in
the F1 generation was not affected. Increase in mortality of pre- and postnatal offspring anddecrease in body weight of preweaning pups were observed in rat dams given a diet containing
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sodium nitrite at 0.0125% (10.75 mg/kg bw/day), 0.025% (21.5 mg/kg bw/day) and 0.05% (43mg/kg bw/day), and the NOAEL is considered to be 10.75 mg/kg bw/day. Reproductive toxicity bycontinuous breeding in the mice was conducted with drinking water at doses of 125, 260 and 425
mg/kg bw/day, and no adverse effect on reproductive performance or necropsy endpoint wereobserved. The NOAEL is estimated to be 425 mg/kg bw/day. Sodium nitrite caused maternal
anemia and the incidence of abortion and fetal mortality increased when administered to pregnant
guinea pigs in drinking water and LOAEL is considered to be at 60 mg/kg bw/day.
From the weight of evidence, sodium nitrite appears to affect erythropoiesis, hematologicalparameters and brain development resulting in mortality and poor growth of offspring.
In humans, sodium nitrite causes smooth muscle relaxation, methaemoglobinemia, and cyanosis.
Infants are particularly sensitive. A large proportion of haemoglobin in infants is in the foetal
haemoglobin form, which is more readily oxidised to methaemoglobin than adult haemoglobin.
Further, reduced nicotinamide-adenine dinucleotide (NADH)-dependent methaemoglobin
reductase, the enzyme responsible for reduction of methaemoglobin back to normal haemoglobin,
has only about half the activity present in adults.

4

HAZARDS TO THE ENVIRONMENT

4.1

Aquatic Effects

The reliable toxicity data of aquatic organisms are summarized in Tables 8 to 11. (The values wereconverted from NO2-N into NaNO2 in those cases where the concentrations were represented as
NO2-N in the original reports).
Acute Toxicity Test Results
Fish
A large number of reliable acute toxicity tests for fish are reported in the literature (Table 8). The
LC50 values obtained vary widely between the species tested; LC50 (96h) = 0.54 mg NaNO2/L for
Oncorhynchus mykiss [Russo et al, 1981]; LC50 (96h) = 35 mg NaNO2/L for Ictalurus punctatus,
LC50 (96h) = 691.0 mg NaNO2/L for Micropterus salmoides [Palachek & Tomasso, 1984]; andLC50 (96h) = 1010.4 mg NaNO2/L for Anguilla japonica [Yamagata & Niwa, 1979]. The reason forthis difference has been attributed to the ability of certain species, such as eels, bass and sunfish toprevent nitrite from crossing the gill membrane and entering the blood, whilst other species such as
rainbow trout concentrate nitrite in their blood [Palachek & Tomasso, 1984]. The range of toxicity
values reported for some species of fish varies widely and is believed to be dependant on the qualityof the water used in the test with pH, chloride and calcium ion concentration all having an
influence. In particular, chloride ion concentration has been shown to be important, with increasing
concentrations leading to a decrease in the toxicity of nitrite [for example, Russo et al, 1981].
Invertebrates
The reliable data available for the acute toxicity of sodium nitrite to invertebrates are summarised inTable 9. As with fish, there is variation in toxicity between species. Sodium nitrite is toxic toinvertebrates such as Cherax quadricarinatus (LC50 (96h) = 4.93 mg NaNO2/L)[Rouse et al, 1995],
whereas other species, such as Procambarus clarkii (LC50 (96h) = 42 mg NaNO2/L) [Gutzmer &Tomasso, 1985] and Penaeus paulensis are much less sensitive (LC50 (96h) = 539.2 mg NaNO2/L)[Cavalli et al, 1996]. Gutzmer & Tomasso (1985) reported that increased levels of chloride ions in
the test water decreased the sensitivity of Procambarus clarkii to nitrite.
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Algae
One reliable study is available. In an algal growth inhibition study [OECD TG 201], green alga
(Desmodesmus subspicatus, formerly known as Scenedesmus subspicatus) was exposed under static
conditions to sodium nitrite at nominal concentrations of 0 and 100 mg/L for 72 hours. The 72-h
ErC50 and the 72-h EbC50 were > 100 mg/L [JAFA, 2005].
Chronic Toxicity Test Results
Fish
No studies available for this endpoint.
Invertebrates
Chen & Chen (1992) reported a NOEC (80 day, growth) of 9.86 mg NaNO2/L for Penaeus
monodon (jumbo tiger prawns).
Algae
One reliable study is available. In an algal growth inhibition study [OECD TG 201], green alga
(Desmodesmus subspicatus) was exposed under static conditions to sodium nitrite at nominal
concentrations of 0 and 100 mg/L for 72 hours. The NOEC was 100 mg/L for growth rate andbiomass.
Toxicity to Microorganisms
Two reliable studies are available. Nalecz-Jawecki and Sawicki (1998) studied the effect of sodium
nitrite on deformation (morphological changes such as shortening, bending of the cell, etc.) andmortality of Spirostomun ambiguum (protozoa). The 48-hour EC50 and LC50 were 421 and 533
mg/L (expressed as NaNO2), respectively. Ostrensky and Lemos (1993) reported a 96h EC50
(mobility) of 7886 mg NaNO2/L and 96h NOEC (mobility) of 3740 NaNO2/L for Tetraselmis chuii.

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Table 8SODIUM NITRITE
Summary of acute/prolonged toxicity of sodium nitrite on fish

OrganismFishRainbow trout, Donaldson
trout(Oncorhynchus mykiss)

Test duration

ResultReference

8 d (flow through)LC50 = 0.69 - 1.92 mg/L*

8 d (flow through)LC0 > 15.2 mg/L*

6 d (flow through)96 h (flow through)96 h (flow through)LC0 > 69.7 mg/L
LC50 = 3.89 mg/L*
LC0 = 2.66 mg/L*
LC50 = 27.7 mg/L*
LC50 = 0.94 - 1.92 mg/L*

96 h (flow through)LC50 = 0.94 - 1.38 mg/L*

96 h (flow through)LC50 = 0.54 - 26.3 mg/L*

96 h (semistatic)

LC50 = 1.49 - 153.8 mg/L*

Russo et al., 1974
Rodriguez-Moreno &Tarazona, 1994
Stormer et al., 1996
Buhl & Hamilton,
2000
Bortz, 1977
Russo et al., 1974
Russo and Thurston,
1977
Russo et al., 1981
Wedemeyer &Yasutake, 197896 h (flow through)11 d (flow through)36 d (flow through)LC50 = 2.73 mg/L*
LC50 = 1.92 mg/L*
LC50 = 1.82 mg/L*

９6 d (flow through)LC50 =11.3 mg/L*

120 h (static)

120-h LC50 = 7.39 mg/L*

96 h (static)

LC50 = 35.0 mg/L*

96 h (static)

LC50 = 7.55 mg/L

96 h (static)

LC50 = 79.8 mg/L*

96 h (semistatic)

LC50 = 118.3 - 150.7 mg/L*

96 h (static)

LC50 = 1,010.4 mg/L*

96 h (static)

LC50 = 691.0 mg/L*

96 h (semistatic)

LC50 = 708.2 mg/L*

96 h (static)

LC50 = 739.3 mg/L*

50d (flow through)LC0 = 98.6 mg/L*

96 h (static)

Cutthroat trout(Oncorhynchus clarki)
Fathead minnow(Pimephales promelas)
Grass carp, white amur(Ctenopharyngodon idella)Channel catfish(Ictalurus punctatus)
Tilapia(Tilapia aurea)
Flatfish(Paralichtys orbignyanus)
Japanese eel(Anguilla japonica)
Largemouth bass
(Micropterus salmoides)

Common eel(Anguilla anguilla)

Thurston et al., 1978
Russo & Thurston,1977
Alcaraz & Espina,
1994
Palachek & Tomasso,
1984
Konikoff, 1975
Palachek & Tomasso,
1984
Bianchini et al., 1996
Yamagata & Niwa,
1979
Palachek & Tomasso,
1984
Kamstra, 1996
Yamagata and Niwa,
1979
Kamstra, 1996*: The values were converted from NO2-N into NaNO2.

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Table 9SODIUM NITRITE
Summary of acute toxicity of sodium nitrite on invertebrates

Organism
Invertebrates
Australian redclaw crayfish(Cherax quadricarinatus)
Blue crab(Callinectes sapidus)
Fleshy prawn(Penaeus chinensis)
Giant Malaysian prawn(Macrobrachium rosenbergi)
Greasyback shrimp(Metapeaeus ensis)
Hard clam(Mercenaria mercenia)
Jumbo tiger prawn(Penaeus monodon)
Northern white shrimp(Penaeus setiferus)
Oyster(Crassostrea virginica)
Red swamp crayfish(Procambarus clarkii)
San paulo shrimp(Penaeus paulensis)

Test duration

ResultReference

96 h (static)
96 h (semistatic)

Rouse et al., 1995
Meade & Watts, 1995

96 h (semistatic)
192 h (semistatic)

LC50 = 4.93 mg/L*
LC50 = 126.7 mg/L*
LC50 = 351.4 - 460.3
mg/L*
LC50 = 182.9 mg/L*
LC50 = 113.1 mg/L*

96 h (semistatic)
192 h (semistatic)

LC50 = 42.4 mg/L*
LC50 = 22.2 mg/L*

96 h (semistatic)

120 h (semistatic)
96 h (static)

LC50 = 34.8 mg/L*
NOEC = 3.5 mg/L*
EC50 = 1100 - 1200
mg/L

Ary & Poirrier, 1989
Chen et al., 1990a
Armstrong et al., 1976
Chen, & Nan, 1991
Epifanio & Srna, 1975240 h (semistatic)

EC50 = 522.4 mg/L*

Chen et al., 1990b72 h (static)

EC50 = 851.7 mg/L*

Alcaraz et al, 199796 h (static)

EC50 = 660 -800 mg/L

Epifanio & Srna, 197596 h (static)

LC50 = 42-112 mg/L

Gutzmer & Tomasso,
1985

96 h (semistatic)

LC50 = 539.2 mg/L*

Cavalli et al., 1996

* : The values were converted from NO2-N into NaNO2.

Table 10

Summary of acute toxicity of sodium nitrite on algae

Organism
Algae
Green Alga
(Desmodesmus
subspicatus)

Table 11

Test duration

ResultReference

72 h (static)

ErC50 > 100 mg/L
EbC50 > 100 mg/L

JAFA, 2005

Summary of chronic toxicity of sodium nitrite on invertebrates

Organism
Invertebrates
Jumbo tiger prawn(Penaeus monodon)

Test duration

Result-Mortality
LC50 > 95.6 mg/L*
80 d-EC50 for weight gain
(semistatic)
EC50 = 114.9 mg/L*
NOEC = 9.86 mg/L** : The values were converted from NO2-N into NaNO2.

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Reference

Chen & Chen, 1992

OECD SIDS

SODIUM NITRITE

Table 12

Summary of chronic toxicity of sodium nitrite on algae

Organism
Algae
Green Alga
(Desmodesmus
subspicatus)

Table 13

Test duration

ResultReference

72 h (static)

NOEC = 100 mg/L (growth rate
and biomass)

JAFA, 2005

Summary of toxicity of sodium nitrite on other organisms

Organism
Prasinophyte(Tetraselmis chuii)Protozoa(Spirostomum
ambiguum)

Test duration
96 h

48 h (Static)

Result(Mobility)
EC50 = 7886 mg/L*
NOEC = 3,740 mg/L*
EC50 (deformation) = 421 mg/L*
LC50 = 533 mg/L*

Reference
Ostrensky & Lemos,
1993
Nalecz-Jawecki &Sawicki, 1998

• * : The values were converted from NO2-N into NaNO2.

4.2

Terrestrial Effects

No reliable data are available.
4.3

Other Environmental Effects

No reliable data are available
4.4

Initial Assessment for the Environment

Sodium nitrite is white or slightly yellow hygroscopic granules, rod or powder, which is very
soluble in water (820 g/L at 20 °C). Melting point, boiling point, vapour pressure and partition
coefficient are 271°C, >320°C (decomposes), 9.9E-17 hPa (25°C) and log Kow = -3.7, respectively.
Fugacity model Mackay level III calculations suggest that the substance will distribute mainly tosoil if released to the air or soil compartments separately or to all three compartments
simultaneously and almost exclusively to water if released to the water compartment. Estimatedvalue of Henry’s constant is 2.06E-07 atm-m3/mole. This substance dissociates immediately into
sodium and nitrite ions in water. The nitrite ion is a component of the nitrogen cycle. In theenvironment, bacteria of the genus Nitrobacter oxidise nitrites to nitrates. Nitrates are reduced tonitrogen by anaerobic bacteria present in soil and sediment. The estimated BCF is 3.162 and hence
bioaccumulation is not significant. Indirect photo-oxidation by hydroxy radicals is predicted tooccur with a half-life estimated at 82.3 days.
The LC50 values for the acute toxicity of sodium nitrite to fish reported in the literature vary widely
between the species tested; LC50 (96h) = 0.54 mg NaNO2/L for Oncorhynchus mykiss; LC50 (96h) =35 mg NaNO2/L for Ictalurus punctatus; LC50 (96h) = 691.0 mg NaNO2/L for Micropterus
salmoides; and LC50 (96h) = 1010.4 mg NaNO2/L for Anguilla japonica, for example. Thisdifference has been attributed to the ability of certain species, such as eels, bass and sunfish toprevent nitrite from crossing the gill membrane and entering the blood, whilst other species such as
rainbow trout concentrate nitrite in their blood. The range of toxicity values reported for somespecies of fish varies widely and is believed to be dependant on the quality of the water used in thetest with pH, chloride and calcium ion concentration all having an influence. In particular, chloride
ion concentration has been shown to be important, with increasing concentrations leading to adecrease in the toxicity of nitrite. As with fish, there is variation in toxicity between invertebrate
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species. Sodium nitrite is toxic to invertebrates such as Cherax quadricarinatus (LC50 (96h) = 4.93
mg NaNO2/L, whereas other species, such as Procambarus clarkii (LC50 (96h) = 18.7 mg
NaNO2/L) and Penaeus paulensis are much less sensitive (LC50 (96h) = 539.2 mg NaNO2/L). The
presence of chloride ions has been found to mitigate nitrite toxicity in some species. Acute toxicity
to green alga (Desmodesmus subspicatus) is > 100 mg/L (72-h ErC50 and EbC50) [OECD TG 201].
No data is available for chronic toxicity of sodium nitrite in fish. In invertebrates, an 80-day NOECof 9.86 mg NaNO2/L for Penaeus monodon has been reported. The NOEC value in green alga
(Desmodesmus subspicatus) is 100 mg/L (72-h for growth rate and biomass) [OECD TG 201].
For other aquatic organisms, the EC50 (48h, deformation) and LC50 (48h) for the protozoa
Spirostomum ambiguum were 421 and 533 mg NaNO2/L, respectively; for the microalgae
Tetraselmis chuii the EC50 (96h, mobility) and NOEC (96h, mobility) were 7886 and 3740 mg
NaNO2/L, respectively.

5

RECOMMENDATIONSHuman Health: The chemical is a candidate for further work.
Environment: The chemical is a candidate for further work.
The chemical possesses properties indicating a hazard to human health (acute toxicity, irritation,
repeated toxicity, mutagenicity, and reproductive toxicity) and the environment (acute toxicity).
Given the wide dispersive use of this substance, member countries are invited to perform an
exposure assessment, and if necessary a risk assessment for these uses. It is acknowledged thatsome uses (e.g. as a food additive) as well as the presence in drinking water are already regulated inmany member countries. It is recommended that the information on possible total exposure from
regulated and non-regulated use be shared between regulatory agencies.

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6SODIUM NITRITEREFERENCES

Agency for Toxic Substances and Disease Registry (ATSDR) (2001). Nitrate/Nitrite Toxicity. US
Department of Health and Human Services. Atlanta.
Abe S and Sasaki M (1977). Studies on Chromosomal Aberrations and Sister Chromatid Exchanges
Induced by Chemicals. Proc. Jpn. Acad. 53, 46-49.
Alcaraz G and Espina S (1994). Effect of Nitrite on the Survival of Grass Carp, Ctenopharngodon
idella (Val.), with Relation to Chloride. Bull. Environ. Contam. Toxicol. 52, 74-79.
Alcaraz G, Chiappa-Carrara X, Vanegas C (1997). Temperature Tolerance of Penaeus Setiferus
Postlarvae Exposed to Ammonia and Nitrite. Aquat. Toxicol. 39, 345-353
Anderson LM, Giner-Sorolla A, Haller IM, Budinger JM (1985). Effects of Cimetidine, Nitrite,
Cimetidine plus Nitrite, and Nitrosocimetidine on Tumors in Mice Following Transplacental plus
Chronic Lifetime Exposure. Cancer Res. 45, 3561-3566.
Armstrong DA, Stephenson MJ, Knight AW (1976). Acute Toxicity of Nitrite to Larvae of theGiant Malaysian Prawn, Macrobrachium rosenbergii. Aquaculture 9, 39-46.
Ary RDJ and Poirrier MA (1989). Acute Toxicity of Nitrite to the Blue Crab (Callinectes sapidus).
Prog. Fish. Cult. 51, 69-72.
Alavantic D, Sunjevaric I, Pecevski J, Bozin D and Cerovic G (1988) In Vivo Genotoxicity of
Nitrates and Nitrites in Germ Cells of Male Mice. I. Evidence for Gonadal Exposure and Lack of
Heritable Effects. Mutation Research, 204, 689-695
Balimandawa M, de Meester C, Leonard A (1994). The Mutagenicity of Nitrite in the
Salmonella/Microsome Test System. Mutat. Res. 321, 7-11.
Bianchini A, Wasielesky W Jr, Miranda Filho KC (1996). Toxicity of Nitrogenous Compounds toJuveniles of Flatfish Paralichthys orbignyanus. Bull. Environ. Contam.Toxicol. 56, 453-459.
Boink ABTJ, Beekhof PK, Dormans JAMA, Speijers GJA (1996). On the Etiology of Nitrite
Induced Hypertrophy of the Zona Glomerulosa of Rat II. National Institute of Public Health andEnvironmental Hygiene, Netherlands. Report 235802 004.
Bortz BM (1977). The Administration of Tetramethylthionine Chloride as a Treatment for NitriteInduced Methemoglobinemia in Rainbow Trout (Salmo gairdneri). MS. Thesis, American
University, Washington, D.C., 54.
Brams A, Buchet JP, Crutzen-Fayt MC, De Meester C, Lauwerys R, Leonard A (1987). A
Comparative Study, with 40 Chemicals, of the Efficiency of the Salmonella Assay and the SOS
Chromotest (Kit Procedure). Toxicol. Lett. 38, 123-133.
Buhl KJ and Hamilton SJ (2000). Acute Toxicity of Fire-Control Chemicals, Nitrogenous
Chemicals, and Surfactants to Rainbow Trout. Trans. Am. Fish. Soc. 129, 408-418.
Calabrese EJ, Moore GS, McCarthy MS (1983). The Effect of Ascorbic Acid on Nitrite-induced
Methemoglobin Formation in Rats, Sheep, and Normal Human Erythrocytes. Regul. Toxicol.
Pharmacol. 3, 184-188.
CAL/EPA (California Environmental Protection Agency) (2000). Evidence on Developmental andReproductive Toxicity of Sodium Nitrite, Reproductive and Cancer Hazard Assessment Section(RCHAS), Office of Environmental Health Assessment (OEHHA).
UNEP PUBLICATIONS

34

OECD SIDS

SODIUM NITRITE

Cavalli RO, Wasielesky W Jr, Franco CS, Filho KM (1996). Evaluation of the Short-Term Toxicityof Ammonia, Nitrite and Nitrate to Penaeus paulensis (Crustacea, Decapoda) Broodstock. Arq.
Biol. Tecnol. 39, 567-575.
Centers for Disease Control (1997). Methemoglobinemia Attributable to Nitrite Contamination of
Potable Water Through Boiler Fuid Additives – New Jersey, 1992 and 1996. Morbidity andMortality Weekly Report 46(09), 202 – 204.
Chapin R and Sloane R (1997). Reproductive Assessment by Continuous Breeding: Evolving Study
Design and Summaries of Ninety Studies. Environ. Health Perspect. 105, 199-395.
Chen J-C and Chen S-F (1992). Effects of Nitrite on Growth and Molting of Penaeus monodon
Juveniles. Comp. Biochem. Physiol. 101C, 453-458.
Chen J-C and Nan F-H (1991). Lethal Effect of Nitrite on Metapenaeus ensis Larvae. J. World
Aquacult. Soc. 22, 51-56.
Chen J-C, Liu P-C, Lei S-C (1990a). Toxicities of Ammonia and Nitrite to Penaeus monodon
Adolescents. Aquacult. 89, 127-137.
Chen J-C, Ting Y-Y, Lin J-N, Lin M-N (1990b). Lethal Effects of Ammonia and Nitrite on Penaeus
chinensis Juveniles. Mar. Biol. 107, 427-431.
Chow CK, Chen CJ, Gairola C (1980). Effect of Nitrate and Nitrite in Drinking Water on Rats.
Toxicology Letters 6, 199-206.
Craun GF, Greathouse DG, Gunderson DH (1981). Methaemoglobin Levels in Young Children
Consuming High Nitrate Well Water in the United States. Int. J. Epidemiol. 10, 309-317.
De Flora S (1981). Study of 106 Organic and Inorganic Compounds in the Salmonella/Microsome
Test. Carcinogenesis 2, 283-298.
De Flora S, Zanacchi P, Camoirano A, Bennicelli C, Badolati GS (1984). Genotoxic Activity andPotency of 135 compounds in the Ames Reversion Test and in a Bacterial DNA-repair Test. Mutat.
Res. 133, 161-198.
Diaz-Barriga Arceo S, Hernandez-Ceruelos A, Madrigal-Bujaidar E (2002) Inhibitory Effect ofChlorophyllin on the Frequency of Micronuclei Induced by Sodium Nitrite in Mice. Phytother Res.
16(8), 754-7
Dollahite JW and Rowe LD (1974). Nitrate and Nitrite Intoxication in Rabbits and Cattle.
Southwest. Vet. 27, 246-248.
Druckery VH, Steinhoff D, Beuthner H, Schneider H, Klarner P (1963). Screening of Nitrite for
Chronic Toxicity in Rats. Arzneimittelforschung 13, 320-323.
Ehrenberg L, Hussain S, Noor Saleh M, Lundquist U (1980). Nitrous Esters-A Genetical Hazard
from Nitrogen Oxides (NOx)? Hereditas 92, 127-130.
El Nahas SM, Globus M, Vethamany-Globus S (1984). Chromosomal Aberrations Induced by
Sodium Nitrite in Bone Marrow of Adult Rats and Liver Cells of Transplacentally Exposed
Embryos. J. Toxicol. Environ. Health 13, 643-647.
Epifanio CE and Srna RF (1975). Toxicity of Ammonia, Nitrite Ion, Nitrate Ion, andOrthophosphate to Mercenaria mercenaria and Crassostrea virginica. Mar. Biol. 33, 241-246.
European Chemicals Bureau (ECB) (2000). IUCLID CD-ROM 2000
35

UNEP PUBLICATIONSOECD SIDS

SODIUM NITRITE

Fahrig R (1979). Evidence that Induction and Suppression of Mutations and Recombination by
Chemical Mutagens in S. cerevisiae During Mitosis are Jointly Correlated. Mol. Gen. Genet. 168,
125-139.
Fassett DW (1973). Nitrates and Nitrites. In: Toxicants Occurring Naturally in Foods. 2nd ed., 7-25.
NAS, Washington.
Finan A, Keenan P, O’Donavan F, Mayne P, Murphy J (1998) Methaemoglobinaemia Associatedwith Sodium Nitrite in Three Siblings. British Medical Journal 317, 1138 – 1139.
Friedman MA, Greene EJ and Epstein SS (1972) Rapid Gastric Absorption of Sodium Nitrite inMice. Journal of Pharmaceutical Sciences, 61(9), 1492-1494
Furukawa F, Nishikawa A, Ishiwata H, Takahashi M, Hayashi Y, Hirose M (2000). Renal
Carcinogenicity of Concurrently Administered Fish Meal and Sodium Nitrite in Fischer 344 rats.
Jpn. J. Cancer Res., 91, 139–147.
Gangolli SD, van den Brandt PA, Feron VJ, Janzowsky C, Koeman JH, Speijers GJA,
Spiegelhalder B, walker R, and Wishnok JS (1994) Assessment: Nitrate, Nitrite and N-nitroso
Compounds. European Journal of Pharmacology: Environmental Toxicology and Pharmacology
Section 292, 1-38.
Giri AK, Talukder G, Sharma A (1986). Sister Chromatid Exchange Induced by Metanil Yellow
and Nitrite Singly and in Combination In Vivo on Mice. Cancer Letters 31, 299-303.
Globus M and Samuel D (1978). Effect of Maternally Administered Sodium Nitrite on Hepatic
Erythropoiesis in Fetal CD-1 Mice. Teratology 18, 367-378.
Gowans WJ (1990). Fatal Methaemoglobinaemia in a Dental Nurse: A Case of Sodium Nitrite
Poisoning. Br. J. Gen. Pract. 40, 470-471.
Gruener N and Shuval H (1973). Health Implications of Environmental Exposure to Nitrates.
Harefuah. 85, 30-32.
Gutzmer MP and Tomasso JR (1985). Nitrite Toxicity to the Crayfish Procambarus clarkii. Bull.
Environ. Contam. Toxicol. 34, 369-376.
Hack W and Dowes AVA (1983). Spinach: A Source of Nitrite Poisoning in Young Children. Ned
Tijdschr Geneekd 127, 1428-1431.
Hirneth H and Classen HG (1984). Inhibition of Nitrate-Induced Increase of Plasma Nitrite andMethemoglobin in Rats by Simultaneous Feeding of Ascorbic Acid or Tocopherol.
Arzneimittelforschung 34(II), 988-991
ICSC (2000). Sodium Nitrite: International Chemical Safety Cards No. 1120
IPCS (1996). Nitrates and nitrites (PIM G016) NITRATES AND NITRITES International
Programme on Chemical Safety Poisons Information Monograph (Group Monograph)
Imaizumi K, Tyuma I, Imai K, Kosaka H, and Ueda Y (1980). In vivo Studies on Methemoglobin
Formation by Sodium Nitrite. International Archives of Occupational and Environmental Health 45,
97-104.
Inoue K, Shibata T, Kosaka H, Uozumi M, Tsuda S, Abe T (1985). Induction of Sister Chromatid
Exchanges by N-nitrosocimetidine in Cultured Human Lymphocytes and its Inhibition by ChemicalCompounds. Mutat. Res. 156, 117-121.
UNEP PUBLICATIONS

36

OECD SIDS

SODIUM NITRITE

Inui N, Nishi Y, Mori M, Taketomi M, Yamamoto M, Tanimura A (1979a). Detection of 8
Azaguanine Resistant Mutants of Embryonic Cells Induced by Products Formed in the Stomach on
Oral Administration of Sodium Nitrite plus Aminopyrine to Pregnant Golden Hamsters. Proc. Jpn.
Acad. 55, 286-289.
Inui N, Nishi Y, Taketomi M, Mori M, (1979b). Transplacental Action of Sodium Nitrite on
Embryonic Cells of Syrian Golden Hamster. Mutat. Tes. 66, 149 – 158.
Inui N, Nishi Y, Hasegawa M, Taketomi M, Yamamoto M, Tanimura A (1980). Induction of 8azaguanine-resistant Mutation and Neoplastic Transformation of Hamster Embryonic Cells by
Coadministration of Sodium Nitrite and Aminopurine. J. Cancer Res. Clin. Oncol. 97, 119 – 128.
Ishidate M Jr. and Odashima S (1977). Chromosome Tests with 134 compounds on Chinese
hamster cells in vitro-A screening for chemical carcinogens. Mutat. Res. 48, 337-353.
Ishidate M Jr, Sofuni T, Yoshikawa K, Hayashi M, Nohmi T, Sawada M, Matsuoka A (1984)
Primary Mutagenicity Screening of Food Additives Currently Used in Japan. Food Chem. Toxicol.
22, 623-636
JECFA (FAO/WHO Joint Expert Committee on Food Additives) (1995). Food Additives Series 35.
JECFA (FAO/WHO Joint Expert Committee on Food Additives) (2003). Food Additives Series: 50
Japan Fertilizer and Ammonia Producers Association (JAFA) (2005). Sodium Nitrite: Algal
Inhibition Test. Safepharm Laboratories Ltd., Report No. 2104/001. Unpublished Data
Japan Industrial Safety and Health Association (JISHA) (2004) Inspection Report of Worker's
Exposure for the OECD SIDS Programme.
Kamstra A, Span JA, van Weerd JH (1996). The Acute Toxicity and Sublethal Effects of Nitrite on
Growth and Feed Utlization of European Eel, Anguilla anguilla (L.). Aquacult. Res. 27, 903-911.
Katz M, Kazmer S, Weinstein D (1980). An Analysis of Weak Mutagens in the Ames Assay. J.
Environ. Pathol. Toxicol. 3, 171-187.
Khera KS (1982). Reduction of Teratogenic Effects of Ethylenethiourea in Rats by Interaction with
Sodium Nitrite In Vivo. Food Chem. Toxicol. 20, 273-278.
Klimmek R, Krettek C, Werner HW (1988). Ferrihaemoglobin Formation by Amyl Nitrite andSodium Nitrite in Different Species In Vivo and In Vitro. Arch. Toxicol. 62, 152-160.
Kociba RJ and Sleight SD (1970). Nitrite Toxicosis in the Ascorbic Acid-Deficient Guinea Pig.
Toxicol. Appl. Pharmacol. 16, 424-429.
Kodama F, Umeda M, Tsutsui T (1976). Mutagenic Effect of Sodium Nitrite on Cultured Mouse
Cells. Mutat. Res. 40, 119-124.
Konikoff M (1975). Toxicity of Nitrite to Channel Catfish. Prog. Fish-Cult. 37, 96-98.
Kosako M and Nishioka H (1982). New Forward Mutation Assay using Low-Concentration
Streptomycin Resistance Mutation in E. coli Strains with Plasmid pKM 101. Sci. Eng. Rev.
Doshisha Univ. 22, 239-249.
Lynch SC, Gruenwedel DW, Russell GF (1983). Mutagenic Activity of a Nitrosated Early Maillard
Product: DNA Synthesis (DNA Repair) Induced in HeLa S3 Carcinoma Cells by Nitrosated 1-(NLtryptophan)-1-deoxy-D-fructose. Food Chem. Toxicol. 21, 551-556.

37

UNEP PUBLICATIONSOECD SIDS

SODIUM NITRITE

Maekawa A, Ogiu T, Onodera H, Furuta K, Matsuoka C, Ohno Y, and Odashima S (1982).
Carcinogenicity Studies of Sodium Nitrite and Sodium Nitrate in F-344 rats. Food Chem. Toxicol.
20, 25-33.
Meade ME and Watts SA (1995). Toxicity of Ammonia, Nitrite, and Nitrate to Juvenile Australian
Crayfish, Cherax quadricarinatus. J. Shellfish Res. 14, 341-346.
MERCK (2004). Sodium Nitrite MSDS according to EC Dir. 91/155/EEC.
Merck Index (2001). Budavari S (ed.), The Merck Index-An Encyclopedia of Chemicals, Drugs,
and Biologicals. Whitehouse Station, NJ, Merck and Co., Inc., No. 8721.
Ministry of Agriculture, Fisheries and Food (MAFF) (1992) Nitrate, Nitrite and NNitrosocompounds in Food: Food Surveillance Paper No. 32, Her Majesty’s Stationary Office,LondonNalecz-Jawecki G and Sawicki J (1998). Toxicity of Inorganic Compounds in the Spirotox Test: A
Miniaturized Version of the Spirostomum ambiguum Test. Arch. Environ. Contam. Toxicol. 34, 1-5
National Academy of Sciences (NAS) (1981). The Health Effects of Nitrate, Nitrite, and N-Nitroso
Compounds. National Academy Press, Washington.
NTP (2001). Toxicology and Carcinogenesis Studies of Sodium Nitrite (CAS No. 7632-00-0) in
F344/N Rats and B6C3F1 Mice (Drinking Water Studies). National Toxicology Program Report No.
NTP TR 495. NIH Publication No. 01-3954.
NTP (1990). Final Report on the Reproductive Toxicity of Sodium Nitrite (CAS No. 7632-00-0) in
CD-1 Swiss Mice. National Toxicology Program Report No. NTP 90-266.
National Institute of Environmental Health Sciences (NIEHS) (1970). Nitrates, Nitrites, andMethemoglobinemia. Research Triangle Park, N.C.: NTIS;
National Institute of Public Health and Environmental Hygiene, Netherlands (1986). Nitrate: Basis
Document Effects. Project Number 840820.
Nyakas C, Buwalda B, Kramers RJ, Traber J, Luiten PG (1994a). Postnatal Develoment of
Hippocampal and Neocortical Cholinergic and Seotonogeric Innervation in Rat: Effects of NitriteInduced Prenatal Hypoxia and Imodipine Treatment. Neuroscience 59, 541-559.
Nyakas C, Buwalda B, Markel E, Korte S, Luiten P (1994b). Life-spanning Behavioural andAdrenal Dysfunction Induced by Prenatal Hypoxia in the Rat is Prevented by the Calcium
Antagonist Nimodipine. Eur. J. Neurosci. 6, 746-753.
Nyakas C, Markel E, Bohus B, Schuurman T, Luiten P (1990). Protective Effect of the Calcium
Antagonist Nimodipine on Discrimination Learning Deficits and Impaired Retention Behavior
Caused by Prenatal Nitrite Exposure in Rats. Behav. Brain Res. 38, 69-76.
Ostrensky A and Lemos D (1993). Effects of Ammonium and Nitrite on Growth of the Marine
Microalgae Tetraselmis chuii. Actas IV Congreso Nac. Acuicult. 485-489.
Palachek RM and Tomasso JR (1984). Toxicity of Nitrite to Channel Catfish (Ictalurus punctatus),
Tilapia (Tilapia aurea), and Largemouth Bass (Micropterus salmoides). Can. J. Fish. Aquat. Sci. 41,
1739-1744.
Riemann H. (1950). On the Toxicity of Hydroxylamine. Acta. Pharmacol. 6, 285-292.

UNEP PUBLICATIONS

38OECD SIDS

SODIUM NITRITE

Rodriguez-Moreno PA and Tarazona JV (1994). Nitrite-induced Methemoglobin Formation andRecovery in Rainbow Trout (Oncorhynchus mykiss) at High Chloride Concentrations. Bull. Environ.
Contam. Toxicol. 53, 113-119.
Rouse DB, Kastner RJ, Reddy KS (1995). Toxicity of Ammonia and Nitrite to Hatchling Redclaw
Crayfish, Cherax quadricarinatus. Freshw. Crayfish 10, 298-303.
Russo RC, Thurston RV, Emerson K (1981). Acute Toxicity of Nitrite to Rainbow Trout (Salmo
gairdneri): Effects of pH, Nitrite Species, and Anion Species. Can. J. Fish. Aquat. Sci. 38, 387-393.
Russo RC and Thurston RV (1977). The Acute Toxicity of Nitrite to Fishes. In: R. A. Tubb (Ed.),
EPA-600/3-77-085, Recent Advances in Fish Toxicol., 118-131 (U.S.NTIS PB-273500).
Russo RC, Smith CE, Thurston RV (1974). Acute Toxicity of Nitrite to Rainbow Trout (Salmo
gairdneri). J. Fish. Res. Board Can. 31, 1653-1655.
Saito T, Taseichi S, Nakajima Y, Yukawa N, Osawa M (1997). Experimental Studies ofMethemoglobinemia Due to Percutaneous Absorption of Sodium Nitrite. Clinical Toxicology 35(1),41-48.
Saito T, Taseichi S, Yukawa N, Osawa M (1996). Fetal Methemoglonemia Caused by Liniment
Solutions Containing Sodium Nitrite. J. Forensic Science 41, 169-171.
Sander C and Jacobi H (1967). Methemoglobinemia Poisoning in a Two Year Old Boy After Eating
Spinach. Z. Kinderheilkd 98, 222-226.
Shuval HI and Gruener N (1972). Epidemiological and Toxicological Aspects of Nitrates andNitrites in the Environment. Am. J. Public Health 62, 1045-1052.
Sinha DP and Sleight SD (1971). Pathogenesis of Abortion in Acute Nitrite Toxicosis in Guinea
Pigs. Toxicol. Appl. Pharmacol. 18, 340-347.
Smith JE and Beutler E (1966). Methemoglobin Formation and Reduction in Man and Various
Animal Species. Am. J. Physiol. 210, 347-350.
Southwood J (1985). ICI Unpublished Report No CTL/L/1003.
Stormer J, Jensen FB, Rankin JC (1996). Uptake of Nitrite, Nitrate, and Bromide in Rainbow Trout,
Oncorhynchus mykiss: Effects of Ionic Balance. Can. J. Fish. Aquat. Sci. 53, 1943-1953.
Takahama U, Oniki, T and Hirota, S (2002). Oxidation of Quercetin by Salivary Components.
Quercetin-Dependant Reduction of Salivary Nitrite under Acidic Conditions Producing Nitric
Oxide. Journal of Agricultural and Food Chemistry 50, 4317 - 4322
Taylor HW and Lijinsky W (1975). Tumor Induction in Rats by Feeding Heptamethyleneimine andNitrite in Water. Cancer Res. 35, 812-815.
Thurston RV, Russo RC, Smith CE (1978). Acute Toxicity of Ammonia and Nitrite to Cutthroat
Trout Fry. Trans. Am. Fish. Soc. 107, 361-368.
Til HP, Falke HE, Kuper CF, Williams M (1988). Evaluation of the Oral Toxicity of Potassium
Nitrite in a 13-Week Drinking Water Study in Rats. Food Chem. Toxicol. 26, 851-859
Tomasso JR (1986). Comparative Toxicity of Nitrite to Freshwater Fishes. Aquat. Toxicol. 8, 129137.
Tsuda H and Kato K (1977). High Rate of Endoreduplications and Chromosomal Aberrations in
Hamster Cells Treated with Sodium Nitrite In Vitro. Mutat. Res. 56, 69-74.
39

UNEP PUBLICATIONSOECD SIDS

SODIUM NITRITE

Tsuda H, Inui N, Takayama S (1973). In Vitro Transformation of Newborn Hamster Cells by
Sodium Nitrite. Biochem. Biophys. Res. Comm. 55, 1117-1124.
Tsuda H, Kushi A, Yoshida D, Goto F (1981). Chromosomal Aberrations and Sister-chromatid
Exchanges Induced by Gaseous Nitrogen Dioxide in Cultured Chinese Hamster Cells. Mutat. Res.
89, 303-309.
Vleeming W, Van de Kuil A, te Biesebeek JD, Meulenbelt J, Boink AB (1997). Effect of Nitrite on
Blood Pressure in Anaesthetized and Freemoving Rats. Food Chem. Toxicol. 35, 615-619
Vorhees CV, Butcher RE, Brunner RL, Wootten V (1984). Developmental Toxicity andPsychotoxicity of Sodium Nitrite in Rats. Food Chem. Toxicol. 22, 1-6.
UBE Industries Ltd (2005). Sodium Nitrite: EPIWIN v3.12 Calculations. Unpublished data.
WHO (World Health Organization) (1985). Health Hazards from Nitrates in Drinking-Water,
Copenhagen.
WHO (World Health Organization) (1996a). Guideline for Drinking-Water Quality 2nd ed. Vol.2,
313-324.
WHO (1996b). Toxicological Evaluation of Certain Food Additives and Contaminants in Food:
Nitrite. WHO Food Additives Series: 35, 269-323.
WHO (2004). WHO FOOD ADDITIVES SERIES: 50 NITRITE (and potential endogenous
formation of N-nitroso compounds) First draft prepared by Dr G.J.A. Speijers and Professor P.A.
van den Brandt
Walker R (1990). Nitrates, Nitrites and N-nitrosocompounds: A Review of the Occurrence in Foodand Diet and the Toxicological Implications. Food Additives and Contaminants, 7(6), 717 – 768
Walker R (1996). The Metabolism of Dietary Nitrates and Nitrites. Biochemical Society
Transactions, 24, 780-785.
Wedemeyer GA and Yasutake WT (1978). Prevention and Treatment of Nitrite Toxicity in Juvenile
Steelhead Trout (Salmo gairdneri). J. Fish. Res. Board Can. 35, 822-827.
Yamagata Y and Niwa M (1979). Toxicity of Nitrite to Eels. The Aquaculture (Suisan Zoshoku) 27,
5-11.
Zeiger E, Anderson B, Haworth S, Lawlor T, Mortelmans K (1992). Salmonella Mutagenicity
Tests: V. Results from the Testing of 311 Chemicals. Environ. Mol. Mutagen. 19, 2-141.

UNEP PUBLICATIONS

40

OECD SIDS

SODIUM NITRITE

S

I

D

S

D o s s i e r
Existing Chemical
CAS No.
EINECS NameEC No.
TSCA Name
Molecular Formula

ID: 7632-00-0
7632-00-0
sodium nitrite
231-555-9
Nitrous acid, sodium salt
HNO2.Na

Producer Related Part
Company:
Creation date:

Safepharm Laboratories
28-FEB-2005

Substance Related Part
Company:
Safepharm Laboratories
Creation date:
28-FEB-2005
Memo:

Sodium Nitrite ICCA HPV SIAM 20

Printing date:
Revision date:
Date of last Update:

04-JAN-2006

Number of Pages:

297

Chapter (profile):
Reliability (profile):
Flags (profile):

Chapter: 1, 2, 3, 4, 5, 6, 7, 8, 10
Reliability: without reliability, 1, 2, 3, 4
Flags: without flag, confidential, non confidential, WGK(DE), TA-Luft (DE), Material Safety Dataset, Risk
Assessment, Directive 67/548/EEC, SIDS

41

04-JAN-2006

UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

1.0.1 Applicant and Company Information
Type:
Name:
Contact Person:
Street:Town:
Country:
Phone:
Telefax:
Email:

lead organisation
Ube Industries Ltd.
Mr. Etsuro Ito
Date:
Seavans North Bldg., 1-2-1, Shibaura, Minato-ku
105-8449 Tokyo
Japan+81-3-5419-66242+81-3-5419-6242
28946u@ube-ind.co.jp

25-APR-2005
Type:
Name:
Contact :Street:Town:
Country:
Phone:
Telefax:
Email:

cooperating company
Nissan Chemical Industries Ltd.
Kazuo NagashimaDate:
7-1, Kanda-Nishiki-cho 3-chome, Chiyoda-ku
101-0054 Tokyo
Japan+81-3-3296-8265+81-3-3296-8210
nagashimak@nissanchem.co.jp

25-APR-2005
Type:
cooperating company
Name:
Mitsubishi Chemical Corporation
Contact Person:
Yasukazu Uchida
Date:
Street:Dai-ichi Tamachi Building, 33-8, Shiba 5-chome, Minato-ku
Town:
108-0014 TokyoCountry:Japan
Phone:+81-3-6414-3620
Telefax:+81-3-6414-3638\@mc.m-kagaku.co.jp
25-APR-2005
Type:
Name:
Contact Person:
Street:Town:
Country:
Phone:
Telefax:
Email:

cooperating company
Sumitomo Chemical Co. Ltd.
Tsuneo NaraDate:
27-1, Shinkawa 2-chome, Chuo-ku
104-8260 Tokyo
Japan+81-3-5543-5196+81-3-5543-5909
narat@sc.sumitomo-chem.co.jp

1.0.2 Location of Production Site, Importer or Formulator
1.0.3 Identity of Recipients
Name of recip.:Street:Town:

Mr. Motohiko Kato, Ministry of Foreign Affairs, Economic
Affairs Bureau, Second International Organizations Div.
2-2-1 kasumigaseki, Chiyoda-ku
100-8919
UNEP PUBLICATIONS

42

OECD SIDS
1. GENERAL INFORMATIONCountry:
Phone:
Telefax:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Japan+81-3-3581-0018+81-3-3581-9470

29-APR-2005
1.0.4 Details on Category/Template
1.1.0 Substance Identification
IUPAC Name:
Smiles Code:Mol. Formula:
Mol. Weight:

sodium nitrite[Na]ON=O
NaNO2
69.00

29-APR-2005
1.1.1 General Substance Information
Purity type:
Substance type:Physical status:
Purity:Colour:typical for marketed substanceinorganicsolid>= 99 - % w/w
white or slightly yellow

Remark:Appearance: powdery crystal
Impurity: Moisture: < 0.3 % w/w, insolubility for water<0.05 % w/w

29-APR-2005(186)

Purity type:
Substance type:Physical status:
Purity:Colour:other
inorganicsolid
96 - 98 % w/w
white or slightly yellow, hygroscopic granules, rods, or
powder.
Very slowly oxidixes to nitrate in air.

Purity type:
Substance type:Physical status:
Purity:Colour:Odour:

typical for marketed substanceinorganicsolid>= 97 - % w/w
white or slightly yellow
no29-APR-2005(162)

1.1.2 Spectra
1.2 Synonyms and Tradenames
Anti-Rust
29-JUN-1995
43

UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

E 250
29-JUN-1995
Erinitrit
29-JUN-1995
Filmerine
29-JUN-1995
Konservierungsstoff E 250
29-JUN-1995
Na-Nitrit
06-MAY-1997
NaNO2
07-OCT-1994
Natriumnitrit
02-DEC-1992
NCI-C02084
29-JUN-1995
Nitrito sodico
20-MAY-1994
Nitrous acid sodium salt (1:1)
02-DEC-1992
Nitrous acid, sodium salt
29-APR-2005
Nitrous acid, sodium salt (8CI, 9CI)
02-DEC-1992
Salpetrige Säure, Na-Salz
07-OCT-1994
Salpetrigsaures Natrium
02-JUN-1998
Sodio nitrito
20-MAY-1994

UNEP PUBLICATIONS

44OECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Sodium nitrite
02-DEC-1992
Sodium nitrite 30%
13-APR-1994
Synfat 1004
29-JUN-1995
1.3 Impurities
Purity type:
CAS-No:EC-No:EINECS-Name:
Mol. Formula:Contents:

typical for marketed substance7732-18-5
231-791-2
water
H2O<= .3 - % w/w

Reliability:
Flag:
29-APR-2005(2) valid with restrictions
Critical study for SIDS endpoint

Purity type:
EINECS-Name:
Contents:

typical for marketed substancewater insoluble matter<= .05 - % w/w

Reliability:
Flag:
29-APR-2005(2) valid with restrictions
Critical study for SIDS endpoint

(186)

(186)

1.4 Additives
1.5 Total Quantity
Quantity:

10000 - 50000 tonnes produced in 2001

Remark:Amount produced in Japan. Worldwide production of sodium
nitrite is not available(122) (176)27-MAY-2005
1.6.1 Labelling
Labelling:
Symbols:

Specific limits:
R-Phrases:45

as in Directive 67/548/EEC(O) oxidizing(T) toxic(N) dangerous for the environment(E) For substances ascribed Nota E the risk phrases R20, R22
to R28 and all combinations of these risk phrases shall be
preceded by the word 'also'. E.g. R23 'also' toxic byinhalation
yes(8) Contact with combustible material may cause fire
UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATION

S-Phrases:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(25) Toxic if swallowed(50) Very toxic to aquatic organisms(1/2) Keep locked up and out of reach of children(45) In case of accident or if you feel unwell, seek medical
advice immediately (show the label where possible)(61) Avoid release to the environment. Refer to special
instructions/Safety data sets

29-APR-2005
1.6.2 Classification
Classified:Class of danger:
R-Phrases:

as in Directive 67/548/EEC
dangerous for the environment(50) Very toxic to aquatic organisms

29-APR-2005
Classified:Class of danger:
R-Phrases:

as in Directive 67/548/EEC
oxidizing(8) Contact with combustible material may cause fire

03-MAY-2005
Classified:Class of danger:
R-Phrases:

as in Directive 67/548/EEC
toxic(25) Toxic if swallowed

03-MAY-2005
1.6.3 Packaging
Memo:

20 kg, 30 kg
Packaging: paper bag (polyethylene; inner packaging), flexible
container

29-APR-2005(186)

1.7 Use Pattern
Type:
Category:type
Non dispersive use

29-APR-2005
Type:
Category:type
Use in closed system

29-APR-2005
Type:
Category:

type
Wide dispersive use

29-APR-2005
Type:
Category:

industrial
Agricultural industry
UNEP PUBLICATIONS

46

OECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

29-APR-2005
Type:
Category:(169)
industrial
Basic industry: basic chemicals

29-APR-2005
Type:
Category:

industrial
Chemical industry: used in synthesis

29-APR-2005
Type:
Category:

industrial
Electrical/electronic engineering industry

29-APR-2005
Type:
Category:(169)
industrial
Fuel industry

29-APR-2005
Type:
Category:(169)
industrial
Metal extraction, refining and processing of metals

29-APR-2005
Type:
Category:

industrial
Paints, lacquers and varnishes industry

29-APR-2005
Type:
Category:

industrial
Personal and domestic use

29-APR-2005
Type:
Category:(169)
industrial
Polymers industry

29-APR-2005
Type:
Category:

industrial
Public domain

29-APR-2005
Type:
Category:

industrial
Textile processing industry

29-APR-2005
Type:
Category:

industrial
other: raw material for caprolactam

29-APR-2005
Type:
47

industrial
UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATION
Category:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

other29-APR-2005
Type:
Category:use
Adhesive, binding agents

29-APR-2005
Type:
Category:

(169)
use
Anti-freezing agents

29-APR-2005
Type:
Category:

(169)
use
Cleaning/washing agents and disinfectants

29-APR-2005
Type:
Category:

(169)
use
Colouring agents

29-APR-2005
Type:
Category:useConstruction materials additives

29-APR-2005
Type:
Category:

(169)
use
Corrosive inhibitors

29-APR-2005
Type:
Category:use
Fillers

29-APR-2005
Type:
Category:use
Food/foodstuff additives

29-APR-2005
Type:
Category:use
Heat transferring agents

29-APR-2005
Type:
Category:useIntermediates

29-APR-2005
Type:
Category:

use
Laboratory chemicals

29-APR-2005
Type:

use
UNEP PUBLICATIONS

48

OECD SIDS
1. GENERAL INFORMATION
Category:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Lubricants and additives

29-APR-2005
Type:
Category:

(169)
use
Non agricultural pesticides

29-APR-2005
Type:
Category:

(169)
use
Oxidizing agents

29-APR-2005
Type:
Category:use
Pesticides

29-APR-2005
Type:
Category:use
Pharmaceuticals

29-APR-2005
Type:
Category:

use
Process regulators

29-APR-2005
Type:
Category:

(169)
use
Reducing agents

29-APR-2005
Type:
Category:use
Stabilizers

29-APR-2005
Type:
Category:use
Surface-active agents

29-APR-2005
Type:
Category:

(169)
use
other: cutting fluids

29-APR-2005
Type:
Category:

(169)
use
other: paint, lacquers and varnishes

29-APR-2005(169)

1.7.1 Detailed Use Pattern

49

UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

1.7.2 Methods of Manufacture
1.8 Regulatory Measures
1.8.1 Occupational Exposure Limit Values
Type of limit:

MAK (DE)

Remark:29-APR-2005

kein MAK-Wert festgelegt(182)

Type of limit:
TLV (US)
Limit value:
5.6 mg/m3
Short term exposure
Limit value:
9.4 mg/m3
Schedule:
15 minute(s)Frequency:
4 times
Remark:Exposure limit values not assigned for sodium nitrite insolution 30%
Exposure limit values referred to nitrogen dioxide

27-MAY-2005(2)

Type of limit:
Limit value:

TLV (US)31 mg/m3

Remark:Exposure limit values no assigned for sodium nitrite insolution 30%
Exposure limit values referred nitric oxide

27-MAY-2005(2)

Type of limit:
other: skin, (HUNGARY)
Short term exposure
Limit value:
1 mg/m3
Remark:29-APR-2005

Jan, 1993

1.8.2 Acceptable Residues Levels
1.8.3 Water Pollution
Classified by:Labelled by:Class of danger:

KBwS (DE)KBwS (DE)
2 (water polluting)29-APR-2005
1.8.4 Major Accident Hazards
Legislation:
Stoerfallverordnung (DE)Substance listed: yes
Remark:29-APR-2005

group of materials concerns 4c: poisonous materials(170)
UNEP PUBLICATIONS

50OECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

1.8.5 Air Pollution
Classified by:Labelled by:
Number:

TA-Luft (DE)TA-Luft (DE)3.1.3 (total dust)

Remark:No classes for inorganic materials except the final list in
3.1.6 TA air. Dust missions, limit after 3.1.3.

29-APR-2005
1.8.6 Listings e.g. Chemical Inventories
1.9.1 Degradation/Transformation Products
1.9.2 Components
1.10 Source of Exposure
Remark:29-APR-2005

Reaction between ammonia and caustic soda

Remark:Toxic substance used in closed systems. Therefore exposure
only occurs as a result of loss of containment.
(ICI Chemicals & Polymers Limited Runcorn, Cheshire)(54)

29-APR-2005
1.11 Additional Remarks
Memo:Work place monitoring data

Method:Air sample was suctioned at the breathing zone of the worker
at the suction rate of 2.0 L/min. and trapped in a filter
through a collection tube and analyzed by LC. Workers arerecommended to wear protective gear such as a mask, rubber
gloves and goggles to prevent exposure.
-Monitoring Data (Maximum Concentration) (mg/m3)--Operation in site 1 (powder production)
Paper bag filling:
0.110
Sampling from process:
0.308
Sampling from product:
0.803
Analysis work:<0.022--Operation in site 2 (liquid production)
Tank car operation:<0.08
Analysis work (process): 0.046
Analysis work (product): <0.014

Result:-Frequency (Time/day)
Paper bag filling:
Sampling from process:Sampling from product:
Analysis work:51

20 days/month2
1
2

UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006--Operation in site 2 (liquid production)
Tank car operation:
2
Analysis work (process): 2
Analysis work (product): 4 times/month-Working time (hrs/day)--Operation in site 1 (powder production)
Paper bag filling:
6
Sampling from process:
0.03
Sampling from product:
0.030
Analysis work:
0.17--Operation in site 2 (liquid production)
Tank car operation:
0.3
Analysis work (process): 0.17
Analysis work (product): 0.08
-Maximum EHEinh(mg/kg/day)--Operation in site 1 (powder production)
Paper bag filling:
1.30 x 10-2
Sampling from process:3.61 x 10-4
Sampling from product:
4.71 x 10-4
Analysis work:
1.33 x 10-4--Operation in site 2 (liquid production)
Tank car operation:
8.56 x 10-4
Analysis work (process): 2.79 x 10-4
Analysis work (product): 4.00 x 10-8

Test condition:

Reliability:
Flag:
29-APR-2005

The concentrations at operation in site 1 (powder
production) were higher than those at operation in site 2(liquid production).
Analysis column: Geilack GL-IC-A25
Separate liquid : 4 mmol/L Na2CO3
Feed rate : 1.0 mL/L
Column temp. : 40 degree C
Detector system : conduct metric detection
Injection volume : 25 micro-L(1) valid without restriction
Critical study for SIDS endpoint
(95)

Memo:

The environmental limitation

Remark:The environmental limitations; 10 mg/L (the sum ofnitrite-nitrogen plus nitrate-nitrogen) in JAPAN

06-JAN-2004
Memo:

Water quality-based limitations

Remark:JAPAN:
Guideline value; 0.05 mg/L (nitrite-nitrogen) for a tap
water quality.
Water quality-based limitations; 10 mg/L (the sum ofnitrite-nitrogen plus nitrate-nitrogen)WHO:acute; 3 mg/L (as nitrite)
chronic; 0.2 mg/L (as nitrite)EU:
UNEP PUBLICATIONS

52

OECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

0.5 mg/L (as nitrite)
USEPA:
1 mg/L
19-JAN-2005
Remark:(123) (196)This product has a 5.1, 23c RID/ADR/ADNR classification andUN number is 1500.

13-JAN-2005
Remark:- Code of the public health. Art. 5149 A 5211. Table C.
- Directive 64/54/The EEC of the 15.11.1963 (preservatives).
Arrete of 20.7.1979 (metal nitrites, salts niters).
Concern: E 250.
- water pollution - KBwS classification (OF)- labelling KBwS (OF)- category of danger (wGK): 2- major risks of accident:- Directive 82/501/The EEC (Seveso)- Substance not listed.

21-JAN-2005
1.12 Last Literature Search
Type of Search:
Remark:Internal and External

ACGIH
AQUIRE (CIS, STN)
BEILSTEIN (STN)
BIOSIS (STN, Dialog)
CHEMCATS (STN)CHRIS (CIS, CHEM-BANK)CSCHEM (STN)
ChemFinder
ECDIN
GMELIN (STN)
HODOC(STN)
HSDB (CIS, STN, DataStar, CHEM-BANK)IARCIRIS (CIS, CHEM-BANK)IUCLIDMSDS-CCOHS (STN, Dialog)
MEDLINE (STN, Dialog, Datastar)
MSDS-OHS (STN)
NCI
NIOSHOHMTADS (CIS, CHEM-BANK)NIOSHTIC(STN, Dialog)
PROMT(STN, Dialog)
REGISTRY (STN, Dialog)
RTECS(STN, CIS, Dialog, CHEM-BANK)SPECINFO (STN)SRC PhysPro Database(SRC: Syracuse Research Corporation)
TOXCENTER (STN)
TOXFILE (Dialog, Datastar)
TSCATS (CIS)

53

UNEP PUBLICATIONSOECD SIDS
1. GENERAL INFORMATIONSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Date of the literature search: 6 Jan, 2004
29-APR-2005
1.13 Reviews
Memo:

NTP (2001). Toxicology and Carcinogenesis Studies of Sodium
Nitrite (CAS No. 7632-00-0) in F344/N Rats and B6C3F1 Mice
(Drinking Water Studies). National Toxicology Program Report
No. NTP TR 495. NIH Publication No. 01-3954.

03-JUN-2005
Memo:

JECFA (FAO/WHO Joint Expert Committee on Food Additives)(2003). Food Additives Series: 50

15-JUL-2005
Memo:

National Academy of Sciences (NAS) (1981). The Health Effectsof Nitrate, Nitrite, and N-Nitroso Compounds. National Academy
Press, Washington.

15-JUL-2005
Memo:

National Institute of Environmental Health Sciences (NIEHS)(1970). Nitrates, Nitrites, and Methemoglobinemia. Research
Triangle Park, N.C.: NTIS;

15-JUL-2005
Memo:

National Institute of Public Health and Environmental Hygiene,
Netherlands (1986). Nitrate: Basis Document Effects. Project
Number 840820.

15-JUL-2005
Memo:

CAL/EPA (California Environmental Protection Agency) (2000).
Evidence on Developmental and Reproductive Toxicity of Sodium
Nitrite, Reproductive and Cancer Hazard Assessment Section(RCHAS), Office of Environmental Health Assessment (OEHHA)-UNEP PUBLICATIONS

54OECD SIDS
2. PHYSICO CHEMICAL PROPERTIESSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

2.1 Melting Point
Value:
Sublimation:
Test substance:
Reliability:
Flag:
27-MAY-2005= 271 degree CnoChemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint

Value:
Decomposition:
Sublimation:= 280 degree C
yes at degree C
no

Test substance:
Reliability:
27-MAY-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Value:
Decomposition:
Sublimation:= 280 degree C
yes at degree C
no

Test substance:
Reliability:
27-MAY-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable

Value:
GLP:

281 degree C
no data

Test substance:
Reliability:
27-MAY-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(120)(83) (119)

(14)

(61)

2.2 Boiling Point
Value:
Decomposition:
Test substance:
Reliability:
Flag:
27-MAY-2005> 320 degree C
yes
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint(78) (82) (83) (120)

2.3 Density
Type:
Value:

density= 2.1 g/cm³ at 20 degree C

Test substance:
Reliability:
27-MAY-2005

Chemical name: sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Type:
Value:

density= 2.17 g/cm³

Test substance:

Chemical name: sodium nitrite (CAS No. 7632-00-0)55(14) (119)UNEP PUBLICATIONSOECD SIDS
2. PHYSICO CHEMICAL PROPERTIESSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Reliability:
27-MAY-2005(2)

valid with restrictions

Type:
Value:

density= 2.2 g/cm³

Test substance:
Reliability:
27-MAY-2005

Chemical name: sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Type:
Value:

density
2.135 g/cm³ at 26 degree C

Method:GLP:otherno data

Test substance:
Reliability:
27-MAY-2005

Chemical name: sodium nitrite (CAS No. 7632-00-0)(4) not assignable(120)(83) (102)(173)

2.3.1 Granulometry
2.4 Vapour Pressure
Value:

at 25 degree C

Method:Year:other (calculated): MPBWIN v1.41
2005

Result:Vapour Pressure = 9.9E-17 hPa (7.44E-17 mm Hg) [Modified Grain
Method]Inputs:Test condition:

Boiling Point: 706.27°C (estimated)
Melting Point: 308.95°C (estimated)
Test substance:
Reliability:
31-MAY-2005

Chemical name: sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(185)

2.5 Partition CoefficientPartition Coeff.: octanol-waterlog Pow:-3.7
Test substance:
Reliability:
Flag:
15-JAN-2004

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint(14) (83) (119)2.6.1 Solubility in different media
Solubility in:
Value:

Water= 820 g/l at 20 degree C
UNEP PUBLICATIONS

56

OECD SIDS
2. PHYSICO CHEMICAL PROPERTIESSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Test substance:
Reliability:
Flag:
16-JAN-2004

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint

Solubility in:
Value:

Water= 816 g/l at 15 degree C

Remark:Solubility at 0°C = 720 g/L
Solubility at 100°C = 1630 g/L
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable

Test substance:
Reliability:
27-MAY-2005

(83)

(176)

Solubility in:
Value:
pH
value:
Conc.:

Water= 818 g/l at 20 degree C
8 - 9
100 g/l at 20 degree C

Remark:Test substance:
Reliability:
27-MAY-2005

Solubility at 80°C = 1355 g/L
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable

Remark:Freely soluble in water. Solutions of 40% may be achieved
at 20 °C.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(82)

Test substance:
Reliability:
27-MAY-2005
Remark:Test substance:
Reliability:
27-MAY-2005(14)very soluble in water 80 % at 20 degree C,slightly soluble in Ethnol 0.3 % and Methanol 0.45%
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(15)

2.6.2 Surface Tension
2.7 Flash Point

Remark:Test substance:
Reliability:
27-MAY-2005

Not combustible but enhances combustion of other substances.
Many reactions may cause fire or explosion. Gives off
irritating or toxic fumes (or gases) in a fire.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(83)

2.8 Auto Flammability
Value:
57

UNEP PUBLICATIONSOECD SIDS
2. PHYSICO CHEMICAL PROPERTIES

Remark:Test substance:
27-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

See section 2.7
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

2.9 Flammability

Remark:Test substance:

See section 2.7
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

2.10 Explosive Properties
Remark:Test substance:
Reliability:
27-MAY-2005

May explode on heating above 530 degree C.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Result:not explosive

Method:other: Stahlhuelsentest (BAM)

Test substance:
14-MAY-2004

Chemical name: Sodium nitrite (CAS No. 7632-00-0)

Result:other

Method:
Year:
GLP:

other
1985
no dataResult:
Test substance:
14-MAY-2004

Explodes at 537 C.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

(83)

(14)

(75)

2.11 Oxidizing Properties
Remark:Test substance:
14-MAY-2004

See section 2.10
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

Result:other

Method:
Year:
GLP:

other
1985
no dataResult:
Test substance:
27-MAY-2005

Strong oxidizing agent.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

Result:other

Method:GLP:otherno data

(83)

(75)

UNEP PUBLICATIONS

58

OECD SIDS
2. PHYSICO CHEMICAL PROPERTIES

Remark:Test substance:
27-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Sodium nitrite is a strong oxidising agent at hightemperature and also is a strong supporter of combustion.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(82)

2.12 Dissociation Constant
12-JAN-2005(174)

Acid-base Const.: pKa = 3.27
Year:
Test substance:
Reliability:
27-MAY-2005

2002
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(174)

2.13 Viscosity
2.14 Additional Remarks
Memo:

The substancedecomposes on contact with acids producing toxic fumes(nitrogen oxides). The substance is a strong oxidant andreacts with combustible and reducing materials causing fireand explosion hazard. The solution in water is a weak

27-MAY-2005

59

(83)

UNEP PUBLICATIONSOECD SIDS
3. ENVIRONMENTAL FATE AND PATHWAYSSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

3.1.1 Photodegradation
Type:
air
INDIRECT PHOTOLYSIS
Sensitizer:
OH
Conc. of sens.: 1500000 molecule/cm³
Rate constant: .00000000000013 cm³/(molecule * sec)
Degradation:
50 % after 82.3 day(s)Method:Year:other (calculated): AOPWIN v1.91
2005

Test condition:

Inputs:Test substance:
Reliability:
27-MAY-2005

12-hour day
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(185)

3.1.2 Stability in Water
Remark:Reliability:
Flag:
27-MAY-2005

This substance dissociates immediately into sodium and nitrite
ions in water(2) valid with restrictions
Critical study for SIDS endpoint

3.1.3 Stability in Soil
3.2.1 Monitoring Data (Environment)
3.2.2 Field Studies
3.3.1 Transport between Environmental Compartments
Method:Year:other: Calculated using EPIWIN V 3.12 Level III Fugacity Model2005

Remark:The substance will distribute mainly to soil if released tothe air or soil compartments separately or to all threecompartments simultaneously and almost exclusively to water if
released to the water compartment.
1000 kg/h emission to
Simultaneous 1000
these compartments
kg/h emission to
separately
air, water and soil
Air
Water
Soil
compartments
In air
5.0
0.0
0.3
1.78
In water
25.0
99.7
22.3
40.20
In soil
69.9
0.1
77.4
58.00
In sediment
0.1
0.2
0.0
0.07
Inputs:Result:

Test condition:

Molecular weight: 69
Henry's Law Constant 2.06E-07 atm-m3/mole (Henrywin program)
UNEP PUBLICATIONS

60

OECD SIDS
3. ENVIRONMENTAL FATE AND PATHWAYSSODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Vapour pressure: 7.44E-17 mm Hg (Mpbpwin program)
Liquid VP: 4.79E-14 mm Hg (super cooled)
Melting point: 309°C (mpbpwin program)
Log Kow: -2.37 (Kowwin program)
Soil Koc: 0.00175 (calc by model)

Reliability:
27-MAY-2005

Half-lives (hr) (based on Biowin (Ultimate) and Aopwin):
Air: 1975
Water: 360
Soil: 720
Sediment: 3240
Biowin estimate: 3.047 weeks(2) valid with restrictions(185)

3.3.2 Distribution
3.4 Mode of Degradation in Actual Use
3.5 Biodegradation
Remark:Test substance:
27-MAY-2005

The nitrite ion is a component of the nitrogen cycle. In theenvironment, bacteria of the genus Notribacter oxidise
nitrites to nitrates. Nitrates are reduced to nitrogen byanaerobic bacteria present in soil and sediment.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

3.6 BOD5, COD or BOD5/COD Ratio
3.7 Bioaccumulation
BCF:

3.16

Method:Year:other: calculation using BCF Program v2.15
2005

Result:
Test condition:

BCF = 3.16, Log BCF = 0.5
Input:

Test substance:
Reliability:
27-MAY-2005

Log Kow = 0.06 (BCF estimate)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(185)

3.8 Additional Remarks
Memo:Henry's Law Constant

Result:Henry's Law Constant at 25°C = 2.06E-07 atm-m3/mole (bondestimate)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(185)

Test substance:
Reliability:
27-MAY-2005
61

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

AQUATIC ORGANISMS
4.1 Acute/Prolonged Toxicity to Fish
Type:
Species:
Exposure period:
Unit:
LC50 :

flow throughOncorhynchus mykiss
96 hour(s)mg/l= .11 - 5.34

Method:Year:other: Russo et al
1981

Method:METHOD FOLLOWED: Russo et al method.

(Fish, fresh water)
Analytical monitoring: yes

Four series of 96-h bioassays were conducted using rainbow
trout. Series 1 (12 test) and Series II (22 tests) wereconducted over the pH range 6.4 - 9.0. The two series wereconducted on two different size ranges of fish and in two
different years. Series III (six tests) was conducted at pH 7
using three different acids (H2SO4, H3PO4 and HNO3) for pH
reduction. Series IV (four tests) was conducted over the pH
range 7.5 - 8.6 at chloride concentrations above background.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
LC50 values and their 95% confidence interval endpoints were
calculated using a computer program developed for the Trimmed
Spearman-Karber Method; the calculations were performed using
an XDS Sgma 7 computer.
METHOD OF CALCULATION:
No data

Remark:ANALYTICAL METHODS: Nitrite concentration determined using themethod described by EPA (1974).
References:
US EPA (1974) Methods for Chemical Analysis of Water andWastes. EPA-625-/6-74-003. Methods Development and Quality
Assurance Research Laboratory, National Environmental researchCenter, Cincinnati, OH. 215-216
Effect of pH:
As pH increased, the toxicity in terms of NO2-N decreased.
Effect of sulfate, phosphate and nitrate ions:
To determine what might be the effect of using an acid otherthan sulfuric acid to reduce pH in the test water, thus adding
different anions. The LC50 values obtained were lowest in thepresence of sulfate and highest in the presence of nitrate.
Effect of chloride ion:
The 96-h LC50 values were an order of magnitude higher than,and followed the same trend as, those obtained for the fish
tested over the same pH range without chloride addition(series I and II). Fish varied in size from 28 - 244 g in thechloride added experiments, but this was not considered to bea factor in results.
UNEP PUBLICATIONS

62

OECD SIDS
4. ECOTOXICITY
Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
The lowest 96-h LC50 was 0.11 mg/L NO2-N (equivalent to 0.54
mg/L NaNO2).
The highest 96-h LC50 was 5.35 mg/L NO2-N (equivalent to 26.3
mg/L NaNO2), in the presence of 10 mg/L chloride.
Table 1: Acute toxicity of nitrite at different pH values torainbow trout (Series I)---------------------------------------------------------Avg (mean) Fish Acid Alkalinity
pH
96h-LC50
Fish size
peror
mg/L CaCO3
mg/L NO2-N
Wt Lengthtank base (range)(range)(95% CI)(g)(cm)---------------------------------------------------------285
28.1
5
H3PO4
109
6.44
0.21
(108-113) (6.28-6.56) (0.13-0.34)
171
23.2
10
H3PO4
171
7.50
0.20
(170-171) (7.47-7.53) (0.17-0.24)
46.7 15.3
20
H3PO4
174
7.52
0.32
(172-175) (7.44-7.63) (0.26-0.39)
53.1 15.7
20
NONE
176
7.68
0.27
(175-177) (7.58-7.79) (0.22-0.32)
387
29.7
5
NONE
159
7.74
0.24
(158-160) (7.69-7.80) (0.17-0.33)
60.5 16.6
20
NONE
177
7.76
0.27
(175-180) (7.71-7.83) (0.23-0.32)
188
23.6
10
NONE
172
7.81
0.19
(171-172) (7.76-7.86) (0.15-0.24)
24.3 12.3
20
NONE
179
8.10
0.28
(178-180) (7.99-8.33) (0.24-0.32)
121
20.5
10
NaOH
176
8.15
0.41
(175-176) (7.94-8.60) (0.32-0.52)
74.8 17.4
10
NaOH
180
8.23
0.38
(179-182) (9.07-8.63) (0.31-0.46)
69.8 17.0
10
NaOH
182
8.24
0.39
(180-183) (8.13-8.55) (0.33-0.47)
341
28.4
5
NaOH
190
9.00
1.67
(189-192) (8.97-9.05) (1.04-2.70)---------------------------------------------------------The range of other water chemistry variables (in mg/L) for alltanks at time of tests were: dissolved oxygen 7.6-9.3; NH3-N
0.00-0.11; Cl- 0.00-1.71; Ca2+ 54.9-65.7; hardness (as CaCO3)
185-208. Temperature range for all tanks was 9.0-10.7°C
Table 2: Acute toxicity of nitrite at different pH values torainbow trout (Series II)---------------------------------------------------------Avg (mean) Fish Acid Alkalinity
pH
96h-LC50
Fish size
peror
mg/L CaCO3
mg/L NO2-N
Wt Lengthtank base (range)(range)(95% CI)(g)(cm)
12.8 10.4
10
H2SO4
120
6.99
0.14
(117-123) (6.84-7.04) (0.12-0.15)
15.3 10.2
10
H2SO4
128
7.02
0.11
(124-130) (6.96-7.07) (0.09-0.13)
10.4 10.0
10
H2SO4
135
7.24
0.15
(128-142) (7.16-7.33) (0.13-0.18)
10.0
9.4
10
H2SO4
150
7.37
0.19
(146-154) (7.32-7.41)-

63

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
9.3

9.2

10

H2SO4

160
7.59
0.18
(158-164) (7.53-7.64) (0.15-0.21)
7.0
9.1
10
NONE
188
7.83
0.40
(188-189) (7.75-7.91)
12.8 10.3
10
NONE
173
7.86
0.21
(172-176) (7.81-7.93) (0.19-0.24)
13.2 10.3
10
NONE
177
7.87
0.22
(174-180) (7.82-7.92) (0.18-0.27)
8.0
8.6
10
NONE
170
7.88
0.36
(168-170) (7.77-7.99) (0.33-0.39)
10.0
9.3
10
NONE
172
7.90
0.21
(170-174) (7.84-7.94) (0.19-0.24)
8.2
8.7
10
NONE
170
7.91
0.30
(168-171) (7.82-8.01) (0.26-0.34)
3.1
6.3
10
NONE
165
7.94
0.25
(164-166) (7.91-8.00) (0.21-0.30)
10.4
9.2
10
NONE
174
7.95
0.17
(172-176) (7.86-8.09) (0.15-0.20)
8.4
8.9
10
NaOH
178
8.27
0.54
(177-179) (8.21-8.36) (0.50-0.60)
12.8 10.2
10
NaOH
185
8.41
0.46
(183-186) (8.32-8.60) (0.40-0.53)
15.5 10.9
10
NaOH
188
8.49
0.45
(186-190) (8.33-8.59) (0.39-0.52)
15.3 10.0
10
NaOH
186
8.61
0.50
(185-188) (8.53-8.74) (0.44-0.57)
8.2
8.8
10
NaOH
181
8.70
0.71
(180-182) (8.64-8.78) (0.63-0.80)
9.3
9.4
10
NaOH
188
8.83
1.17
(187-190) (8.77-8.90) (0.82-1.67)
10.4
9.6
10
NaOH
191
8.83
0.61
(190-193) (8.75-8.91) (0.52-0.71)
7.0
8.7
10
NaOH
202
9.03
1.10
(201-203) (8.94-9.09)
8.0
8.8
10
NaOH
190
9.04
1.12
(188-192) (8.97-9.12) (0.91-1.37)---------------------------------------------------------The range of other water chemistry variables (in mg/L) for alltanks at time of tests were: dissolved oxygen 6.6-9.3; NH3-N
0.00-0.06; Cl- 0.00-0.47; Ca2+ 46.8-61.3; hardness (as CaCO3)
178-209. Temperature range for all tanks was 8.9-14.7°C
Table 3: Acute toxicity of nitrite at pH 7 to rainbow trout
using different acids (Series III)----------------------------------------------------------Avg (mean) Fish Acid Alkalinity
pH
96h-LC50
Fish size
peror
mg/L CaCO3
mg/L NO2-N
Wt Lengthtank base (range)(range)(95% CI)(g)(cm)----------------------------------------------------------15.3 10.2
10
H2SO4
128
7.02
0.11
(124-130) (6.96-7.07) (0.09-0.13)
12.8 10.4
10
H2SO4
120
6.99
0.14
(117-123) (6.84-7.04) (0.12-0.15)
13.2 10.7
10
H3PO4
152
6.99
0.18
(151-153) (6.95-7.06) (0.13-0.26)
13.7 10.8
10
H3PO4
150
6.98
0.18
(146-155) (6.98-7.04) (0.16-0.21)
13.7 10.6
10
HNO3
137
7.01
0.29
(130-144) (6.95-7.08) (0.26-0.32)
UNEP PUBLICATIONS

64

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
18.2

136
7.01
0.26
(131-140) (6.95-7.16) (0.23-0.29)
The range of other water chemistry variables (in mg/L) for alltanks at time of tests were: dissolved oxygen 6.6-6.8; NH3-N
0.00-0.06; Cl- 0.10-0.63; Ca2+ 48.9-52.9; hardness (as CaCO3)
192-201. Temperature range for all tanks was 9.4-14.0°C

Test condition:

11.8

10

HNO3

Table 4: Acute toxicity of nitrite at 10 mg/L chloride overdifferent pH values to rainbow trout (Series IV)---------------------------------------------------------Avg (mean) Fish Acid Alkalinity
pH
96h-LC50
Fish size
peror
mg/L CaCO3
mg/L NO2-N
Wt Length tank base (range)(range)(95% CI)(g) (cm)----------------------------------------------------------28.2 12.9
10
HCl
174
7.50
3.74
(173-176) (7.38-7.61) (3.25-4.30)
79.0 17.6
10
NONE
177
7.90
3.54
(176-178) (7.83-7.96) (2.96-4.22)
147 22.0
10
NaOH
188
8.47
4.35
(186-190) (8.39-8.58) (3.60-5.26)
244 26.1
10
NaOH
184
8.59
5.34
(8.50-8.67) (4.43-6.45)
The range of other water chemistry variables (in mg/L) for alltanks at time of tests were: dissolved oxygen 7.2-9.6; NH3-N
0.00-0.06; hardness (as CaCO3) 199-206. Temperature range forall tanks was 9.9-10.7°C
TEST ORGANISMS:
Size: See Tables 1-4
Age: no data
Pretreatment: fish were acclimated to the test pH by gradually
adjusting the dilution water pH over a 24-hour period to thedesired value and maintaining that value for 48 hours before
addition of sodium nitrite.
Supplier: Fish Cultural Development Center, US Fish andWildlife Service, Bozeman, Montana, USA.
DILUTION WATER:
Source: Ground spring water
Chemistry: no data
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: See Tables 1-4
Renewal of test solution: Approximately 5 hours for 62 L tankand 1.3 hours for 350 L tank.
Exposure vessel type: 62 L plastic tanks or 350 L circularglassfibre tanks
Number of replicates, fish per replicate: See Tables 1-4-Water parameters:

65

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
CASE A-1 to 12:
Temperature; 9.0 - 10.7 degree C
Hardness (mg/L CaC03); 185 - 208
Alkalinity (mg/L CaC03); (see Table 1)
Dissolved O2 (mg/L); 7.6 - 9.3
pH; (see Table 1)
CASE B-1 to 22:
Temperature; 8.9 - 14.7 degree C
Hardness (mg/L CaC03); 178 - 209
Alkalinity (mg/L CaC03); (see Table 2)
Dissolved O2 (mg/L); 6.6 - 9.3
pH; (see Table 2)
CASE C-1 to 6:
Temperature; 9.4 - 14.0 degree C
Hardness (mg/L CaC03); 192 - 201
Alkalinity (mg/L CaC03); (see Table 3)
Dissolved O2 (mg/L); 6.6 - 6.8
pH; (see Table 3)
CASE D-1 to 4:
Temperature; 9.9 - 10.7 degree C
Hardness (mg/L CaC03); 199 - 206
Alkalinity (mg/L CaC03); (see Table 4)
Dissolved O2 (mg/L); 7.2 - 9.6
pH; (see Table 4)
Intensity of irradiation: Room light
Photoperiod: No data
Feeding: No
Aeration: No data
TEST PARAMETER: Mortality

Test substance:
Reliability:
Flag:
13-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured three times during the test
Chemical Name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well-reported literature study
Critical study for SIDS endpoint
(154)

Type:
Species:staticother: Ictalurus punctatus (Channel Catfish), Tilapia aurea(Tilapia), Micropterus salmoides (Largemouth Bass)
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: yes
LC50 (Channel catf7.1) :7.1
LC50 (Largemouth B140.:140.2
LC50 (Tilapia) : 16.2
Method:Year:other: Palachek & Tomasso method
1984

Method:METHOD FOLLOWED: Palachek & Tomasso method.
DEVIATIONS FROM GUIDELINE: Not applicable

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66

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
STATISTICAL METHODS: none
METHOD OF CALCULATION: Median lethal concentrations were
estimated using the method of Thompson (1947)
ANALYTICAL METHODS: Nitrite concentration determined using themethod described by EPA (1974).
References:
Thompson WR (1947) Use of Moving Averages and Interpolation to
Estimate Median-Effective Dose. Bacteriol. Rev. 11, 115-145
US EPA (1974) Methods for Chemical Analysis of Water andWastes. EPA-625-/6-74-003. Methods Development and Quality
Assurance Research Laboratory, National Environmental researchCenter, Cincinnati, OH. 215-216
Determination of methemoglobin and plasma nitrite levels:
Methemoglobin and plasma nitrite concentrations were
determined using five fish per aquarium exposed to nitrite
concentrations ranging from 1.5 to 194.9 mg/L. After 24 hours
of exposure, fish were weighed, the caudal peduncle wassevered, and blood was collected into capillary tubes from thehaemal arch. Methemoglobin levels were determined
spectrophotometrically (Evelyn & Malloy, 1938) after blood
samples were lysed and centrifuged to remove turbidity. Total
hemoglobin was determined according to Hainline (1958). Plasma
nitrite levels were determined by a modification of the azo
dye method (EPA 1974).

Result:Analysis of variance followed by a student-Newman-keuls
multiple range test was employed to test for difference among
species.
Channel catfish: LC50 (96h) = 35 mg/L NaNO2
Tilapia: LC50 (96h) = 79.8 mg/L NaNO2
Largemouth Bass: LC50 (96h) = 691 mg/L NaNO2
The 24 hour dose-response studies showed that methemoglobin
levels increased as environmental nitrite levels increased,with the exception of largemouth bass whose methemoglobin
levels did not increase until nitrite concentrations reached48.7 mg/L The channel catfish were the most susceptible andhad the highest methemoglobin levels compared with the otherspecies.
Channel catfish and tilapia exposed to 24.4 mg NO2-N/L for 24h
had levels of 76.9+/-5.0 and 61.3+/-7.9 mg plasma nitrite/L,
respectively. Plasma nitrite levels in largemouth bass did
not differ from control levels until environmental
concentrations reached 48.7 mg NO2-N/L or greater.

Test condition:
TEST ORGANISMS:
Largemouth Bass:
Size: 2.8+/-0.0 g
Age: no data
Supplier: National Fish Hatchery and Technology Center, San
Marcos, Texas
67

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Channel Catfish:
Size: 3.0+/-0.1 g
Age: no data
Supplier: Texas Parks and Wildlife Department, San Marcos Fish
Hatchery
Tilapia:
Size: 3.4+/-0.2 g
Age: no data
Supplier: Texas A&M University Aquaculture Research Station,
Texas
PRETREATMENT: All fish were acclimatized for at least fourweeks prior to testing in 252 L fiberglass tanks supplied bywell water at a flow rate of seven turnovers per hour. Fishwere fed a commercial fish food (40% protein) ad libitum every
48 hours. Feeding was discontinued 24 hours prior totransferring fish into experimental aquaria.
DILUTION WATER:
Source: Ground spring water
Chemistry: Hardness 202.4 mg/L CaC03; Alkalinity 165.5 mg/L
CaC03; Dissolved O2 8.1 mg/L; pH 7.7 (8.2 max)
Temperature: 23°C
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: Measured nitrite
concentrations ranged from 99.7+/-1.1% of nominal to102.0+/-2.3% of nominal throughout the study.
REFERENCE SUBSTANCE: None
TEST SYSTEM (LC50 Determinations):
Concentrations:
Largemouth bass: 57.1-374.2 mg/L NO2-N
Channel catfish: 2.7-28.7 mg/L NO2-N
Tilapia: 11.9-77.9 mg/L NO2-N
Renewal of test solution: None, static test
Exposure vessel type: 30 L glass aquaria
Number of replicates, fish per replicate: Three or more
replicates; 10 fish per dose (largemouth bass and channel
catfish), 5 fish per dose (Tilapia).
Water parameters: See Table 1
Intensity of irradiation: Room light
Photoperiod: No data
Feeding: No
Aeration: Constant aeration to maintain dissolved oxygen
levels near saturation.
TEST PARAMETER: Mortality

Test substance:

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured every 24 hours
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
UNEP PUBLICATIONS

68OECD SIDS
4. ECOTOXICITY
Conclusion:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Flag:
06-MAY-2005

The toxicity of nitrite varies considerably among species
tested under similar water quality conditions. These
differences are related to the the extent to which nitrite isconcentrated in the plasma and the associated blood
methemoglobin levels. Therefore, channel catfish have a lower
resistance to nitrite than tilapia or largemouth bass becasue
nitrite is more concentrated in catfish plasma. among thethree species, largemouth bass has the greatest resistance toenvironmental nitrite as well as the lowest methemoglobin
levels due to lower plasma nitrite concentrations. The low
plasma nitrite levels may be indicative of a more selective
chloride uptake cell located in the gills, resulting in
exclusion of nitrite.
(2) valid with restrictions
Well-reported literature study
Critical study for SIDS endpoint
(141)

Type:
Species:
Exposure period:
Unit:
LC50:

flow throughOncorhynchus mykiss
96 hour(s)mg/l= 5.62

Method:Year:
GLP:

other: Bortz (1977)
1977
noMethod:METHOD FOLLOWED: Based on Doudoroff et al (1951), Doudoroff(1971) and Committee on Methods for Toxicity Tests with
Aquatic Organisms (1975)

Reliability:(Fish, fresh water)
Analytical monitoring: yes

DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: none
METHOD OF CALCULATION: LC50 calculated by the Doudoroff method(1971)ANALYTICAL METHODS: not applicable
References:
Committee on Methods for Toxicity Tests with Aquatic Organisms(1975) Methods for Acute Toxicity Tests with fish,
Macroinvertebrates and Amphibians. EPA Report 660-3-75-009.
page 61
Doudoroff P (1971) In, American Public Health Association:
Standard Methods for the Examination of Water and Waste Water.
13th edition. 562-580

Result:Doudoroff P, Anderson BG, Burdick, GE, Galtsoff, PF, Hart WB,
Patrick R, Strong, ER, Surber EW and VanHorn WM (1951)
Bioassay Methods for the Evaluation of Acute Toxicity ofIndustrial Waastes to Fish. Sewage and Industrial Wastes, 23,1380-1397
Expressed as NaNO2:
LC50 (96h) = 27.7 mg/L

Test condition:
69

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
TEST ORGANISMS:
Size: Weight: 40.9-199.5 g; Length 17.2-27.1 cm
Age: no data
Pretreatment: Fish were quarantined in two 150 gallon
fiberglass tanks for at least ten days prior to testing. Fishwere fed a diet of trout pellets. Incoming, dechlorinated citywater (activated charcoal filter) with a flow rate of
approximately 25 gallons per hour was chilled to 12.9+/-0.9°C.
Supplier: Eastern Fish Disease Laboratory and Hatchery,
Leetown, West Virginia.
DILUTION WATER:
Source: Dechlorinated city water
Water parameters:
Hardness (mg/L CaC03); 137 (128-148)
Dissolved O2 (mg/L CaC03); 9.0 (7.3- 9.0)
Alkalinity (mg/L CaC03); 75 (66-78)
pH; 6.99 (6.90-7.10)
Temperature: 12.9 (12.0-13.8) °C
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: Stock solution concentration of 63.6 g/L sodium
nitrite used. Delivered to the testing tanks using a diluter
with a mean flow rate of 380 mL/min.
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: 0, 2.62, 4.52, 6.21, 9.48 and 14.87 mg/L NO2-N
Renewal of test solution:
Exposure vessel type: 54 L fiberglass tanks.
Number of replicates, fish/replicate: 6 test vessels perconcentration, 10 fish/test vessel.
Test temperature: 12.0-13.8°C
Dissolved oxygen: 9.0 (7.3-9.0) mg/L O2
pH: 6.99 (6.90-7.10)
Alkalinity: 75 (66-78) mg/L CaCO3
Hardness: 137 (128-148) mg/L CaCO3
Chlorine: <100 µg/L
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no data
Aeration: no data
TEST PARAMETER: Mortality

Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: No
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade(2) valid with restrictions
Peer reviewed Masters Thesis

13-MAY-2005
Type:

(21)
semistatic
UNEP PUBLICATIONS

70

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Species:other: Paralichtys orbignyanus (flatfish)
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: yes
96-h LC50 (winter) := 24.0196-h LC50 (summer) := 30.57
Method:Year:
GLP:

other: Bianchini et al method
1996
noMethod:METHOD FOLLOWED: Bianchini et al method.
According to the frequent seasonal extremes of temperature andsalinity of the estuarine and coastal water where flatfishes
were captured, two experimental conditions were established:
the 'winter condition' (0% salinity and 12°C) and the 'summer
condition' (30% salinity and 25°C).
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
LC50 values determined using the Trimmed Spearman Karber
method.
METHOD OF CALCULATION:
No data
ANALYTICAL METHODS: Nitrite concentration determined using themethod described by Bendschneider and Robinson (1952)

Result:References:
Bendschneider K and Robinson RJ (1952) A New
Spectrophotometric Method for Determination of Nitrite in Sea
Water. J Mar Res, 11, 87-96
Expressed as NaNO2:

Test condition:

LC50 = 118.3 - 150.7 mg/L
TEST ORGANISMS:
Size: Weight: 88+/-17 g
Age: Juveniles
Pretreatment: Fish were acclimated in 1000 L tanks to 30%
salinity and 20°C for 15 days. Water was continuously aerated
and the photoperiod was 12L:12D. fish were fed ad libitum with
fry of mullet Mugil platanus or silverside Odonthestes sp. andsmall crustaceans like the shrimps Penaeus paulensis andArtemesia longinaris. The acclimation medium was 50% renewed
daily.
Supplier: Wild fish captured at the Cassino beach or at theestuary of the Patos Lagoon in Southern Brazil.
DILUTION WATER:
Source: no data
Chemistry: no data
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:

71

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: 'winter condition' 0, 15, 20, 25, 30, 40, 60,
90 or 120 mg/L NO2-N; 'summer condition' 0, 10, 20, 25, 30,
40, 50 or 60 mg/L N)2-N.
Renewal of test solution: Semi static test, 100% renewal
daily.
Exposure vessel type: 30 L plastic tanks
Number of fish per dose: 10
Test temperature: 'summer' and 'winter' conditions as
described in method.
Dissolved oxygen:
pH:
Alkalinity:
Hardness:
Intensity of irradiation:
Photoperiod: 12 h light, 12 h dark.
Feeding: No
Aeration: Continuous
TEST PARAMETER: Mortality

Test substance:
Reliability:
16-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Chemical name: Sodium Nitrite (CAS No: 7632-00-0)
Purity: Pro Analytical
Supplier: Merck(2) valid with restrictions
(16)

Type:
Species:
Exposure period:
Unit:
LC50 :

flow throughOncorhynchus mykiss
96 hour(s)mg/l= .19 - .39

Method:Year:other: Russo et al method
1974

Method:METHOD FOLLOWED: Russo et al own method.

(Fish, fresh water)
Analytical monitoring: yes

DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
No data
METHOD OF CALCULATION:
No data
ANALYTICAL METHODS: Nitrite concentration determined using themethod described in Strickland and Parsons (1972)
References:
Strickland JDH and Parsons TR (1972) A Practical Handbook of
UNEP PUBLICATIONS

72

OECD SIDS
4. ECOTOXICITY

Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Seawater Analysis. Bull. Fish Res. Board Can. 167, 77-80
Table 1: Acute toxicity of nitrite to rainbow trout----------------------------------------------------------Avg wt
Concn
LC50
LC50
of fish range tested (mg/L NO2-N) (mg/L NaNO2)(g)(mg/L No2-N)

Test condition:

2.3
0.07 - 1.09
11.9
0.10 - 0.34
12.1
0.11 - 0.37
14
0.06 - 0.90
235
0.06 - 0.32
TEST ORGANISMS:

0.39
0.19
0.22
0.27
0.20

1.92
0.94
1.08
1.33
0.99

Size: Weight: 2 - 235 g
Age: no data
Pretreatment: Acclimation time for the fish to theirsurroundings differed among the tests, but in all cases test
fish were acclimated to the test dilution water for at least
one week and to the test tanks for at least 2 days.
Supplier: No data - hatchery-reared.
DILUTION WATER:
Source: Ground spring water
Chemistry: no data
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: See Table 1
Renewal of test solution: Turnover time approximately 5 hours(2 hours for 235 g fish)
Exposure vessel type: 64 L plastic tanks (660 L circularglassfibre tanks for 235 g fish)
Number of replicates, fish per replicate: 1 test vessel per
concentration, 10-20 fish per vessel, depending on weight.
Test temperature: 9.5 - 12.6°C
Dissolved oxygen: 5.9 - 8.6 (mg/L)
pH: 7.8 - 8.1
Alkalinity: 169 - 195 mg/L CaCO3
Hardness: 197 - 200 mg/L CaCO3
Intensity of irradiation: Room light
Photoperiod: no data
Feeding: 2 and 12 g fish not fed; 14 g fish fed 4 times daily
with commercial trout feed.
Aeration: no data
TEST PARAMETER: Mortality

Test substance:
73

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured at 24 hour intervals
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Purity: Reagent grade(2) valid with restrictions
Well-reported literature studyType:flow throughSpecies:Oncorhynchus mykiss
Exposure period: 96 hour(s)
Unit:
mg/l
LC50 (72h; lowest) := .22
LC50 (96h; lowest) := .19(Fish, fresh water)
Analytical monitoring: yes

Method:Year:other: Russo & Thurston
1977

Method:METHOD FOLLOWED: Russo & Thurston method.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
LC50 values and their 95% confidence limits were calcualted
from the experimental data using the Spearman-Karber method.
METHOD OF CALCULATION:
No data
ANALYTICAL METHODS: Nitrite concentration determined using themethod described by EPA (1974)

Result:References:
US EPA (1974) Methods for Chemical Analysis of Water andWastes. EPA-625-/6-74-003. Methods Development and Quality
Assurance Research Laboratory, National Environmental researchCenter, Cincinnati, OH. 215-216
Expressed as NaNO2:
LC50 (96h) = 0.94 - 1.38 mg/L
Expressed as NO2-N:
Case : Age/length; 20.6 g, 11.8 cm: Water parameters;
Temperature 10-10.2, pH = 7.94-8.12
72h LC50 = 0.29 (0.24 - 0.36) mg/L
Case : Age/length; 24.3 g, 12.3 cm: Water parameters;
Temperature 10.1-10.3, pH = 7.99-8.33
72h LC50 = 0.32 (0.27 - 0.38) mg/L
96h LC50 = 0.28 (0.24 - 0.33) mg/L
Case : Age/length; 53.1 g, 15.7 cm: Water parameters;
Temperature 9.7-10, pH = 7.58-7.79
72h LC50 = 0.35 (0.29 - 0.41) mg/L
96h LC50 = 0.27 (0.22 - 0.33) mg/L
Case : Age/length; 60.5 g, 16.6 cm: Water parameters;
Temperature 9.7-9.9, pH = 7.71-7.83
72h LC50 = 0.30 (0.25 - 0.36) mg/L
96h LC50 = 0.27 (0.23 - 0.32) mg/L
UNEP PUBLICATIONS

74

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Case : Age/length; 188 g, 23.6 cm: Water parameters;
Temperature 10.3-10.7, pH = 7.76-7.86
72h LC50 = 0.22 (0.17 - 0.28) mg/L
96h LC50 = 0.19 (0.15 - 0.25) mg/L

Test condition:
TEST ORGANISMS:
Size: Weight: See RESULTS
Age: no data
Pretreatment: Fish were acclimated to the test tanks for atleast 2 days prior to testing.
Supplier: Bozeman (Montana) Fish Cultural Development Centre,
US Fish and Wildlife Service
DILUTION WATER:
Source: Ground spring water
Chemistry: no data
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: See RESULTS
Renewal of test solution: Approximately 5-6 hours (64 L tanks)
or 1.3 hours (350 L tanks)
Exposure vessel type: 64 L plastic tanks or 350 L fibreglass
tanks
Number of replicates, fish per replicate: I tank per dose, 10- 20 fish/tank.
Test temperature: See RESULTS
Dissolved oxygen: 7.9 - 10.0 mg/L
pH: See RESULTS
Alkalinity: 171 - 191 mg/L CaCO3
Hardness: 188 - 207 mg/L CaCO3
Intensity of irradiation: Room light
Photoperiod: no data
Feeding: No
Aeration: no data
TEST PARAMETER: Mortality
Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well-reported literature study

25-JUL-2005
Type:
Species:
Exposure period:
Unit:
75

(152)
staticOncorhynchus mykiss
96 hour(s)mg/l(Fish, fresh water)
Analytical monitoring: yes

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

LC0:
LC50:
Limit Test:

= .54
= .79
no

Method:
Year:
GLP:

other
2000
no

Method:METHOD: Based on ASTM (1989) Standard Guide for Conducting
Acute Toxicity Tests with Fishes, Macroinvertebrates, andAmphibians. Annual Book of ASTM Standards, 11.04, 360-379,
ASTM, Philadelphia

Result:METHOD OF CALCULATION: Median lethal concentration and the 95%
confidence intervals were calculated by the moving-averageangle method (Peltier and Weber, 1985)
Expressed as NaNO2:

Test condition:

LC50 (96h) = 3.89 mg/L
LC0 (96h) = 2.66 mg/L
TEST ORGANISMS:
Size:
Weight: 251 +/- 63 mg; Length: 33 +/- 3 mm.
Age: 40 days posthatch juveniles
Pretreatment: The fish were cultured in well water that wasmaintained at 12-13 degree C, as described in Buhl and
Hamilton (1998). The chemical characteristics of the culture
water, which were monitored weekly according to standard
procedures (APHA et al. 1989), were as follows: hardness336-1,060 mg/L as CaCO3; alkalinity 204-289 mg/L as CaCO3; pH
7.4-7.8; and conductivity 903-1,890 µS/cm at 25 degree C.
Dissolved oxygen concentrations were greater than or equal to66% of the saturation.
Supplier: Ennis National Fish Hatchery (Ennis, Montana)
DILUTION WATER:
Source: Standardized reconstituted soft water (ASTM 1989)
Chemistry: Hardness 41 (40-42) mg/L as CaCO3; alkalinity
31 (30-32) mg/L as CaCO3; PH 7.1 (7.0-7.2); conductivity
159 (154-161) µmhos/cm at 25 degree C.
Temperature: 12+/-1°C
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: Measured
concentrations of NO2-N at 96h were 79-89% of initial values.
REFERENCE SUBSTANCE: None
TEST SYSTEM (LC50 Determinations):
Concentrations: no data
Renewal of test solution: None, static test
Exposure vessel type: no data
Number of replicates, fish per replicate: no data
Water parameters:
Intensity of irradiation: Room light
UNEP PUBLICATIONS

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Photoperiod: No data
Feeding: No
Aeration: no data
TEST PARAMETER: Mortality

Test substance:
Reliability:
13-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured at start of test and at 96h
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: No data
Supplier: J. T. Baker (Phillipsburg, New Jersey)(2) valid with restrictions
(28)

Type:
flow throughSpecies:other: Oncorhynchus clarki
Exposure period: 36 day(s)
Unit:
mg/l
Analytical monitoring: yes
LC50(36d, lower) := .37
LC50(11d, lowest) := .39
LC50(96h, lower) := .48
Method:Year:other: Thurston et al
1978

Method:METHOD FOLLOWED: Thurston et al own method.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
No data
METHOD OF CALCULATION: LC50 values calculated using a computer
program developed for the trimmed Spearman-Karber method.
ANALYTICAL METHODS: Nitrite concentration determined using themethod described in Strickland and Parsons (1972)

Result:References:
Strickland JDH and Parsons TR (1972) A Practical Handbook of
Seawater Analysis. Bull. Fish Res. Board Can. 167, 77-80
Expressed as Sodium nitrite:
Test 1:
LC50 (36 d) = 1.87 mg/L
Test 2:
LC50 (11 d) = 2.66 mg/L
LC50 (36 d) = 1.82 mg/L
Test 3:
LC50 (96h) = 2.76 mg/L
LC50 (11d) = 2.31 mg/L

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4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Test 4:
LC50 (96h) = 2.37 mg/L
LC50 (11d) = 1.92 mg/L
There was no significant difference between the two fish sizes
tested in their susceptibility to nitrite. Most of the test
fish that died changed from their normal light grey colour toblack prior to death. Surviving fish showed a correlation
between degree of darkening and nitrite concentration.

Test condition:
TEST ORGANISMS:
Size: Tests 1 & 2 = 1g; Tests 3 & 4 = 3g
Age: Fry
Supplier: Arlee, Montana, State Fish Hatchery
PRETREATMENT: Fish were acclimated to the bioassay tanks for
2-4 days prior to testing. Fish fed a commercial salmon ration
3 times/day.
DILUTION WATER:
Source: Ground spring water
Chemistry: Hardness 199 mg/L as CaC03; Alkalinity 176 mg/L as
CaC03; pH 8.0
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: no data
REFERENCE SUBSTANCE: None
TEST SYSTEM (LC50 Determinations):
Concentrations: Test 1, 0.16-0.50 mg/L NO2-N; Test 2,
0.19-0.59 mg/L NO2-N; Test 3, 0.19-2.86 mg/L NO2-N; Test 4,
0.29-1.00 mg/L NO2-N.
Renewal of test solution: Flow rate 500 mL every 3-4 minutes(equivalent to a tank change every 8 hours)
Exposure vessel type: 62 L tanks
Number of replicates, fish per replicate: One replicate, 20
fish per tank (Tests 1&2); 10 fish per tank (Tests 3&4)
Water parameters: See Table 1
Intensity of irradiation: Room light
Photoperiod: No data
Feeding: Commercial salmon ration 3 times/day
Aeration: yes
TEST PARAMETER: Mortality
MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Table 1: Test Water Parameters
Test No.

Temp (°C)

pH

UNEP PUBLICATIONS

Dissolved
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4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Mean(range)Test substance:
Reliability:

Mean(range)oxygen(mg/L)
Mean(range)
1
12.4
7.85
8.5
(11.5-13.0)(7.75-7.97)(7.8-7.9)
2
12.4
7.88
8.6
(11.7-13.3)(7.78-7.98)(7.9-9.0)
3
11.8
7.88
8.6
(11.7-12.0)(7.83-7.96)(8.2-8.9)
4
12.1
7.80
8.1
(11.9-12.3)(7.72-7.88)(7.3-8.4)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well reported literature study

20-MAY-2005
Type:
Species:
Exposure period:
Unit:
LC50 :

semistatic
Oncorhynchus mykiss
96 hour(s)mg/l= .3 - 31.2

Method:
Year:

other
1978

Method:Effect: mortality
Fresh water (soft water; temperature; 10 degree C, hardness
25 mg/L CaC03)
Age/Weight: juvenile, 5, 10, 15 grams
Expressed as sodium nitrite:

Remark:Result:(177)(Fish, fresh water)
Analytical monitoring: yes

LC50 (96h) = 1.49 - 153.8 mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
25 mg/L (CaCO3), pH = 6.2
LC50 = 0.5 (0.4 - 0.6) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 25 mg/L (CaCO3), pH = 6.2
LC50 = 0.9 (0.8 - 1.1) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
50 mg/L (CaCO3), pH = 6.8
LC50 = 0.5 (0.3 - 0.6) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 50 mg/L (CaCO3), pH = 6.8
LC50 = 1.9 (1.7 - 2.7) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
150 mg/L (CaCO3), pH = 7.3
LC50 = 5.8 (5.0 - 6.7) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 150 mg/L (CaCO3), pH = 7.3
LC50 = 0.5 (0.4 - 0.6) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
300 mg/L (CaCO3), pH = 7.8
LC50 = 10.3 (8.5 - 12.5) mg/L

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 300 mg/L (CaCO3), pH = 7.8
LC50 = 12.1 (10.7 - 13.8) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
50 mg/L (CaCO3), pH = 6.0
LC50 = 0.3 (0.2 - 0.4) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 50 mg/L (CaCO3), pH = 6.0- 45/297 LC50 = 1.5 (1.2 - 1.8) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
50 mg/L (CaCO3), pH = 7.0
LC50 = 2.3 (1.0 - 2.9) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 50 mg/L (CaCO3), pH = 7.0
LC50 = 1.9 (1.7 - 2.7) mg/L
Case : Age/weight; Juvenile, 5 g: Water parameters; Hardness
50 mg/L (CaCO3), pH = 8.0
LC50 = 2.5 (2.3 - 2.8) mg/L
Case : Age/weight; Juvenile, 10 g: Water parameters;
Hardness 50 mg/L (CaCO3), pH = 8.0
LC50 = 3.6 (3.1 - 4.2) mg/L

Test condition:

Test substance:
Reliability:
23-MAY-2005

Case : Age/weight; Juvenile, 15 g: Water parameters;
Hardness 50 mg/L (CaCO3), pH = 6.8
Salt level; 0 - 200 mg/L
Total chloride presentation; NaCl 1.0-124 (mg/L)
LC50 = 0.54 - 1.5 mg/L
Total chloride presentation; CaCl2 1.9-130.5 (mg/L)
LC50 = 0.64 - 31.2 mg/L
-Water parameters:
Temperature; 10 degree C
Hardness (mg/L CaC03); 25, 50, 150, 300
Dissolved O2 (mg/L); 8-10
pH; 6.0, 6.2, 6.8, 7.0, 7.3, 8.0
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade(2) valid with restrictions
(193)

Type:
Species:
Exposure period:
Unit:
NOEC:
Limit Test:

flow throughAnguilla anguilla
50 day(s)
mg/l
= 15
no

Method:
Year:
GLP:

other
1996
no

Remark:50-d LC0 = 73.9 mg/L*(Fish, fresh water, marine)
Analytical monitoring: yes

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4. ECOTOXICITY

Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006* : The values were converted NO2-N into NaNO2.
50-d NOEC = 15.0 mg/L NO2-N
The sublethal effects of nitrite on growth and feed
utilization were evaluated in a feeding trial lasting 77
days, divided into an acclimation period and two
experimental periods. Eels of 24 g on average were divided
over 20 aquaria, connected to five separate recirculation
systems. In each system. the desired nitrite concentrationlevel was maintained by water suppletion and continuous
addition of NaNO2. Fish were continuously exposed to levelsof 0, 1, 5, 10 or 20 g m/L NO2-N. Half of the experimentalgroups were fed ad libitum to study effects on feed intake,while the other half were fed a restricted ration to study
effects on feed utilization. At the start and end or eachexperimental period. nitrite in the blood plasma,
haemoglobin and methaemoglobin were measured, Fish weightand body composition were used to calculate specific growthrate and conversion efficiencies.
No significant relationship between mortality and the levelof nitrite could be demonstrated. The mortality during theexperiment was relativively high and highly variable between
individual tanks. The mortality increased in all treatments
during the experiment. Mortality resulted exclusively fromagonistic behaviour between fish, a well-known phenomenon
when keeping eels in relatively low densities.

Test condition:

Tn the range of concentrations studied, no significant
effect of nitrite on maximum growth rate or feed utilization
couldh be demonstrated. At the start of the experiment, lowconcentrations of nitrite were detected in the blood plasma,
which suggests an ability of the eel to adapt toenvironmental nitrite. Nitrite. in the range normallyencountered in intensive eel farms (max. 15 g/m3 NO2-N). cantherefore be considered a factor of little significance.
Experimental set-up
ln five independent recirculation system, each equipped withfour aquaria (40 L), five different target levels of nitrite(0, 1, 5, 10 and 2O g/m3 NO2-N) were maintained. The maximum
concentration maintained was aimed at approximately 15% of
the 96-h LC5O. The range applied covers the concentrations
normally encountered in recirculation systems.
In each system, the fish in two aquaria were fed tosatiation, to detect effects of nitrite on maximum growthrate. Fish in the other two aquaria were fed an equal andrestricted ration to detect effects of nitrite on feed
utilization. By feeding a restricted ration, feed waste isminimized, which enables an accurate calculation of
conversion efficiencies. Moreover, confounding interactions
between conversion efficiency and feeding level are
eliminated.
The experiment lasted 77 days, subdivided into an
acclimation period of 27 days and two experimental periodsof 25 days each (periods 1 and 2). These two experimental
periods allow observations on time-related effects.
Sampling and measurements
Mortality was recorded daily. At the start of each

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Test substance:
Reliability:
23-MAY-2005

experimental period and at the end or the experiment, fishof each aquarium were weighed and counted. Blood samples
were taken and fish sampled were withheld for analysis ofbody composition, in which approximately 15 fish per talkwere killed (2 phenoxyethanol), frozen and at a later stage,
ground and homogenized. Dry matter content of fish and feed
was determined by feeze-drying. Protein content was measured
in dried material by determination of N-Kjeldhl (protein 6.25 X NKi). Fat Content was determined in dried material
according to Bligh and Dyer (1959). The energy content of
the fish and feed tvas calculated from protein, fat andcarbohydrate using conversion factors of 23.64, 39.54 and17.15 kJ/g respectively, as determined for Clarias
gariepnus.
At each sampling, blood was collected from at least 10
individuals per tank. Pump failure at the end of period 2 inthe systems with 0 and 10 g/m3 nitrite, prevented samplingof blood in these groups.
Fish were anaesthetized with 2-phenoxyethanol and blood was
subsequently sampled with a heparinized syringe from thevena caudalis. Blood samples were pooled per aquarium.
Haemoglobin and methaemogiobin were determined according to
Evelyn and Malloy (1938) with a CO-Oximeter IL482.
Nitrite in the blood plasma was determined according to
Shechter, Gruner and Shuval(1972).
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(100)

Type:
Species:
Exposure period:
Unit:
LC50:
LC50 (48h) :LC50 (72h) :LC50 (96h) :staticCtenopharyngodon idella (Fish, fresh water)
120 hour(s)mg/lAnalytical monitoring: yes= 1.5= 4.45= 3.04= 1.71

Method:Year:
GLP:

other: Alcarez & Espina method
1994
noMethod:METHOD FOLLOWED: Alcarez & Espina own method.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
Not applicable
METHOD OF CALCULATION:Median lethal concentrations were calculated using the DORES
program from Ramirez (1989).
ANALYTICAL METHODS: Nitrite concentration was quantified by
the AZO dye colorimetric method (APHA, 1985)
References:
American Public Health Association (1985) Standard Methods for
the Examination of water and Wastewater. 16th ed. APHA,UNEP PUBLICATIONS

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Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Washington
Expressed as NaNO2:
LC50 (96h) = 8.43 mg/L
LC50 (120h) = 7.39 mg/L

Test condition:

There was no mortality in the control group. The number ofdeaths in each dose group was not reported in the literature.
TEST ORGANISMS:
Size: Weight: 0.17 - 0.75 g
Age: Juveniles
Pretreatment: The test fish were held for 15 days in 60L
aquaria with tap water at 24 deg C, pH 7, 6.8 mg O2/L,
alkalinity 44 mg CaCO3/L and 125 mg CL-/L.
Supplier: Centro de Produccion Piscicola, Tezontepec, Estado
de Hidalgo, Mexico.
DILUTION WATER:
Source: soft water
Chemistry: pH 6.7 - 6.9, alkalinity 44 mg CaCO3/L, 6.1-6.4 mg
O2/L and 3 mg CL-/L.
Temperature: 24°C
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: Control (dilution water), 1, 2, 4, 8 or 10 mg
N-NO2-/L
Renewal of test solution: None - static test
Exposure vessel type: 20L glass aquaria
Number of replicates, fish per replicate: 1 test vessel per
concentration, 10 fish per vessel.
Test temperature: 24 °C
Dissolved oxygen: Not reported during test
pH: Not reported during test
Intensity of irradiation: Room light
Photoperiod: 12 hours light/12 hours darkness
Feeding: No
Aeration: Mild, continuous
TEST PARAMETER: Mortality

Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured at 24 hour intervals
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 99.9%
Supplier: Merck(2) valid with restrictions
Well-reported literature study

16-MAY-2005
Type:
83

(6)
semistatic
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Species:
Exposure period:
Unit:
LC50:

Anguilla anguilla
96 hour(s)mg/l= 143.7(Fish, fresh water, marine)

Method:
Year:
GLP:

other
1996
no data

Method:Fish, reared from common eel, were obtained from acommercial eel farm, where the fish had been exposed tonitrite in concentrations of up to 1.5 g/m3 NO2-N, according
to the farmer. The eels (21.9 +/- 5.6 g) were allowed toacclimate for 2 weeks in an aerated storage tank which wascontinuously supplied with IJmuiden tap water (at about 25
degree C). No mortality was observed during this period. Twodays before exposure to nitrite, fish were transferred toaerated 40-L aquaria filled with tap water, which was changed
every morning.

Analytical monitoring: yes

Remark:Desired concentrations were obtained by addition of NaNO2
to IJmuiden tap water. Water in the aquaria was changed once
every day. Water temperature, pH and concentrations of oxygenand nitrite were measured daily. PH and oxygen were measured
with electrodes (WTW, Germany). Nitrite in water as measured
spectrophotometrically.
96-h LC50 = 708.2 mg/L*

Result:* : The values were converted NO2-N into NaNO2.
Expressed as NaNO2:

Test condition:

LC50 (96h) = 708.2 mg/L
The acute toxicity of nitrite to European eel was measured
by determination of the 96-h LC50 in a semi-static assay.
Each aquarium was stocked with 10 fish. A series of six
aquaria with increasing concentration (0, 120, 192, 307, 492
and 786 g m-3 NO2-N) was used to determine each LC50, in
triplicate.

Test substance:

Reliability:

The average values of the water temperature, pH and oxygen
concentration were 21.2 degree C, 8.36 and 8.7 g/m3
respectively. The average nitrite concentration, as measured
in the different treatments, was 0, 121, 193, 318, 488
and 823 g/m3 NO2-N. The concentration of the major ion
species in the IJmuiden tap water was determined oncein a composite sample. K and Na were measured byflame-ionization, the other species spectrophotometrically.
Concentrations were: Na, 69; K, 12: Ca, 76: Mg, 15:
HCO3, 134: Cl,117; SO4, 106 g/m3. Dead fish were removed
from the tank daily.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Pro analysis grade
Supplier: Merck(2) valid with restrictions
Well reported literature study.

20-MAY-2005
Type:

(100)
flow through
UNEP PUBLICATIONS

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Species:
Exposure period:
Unit:
LC0:

Oncorhynchus mykiss
8 day(s)mg/l> 3.09

Method:
Year:
GLP:

other
1994
no

(Fish, fresh water)
Analytical monitoring: no

Method:METHOD FOLLOWED: Rodriguez-Moreno and Tarazona method
Fish were exposed for 8 days and observed during an
additional post-exposure period of 5 days. At 72, 192, 240
and 312 hr fish were anesthetized (2-phenoxy ethanol, 0.3%)
and bled from the caudal vein using insulin heparinizedsyringes with 21G x 1.1/2", 0.8 x 40 No.2 Luer needles, forthe measurement of methenoglobin and hematocrit. Fish wereidentified by their head-tail length.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: One-way analysis of varianceStudent's t-tests were used to analyse data.

andMETHOD OF CALCULATION: none
ANALYTICAL METHODS: Nitrite concentration determined dailyusing the spectrophotometric method (Rodier 1981)

Remark:Result:References:
Rodier J (1981) Analisis de las Aquas Naturales, Residuales yde Mar. Omega. Barcelona, 151-152
LC0 > 15.2 mg/L** : The values were converted NO2-N into NaNO2.
Expressed as NaNO2:
LC0 (8 d) >15.2 mg/L
One fish at the lowest nitrite concentration died during thepost exposure period. Clinical data showed infection of the
bleeding area as the cause of the death.
Hematocrits did not show significant differences through theexposure and recovery periods, nor between groups; showing anegligible effect of the periodic bleeding.
Only the highest nitrite concentration produced a significant
increase in methemoglobin values, with the extreme value, near
50%, after 192 h of exposure. The recovery of methemoglobin
levels was very rapid; 48 h after transfer to nitrite-freewater, only a slight increase could be observed and after 120
h levels had returned to pre-exposure values and showed nodifferences when compared to control fish.

Test condition:
TEST ORGANISMS:
Size: length = 18.9+/-0.4 cm
Age: no data
Pretreatment: Fish were acclimated to laboratory conditions
85

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
for more than 2 weeks. Fish were fed a commercial trout food
(DIBAQ AE-7) once a day.
Supplier: Una fish farm, Cuenca, Spain
DILUTION WATER:
Source: Decalcified groundwater
Chemistry: hardness 74.44+/-0.40 mg/L as CaCO3; alkalinity
195.53+/-21.88 mg/L as CaCO3; dissolved oxygen 10.80+/-0.50
mg/L; pH 7.47+/-0.41; chloride 82.36+/-0.43 mg/L as NaCl
Temperature: 14.0+/-0.5°C
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: 0, 0.68+/-0.05, 1.69+/-0.05, 3.09+/-0.11 mg
NO2-N/L
Renewal of test solution: flow rate = 20.45 L/hExposure vessel type: 30 L glass aquaria
Number of fish per dose: 3
Test temperature:
See dilution water
Dissolved oxygen: See dilution water
pH: See dilution water
Alkalinity: See dilution water
Hardness: See dilution water
Intensity of irradiation:
Photoperiod: no data
Feeding: yes
Aeration: no data
TEST PARAMETER: Mortality

Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Supplier: Merck, Germany(2) valid with restrictions
Well reported literature study

20-MAY-2005

(147)

Type:
Species:
Exposure period:
Unit:
LC50:

staticAnguilla anguilla
96 hour(s)
mg/l
= 150

Method:
Year:

other
1979

Method:Effect: mortality
Fresh water
Concentration: total
Weight: 2.4 grams
96-h LC50 = 739.3 mg/L*

Remark:(Fish, fresh water, marine)
Analytical monitoring: yes

UNEP PUBLICATIONS

86OECD SIDS
4. ECOTOXICITY

Result:

Test condition:

Test substance:
Reliability:
20-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006* : The values were converted NO2-N into NaNO2.
24h LC50 = 351 mg/L
48h LC50 = 279 (255 - 306) mg/L
72h LC50 = 210 (188 - 262) mg/L
96h LC50 = 150 (128 - 172) mg/L
-Water parameters:
Temperature; 25 degree C
Dissolved O2 (%); >86
pH; 6.9 - 7.7
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
(202)

Type:
Species:
Exposure period:
Unit:
LC50:

staticAnguilla japonica
96 hour(s)
mg/l
= 205

Method:
Year:

other
1979

Method:Effect: mortality
Fresh water
Weight: 3.6 grams
96-h LC50 = 1010.4 mg/L*

Remark:Result:

Test condition:

Test substance:
Reliability:

Analytical monitoring: yes* : The values were converted NO2-N into NaNO2.
24h LC50 = 460 (408 - 628) mg/L
48h LC50 = 299 (265 - 340) mg/L
72h LC50 = 245 (206 - 286) mg/L
96h LC50 = 205 (160 - 241) mg/L
-Water parameters:
Temperature; 25 degree C
Dissolved O2 (%); >86
pH; 6.9 - 7.7
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well reported literature study

20-MAY-2005

(202)

Type:
Species:
Exposure period:
Unit:
LC0:

flow throughOncorhynchus mykiss
6 day(s)mg/l= 69.69

Method:
Year:
GLP:

other
1996
no

Result:

The effects of uptake into blood plasma of NO2-, NO3-, andBr- from 1 mM ambient concentrations were studied in rainbow
trout (Oncorhynchus mykiss). Nitrite and bromide wereconcentrated in plasma, competing for the branchial chloride
uptake mechanism. Nitrate appeared to be taken up passively,
with plasma concentrations remaining below ambient [NO3-]

87(Fish, fresh water)
Analytical monitoring: yes

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Test substance:
Reliability:
23-MAY-2005

after 8 days exposure. This limited uptake appeared central
to the low toxicity of NO3-, and did not measurably
influence electrolyte balance or haematology. Plasma [Br-]increased to 51 mM during 14 days, which was paralleled by a
1: 1 stoichiometrical decrease in plasma [Cl-]. This was the
only detected effect of Br- exposure and was tolerated
without mortality. Nitrite-exposed trout fell into two
distinct groups. Trout dying before 2 days of NO2- exposure
quickly developed methaemoglobinaemia; high plasma [NO2-],[lactate], and [K+]; and low [Cl-]. In trout surviving up to
4 days, plasma [NO2-] and methaemoglobin rose more slowly,
plasma [Cl-] decreased less, and extracellular lactate andpotassium levels were not significantly elevated. In bothgroups, plasma [NO3-] rose to values comparable with plasma[NO2-] (about 3 mM), reflecting an internal conversion of
nitrite to nitrate. Nitrite-exposure significantly decreased
skeletal muscle [K+], whereas no significant changes wereobserved in cardiac muscle.
Rainbow trout were obtained from a local hatchery. Two
different size-classes of fish were used in the experiments.
Larger fish (weight 336 +/- 58 g, mean +/- SD, N = 33) wereused in cannulation experiments, and smaller ones (weight
119 +/- 27 g, N = 93) were used uncannulated. The fish wereacclimated to aerated Odense tap water for at least one
month before experiments.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(171)

Type:
Species:
Exposure period:
Unit:
LC50:

staticIctalurus punctatus
96 hour(s)mg/l= 7.55

Method:
Year:

other
1975

Method:Effect: mortality
Fresh water
Age/Weight: 40 grams
24h LC50 = 10.3 (8.58 - 12.3) mg/L
48h LC50 = 8.77 (7.55 - 10.2) mg/L
72h LC50 = 8.31 (7.03 - 9.83) mg/L
96h LC50 = 7.55 (6.85 - 8.37) mg/L
-Water parameters:
Temperature; 21 degree C
Dissolved O2 (mg/L); >7.4
Alkalinity (mg/L CaC03); 50-70
pH; 7.2-7.8
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Test condition:

Result:

Test condition:

Test substance:
Reliability:
23-MAY-2005(Fish, fresh water)
Analytical monitoring: yes

(107)

Type:
flow throughSpecies:
Pimephales promelas
Exposure period: 96 hour(s)
Unit:
mg/l
LC50 (72h; lower) := 3.94(Fish, fresh water)
Analytical monitoring: yes

UNEP PUBLICATIONS

88

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

LC50 (96h; lower) := 2.3
Method:
Year:

other
1977

Method:Effect: mortality
Fresh water
Age/Weight: variable (see RESULT)
96-h LC50 =11.3 mg/L*

Remark:Result:

Test condition:

Test substance:
Reliability:
23-MAY-2005* : The values were converted NO2-N into NaNO2.
Case : Age/length; 2.3 g, 6.2 cm: Water parameters;
Temperature 12.7-13.2, pH = 8.03-8.09
72h LC50 = 5.54 (3.86 - 7.95) mg/L
96h LC50 = 2.99 (2.35 - 3.81) mg/L
Case : Age/length; 2.3 g, 6.4 cm: Water parameters;
Temperature 12.5-12.8, pH = 7.96-8.10
72h LC50 = 3.94 (2.37 - 6.55) mg/L
96h LC50 = 2.3 mg/L
-Water parameters:
Temperature; (see RESULT)
Hardness (mg/L CaC03); 199 (188 - 207)
Alkalinity (mg/L CaC03); 177 (171 - 191)
Dissolved O2 (mg/L); 7.9 - 10.0
pH; (see RESULT)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
(152)

Type:
flow throughSpecies:Oncorhynchus mykiss
Exposure period: 8 day(s)
Unit:
mg/l
LC50 (lower val.) := .14(Fish, fresh water)
Analytical monitoring: yes

Method:
Year:

other
1974

Method:Effect: mortality
Fresh water
Age/Weight: 12 grams
8-d LC50 = 0.69 - 1.92 mg/L*

Remark:Result:
Test condition:

Test substance:
Reliability:
23-MAY-2005
Type:
89

* : The values were converted NO2-N into NaNO2.
8d LC50 = 0.14 mg/L
8d LC50 = 0.15 mg/L
-Water parameters:
Hardness (mg/L CaC03); 199 (197-200)
Alkalinity (mg/L CaC03); 176 (169-195)
pH; 7.9 (7.8-9.1)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions(153)
staticUNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY
Species:
Exposure period:
Unit:
LC50:
Year:
Method:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Lepomis cyanellus
96 hour(s)
mg/l
= 160

(Fish, fresh water)
Analytical monitoring: no

1986
METHOD FOLLOWED: Tomasso own method
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: no data
METHOD OF CALCULATION: No data

Result:ANALYTICAL METHODS: not applicable
Expressed as NaNO2:

Test condition:

LC50 (96h) = 788.6 mg/L
TEST ORGANISMS:
Size:
Weight: 7.3+/-0.3 g
Age: no data
Pretreatment: Fish were acclimated to laboratory conditions
for at least one month prior to testing (temperature = 23°C;
pH=7.2-7.4; hardness=300 mg/L as ca CO3; dissolved oxygen >6.0
mg/L; alkalinity = 255 mg/L as CaCO3; chloride = 22 mg/L;
nitrite <0.01 mg/L; sulfate = 31 mg/L; nitrate-nitrogen = 7.4
mg/L; total phosphorous <0.1 mg/L).
Supplier: US Fish and Wildlife Service National Fish Hatcheryand Technology Center (San Marcos)
DILUTION WATER:
Source: no data
Chemistry:
Temperature:
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: no data
REFERENCE SUBSTANCE: None
TEST SYSTEM (LC50 Determinations):
Concentrations: no data
Renewal of test solution: None, static test
Exposure vessel type: Glass aquaria containing either 15 or 30
L of test solution.
Number of replicates, fish per replicate: 2-8 replicates, 5fish per replicate.
Water parameters: Oxygen near saturation; Temperature 23°C; pH
7.9-8.4; alkalinity 236+/-5 mg/L as CaCO3; hardness 240+/-5
mg/L as CaCO3
Intensity of irradiation: Room light
Photoperiod: No data
Feeding: No
Aeration: yes
UNEP PUBLICATIONS

90OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
TEST PARAMETER: Mortality

Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: Test
concentrations measured at start of test and at 96h(4) not assignable
Insufficient experimental detail23-MAY-2005

(179)

Type:
Species:
Exposure period:
Unit:
LC50:

semistatic
other: Dicentrarchus labrax (Sea Bass)
96 hour(s)mg/lAnalytical monitoring: yes= 90 - 100

Method:Year:other: Scarano et al
1984

Method:METHOD FOLLOWED: Scarano et al method.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: no data
METHOD OF CALCULATION: no data
ANALYTICAL METHODS: Nitrite concentration determined using thesulfanilimide naphthalenediamine method described by
Strickland and Parsons (1972)

Result:References:
Strickland JDH and Parsons TR (1972) A Practical Handbook of
Seawater Analysis, 2nd edn. Fisheries research Board of Canada
Buletin, 167
Expressed as NaNO2:

Test condition:

LC50 = 443 - 492 mg/L
TEST ORGANISMS:
Size: 12-14 cm
Age:
Pretreatment: Fish were reared in water from the same sourceas the test water.
Supplier: no data
DILUTION WATER:
Source: Sea water
Chemistry: As test system
Temperature: As test system
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:

91

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Concentrations: 0, 25, 50, 75, 100 or 150 mg/L NO2-N
Renewal of test solution: Semi-static test - Seawater changed
daily
Exposure vessel type: Glass aquaria
Number of fish per dose: 6
Test temperature: 26°C
Dissolved oxygen: >95% saturation
pH: 8.1
Salinity: 36%
Alkalinity:
Hardness:
Intensity of irradiation:
Photoperiod:
Feeding: No
Aeration: Continuous
TEST PARAMETER: Mortality

Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Insufficient experimental detail23-MAY-2005

(158)

Type:
Species:
Exposure period:
Unit:
LC50:

flow throughRutilus rutilus
14 day(s)mg/l= 10.1

Method:Year:other: Solbe et al
1985

Method:METHOD FOLLOWED: Solbe et al method(Fish, fresh water)
Analytical monitoring: yes

DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
Not applicable
METHOD OF CALCULATION:Median lethal concentrations were calculated using methods
based on probit analysis.
Remark:Result:
Test condition:

Test substance:
Reliability:

ANALYTICAL METHODS: none
14-d LC50 = 49.8 mg/L** : The values were converted NO2-N into NaNO2.
LC50 = 10.1 (8.98 - 11.2) mg/L
-Water parameters:
Temperature; 16.1 degree C
Hardness (mg/L CaC03); 268
Alkalinity (mg/L CaC03); 186
Dissolved O2 (%); >80.0
pH; 7.40
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade(4) not assignable
Insufficient experimental detail
UNEP PUBLICATIONS

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OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

16-MAY-2005

(167)

Type:
Species:
Exposure period:
Unit:
LC50:

flow throughCyprinus carpio
10 day(s)mg/l= 15.6

Method:
Year:

other
1985

Method:METHOD FOLLOWED: Solbe et al method(Fish, fresh water)
Analytical monitoring: no

DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
Not applicable
METHOD OF CALCULATION:Median lethal concentrations were calculated using methods
based on probit analysis.
Remark:Result:
Test condition:

Test substance:
Reliability:

ANALYTICAL METHODS: none
10-d LC50 = 76.9 mg/L** : The values were converted NO2-N into NaNO2.
LC50 = 15.6 (13.3 - 17.9) mg/L
-Water parameters:
Temperature; 14.2 degree C
Hardness (mg/L CaC03); 281
Alkalinity (mg/L CaC03); 195
Dissolved O2 (%); 98.8
pH; 7.62
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade(4) not assignable
Insufficient experimental detail

16-MAY-2005

(167)

Type:
Species:
Exposure period:
Unit:
LC50:

staticother: Micropterus treculi
96 hour(s)mg/lAnalytical monitoring: yes= 187.6

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: 6.5 grams
96-h LC50 = 924.6 mg/L*

Remark:Test condition:

Reliability:
93* : The values were converted NO2-N into NaNO2.
-Water parameters:
Temperature; 22 degree C
Hardness (mg/L CaC03); 203-222
Alkalinity (mg/L CaC03); 163-183
pH; 7.9-8.4(4) not assignable
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Insufficient experimental detail

20-MAY-2005

(180)

Type:
Species:
Exposure period:
Unit:
LC50:

staticGambusia affinis
96 hour(s)
mg/l
= 7.5

Method:Year:other: Wallen et al
1957

Test condition:

TEST ORGANISMS:(Fish, fresh water)
Analytical monitoring: no

Size: no data
Age: Adult females
Pretreatment: Fish kept in the laboratory for 2-3 weeks prior
to tests. Terramycin added to water to eliminate tail rot.
fish fed on plankton and detritus collected locally, alongwith various artificial foods.
Supplier: fish collected from stillwater Creek, Payne County,
OK
DILUTION WATER:
Source: Collected from local farm pond.
Chemistry: pH 7.8-8.3
Temperature: room temperature
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: No data
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: 0, 10, 18, 32, 56 100 ppm
Renewal of test solution: Static test
Exposure vessel type: Pyrex jars, 12 inches high by 12 inches
in diameter containing 15L of water
Number of fish per dose: 10
Test temperature: 21-24°C
Dissolved oxygen:
pH: 7.1-7.5
Alkalinity: <100 mg/L CaCO3
Hardness:
Intensity of irradiation:
Photoperiod:
Feeding: No
Aeration: Continuous
TEST PARAMETER: Mortality
Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: no
Chemical name: sodium nitrite (CAS No. 7632-00-0)
Purity: stated as chemically pureSupplier: no data
(4) not assignable
Insuficient experimental detail
UNEP PUBLICATIONS

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OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

20-MAY-2005

(192)

Type:
Species:
Exposure period:
Unit:
LC50:

staticOncorhynchus mykiss
24 hour(s)
mg/l
= 9.8

Method:Year:other:Eddy et al
1983

Method:Effect: mortality
Fresh water
Age/Weight: 10-25 grams-Water parameters:
Temperature; 10 degree C
pH; 7.0
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(3) invalid

Test condition:
Test substance:
Reliability:
19-MAY-2005(Fish, fresh water)
Analytical monitoring: no

(51)

Type:
staticSpecies:
Salmo salar
Exposure period: 24 hour(s)
Unit:
mg/l
LC50 (fresh water) := 10.08
LC50 (salt water) := 315(Fish, fresh water, marine)
Analytical monitoring: no

Method:Year:other: Eddy et al
1983

Method:Effect: mortality
Salt water, Fresh water
Fresh water:-Water parameters:
Temperature; 10 degree C

Test condition:

Test substance:
Reliability:
19-MAY-2005

Salt water:-Water parameters:
Temperature; 10 degree C
Salinity; 16 ppt
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(3) invalid
(51)

Type:
Species:
Exposure period:
Unit:
LC50 (lower) :staticPimephales promelas
96 hour(s)
mg/l
= 20

Method:Year:other: Ewell et al
1986

Method:Effect: mortality
Fresh water

95(Fish, fresh water)
Analytical monitoring: no

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

Result:

Test condition:

Test substance:
Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Age/Weight: juvenile, 0.2-0.5 gram
LC50 > 20 mg/L
LC50 = 20 mg/L
The lower value was = 20 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5
Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

19-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50:

staticPerca fluviatilis
24 hour(s)mg/l= 82.8

Method:
Year:

other
1986

Method:Reliability:
20-MAY-2005

Effect: mortality
Fresh water
Age/Weight: 20-40 grams
Purpose of this study;
This study using whole animals was conducted to explore therelationship between chloride and nitrite uptake and to
relate this to the toxicity of nitrite for a variety offresh water teleosts, using rainbow trout and perch as theprincipal examples.
Therefore, there were only 24h LC50 values.
-Water parameters:
pH; 6.9-7.4
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(3) invalid
(198)

Type:
Species:
Exposure period:
Unit:
LC50:

staticTinca tinca
24 hour(s)mg/l= 3450

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: 113-168 grams
Purpose of this study;
This study using whole animals was conducted to explore therelationship between chloride and nitrite uptake and to

Remark:Test condition:
Test substance:

Remark:(Fish, fresh water)
Analytical monitoring: no(Fish, fresh water)
Analytical monitoring: no

UNEP PUBLICATIONS

96

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Reliability:
20-MAY-2005

relate this to the toxicity of nitrite for a variety offresh water teleosts, using rainbow trout and perch as theprincipal examples.
Therefore, there were only 24h LC50 values.
-Water parameters:
pH; 6.9-7.4
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(3) invalid
(198)

Type:
Species:
Exposure period:
Unit:
LC50:

staticCyprinus carpio
24 hour(s)mg/l= 2415

Method:
Year:

other
1986

Method:Reliability:
20-MAY-2005

Effect: mortality
Fresh water
Age/Weight: 2-78 grams
Purpose of this study;
This study using whole animals was conducted to explore therelationship between chloride and nitrite uptake and to
relate this to the toxicity of nitrite for a variety offresh water teleosts, using rainbow trout and perch as theprincipal examples.
Therefore, there were only 24h LC50 values.
-Water parameters:
pH; 6.9-7.4
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(3) invalid
(198)

Type:
Species:
Exposure period:
Unit:
LC50:

staticAnguilla anguilla
24 hour(s)mg/l= 5520

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: 59-138 grams
Purpose of this study;
This study using whole animals was conducted to explore therelationship between chloride and nitrite uptake and to
relate this to the toxicity of nitrite for a variety offresh water teleosts, using rainbow trout and perch as theprincipal examples.
Therefore, there were only 24h LC50 values.
-Water parameters:
pH; 6.9-7.4
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade

Test condition:
Test substance:

Remark:Test condition:
Test substance:

Remark:Test condition:
Test substance:
97(Fish, fresh water)
Analytical monitoring: no(Fish, fresh water, marine)
Analytical monitoring: no

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Reliability:
20-MAY-2005

(3)

Type:
Species:
Exposure period:
Unit:
LC50:
EC50 :

staticother: Diplodus sargus
24 hour(s)mg/lAnalytical monitoring: no= 1360= 330

Method:
Year:

other
1980

Method:Effect: feeding behavior for EC50, mortality for LC50
Salt water
Age/Weight: larvae
EC50 = 330 (270 - 410) mg/L
LC50 = 1360 (1170 - 1590) mg/L
-Water parameters:
Temperature; 15 degree C
Dissolved O2 (mg/L); 7.9-8.1
Alkalinity (mg/L CaCO3); 108-123
pH; 7.79-7.85
Salinity; 34.4-35.7 ppt
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: No data
(3) invalid

Result:
Test condition:

Test substance:
Reliability:
20-MAY-2005

invalid
(198)

(27)

Type:
Species:
Exposure period:
Unit:
LC50:
EC50 :

staticother: Gaidropsarus capensis
24 hour(s)mg/lAnalytical monitoring: no= 2210= 450

Method:
Year:

other
1980

Method:Effect: feeding behavior for EC50, mortality for LC50
Salt water
Age/Weight: larvae
EC50 = 450 (380 - 530) mg/L
LC50 = 2210 (1900 - 2560) mg/L
-Water parameters:
Temperature; 15 degree C
Dissolved O2 (mg/L); 7.9-8.1
Alkalinity (mg/L CaCO3); 108-123
pH; 7.79-7.85
Salinity; 34.4-35.7 ppt
Chemical name: Sodium nitrite (CAS No.. 7632-00-0)
Purity: no data
(3) invalid

Result:
Test condition:

Test substance:
Reliability:
20-MAY-2005
Type:
Species:
Exposure period:
Unit:
LC50:

(27)
staticother: Heteromycteris capensis
24 hour(s)mg/lAnalytical monitoring: no= 2440
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OECD SIDS
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

EC50 := 340

Method:
Year:

other
1980

Method:Effect: feeding behavior for EC50, mortality for LC50
Salt water
Age/Weight: larvae
EC50 = 340 (270 - 440) mg/L
LC50 = 2440 (2200 - 2690) mg/L
-Water parameters:
Temperature; 15 degree C
Dissolved O2 (mg/L); 7.9-8.1
Alkalinity (mg/L CaCO3); 108-123
pH; 7.79-7.85
Salinity; 34.4-35.7 ppt
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: no data
(3) invalid

Result:
Test condition:

Test substance:
Reliability:
20-MAY-2005

(27)

Type:
Species:
Exposure period:
Unit:
LC50:
EC50 :

staticother: Lithognathus mormyrus
24 hour(s)mg/lAnalytical monitoring: no= 1230= 360

Method:
Year:

other
1980

Method:Effect: feeding behavior for EC50, mortality for LC50
Salt water
Age/Weight: larvae
EC50 = 360 (260 - 480) mg/L
LC50 = 1230 (1020 - 1470) mg/L
-Water parameters:
Temperature; 15 degree C
Dissolved O2 (mg/L); 7.9-8.1
Alkalinity (mg/L CaC03); 108-123
pH; 7.79-7.85
Salinity; 34.4-35.7 ppt
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: no data
(3) invalid

Result:
Test condition:

Test substance:
Reliability:
20-MAY-2005(27)
date: 04-JAN-2006

Type:
Species:
Exposure period:
Unit:
LC50:
EC50 :

staticother: Synaptura kleini
24 hour(s)mg/lAnalytical monitoring: no= 2110= 350

Method:
Year:

other
1980

Method:Effect: feeding behavior for EC50, mortality for LC50
Salt water

99

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

Result:
Test condition:

Test substance:
Reliability:
20-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Age/Weight: larvae
EC50 = 350 (250 - 500) mg/L
LC50 = 2110 (1670 - 2670) mg/L
-Water parameters:
Temperature; 15 degree C
Dissolved O2 (mg/L); 7.9-8.1
Alkalinity (mg/L CaC03); 108-123
pH; 7.79-7.85
Salinity; 34.4-35.7 ppt
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: no data
(3) invalid
(27)

Type:
Species:
Exposure period:
Unit:
LC50:

staticIctalurus punctatus
96 hour(s)
mg/l
= 1.3

Method:
Year:

other
1976

Method:Effect: mortality
Fresh water
Age/length: fingerling, 50-76 mm
Water temperature 22 and 30 degree C: both LC50s were 1.3
mg/L.

Result:(Fish, fresh water)
Analytical monitoring: no

Reliability:
20-MAY-2005

The 0.048 and 0.083 values as LC50 were reported in thisreport. These data vary widely. This repot was assigned as(3) invalid.
-Water parameters:
Temperature; 22, 30 degree C
Hardness (mg/L CaC03); 102
Alkalinity (mg/L CaC03); 220
pH; 8.6-8.8
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(3) invalid
(42)

Type:
Species:
Exposure period:
Unit:semistatic
Oncorhynchus tschawytscha (Fish, fresh water, marine)
10 day(s)mg/lAnalytical monitoring: yes

Method:Year:other: APHA 1965
1974

Method:Effect: Tolerance
Fresh water
Life stage/length/weight: fingerling, 1.50-10.55 grams,
51-103 mm
TLm (96h) = 2.9 ppm NO2
TLm (7d) = 2.4 ppm NO2-Water parameters:
Temperature; 13.6 - 15.6 degree C
Dissolved O2 (mg/L); 7
pH; 6.8 - 7.2

Test condition:

Test substance:

Result:
Test condition:

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Reliability:
20-MAY-2005

(3)

Type:
Species:
Exposure period:
Unit:
LC50:

staticMorone saxatilis (Fish, estuary, marine)
24 hour(s)mg/lAnalytical monitoring: no= 163 measured/nominal

Method:
Year:
GLP:

other
1991
no

Result:Reliability:
20-MAY-2005

Striped bass mortality showed a clear dose-response relation
to NO2- concentration.
The 24-h LC50 value was 163.0 +/-8.8 mg NO2-/L.
As NO2- in the water was increased from 150 mg/L to 175
mg/L, mortality increased sharply from 20 % to 80%.
Striped bass averaging 27 +/-2 cm (SE) in standard lengthand 250 +/-4.4 g in live weight were maintained at theSoutheastern Fish Cultural Laboratory, Marion, Alabama, forat least 4 weeks in 1,200-L fiberglass tanks supplied withaerated well water at a flow rate of two turnovers per hour.
Physicochemical characteristics of the water weretemperature 23 degree C, pH 7.5, hardness 106 mg/L as
calcium carbonate, alkalinity 108 mg/L as calcium
carbonate, dissolved oxygen >6.0 mg/L, Cl- 38.6 mg/L, NO2and ammonia <0.01 mg/L. Fish were fed commercial food (40%protein) daily; feeding was discontinued 48 h before thefish were transferred to experimental tanks.
Survival of striped bass during exposure to NO2- (added as
sodium nitrite) was determined in triplicate in a series ofnine treatments in which the NO2- concentration ranged from50 to 250 mg/L increments of 25 mg/L. In an experiment toevaluate the protective effects of Cl-, either CaCl2(62.5-5,000 mg/L as Cl-) or NaCl (500-2,500 mg/ L as Cl-)
was added to tanks containing 250 mg NO2-/L, a concentration
normally lethal to striped bass in fresh water. Nitrite (250mg/L) and freshwater controls were included in triplicat
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: no data
(4) not assignable(117)

Species:
Exposure period:
Unit:
LC50:

other: Seriola quinqueradiata
96 hour(s)mg/lAnalytical monitoring: no> 147

Method:Year:
GLP:

other: APHA/AWWA/WPCF 1981
1991
noResult:Mortality
40 % at 147 mg/L for 96
Therefore, 96-h LC50 is greater than 147 mg/L.
Temperature 25.5 +/- 1 degree C
juvenile 20g, 10/group
pH; 8.0 - 8.2
Salinity 32.2 - 33.3

Test condition:

Test substance:

Test condition:

101

invalid(195)

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4. ECOTOXICITY
Test substance:
Reliability:
20-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Substance name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Supplier: WAKO Chemical, Japan(4) not assignable
(172)

Type:
staticSpecies:Morone sp.
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: no
LC50 (a case as water condition: accumated salinity; 1g/L) := 35 measured/nominal
LC50 (a case as water condition: accumated salinity; 8g/L) :> 100 measured/nominal
LC50 (overall all calcium conc. tested) := 12.8 measured/nominal
Method:
Year:
GLP:

other
1993
no

Result:Environmental calcium did not affect nitrite toxicity, andthe 96-h LC50 of nitrite-nitrogen (nitrite-N) was 12.8 +/1.6 mg/L (mean +/- SE) over all calcium concentrations
tested. The 96-h LC50 of nitrite-N for fish acclimated to asalinity or 1 g/L was 35.0 +/- 2.3 mg/L (mean +/- SE),
whereas LC50s of nitrite-N for fish acclimated to salinities
of or higher than 8 g/L were greater than 100 mg/L (thehighest exposure level).
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

Test substance:
Reliability:
20-MAY-2005(4)

not assignable

Species:
Unit:
LC0:
LC50:
LC100:

Leuciscus idus
mg/l
= 165
= 360
= 462

Method:
Year:

other
1978

Test substance:
Reliability:
20-MAY-2005

Chemical name: Sodium nitrite (CAS No 7632-00-0)(4) not assignable

Species:
Unit:
LC0:
LC50:
LC100:

Leuciscus idus
mg/l
= 300
= 565
= 700

Method:
Year:

other
1978

Test substance:
Reliability:
20-MAY-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(194)(Fish, fresh water)
Analytical monitoring:(99)(Fish, fresh water)
Analytical monitoring:(99)

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Type:
Species:
Exposure period:
Unit:
LC50:

staticCynoscion nebulosus
24 hour(s)
mg/l
= 980

Method:
Year:

other
1987

Method:Effect: mortality
Salt water
Life stage: egg-larvae-Water parameters:
Temperature; 26-27 degree C
Salinity; 25-30 ppt
pH; 7.45-8.0
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(3) invalid

Test condition:

Test substance:
Reliability:
20-MAY-2005(Fish, marine)
Analytical monitoring: yes

(44)

Type:
staticSpecies:other: Chanos chanos
Exposure period: 48 hour(s)
Unit:
mg/l
LC50 (salt water) := 675
LC50 (fresh water) := 12

Analytical monitoring: no

Method:
Year:

other
1987

Method:Effect: mortality
Salt water, Fresh water
Age/Weight: juvenile, 31 grams
Salt water:
LC50 = 675 (435.8 - 1045.4) mg/L

Result:

Test condition:

Test substance:
Reliability:
20-MAY-2005

Fresh water:
LC50 = 12 (7.4 - 19.6) mg/L
-Water parameters:
Temperature; 27.4-27.8 degree C
Hardness (mg/L CaC03); 203-222
Salinity; 16 ppt
pH; 8.0-8.5
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(3) invalid
(8)

Type:
Species:
Exposure period:
Unit:
LC50:

staticOncorhynchus tschawytscha (Fish, fresh water, marine)
48 hour(s)mg/lAnalytical monitoring: yes= 5.8

Method:
Year:

other
1977

Method:Effect: mortality

103

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Result:
Test condition:
Test substance:
Reliability:
20-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Fresh water
Age/Weight: fingerling, 13.4 grams
LC50 = 5.8 (3.0 - 11.0) mg/L
-Water parameters:
Temperature; 9.1 (9.0-9.4) degree C
pH; 7.8 (7.8-7.9)
Chemical name: Sodium nitrite
Purity: Reagent grade(3) invalid
(43)

Type:
Species:
Exposure period:
Unit:
LC0:
LC100:

staticSemolitus atromaculatus (Fish, fresh water)
24 hour(s)mg/lAnalytical monitoring: no
= 81
= 400

Method:
Year:

other
1952

Method:Effect: mortality
Fresh water
Concentration: total
Length: 8-10 cm-Water parameters:
Temperature; 15-21 degree C
Hardness (mg/L CaC03); 98.0
pH; 8.3
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Commercial grade(3) invalid

Test condition:

Test substance:
Reliability:
20-MAY-2005

(64)

Type:
Species:
Exposure period:
Unit:
LC50:
LC50 (24h) :flow throughRasbora heteromorpha
48 hour(s)
mg/l
= 43
= 77

Method:
Year:

other
1969

Method:Effect: mortality
Fresh water
Length: 1.3-3 cm-Water parameters:
Temperature; 20 degree C
Hardness (mg/L CaC03); 250
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 98%(3) invalid

Test condition:
Test substance:
Reliability:
20-MAY-2005
Type:
Species:
Exposure period:
Unit:
LC50:

(Fish, marine)
Analytical monitoring: no(4)
staticSciaenops ocellata
48 hour(s)mg/l= 85.7(Fish, marine)
Analytical monitoring: yes

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Method:
Year:
GLP:

other
1989
no data

Method:Effect: mortality
Salt water
Age/Weight: fingerling, 5.6 grams-Water parameters:
Temperature; 24-25 degree C
Salinity; 36.0 ppt
pH; 7.4-7.7
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(3) invalid

Test condition:

Test substance:
Reliability:
20-MAY-2005(199)

Species:
Exposure period:
Unit:
NOEC:
Limit Test:

Salmo gairdneri
49 day(s)
mg/l
= .5
no

Method:
Year:

other
1978

Remark:Test substance:
Reliability:
25-JUL-2005

Exposure to 0.1 mg NO2-/l for 6 months in freshwater caused
no lethality, growth reduction, gill histological changes
orhaematological dyscrasions after 7 weeks. Although 0.05
mg NO2-/l caused significant increase inmethaemoglobin levels, the change was slight and not of
biological significance.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(193)

Type:
Species:
Exposure period:
Unit:
LC50:

staticIctalurus punctatus
24 hour(s)mg/l= 1.52

Method:
Year:

other
1980

Method:Effect: mortality
Fresh water
Life stage/length: fingerling, 7-13 cm-Water parameters:
Temperature; 21 - 24 degree C
Hardness (mg/L CaC03); 40
Alkalinity (mg/L CaC03); 47
pH; 7.0
Chemical name: Sodium nitrite
Purity: Reagent grade(3) invalid

Test condition:

Test substance:
Reliability:
23-MAY-2005(Fish, estuary, fresh water)
Analytical monitoring:(Fish, fresh water)
Analytical monitoring: yes(181)

4.2 Acute Toxicity to Aquatic Invertebrates
105

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Type:
Species:
Exposure period:
Unit:
LC50 :

semistatic
other: Penaeus paulensis
96 hour(s)mg/lAnalytical monitoring: no= 109.4

Method:
Year:

other
1996

Method:METHOD FOLLOWED: Cavalli et al method.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: LC50 calculated with the Trimmed Spearman
Karber method
METHOD OF CALCULATION: no data

Result:ANALYTICAL METHODS: none
Expressed as sodium nitrite:
LC50 (96h) = 539.2 mg/L
No mortality was observed in the control units.
-LC50 (mg NO2-N/L) and their 95% confidence limits of nitrite
for
Penaeus paulensis broodstock over time.
- 77/297 date: 04-JAN-2006
24-h LC50 = 291.3 (279.4 - 303.7)
48-h LC50 = 146.7 (139.5 - 154.3)
72-h LC50 = 127.6 (116.7 - 139.5)
96-h LC50 = 109.4 (90.1 - 132.7)

Test condition:
TEST ORGANISMS:
Size: females 53.1+/-7.7 g, carapace length 7.05+/-0.53 mm;males 28.0/-2.7 g, carapace length 5.80+/-0.26 mm
Age: no data, but individuals in the intermoult period
selected for testing.
Pretreatment: After capture in the wild, shrimp weremaintained in 10-ton tanks for 3-4 months.
Supplier: Wild-caught
DILUTION WATER:
Source: 1.0 µm filtered water
Chemistry:
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: not measured
REFERENCE SUBSTANCE: none

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
TEST SYSTEM:
Concentrations: 0, 50, 100, 150, 200, 300 or 400 mg/L NO2-N
Renewal of test solution: 70%/day exchange
Exposure vessel type: 15L tank
Number of replicates: 2 replicates, 2 females and one male pertank.
Water parameters: temperature 27+/-0.2°C; salinity 32 ppt; pH
7.7+/-0.1
Intensity of irradiation: no data
Photoperiod: 15 h light/9 h dark
Feeding: no
Aeration: moderate, continuous
TEST PARAMETER: Mortality (shrimp were considered dead whenpresenting no response to mechanical stimuli)

Test substance:
Reliability:
Flag:
23-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: no
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well reported literature study
Critical study for SIDS endpoint
(31)

Type:
staticSpecies:other: Procambarus clarkii
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: yes
LC50(96h, low chloride) := 28
LC50 (96h, high chloride) := 75
Method:
Year:

other
1985

Method:METHOD FOLLOWED: Gutzmer & Tomasso method.
26 trials were conducted. 19 trials tested the effect of
crayfish weight on tolerance to nitrite; 14 trials tested
effect of gender on tolerance to nitrite (conductedsimultaneously with size trials) and seven trials tested theeffect of the addition of 100 mg/L environmental chloride on
tolerance to nitrite toxicity.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: A two-tailed t-test, one way analysis ofvariance (ANOVA) and Student-Newman-Keuls (SNK) multiple range
test were used where appropriate.
METHOD OF CALCULATION: no data
ANALYTICAL METHODS: Nitrite concentration analysed usingazodye method (EPA 1974)

Result:107

References: US EPA (1974) Methods for Chemical Analysis of
Water and Wastes. Office of Technology Transfer, Washington,
DC.
Expressed as sodium nitrite:
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
LC50 (96 h) = 42 mg/L
(22 mg/L chloride)
LC50 (96 h) = 112 mg/L (100 mg/L chloride)
Neither gender nor weight significantly
nitrite to crayfish size.

affected LC50 ofEnvironmental chloride significantly increased the LC50 values
at all time periods tested. These results indicate thatchloride inhibits nitrite toxicity in crayfish, probably bycompetitively excluding nitrite from active transport sites ongill cells that normally transport chloride.
Test condition:
TEST ORGANISMS:
Size: Gender/size trials 0.5+/-0.03g to 12.4+/-1.76g; chloride
inhibition tests 1.57+/-0.22g to 17+/-1.65g
Age:
Pretreatment: Animals were held at least 48-h prior to testingin 252 L fiberglass tanks supplied with well water at the San
Marcos National Fish Hatchery and Technology Center. Flow rate
6-7 turnovers/hour. Animals were fed a formulated fish food(40% protein) when first placed in the tanks. Feeding wassuspended 24 h before crayfish were placed in the experimental
aquaria for testing.
Supplier: Southwest Texas State University, San Marcos, Texas,
USA
DILUTION WATER:
Source: Well water
Chemistry: temperature 23°C; pH 7.2; dissolved oxygen > 6.0
mg/L; hardness 310 mg/L as calcium carbonate; chloride 22
mg/L.
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: Nitrite
concentration between 144 and 114% of nominal.
REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: 10 to 83.5 mg/L for gender and weight tests;
29 to 242 mg/L for chloride inhibition tests.
Renewal of test solution: none, static test
Exposure vessel type: 15 L glass aquaria
Number of replicates: One replicate, 5 crayfish per dose.
Water parameters: pH 7.9-8.3; dissolved oxygen 6.9-7.5 mg/L;
alkalinity 153-196 mg/L as CaCO3; hardness 198-232 mg/L as
CaCO3.
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no
Aeration: constant to maintain dissolved oxygen close tosaturation.
TEST PARAMETER: Mortality
MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
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4. ECOTOXICITY
Test substance:
Reliability:
Flag:
23-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Well reported literature study
Critical study for SIDS endpoint
(73)

Type:
Species:
Exposure period:
Unit:
LC50 :

staticother: Cherax quadricarinatus
96 hour(s)mg/lAnalytical monitoring: no= 1

Method:Year:other: APHA 1980
1995

Method:METHOD FOLLOWED: APHA (1980)
DEVIATIONS FROM GUIDELINE: None
STATISTICAL METHODS: Finney (1971)
METHOD OF CALCULATION: LC50 values calculated from a basic
microcomputer program
ANALYTICAL METHODS: Nitrite concentration determined by thediazotisatin method (APHA, 1980)
References: APHA, American Water Works Association and Water
Pollution Control Federation (1980) Standard Methods for the
Examination of Water and Wastewater. 15th edn. APHA,
Washington, DC

Result:Finney DJ (1971) Probit analysis. Cambridge University Press.
London/New York, NY 333pp
Expressed as sodium nitrite:
LC50 (96h) = 4.93 mg/L
LC50 (mg/L NO2-N)
values in mg/L for hatchling reclaw crayfish. pH 8.3,
temperature 28 degree C

Test condition:

24-h LC50 = 1.4
48-h LC50 = 1.1
72-h LC50 = 1.1
96-h LC50 = 1.0
TEST ORGANISMS:
Size:
Age: Hatchlings
Pretreatment: Feed withheld 24h prior to transfer totreatment tanks
Supplier: redclaw broodstock produced at the Aubum University
Agricultural Experiment Station, Auburn Alabama
DILUTION WATER:
Source:Chemistry:

109

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: Final nitrite
concentrations varied less than 7% from the original
concentration.
REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: 0, 0.5-3.5 mg/L NO2-N at 0.5 mg/L intervals
Renewal of test solution: Static test, but nitrite
concentrations adjusted to initial levels if necessary every
24h
Exposure vessel type: 4 L plastic jars filled with 3L ofculture water
Number of replicates: Triplicate, 4 crayfish per concentration
Water parameters: temperature 28+/-1°C; pH 8.3; dissolved
oxygen 7.4 mg/L; alkalinity 20 mg/L; hardness 54 mg/L
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no
Aeration: gentle to maintain dissolved oxygen levels at
saturation
TEST PARAMETER: Mortality

Test substance:
Reliability:
Flag:
26-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint
(150)

Type:
Species:
Exposure period:
Unit:
LC50 :
LC50 (96h) :semistatic
other: Macrobrachium rosenbergii
192 hour(s)mg/lAnalytical monitoring: yes
= 4.5
= 8.6

Method:
Year:

other
1976

Method:METHOD FOLLOWED: Armstrong et al method
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: 2-Way

ANOVA

METHOD OF CALCULATION: no data
ANALYTICAL METHODS: Nitrite concentration analysed using asulfanilamide-based colourimetric reaction (Federal Water
Pollution Control Administration, 1969)
References: Federal Water Pollution Control Administration(1969) FWPCA Methods for Chemical Analysis of Water and Waste.
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Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
US Dep. Inter. Washington DC, 181-187
Expressed as sodium nitrite:
LC50 (96h)= 42.4 mg/L
LC50 (192h) = 22.2 mg/L

Test condition:
TEST ORGANISMS:
Size: 80-140 µg
Age: 10-14 day-old larvae
Pretreatment:
Supplier: in-house, University of California, Davis
DILUTION WATER:
Source:Chemistry:
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: Nitrite
concentration never less than 94% of nominal at 24 hour change
REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: Broods 1&2 0.3-970 mg/L NO2-N; Brood 3 1.8-30 mg/L NO2-N
Renewal of test solution: Every 24 hours
Exposure vessel type: 250 mL glass beakers immersed in aconstant temperature bath
Number of replicates: triplicate, 15 larval shrimp perconcentration
Water parameters: temperature 28+/-0.5°C; salinity 12+/-0.5
ppt; dissolved oxygen 5.7+/-0.7 mg/L; pH 7.98+/-0.05 (t=0h)
and 8.22+/-0.03 (t=24h)
Intensity of irradiation: no data
Photoperiod: no data
Feeding: newly hatched brine shrimp naupii every 24 h whensolutions were changed.
Aeration: no
TEST PARAMETER: Mortality (cessation of heart beat in thefirst 24 h and development of opaqueness in immobile animals
after 24 h).
MONITORING OF TEST SUBSTANCE CONCENTRATION: yes, every 24
hours
Test substance:
Reliability:

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Well reported literature study

24-MAY-2005
Type:
Species:
Exposure period:
Unit:
LC50 :
111(11)
semistatic
other: Penaeus chinensis
192 hour(s)mg/lAnalytical monitoring: no= 22.95
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

LC50 (96h) := 37.1

Method:
Year:
GLP:

other
1990
no

Method:METHOD FOLLOWED: Hubert (1980) and the American Public Health
Association (1985)
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
METHOD OF CALCULATION:ANALYTICAL METHODS: none
References:
American Public Health Association (1985). Standard Methods
for the Examination of Water and Wastewater. 16th ed. American
Public Health Association, American Water Works Associationand Water Pollution Control Federation, Washington DC.

Result:Hubbert JJ (1980) Bioassay. Kendall Hunt Publishing Co.
TorontoExpressed as sodium nitrite:
LC50 (96h) = 182.9 mg/L
LC50 (192h) = 113.1 mg/L
LC50 values of Nitrite-N mg/L
24-h LC50 = 339
48-h LC50 = 286
72-h LC50 = 117
96-h LC50 = 37.1
120-h LC50 = 26.98
144-h LC50 = 26.98
168-h LC50 = 24.36
192-h LC50 = 22.95

Test condition:
TEST ORGANISMS:
Size: mean body length 3.96+/- 0.18 cm; weight 0.36 +/- 0.06 g
Age: juveniles
Pretreatment: Acclimated for about 1 week in 500 L holdingtanks
Supplier: Tainan Branch, Taiwan Fisheries Research Institute
DILUTION WATER:
Source: Seawater pumped from the Keelung coast adjacent to
the University was filtered through a sand and gravel bed by
air-lifting, and aerated for 3 d before use.
Chemistry:
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: Distilled waterPreparation: Nitrite test solutions were prepared bydissolving 4.93 g of sodium nitrite with distilled water tomake 1000 mg/L "nitrite-N" (nitrite as nitrogen), and then
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
diluted to desired concentrations with seawater.
STABILITY OF THE TEST CHEMICAL SOLUTIONS:REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: The nominal concentrations of nitrite-N ranged
in 10 mg/L increments from 20 to 80 mg/L, in 40 mg/L
increments from 80 to 200 mg/L, and in 50mg/L increments from
200 to 400 mg/L.
Renewal of test solution: daily
Exposure vessel type: 30 L polyethylene tanks containing 10 L
test solution
Number of replicates: Triplicate, 8 prawns/test
concentration/tank
Water parameters: temperature 26+/-2°C; dissolved oxygen
5.6+/-0.2 mg/L; pH 7.94+/-0.06.
Intensity of irradiation: no data
Photoperiod: no data
Feeding: Diet (protein 42.9%) designed for Penaeus monodon by
Tairon Feedstuff Co. (Taipei, Taiwan) three times a day(10:00, 16:00, 22:00 hrs) at 15% body wt/d.
Aeration: yes
TEST PARAMETER: Mortality

Test substance:
Reliability:

MONITORING OF TEST SUBSTANCE CONCENTRATION: no
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Supplier: Merck(2) valid with restrictions
Well reported literature study

24-MAY-2005

(39)

Type:
Species:
Exposure period:
Unit:
NOEC:
LC50 :

semistatic
other: Metapeaeus ensis
120 hour(s)mg/lAnalytical monitoring: yes= .71= 7.06

Method:
Year:
GLP:

other
1991
no

Method:Effect: immobilisation, intoxicant
Salt water
Expressed as sodium nitrite:

Remark:Result:113

120-h LC50 = 34.8 mg/L
120-h NOEC = 3.5 mg/L
Percentage mortalities of shrimp exposed to various
concentrations of nitrite are presented in Table. Only one
N3 larvae and one M2 larva died in the control solution; noZ2 or PL1 larvae died in control solutions.
The probit of mortality of the larvae exposed to nitrite-N
had a linear relationship with log nitrite-N at various
times of exposure.
The LC50s and associated 95% confidence limits of nitrite-N
UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

Test condition:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
for different stages of M. ensis larvae are shown below. The
24 h LC50 of nitrite-N was 31.29, 16.05, 47.60, and 70.06
mg/L on N3, Z2, M2, and PL1, respectively. PL1 larvae werethe most tolerant and Z2 the least tolerant to nitrite.
The LC50 decreased with increase of exposure time for all
stages of M. ensis larvae tested.
The LC50 declined sharply during the first 12-36 h for M2
and PL1. The "threshold time" (a time at which responses
cease) for PL1 was 108 h. The "incipient LC50" (the LC50 foran exposure time at the asymptotic point of the toxicity
curve) was determined to be 7.06 mg/L nitrite-N for PL1 in asalinity of 33 ppt at a pH of 8.20 and a water temperatureof 30 degree C.
Relation between probit of mortality and nitrite-N
concentrations as mg/L at various time, and LC50 and 95%
confidence limits.
-----------------------------------------------------------Time (h)LC50 Nitrite-N (mg/L)-----------------------------------------------------------Nauplius third substage (N3)1240.36 (21.91 - 75.90)
24
31.29 (16.16 - 61.25)-----------------------------------------------------------Zoea second substage (Z2)1233.66 (25.10 - 45.53)
24
16.05 (10.77 - 23.95)-----------------------------------------------------------Mysis second substage (M2)12110.77 (48.17 - 262.59)
24
47.60 (36.68 - 57.12)
36
34.59 (28.93 - 41.36)
48
20.67 (16.14 - 26.61)-----------------------------------------------------------Postlarva first substage (PL1)12132.60 (80.33 - 226.68)
24
70.06 (57.17 - 85.85)
36
40.48 (30.88 - 54.43)
48
27.10 (18.16 - 40.81)
60
18.11 (11.43 - 28.91)
72
12.76 (7.14 - 23.02)
84
11.64 (6.73 - 20.15)
96
9.13 (5.16 - 16.30)
108
7.06 (4.39 - 11.47)
120
7.06 (4.39 - 11.47)-----------------------------------------------------------Fertilized eggs released from a single brood were hatched
and reared to different stages in the laboratory. The larvae
used in the study were third nauplius substage (N3), second
zoea substage (Z2), second mysis substage (M2), and first
postlarva substage (PL1).
Seawater (33 ppt) pumped from the Keelung coast adjacent to
the National Taiwan Ocean University was filtered throughsand and gravel filters and aerated three days before use intoxicity tests.
Nitrite test solutions were prepared by dissolving 4.93 g ofreagent grade sodium nitrite with 1.00 L of distilled water
to make a stock solution of 1,000 mg/L nitrite-N.
The stock solution was then diluted to desiredconcentrations with seawater The nominal nitrite-N
concentration ranged in geometric progression (factor of 2)
UNEP PUBLICATIONS

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OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
from 1 to 64 mg/L (plus a 96 mg/L treatment) for N3, from 2
to 64 mg/L (plus a 12, 24 and 96 mg/L treatment) for Z2,
from 2 to 64 mg/L (plus a 24 and 96 mg/L treatment) for M2,
and from 2 to 128 mg/L (plus a 24 and 96 mg/L) for PL1.
Concentrations of nitrite-N were measured
spectrophotometrically by the diazotization method(Strickland and Parsons 1972).
Toxicity tests were conducted according to Hubert (1980)
and the American Public Health Association et al. (1985).
Shrimp were collected randomly from the holding tank andexposed to test and control solutions in triplicate 1.00 L
polyethylene beakers containing 1.00 L of the test solution.
Each beaker contained 15 test larvae for N3, Z2 or M2, or 1O
test larvae for PL1. All breakers were aerated by an airstone. During the experiments, shrimp were fed artificial
plankton BP (Nippai Co. Ltd, Tokyo, Japan) for zoea, mysis
and postlarvae three times a day. However, nauplius larvae
were not fed (American Public Health Association et al.
1985).
Toxicity tests were conducted using the "static renewal
method" (Hubert 1980; Buikema et al. 1982; American Public
Health Association et al. 1985) with test solutions renewed
daily. In all test solutions, dissolved oxygen (DO)maintained 5.4-5.6 mg/L, pH 8.10-8.30 and water temperature
29-31 degree C. Observations were usually made at 12 hintervals up to 24 h for N3 and Z2; to 48 h for M2; and to
132 h for PL1. Death was assumed when shrimps were immobile
and showed no response when the beaker was shaken gently.
The dose response of test organisms was determined byplotting probit transformed percent mortality against log
concentration (Finney 1971 ; Buikema et al.1982). The
median lethal concentration (LC50) of nitrite-N andassociated 95% confidence limits were calculated from a
microcomputer program (Trevors and Lusty 1985).

Reliability:
24-MAY-2005

Chemical analysis of saltwater water
Salinity; 33 ppt
Total alkalinity; 108 mg/L as CaCO3
Total hardness; 6,214 mg/L as CaCO
Chemical name: Sodium Nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Metapenaeus ensis larvae at different stages were exposed
to a series or nitrite-N (nitrite as nitrogen)concentrations in static renewal toxicity tests. Larvae atzoea stage were the most susceptible, and postlarvae werethe most tolerant to nitrite among the larvae tested. The 24
h LC 50s were 31.29, 16.05, 47.60 and 70.06 mg/L nitrite forthird nauplius substage (N3), second zoeasubstage (Z2),second mysis stage (M2), and first postlarvae substage(PL1). respectively, in 33 ppt seawater at a pH of 8.20 anda water temperature of 30 C. The 48 h LC50S for M2 and PL1
were 20.67 and 27.10 mg/L nitrite-N. respectively. The''threshold time" was 108 h, and "incipient LC50" for M.
ensis PL1 was 7.06 mg/L nitrite-N. A "safe level" forrearing M. ensis larvae was estimated to be 0.71mg/L
nitrite-N in the hatche(2) valid with restrictions
(37)

Type:

staticTest substance:
Conclusion:

115

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4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Species:other: Crassostrea virginica
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: noEC50 (adult) := 660
EC50 (juvenile) : = 800
Method:
Year:

other
1975

Method:METHOD FOLLOWED: Epifanio and Srna method.
After 96-h exposure to a toxin, surviving individuals weretransferred to uncontaminated seawater in which they underwent
a 24-h recovery period. The number surviving after thisrecovery period was used in calculation of 96-h mean lethal
tolerance limits.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: no data
METHOD OF CALCULATION: no data
ANALYTICAL METHODS: none

Test condition:
TEST ORGANISMS:
Size: (a) 13-17 mm (b) 46-62 mm
Age: (a) Juveniles, (b) Adults
Pretreatment: Held in a recirculating sea-water system and fed
a diet of cultured algae for at least 3 weeks prior to use inan experiment. Test individuals were starved during the 24 h
immediately preceeding a test.
Supplier: Juveniles hatchery reared by test lab, adults
collected locally.
DILUTION WATER:
Source: Seawater pumped from Breakwater Harbour at the mouthof Delaware Bay, USA
Chemistry: Temperature 20/-2°C; Salinity 27+/-2%
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: not measured
REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: 1.0E-02-10.0E-02 M/L
Renewal of test solution: none, static test
Exposure vessel type: Glass aquaria containing 30 L sea water
Number of replicates: duplicate, 10 specimens per aquarium
Water parameters: Temperature 20/-2°C; Salinity 27+/-2%;
oxygen 7-8.2 ppm; pH 7.7-8.23
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no
Aeration: Continuous
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OECD SIDS
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
TEST PARAMETER: Mortality

Test substance:
Reliability:
23-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: no
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
(55)

Type:
staticSpecies:other: Mercenaria mercenia
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: noEC50 (adult) := 1200EC50 (juvenile) : = 1100
Method:
Year:

other
1975

Method:METHOD FOLLOWED: Epifanio and Srna method.
After 96-h exposure to a toxin, surviving individuals weretransferred to uncontaminated seawater in which they underwent
a 24-h recovery period. The number surviving after thisrecovery period was used in calculation of 96-h mean lethal
tolerance limits.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS: no data
METHOD OF CALCULATION: no data
ANALYTICAL METHODS: none

Test condition:
TEST ORGANISMS:
Size: (a) 4.7-5.2 mm (b) 28-32 mm
Age: (a) Juveniles, (b) Adults
Pretreatment: Held in a recirculating sea-water system and fed
a diet of cultured algae for at least 3 weeks prior to use inan experiment. Test individuals were starved during the 24 h
immediately preceeding a test.
Supplier: Juveniles hatchery reared by test lab, adults
collected locally.
DILUTION WATER:
Source: Seawater pumped from Breakwater Harbour at the mouthof Delaware Bay, USA
Chemistry: Temperature 20/-2°C; Salinity 27+/-2%
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: none
Preparation: not applicable
STABILITY OF THE TEST CHEMICAL SOLUTIONS: not measured
REFERENCE SUBSTANCE: none
TEST SYSTEM:
117

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4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Concentrations: 1.0E-02-10.0E-02 M/L
Renewal of test solution: none, static test
Exposure vessel type: Glass aquaria containing 30 L sea water
Number of replicates: duplicate, 10 specimens per aquarium
Water parameters: Temperature 20/-2°C; Salinity 27+/-2%;
oxygen 7-8.2 ppm; pH 7.7-8.23
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no
Aeration: Continuous
TEST PARAMETER: Mortality

Test substance:
Reliability:
23-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: no
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
(55)

Type:
semistatic
Species:other: Callinectes sapidus
Exposure period: 96 hour(s)
Unit:
mg/l
Analytical monitoring: yes
LC50 (pre-molt juvenile) := 71.3
LC50 (intermolt juvenile) := 93.4
Method:
Year:

other
1989

Method:METHOD FOLLOWED: Ary & Poirrier method.
Two nitrite bioassay experiments were conducted: one withpremolt crabs near ecdysis and one with intemolt crabs.
DEVIATIONS FROM GUIDELINE: Not applicable
STATISTICAL METHODS:
METHOD OF CALCULATION: LC50 calculated using trimmed
Spearman-Karber method.
ANALYTICAL METHODS: Nitrite concentration was measured by thediazotisation method (APHA et al 1980)

Result:References:
APHA, American Water Works Association and Water Pollution
Control Federation (1980) Standard Methods for the Examinationof Water and Wastewater. 15th edn. APHA, New York
Based on Sodium nitrite:
LC50 (96h) = 351.4 - 460.3 mg/L

Test condition:
TEST ORGANISMS:
Size:
Age: premolt and intermolt
Pretreatment: Held in closed, recirculating-seawater systems.
Intermolt crabs acclimatised for 72-168 h. Premolt held until
UNEP PUBLICATIONS

118

OECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
within 4 days of ecdysis
Supplier: Collected from Clermont Harbor, Mississippi
DILUTION WATER:
Source: 3-5 day old aerated New Orleans city tap water
dechlorinated with sodium thiosulfate. Artificial sea salts(Rila Marine Mix) were added.
Chemistry: salinites averaged 17.6 ppt and ranged from 14.0 19.0 ppt.
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration:
Preparation:
STABILITY OF THE TEST CHEMICAL SOLUTIONS: no data
REFERENCE SUBSTANCE: none
TEST SYSTEM:
Concentrations: 0, 10, 25, 50, 75, 100, 150, 200 mg/L NO2-N
Renewal of test solution: daily
Exposure vessel type: Plastic box, 50.8 x 30.5 x 15.2 cm
Number of replicates: 22 premolt crabs, 10 intermolt crabs per
test concentration, all individually housed.
Water parameters: temperature 21-24°C; pH 7.8 (7.5-7.9)
Intensity of irradiation: no data
Photoperiod: no data
Feeding: no
Aeration: yes
TEST PARAMETER: Mortality

Test substance:
Reliability:
26-MAY-2005

MONITORING OF TEST SUBSTANCE CONCENTRATION: yes, daily prior
to test solution renewal
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
(12)

Type:
Species:
Exposure period:
Unit:
LC50 :

semistatic
other: Cherax quadricarinatus
96 hour(s)mg/lAnalytical monitoring: no= 25.9

Method:
Year:

other
1995

Method:Remark:Effect: mortality, increasing
Fresh water
96-h LC50 = 126.7 mg/L*

Result:* : The values were converted NO2-N into NaNO2.
Expressed as sodium nitrite:
LC50 (96h) = 126.7 mg/L
No mortalities were observed in control individual
throughout the experiments. Survival was substantially

119

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

Test condition:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
reduced when juvenile crayfish were exposed to nitrite. At 0
and 10 mg/L total NO2-N, no mortalities were observed
through 120 hr of exposure. At 25, 50, and 100 mg/L total
NO2-N, average LT50s were 96, 22, and 5 hr, respectively.
The calculated LC50 values for 24, 48, and 96 hr were 42.9+/-O.22, 37.1 +/- 0.16 and 25.9 +/- 0.35 mg/L NO2-N,
respectively.
-AnimalJuveniles were obtained from broodstock females maintainedin Campbell Hall at the University of Alabama at Birmingham(UAB). Broodstock individuals were held in raceways (28degree C) with associated recirculating biofilters to ensure
water quality and the health of broodstock animals.
Juveniles used ranged in size from 9 - 13 mm total length(10 - 25 mg wet weight) and were fed AB crayfish feed (UAB
Research Foundation). Juveniles lacking appendages were
excluded for use in experiments.

Reliability:
26-MAY-2005-Toxicity Assays
Preliminary experiments determined the range ofconcentrations of nitrite to be examined (data not shown).
For each test solution examined, 10 siblings were placed
individually in polystyrene bowls containing 100 mL of thedesired test solution. In many cases, the variability insurvival of siblings among females was high, thus numerous
other groups of siblings from other females were exposed tothe toxicants to increase the statistical value of mean
lethal times and concentrations. All juveniles used for
toxicity experiments were not fed during exposure nitrite.
Stock solutions were made by mixing 4.92 g sodium nitrite
with 1 L of conditioned freshwater (28 degree C, pH 7.5 +/0.2, alkalinity 70 +/- 5 mg/L, hardness 300 +/- 10 mg/L, andchloride 450 mg/L).
Test toxicant solutions were all maintained at 28 degree C
and, if necessary, were adjusted to pH 7.5 +/- 0.2 using theappropriate amounts of 1 M NaOH or HCl. Other water quality
parameters of the test toxicant solutions were maintained.
Survival of juveniles was determined at concentrations of 0
(control), 10, 25, 50, and 100 mg/L total nitrite-nitrogen(NO2-N). The dose response of crayfish was determined byplotting the probit of mortality transformed from percent
mortality against log concentration (Buikema et al. 1982).
Moving averages and interpolation were used to determine
LC50 (+/-SD) (Btlikema et al, 1982).
(2) valid with restrictions
(118)

Type:
Species:
Exposure period:
Unit:
EC50:

staticother: Penaeus setiferus
72 hour(s)mg/lAnalytical monitoring: yes= 172.8

Method:
Year:

other
1997

Method:Effect: mortality, increasing
Salt water
Life stage: post larvae
Expressed as sodium nitrite:

Remark:UNEP PUBLICATIONS

120

OECD SIDS
4. ECOTOXICITY

Test condition:
Test substance:
Reliability:
26-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
EC50 (72h) = 851.7 mg/L
-Water parameters:
Temperature; 28 degree
Salinity; 30 +/- 1 o/oo
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 99%(2) valid with restrictions
(7)

Type:
Species:
Exposure period:
Unit:
EC50:

semistatic
other: Penaeus monodon
240 hour(s)mg/lAnalytical monitoring: no= 106

Method:
Year:
GLP:

other
1990
no

Method:Effect: length increase
Salt water
240-h EC50 = 522.4 mg/L*

Remark:Result:* : The values were converted NO2-N into NaNO2.
All the prawns were killed by exposure to nitrite-N atconcentrations of 280 mg/L nitrite-N for 12 h, 260 mg/L for
24 h, 240 mg/L for 72 h, 220 mg/L for 132 h, 200 mg/L for
192 h, or 180 mg/L for 216 h, while those exposed to 160
mg/L for 12 h, to 140 mg/L for 24 h and to 120 mg/L
nitrite-N for 60 h survived.
The LT50 was 201 h and 14.4 h for prawns exposed to 120 and
200 mg/L nitrite-N, respectively.
24-h EC50 = 218
48-h EC50 = 193
96-h EC50 = 171
144-h EC50 = 140
192-h EC50 = 128
240-h EC50 = 106(mg/L)(salinity 20ppt, pH 7.57 and water temperature 24.5 degree
C)

Test condition:

The EC50 values decreased with increasing exposure times.
The P. monodon adolescents were shipped to the laboratoryfrom a private nursery located at Pingtung, Taiwan, andacclimated for 1 week before use.
The prawns had an average total length of 91.0 +/- 8.0 mm,
an average carapace length of 21.4 +/- 2.8 mm, and weighed
4.87 +/- 1.4 g. These sizes are categorized as adolescentsby Motoh (1985). Seawater pumped from the Keelung coast was
filtered through a sand and gravel filter and salinity was
adjusted to 20 ppt with municipal water, which had beendechlorinated with sodium thiosulfate and aerated 3 days
before use. The chemical characteristics of the water used
are shown below.
Nitrite test solutions were prepared by dissolving
requisite amounts of sodium nitrite (Merck GR grade) in 20

121

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
ppt of seawater. The nominal concentrations of nitrite-N
were prepared in 10 mg/L increments from 120 to 280 mg/L.
Chemical analysis of the water used in bioassays
Salinity; 20 ppt
Total alkalinity; 1.6 me/L
Total hardness;3180mg/L as CaCO3
pH; 7.57

Reliability:
26-MAY-2005

Prawns were sampled randomly from the stocking tanks andexposed to each test solution and control in triplicate
tarlks. Bioassay experiments to establish tolerance limits
were conducted in 15-L circular glass tanks containing 101
of the test solution (Franson, 1980; Hubert, 1980). Eachtank was placed in a water bath (24-25 degree C) andcontained ten test animals. All tanks were aerated by anair-stone with a blower. Each test solution was renewed
daily, in accordance with a static renewal method for
toxicity tests (Buikema et al., 1982 ). During theexperiment, the prawns were fed commercial prawn feed twice
a day at a rate of 10% of body weight per day. In all test
solutions, dissolved oxygen was 5.6-6.2 mg/L; pH varied from7.49 to 7.67 during the experiment.
Observations were usually made at 12-h intervals up to 264
h for the nitrite test. Death was assumed when prawns were
immobile and showed no response when touched with a glassrod. The dose response of test organisms combined from
triplicate tanks of each solution was determined byplotting probit transformed percent mortality against log
concentration (Finney, 1971; Buikema et al., 1982). The LC50
value of nitrate and their 95% confidence limits were
calculated from a microcomputer program (Hubert, 1980;
Trevors and Lusty, 1985).
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: GR grade
Supplier: Merck(2) valid with restrictions
(38)

Type:
Species:
Exposure period:
Unit:
LC50 (lower) :staticAsellus intermedius
96 hour(s)
mg/l
= 20

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: juvenile, 0.012 grams
LC50 > 20 mg/L
LC50 = 20 mg/L

Test substance:

Result:

Test condition:(Crustacea)
Analytical monitoring: no

The lower value was = 20 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5

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122OECD SIDS
4. ECOTOXICITY

Test substance:
Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

23-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50 (lower) :staticDaphnia magna
96 hour(s)
mg/l
= 8.3

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Life stage: 1st and 2nd instar larvae
LC50 = 9.7 mg/L
LC50 = 8.3 mg/L

Result:

Test condition:

Test substance:
Reliability:(Crustacea)
Analytical monitoring: no

The lowest value was = 8.3 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5
Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

23-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50 (lower) :staticother: Dugesia tigrina
96 hour(s)mg/lAnalytical monitoring: no= 20

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: juvenile, 0.006 grams
LC50 > 20 mg/L
LC50 = 20 mg/L

Result:

Test condition:

The lower value was = 20 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5
Food was withheld for the 24 preceding start of the test.

123

UNEP PUBLICATIONSOECD SIDS
4. ECOTOXICITY
Test substance:
Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

23-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50 :

staticGammarus fasciatus
96 hour(s)
mg/l
= 6.5

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: juvenile, 0.007 grams
LC50 = 6.5 mg/L
LC50 = 6.5 mg/L

Result:

Test condition:

Test substance:
Reliability:(Crustacea)
Analytical monitoring: no

The both values were 6.5 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5
Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

23-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50 (lower) :staticother: Ramshorn snail (Helisoma trivolvis)
96 hour(s)mg/lAnalytical monitoring:= 12

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: juvenile, 0.1806 grams
LC50 = 12.0 mg/L
LC50 = 20.0 mg/L

Result:

Test condition:

Test substance:

The lower value was 12.0 mg/L.
-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5
Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
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OECD SIDS
4. ECOTOXICITY
Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(4) not assignable
Non standard method involving simultaneous exposure of anumber of species

23-MAY-2005

(57)

Type:
Species:
Exposure period:
Unit:
LC50 :

semistatic
other: Penaeus monodon
96 hour(s)mg/lAnalytical monitoring: no= 13.55

Method:
Year:

other
1988

Method:Effect: mortality
Salt water
Life stage: nauplius, zoea, mysis, post-larvae
Expressed as sodium nitrite:

Result:LC50 (96h) = 66.8 mg/L
Case : Life stage; nauplius: Water parameters; pH =8.10-8.30
24h LC50 = 5.0 (4.0 - 6.24) mg/L NO2-N
Case : Life stage; zoea: Water parameters; pH = 8.05-8.30
24h LC50 = 13.2 (8.99 - 19.38) mg/L NO2-N
Case : Life stage; mysis: Water parameters; pH = 7.92-8.30
24h LC50 = 20.65 (12.02 - 35.45) mg/L NO2-N
48h LC50 = 8.3 (5.81 - 11.85) mg/L NO2-N

Test condition:
Test substance:
Reliability:

Case : Life stage; post-larvae: Water parameters; pH =7.85-8.30
24h LC50 = 61.87 (51.61 - 74.16) mg/L NO2-N
48h LC50 = 33.17 (26.79 - 41.06) mg/L NO2-N
72h LC50 = 20.53 (16.20 - 26.00) mg/L NO2-N
96h LC50 = 13.55 (11.21 - 16.38) mg/L NO2-N-Water parameters:
Dissolved O2 (mg/L); 5.1-5.4
pH; (see RESULT)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: GR grade(4) not assignable
Insufficient experimental detail24-MAY-2005

(40)

Type:
Species:
Exposure period:
Unit:
LC50 :

staticDaphnia magna
24 hour(s)mg/l= 43.6

Method:
Year:

other
1977

Method:Effect: mortality
Fresh water-Water parameters:

Test condition:
125(Crustacea)
Analytical monitoring: no

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Reliability:

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ID: 7632-00-00
DATE: 04-JAN-2006
Temperature; 20-22 degree C
Hardness (mg/L CaC03); 70
pH; 7.6-7.7(4) not assignable
Insufficient experimental detail

26-MAY-2005

(25)

Type:
Species:
Exposure period:
Unit:
LC50 :

staticother: Thamnocephalus platyurus
24 hour(s)mg/lAnalytical monitoring: no= 3.9

Method:
Year:

other
1995

Method:Effect: mortality, increasing
Fresh water
Mean 24 h LC50 (in mg/L) +/- SD = 3.90 +/- 0.24
Thammocephalus platyurus (n=3)-Cyst Hatching and Larval Molting
The T. plalyurus used in this study was originally collectedfrom temporary desert pools west of Los Angeles, California.
Laboratory populations were established that have been
inbred and selected for cyst production. Subsequently, allT, plalyurus resting eggs used in this study arelaboratory-produced cysts from controlled continuous
cultures.
The hatching rate of T. plalyurus cysts Was determined byhydrating 100 +/- 50 cysts in a moderately hard freshwater
medium [U.S. Environmental Protection Agency (EPA), 1985],
referred to as EPA water hereafter. Cyst incubation was
performed in polystyrene multiwell plates (6 wells, 10 mL
contents. water depth +/- 1 cm) at 25 degree C undercontinuous illumination (white fluorescenl lamp: 1000-2000
lux). Unless otherwise specified, this temperature and light
conditions will be referred to as the standard incubation
conditions for all further experiments. Each experiment was
set up in 3 replicates. Hatching results were determined bycounting and removing the nauplii at regular intervals
during a period of 5 days. To determine the effect of a
medium with lower water hardness (10 instead of 80-100 mg
CaCO3/L. ion composition, and a lower pH (6.5-7.0 instead of
7.6-7.9) on the hatching success, the EPA water was diluted
with deionized water in a ratio 1:8. This dilution factor
was rested based on previous satisfactory results with S.
proboscideus cyst hatching.
To study the molting time, 25 mg of T. plalyurus cysts were
hydrated in 100 mL EPA water in an Erlenmeyer flask withgentle bottom aeration, and incubated in standard
conditions. After 12 h, a single random harvest of early
hatchers was obtained by gentle suction using a Pasteur
pipette. Subsequently, each hatched larva (instar 1-naupliusor E2 phase hatcher) was placed in one well of a 96-wellpolystyrene multiwell plate in 300 micro-L EPA water,
Incubation was continued under standard conditions allowing
the un fed nauplii to molt further. To determine thepercentage of larvae in a particular instar stage,observations were made every hour fora local period of 10 h.
A total of 72 observations were made. Distinction of theResult:
Test condition:

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DATE: 04-JAN-2006
first larval stages under the dissection microscope (50 xmagnihcation) was done on the basis of the body size and thenumber of body segments as described by Bernice (1972).

Test substance:
Reliability:
23-MAY-2005-Toxicity Test Procedurestatic acute toxicity tests were conducted in conventional
24-well polystyrene multiwell plates (6 columns with 4 rows)
according to the standard operational procedure of the
Streptoxkit F test (Centeno et al., 1993a).
Each test comprised one control and five toxicant
concentrations, with three replicates per treatment. Eachreplicate consisted of one well receiving 10 nauplii.
The plates were incubated in darkness at 25 +/- 1 degree C
for 24 h, after which the number of dead larvae in each well
was counted under a dissection microscope at 1o-12 x
magnification. Larvae were considered dead when no movementof the appendages was noted within 10s of observation.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(3) invalid
(32)

Type:
Species:
Exposure period:
Unit:
LC50 :

staticother: Streptocephalus proboscideus
24 hour(s)mg/lAnalytical monitoring: no= 4.1

Method:
Year:

other
1995

Method:Effect: mortality, increasing
Fresh water
Streptocephalus proboscideus (n=9)
Mean 24 h LC50 (in mg/L) +/- SD = 4.10 +/- 1.30
See: Test Condition of the adjacent test with Thamnocephalus
platyurus
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(3) invalid(32)

Result:
Test condition:
Test substance:
Reliability:
23-MAY-2005

4.3 Toxicity to Aquatic Plants e.g. Algae
Species:
Scenedesmus subspicatus (Algae)
Endpoint:
other: growth rate and biomass
Exposure period: 72 hour(s)
Unit:
mg/l
Analytical monitoring: yes
NOEC:
100
EC50 (growth rate) :> 100
EC50 (biomass) : > 100
Limit Test:
yes
Method:Year:
GLP:
Test substance:

OECD Guide-line 201 "Algae, Growth Inhibition Test"
2005
yes
as prescribed by 1.1 - 1.4

Result:Analysis of the test concentrations at 0 and 72 hours showedmeasured test concentrations to be near nominal, hence the127

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ID: 7632-00-00
DATE: 04-JAN-2006
EC50 values were estimated beased on the nominal test
concentrations only.
Additional analysis of the test samples was conducted for thepresence of sodium nitrate at both 0 and 72 hours in order todetermine whether conversion of nitrite to nitrate occurred.
The results obtained showed measured test concentrations ofless than 1% of nominal for sodium nitrite at 0 hours and 5%
of nominal at 72 hours thereby indicating that no conversion
occurred.
Table 1: Measured test concentrations----------------------------------------------------------Sample
NominalMeasured
Percent ofConcentration
Concentration
Nominal(mg/L)(mg/L)(%)----------------------------------------------------------0 Hours
Control<LOQ
100 R1-R3
98.7
99
100 R4-R6
99.6
100----------------------------------------------------------72 Hours
Control<LOQ
100 R1-R3
93.3
93100 R4-R6
94.8
95----------------------------------------------------------LOQ = Limit of quantitation
R1-R6 = Replicates 1-6
Table 2: Cell densities and pH values in the definitive test----------------------------------------------------------Nominal
Cell Densiities* (cells/mL)
Concentration---------------------------------------------(mg/L)
0h
24h
48h
72h
----------------------------------------------------------Control
R1
9.80E+03
2.63E+04
5.33E+04
2.86E+05
R2
8.48E+03
2.92E+04
5.92E+04
3.18E+05
R3
8.76E+03
2.68E+04
5.88E+04
2.97E+05
Mean
9.01E+03
2.74E+04
5.71E+04
3.00E+05----------------------------------------------------------100
R1
8.28E+03
2.59E+04
6.34E+04
3.50E+05
R2
7.35E+03
2.95E+04
6.59E+04
3.05E+05
R3
7.07E+03
2.32E+04
6.23E+04
3.69E+05
R4
8.01E+03
2.39E+04
5.26E+04
3.88E+05
R5
7.63E+03
3.08E+04
7.37E+04
3.57E+05
R6
7.99E+03
2.96E+04
8.32E+04
4.70E+05
Mean
7.72E+03
2.72E+04
6.68E+04
3.71E+05----------------------------------------------------------* cell densities represent the mean number of cells/mL
calculated from the mean of the cell counts from 3 counts foreach of the replicate flasks.
R1-R6 = Replicates 1 - 6
Table 3: Inhibition of growth rate and biomass----------------------------------------------------------UNEP PUBLICATIONS

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NominalConcentration

Area under%Growth%Curve at
Inhibition Rate Inhibition72 h(0-72h)----------------------------------------------------------Control
5.09E+06
0.049 100
6.25E+06[23]
0.054 [10]----------------------------------------------------------[] Increase in growth as compared to the controls
Based on nominal concentrations:

Test condition:

EbC50 (72h) >100 mg/L
ErC50 (0-72h) >100 mg/L
- Test Organisms: Scenedesmus subspicatus strain CCAP 276/20
Supplier: Culture Collection of Algae and Protozoa,
Dunstaffnage Marine Laboratory, Oban, Argyll, Scotland
Method of Cultivation: Cultures were maintained in thelaboratory by the periodic replenishment of the culture medium
Pretreatment: The culture was maintained in the laboratory ata temperature of 21+/-1 deg C under conditions of continuous
illumination (7000 lux) and constant aeration- Test Conditions:
Medium:
NaNO3
MgCl2.6H2O
CaCl2.2H2O
MgSO4.7H2O
K2HPO4NaHCO3
H3BO3
MnCl2.4H2O
ZnCl2
FeCl3.6H2O
CoCl2.6H2O
Na2MoO4.2H2O
CuCl2.2H2O
Na2EDTA.2H2O
Na2SeO3.5H2O

25.5 mg/L
12.164 mg/L
4.41 mg/L
14.7 mg/L
1.044 mg/L
15 mg/L
0.1855 mg/L
0.415 mg/L
0.00327 mg/L
0.159 mg/L
0.00143 mg/L
0.00726 mg/L
0.000012 mg/L
0.30 mg/L
0.000010 mg/L

Exposure Vessel Type: 250 mL glass conical flasks fitted withfoam bungs containing 100 mL of solution
Nominal concentrations: 0 (control), 100 mg/L
Vehicle: Test medium
Stock solution: 100 mg of test material was dissolved inculture medium and the volume adjusted to 500 mL to give a 200
mg/L stock solution. This stock solution was mixed with algal
suspension (500 mL) to give the required test concentrationof 100 mg/L.
Number of replicates: 6 for treatment group, 3 for controls.
Initial cell density: 10,000 cells/mL
Temperature: 24+/-1 deg C
pH: 7.3 (0 hours) - 7.8 (72 hours)
Light condition: Continuous illumination (7000 lux)
Shaking: Constant saking at 150 rpm-Methods of analysis: Samples were taken from the control(replicates R1-R3 pooled) and the 100 mg/L test group(replicates R1-R3 and R4-R6 pooled) at 0 and 72 hours for
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ID: 7632-00-00
DATE: 04-JAN-2006
quantitiative analysis. Duplicate samples were taken at 0 and
72 hours and stored at approximately -20 deg C for further
analysis if necessary.

Flag:
04-JAN-2006-Statistical analysis: A Student's t-test incorporating
Bartlett's test for homogeneity of variance was carried out on
the area under the growth curve data at 72 hours for thecontrol and the 100 mg/L test concentration to determine
statistically significant differences between the test andcontrol groups. All statistical analyses were performed using
the SAS computer software package.
(1) valid without restriction
Study conducted to OECD TG
Critical study for SIDS endpoint(94)

Species:
Endpoint:

other algae
other: CO2 Fixation

Reliability:

Year:
Method:1978
METHOD FOLLOWED: Wodzinski et al method
Algae were grown at 25°C on a rotary shaker (170 rpm) withconstant illumination in 500 mL Erlenmeyer flasks containing
100 mL of Bristol solution at pH 6.0. When the optical density
at 580 nm had reached about 0.2, the cells were collected bycentrifugation and resuspended in Bristol solution to an
optical density of 0.01 to 0.05, depending on the activity of
the culture. Sodium nitrite solution was prepared in Bristol
solution of the desired pH immediately before use.
The reaction mixture consisted of 1.0 mL each of resuspended
cells, Bristol solution and the sodium nitrite solution in
test tubes (13 x 120 mm). Test tubes containing the same
ingredients were wrapped in aluminium foil to measure activity
in the dark. All tubes were incubated at 25°C for 40 min
under 450 µEinsteins of light/m2/s, after which 0.25 mL ofBristol solution containing 0.05 µCi of H[14]CO3- with a
specific activity of 59 mCi/mmol was added to each tube. thetubes were then sealed with serum stoppers and incubated foran additional 30 minutes.
The uptake of [14]CO2 was terminated by injection of 0.4 mL of
37% formaldehyde into each tube. 1 mL portions from each tube
were then filtered through 0.45 µm filters and the cells thus
retained were washed with 10 mL of 1.0 MM H2SO4 to remove
residual [14]CO2. after drying, the filters were placed in
scintillation vials containing 10 mL of Bray liquid
scintillation cocktail and the radioactivity was counted. The
activity of sodium nitrite-free cells was determined
simultaneously and the results expressed as a percent activity
compared with these controls.

Result:The same procedure was used to determine the effects ofnitrite on [14]CO2 uptake by algae grown and tested at ahigher pH. In these instances the concentration of phosphatein the Bristol solution was increased to 0.01 M and the pH wasadjusted to 7.7
Table: Sensitivity of algal photosynthesis to nitrite at pH 6
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ID: 7632-00-00
DATE: 04-JAN-2006----------------------------------------------------------Microbial groupGenus% inhibition
by 1.0 mM NO2----------------------------------------------------------Blue-green algae
Anacystis nidulans
Lyngbya sp.
Anabaena flos-aquae
Oscillatoria sp.
Schizothrix sp.
Synechococcus cedrorum
Calothrix anomala
Fischerella muscicola
Cylindrospermum sp.

60
97
95
97
91
77
100
99
98

Scenedesmus quadricauda
Ulothrix fimbriata
Chlamydomonas reinhardtii
Ankistrodesmus falcatus
Schizomeris leibleinii
Oedogonium foeolarum
Staurastrum sp.
Draparnaldia pulmosa
Gloeocystis vesiculosa

0
5
1
0
12
0
0
19
0

Green algae----------------------------------------------------------The nine genera of blue-green algae tested were strongly
inhibited by 1.0 mM nitrite, the rate of CO2 fixation being
reduced by 60 - 100%. On the other hand, the activity of nine
genera of green algae was little or not at all affected at
this nitrite concentration.

Test condition:

The IC50 ([14]CO2 uptake) by Anabaena flos-aquae wascalculated to be 100 uM nitrite (6.9 mg/L as NaNO2)TEST ORGANISMS:
Blue-green algae
Anacystis nidulans
Lyngbya sp.
Anabaena flos-aquae
Oscillatoria sp.
Schizothrix sp.
Synechococcus cedrorum
Calothrix anomala
Fischerella muscicola
Cylindrospermum sp.
Green algae
Scenedesmus quadricauda
Ulothrix fimbriata
Chlamydomonas reinhardtii
Ankistrodesmus falcatus
Schizomeris leibleinii
Oedogonium foeolarum
Staurastrum sp.

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Test substance:
Reliability:
17-OCT-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Draparnaldia pulmosa
Gloeocystis vesiculosa
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(200)

Species:
Endpoint:
Exposure period:
Unit:
EC10:

other aquatic plant: chlorococcales
other: Assimilation-Depletion test (A-D test)
24 hour(s)mg/lAnalytical monitoring:> 670

Method:
Year:

other
1991

Remark:The Assimilation-Depletion test (A-D test) is in principle
the modelling of the two basic reactions of the biologicalself-purification of waters in form of two parall in-vitro
tests for the determination of the ecophysiological effectsof wastewaters and their constituents.
The two basic reactions of biological self-purification innatural waters are:a) the bacterial decomposition of organic pollutants andtheir oxidative recycling as simple inorganic compounds(like CO2 and NO2)b) the incorporation of the resulting mineralization
products by algae and other plants by producing organic
substances through photosynthesis ("assimilation").
The bacterial decomposition processes are oxygen-consuming(depletion) white the bioproduction of plants throughphotosynthesis releases molecular oxygen which - in turn is again available for bacterial decomposition of organics.
Thus. the two processes are directly interconnected andestablish - provided the material budget is balanced - abiological equilibrium in the surface water.
Aquatic bacteria and algae consequently constitute in thissense a genuine part of an ecosystem which is suitable toserve in form of the A-D test as a model of the metabolic
dynamics in the water body and as an indicator ofanthropogenic impacts through sewage, industrial andmunicipal wastewaters or through specific micro pollutants.
The measured parameters of the A-D test are the 02 depletionof mixed bacterial populations (Depletion test) and thephotosynthetic oxygen production of planktonic algae(Assimilation test). They are measured in dilution series
depending on the concentration of the wastewater or
pollutant. Any inhibition or promotion of microbial growth
are reflected in the result because of the test duration of
24 hours.
The significance of the A-D test for water management
purposes lies in the possibility of being able to quantify
harmful effects on the oxygen budget of water bodies.
Therefore this method has a central position inwater-toxicological studies of the Federal Institute ofHydrology.
The test shows the "effective concentrations" (EC-values)
which produce inhibition effects of 10% (24 h EC 10 value)
at a temperature of 20 degree C after a test period of 24
h. The concentrations were computed from the weighed samples(nominal concentration). In the case of inorganic substances
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Test substance:
Reliability:
26-MAY-2005

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ID: 7632-00-00
DATE: 04-JAN-2006
the concentrations are related to the effective ion, in caseof organics to the indicated molecular compound.
The pH of the original solution has not been standardized;
exceptions have been marked accordingly. Substances that are
difficult to dissolve in water have been emulsified by meansof a high-speed disperser.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(109)

Species:other algae: See Test Condition
Endpoint:
growth rate
Exposure period: 14 day(s)
Unit:
mg/l
Analytical monitoring: noEC100 (median for 13 species) := 4600EC100 (range for 13 species) := 580 - 9200
Method:Year:
GLP:
Test substance:

other
1984
no
other TS

Method:-Growth experiments.
Growth experiments were performed in 250-uL cultures on
microtitration plates (Flow Laboratories) using a proceduresimilar to those of Heldal et al. (1978) and Blanck et al.
(1983). A plate contains 8 X 12 wells (250 uL). Chemicals in
distilled water (100 uL) were spread into the wells by
successive twofold dilutions using a 12-channel pipet. The
resulting geometric concentration series (factor 0.5)
covered 4.2 orders of magnitude (14 concentrations on twoplates). Algal suspension (150 uL) was inoculated into eachwell giving an initial chlorophyll a concentration of 10
ng/mL. Each culture contained nutrients corresponding to Z8
at 10% strength.
Four replicates were used for each concentration. Thus, twoplates were used to test one compound on three algal
species. All handling of the microtitration plates was done
under aseptic conditions. Test cultures were incubated under
the same growth conditions as the precultures. Growth
inhibition was estimated by visual inspection (cf. Blanck etal., 1983) after 14 days by recording the lowest
concentration of the tested compounds giving no detectable
growth (EC100).
It was suspected that adsorption of chemicals to the wells
or to the pipet tips during the dilution sequence could
distort the concentration series. No such effect was evident
for any of the chemical as checked by comparing EC values
obtained by successive dilutions on the plates and frompremade solutions. Furthermore, repeated testing with one of
the algae, Monoraphidium pusillum, showed that replicate
EC100's only exceptionally deviated more than a factor of 2(i.e., one row on the plates which corresponds to oneclass). Thus experimental errors contribute no more than one
class to the recorded variation in sensitivity.
-Chlorophyll a, carbon, and nitrogen determinations.
Algal chlorophylls were extracted with dimethyl sulfoxide at

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65 degree C for 30 min (Hiscox and Israelstam, 1979) andmeasured in 1:1 dimethyl sulfoxide and 90% acetone (Shoafand Lium, 1976). The chlorophyll a concentrations were
calculated using the equations of Jeqrey and Humphrey(1975).
Samples for carbon and nitrogen analyses were prepared byfiltering aliquots of the algal suspensions onto a Whatman
glass micro fiber filter (Type GF/F, 14 mm in diameter)
precombusted at 450 degree C. Filters were washed in
distilled water and any residual (bi)carbonate was driven
off by exposing the filters to HCl vapor after which they
were dried in a vacuum desiccator. Dried filters were packed
into tin capsules for analysis of carbon and nitrogen,performed on a Carlo-Erba Model 1106 elemental analyzer
using benzimidazole as standard. Results were used to
calculate chlorophyll a/carbon and chlorophyll a/nitrogenratios for all inocula used in the growth experiments. Fromthese data the amounts of carbon and nitrogen initiallypresent in the test cultures were calculated.

Result:

Test condition:-Calculations.
Rank correlations between EC100 and initial carbon content
of algal cultures were estimated using a nonparametric test
calculating Spearman's rank correlation coeffcient. A
correction for ties was made. A least-squares linear
regression line was fitted to the data.
-Median and range of EC100 values obtained for Sodium
nitrite tested on 13 algal species
EC100 (mg/L) = 4600 (median), 580 - 9200 (Range)
Log(EC100 max/ EC100 min) = 1.2-Variation algal sensitivity as corrected for differences incarbon content initially present in test culture
EC100 max/ EC100 min (Chlorophyll a basis) = 16
EC100 max/ EC100 min (Carbon basis) = 29
- Cultivation of algae.
Axenic strains of 13 algal species were kept on agar slants(CCAP, 1976). None of the strains were, to our knowledge,
isolated from an environment known to be severely polluted.
Precultures were grown in an inorganic medium, Z8 (Kotai,1972), modified by the addition of Si (0.16 mM) and vitamins(thiamine, 200 ug/liter; biotin, 1 ug/L; B12 , 1 ug/L).
Cultures were continuously illuminated by Cool White
fluorescent tubes (General Electric F96 PG 17CWX Power
Groove de Luxe) at an irradiance of 10 +/- 1 W/m2 at 400-700
nm. The temperature was 20 +/- 1 degree C. Log phase cells
were used as inoculum for the growth experiments.
Prior to inoculation of the test cultures the precultures
were tested for bacterial contamination by streaking onto
agar plates (CCAP, 1976).
-Test compounds.
Stock solutions of the chemicals in sterile distilled water
were freshly prepared under aseptic conditions prior to eachexperiment. pH was adjusted to 6.5-7.5 using HCl or NaOH.
Whenever a cosolvent (ethanol) was used, the analconcentration never exceeded 0.2%.
SOURCE AND TAXONOMIC IDENTITY OF THE ALGAL STRAINS-Chlorophyta
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DATE: 04-JAN-2006--Volvocales
Chlamydomonas dysosmos Moewus; CCAP 11/36a--Chlorococcales
Chlorella emersonii Emerson; CCAP 211/8h
Kirchneriella contorta (Schmidle) Bohlin; Isolated from
Lake Skarvlangen, 1981, by the authors.
Monoraphidium pusillum (Printz) Komarkava -Legn; Isolated
from Lake Lilla Stockelidsvatten, 1978, by Hans Blanck
Scenedesmus obtusiusculus Chod.; Dr. C-M. Larsson,
University of Stockholm, originally obtained from Agricult.
Univ. Wageningen
Selenastrum capricornutum Printz; CCAP 278/4-Ulotrichales
Klebsormidium marinum Deason; UTEX 1706--Chaetophorales
Raphidonema longiseta Vischer; UTEX 339-Xanthophyta--Heterococcales
Bumilleriopsis jillformis Vischer; CCAP 809/2
Monodus subterraneus Petersen; CCAP 848/1--Heterotrichales
Tribonema aequale Paxher; CCAP 880/1-Cyanophyta--Oscillatoriales"LPP sp."; PCC 6402--Chrobcoccales
Synechococcus leopoliensis (Racib.) Komarek; UTEX 625

Test substance:
Reliability:
26-MAY-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Pro analysis 98.5%
Manufacturer: Merck(4) not assignable(18)

Species:
Exposure period:
Unit:
NOEC:

Scenedesmus quadricauda (Algae)
8 day(s)mg/lAnalytical monitoring:= 1230

Method:
Year:

other
1978

Reliability:
26-MAY-2005(4)

Species:
Exposure period:
Unit:
TGK :

Scenedesmus quadricauda (Algae)
8 day(s)mg/lAnalytical monitoring:= 1233

Method:
Year:

other
1977

Reliability:
26-MAY-2005(4)

Species:
Unit:
TGK :

Scenedesmus quadricauda (Algae)
mg/l
Analytical monitoring:> 1000135

not assignable(26)

not assignable(24)

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ID: 7632-00-00
DATE: 04-JAN-2006

Method:
Year:

other
1960

Reliability:
26-MAY-2005(4)

not assignable(23)

4.4 Toxicity to Microorganisms e.g. Bacteria
Type:Species:
Unit:
See result :otherother protozoa

Method:
Year:
GLP:

other
1998
no

Method:Test Procedure
Preliminary Bioassay: The aim of the preliminary test was tofind a level of toxicity of the sample tested. The test was
carried out in conventional 24-well (6 X 4) polystyrene
multiwell plate. Each test had one control and 11 toxicant's
concentrations with two duplicates.
Two mL of tested sample was placed in A1 and C1. All otherwelts were filled with 1 mL Tyrod solution (diluent). Serial
dilution (2X) of the tested sample was prepared bytransferring of 1 mL of the sample from A1 to A2, after
mixing from A2 to A3 up to B5. The same dilution was
prepared in rows C and D. B6 and D6 contained only diluent
as a control. One drop of Spirostomum ambiguum suspension(containing 1O-20 cells) was added to each well. After 24 hincubation in darkness at 25 degree C, toxicity wasestimated with the aid of binocular. Concentrations to thedefinitive test were then chosen: between 0 and 100%lethality of S. ambiguum.

Analytical monitoring: no

Definitive Test: The test was carried out in a conventional
24-well (6 X 4) polystyrene multiwell plate. Each test was
one control and five toxicant's concentrations with three
duplicates per concentration.
Dilution of the sample (logarithmic progression) was madedirectly in the plate. For this purpose, the following
amount of diluent and sample was added to all four cells ineach column: 0, 0.44, 0.68, 0.82, 0.90, 1.00 mL of diluent
and 1.00, 0.56, 0.32, 0.18, 0.10, 0 mL of sample. To
minimize dilution of the test solutions, the protozoa werefirst transferred (35 per well) with the aid of a
micropipette into the bottom row (D). which served as
rinsing wells. Then, under a binocular microscope (8Xmagnification), protozoa were subsequently transferred into
the three wells of the same column (10 cells per well). The
plates were incubated in darkness at 25 degree C. Two kindsof test responses were observed: (1) different deformations(E), which means morphological changes such as shortening,bending of the cell, and so forth; and (2) lethal response(L), spherical deformation and autolysis. On this basis twovalues were calculated for each row of the microplate: EC50:
the concentration producing different deformations of 50% of
the test organisms, and LC50: the concentration producing
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Result:

Test condition:

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lethal response of 50% of the test organisms. The EC50 and
LC50 values were determined by graphical interpolation oftest response versus toxicant concentration (log scale).
Mean values (EC50 and LC50) +/- SD were then calculated foreach microplate.
Toxicity in Spirotox test, unit; ppm (mg of anion/L)
24-h EC50 = 285 +/- 135
24-h LC50 = 430 +/- 92
48-h EC50 = 281 +/- 137
48-h LC50 = 355 +/- 127
Results (mean of three tests +/- SD) are expressed in ppm(mg of anion/L). EC50 is the concentration producing
different deformations of 50% of the test organisms after 24
h (48 h) of incubation. LC50 is the concentration producing
lethal response of 50% of the test organisms after 24 h (48h) of incubation
Protozoan Spirostomum ambiguum
Spirostomum ambiguum is one of the biggest protozoans, 2-3mm long (Raabe 1970). The strain used in the work was
originally collected in Kampinos National Park near Warsaw
and has been cultured in laboratory for more than 20 years.
Culturing the Spirostomum ambiguum
S. ambiguum was routinely cultured in 5-1 aquariums
containing 4 L of natural, unpolluted water originating froma very deep source (pH = 7.5; total hardness 150 mg
CaCO3/L). Cultures were maintained at 20-25 degree C in
darkness. Protozoa were fed once a week with a diet offlaked oats and dried alder leaves (50:1). Every 4 weeks,
two-thirds of the water in the aquarium was replaced withfresh water.

Reliability:
Flag:
27-MAY-2005

Preparation of the Protozoa for the Test
In order to prepare the protozoa for the test, it wasnecessary to rinse them from the culturing medium. Several
hundred cells were taken from the culture and placed in a
50-mL cylinder. After the cells had fallen to the bottom,
water was poured out and organisms were rinsed three times
with diluent Diluted Tyrod solution, 1:64 was used; it wasmade upof 125 mg NaCl, 3.1 mg KCl, 3.1 mgCaCl2, 1.55 mg
MgCl2, 15.6 mg NaHCO3, and 0.78 mg NaH2PO4 per Liter ofdeionized water (Milli-Q quality)L Total hardness was 2.8 mg
CaCO3/L and pH 7.4 +/- O.2.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade(2) valid with restrictions
Critical study for SIDS endpoint
(128)

Type:
Exposure period:
Unit:
NOEC:
EC50:

other
96 hour(s)mg/l= 757.9= 1600

Method:
Year:
GLP:

other
1993
no

Test substance:

137

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Remark:Result:

Test condition:

Test substance:
Reliability:
Flag:
27-MAY-2005

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96-h NOEC = 3735 mg/L** : The values were converted NO2-N into NaNO2.
organism : Tetraselmis chuii
endpoint : mortality reduction
EC50 (concentration that cause lost of mobility on 50% of
the population)
24-h EC50 = 2,200 mg/L NO2-N
48-h EC50 = 1,510 mg/L NO2-N
72-h EC50 = 1,590 mg/L NO2-N
96-h CC50 = 1,600 mg/L NO2-N
24-h NOEC = 67.4 mg/L NO2-N
48-h NOEC = 222.8 mg/L NO2-N
72-h NOEC = 413.8 mg/L NO2-N
96-h NOEC = 757.9 mg/L NO2-N-Effects of nitrite on growth of the marine micoralgae(Tetraselmis chuii)
Toxicity of nitrite on the microalgae T. chuii was studiedin static bioassay.
Chemical name: sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint(140)

4.5 Chronic Toxicity to Aquatic Organisms
4.5.1 Chronic Toxicity to Fish
4.5.2 Chronic Toxicity to Aquatic Invertebrates
Species:
Endpoint:
Exposure period:
Unit:
NOEC:
EC50:
LC50 :

other: Penaeus monodon (salt water shrimp)
other: Mortality and Growth
80 day(s)mg/lAnalytical monitoring: yes= 2= 23.31> 20

Method:
Year:
GLP:

other
1992
no

Method:METHOD FOLLOWED: APHA (1985), Buikema et al (1982)
DEVIATIONS FROM GUIDELINE:STATISTICAL METHODS: LC50 calculated with the Trimmed Spearman
Karber method
METHOD OF CALCULATION: no data
ANALYTICAL METHODS: Nitrite determined using the method ofStrickland and Parsons (1972)

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References:
APHA (1985) Standard Methods for the Examination of Water andWastewater. 16th edn. American Public Health Association,
American Water Works Association and Water Pollution Control
Federation, Washington DC
Buikema AL jr., Niedertehner RR and CairnsJ Jr. (1982)
Biological Monitoring - IV. Toxicity Testing. Water Res. 16,
239-262

Remark:Strickland JDH and Parsons TR (1972) A Practical Handbook of
Seawater Analysis. Fisheries Research Board of Canada, Ottowa,
Canada.
-Mortality
80-d LC50 > 95.6 mg/L*-EC50 for weight gain
80-d EC50 = 114.9 mg/L*
80-d NOEC = 9.86 mg/L** : The values were converted NO2-N into NaNO2.

Result:-----------------------------------------------------------Nominal
nitrite-N (mg/L)
Survival-----------------------------------------------------------Control
0.118 +/- 0.004
30
2
1.955 +/- 0.020
30
43.920 +/- 0.1402987.735 +/- 0.200
2620
19.789 +/- 0.300
21------------------------------------------------------------Mortality
80-d LC50 > 20 mg/L (Nitrite-N)-EC50 for length increase (Nitrite-N)
20-d EC50 = 16.14 mg/L
30-d EC50 = 18.20 mg/L
40-d EC50 = 19.96 mg/L
50-d EC50 = 22.50 mg/L
60-d EC50 = 26.20 mg/L
-EC50 for weight gain (Nitrite-N)
10-d EC50 = 16.99 mg/L
20-d EC50 = 17.41 mg/L
30-d EC50 = 18.03 mg/L
40-d EC50 = 20.12 mg/L
50-d EC50 = 21.85 mg/L
60-d EC50 = 22.45 mg/L
70-d EC50 = 24.85 mg/L
80-d EC50 = 23.31 mg/L
-NOEC[MATC (maximum acceptable toxicant concentration) ]= 2
mg/L (Nitrite-N)
Survival of the shrimps exposed to different test solutions
at various periods is shown below. All shrimps exposed tolower than 8 mg/L nitrite-N after 30 days, and those exposed
to 2 mg/I nitrite-N and the control survived after 80 days.
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At growth in weight and length of the P. monodon juveniles
reared in each test solution, a one-way analysis of varianceindicated that weights of shrimps exposed to 4, 8 and 20 mg/L
were significantly lower (P < 0.05) than those exposed to
2mg/L nitrite-N and controls after 20 days.
Analysis also indicated that weights of shrimps exposed to 2
mg/L were significantly lower (P < 0.05) than those exposed ascontrols after 60 days. The MATC (maximum acceptable toxicant
concentration) was 4, 2, and less than 2 mg/L after 10, 30,
and 60 days of exposure.
At the relationship between weight and length, statisticalanalysis indicated that no significant difference (P > 0.05)
in growth factor was observed among the shrimps exposed ascontrols, or to 2, 4 and a mg/L. A significant difference (P<0.05) or growth factor was found between those exposed to 20
mg/I nitrite-N and control. The MATC for P. monodon juveniles
was 8 mg/L nitrite-N calculated from the growth factor.
The linear regression of mean individual weight gain vsconcentration or nitrite-N was significant (p<0.05) after
various periods. The mean individual final weight (5.71 g)of the control animals was 4.11 times their initial weight(1,39 g). However, the mean individual final weight (4.00 g)of the shrimps exposed to 20 mg/L nitrite-N was 2.72 times
their initial weight (1.47 g). The EC50 (concentration that
reduced growth by 50% of that of the controls) for weight gain
was 17.41, 20.12 and 22.45 mg/L nitrite-N after 20, 40 and 60
days of exposure.
Linear regression of mean individual length increase vsconcentration of nitrite-N was significant (P < 0.05) after
various periods except at 10, 70 and 80 days. The mean
individual final length (9.44 cm) of the control animals
was 1.57 times their initial length (6.00 cm), However, themean individual final length (8.42cm) of the shrimps exposed
to 20 mg/L nitrite-N was 1.37 times their initial length (6.16cm). The EC50 for length increase was 16.14, 19.96 and26.20mg/L nitrite-N after 20, 40 and 60 days of exposure.
The ratio or carapace length to total length of the P.
monodon juveniles exposed to different test solutions isgiven. Statistical analysis indicated that this ratio forshrimps exposed to 2 mg/L was significantly lower (P < 0.05)
than for those of the controls.
Nitrite increased molting frequency of P. monodon juveniles
during the 80 days of bioassay. In the control solution, 7molted 6 times, 11 molted 7 times and 4 shrimps molted 8
times. In the 20 mg/1 nitrite-N, 4 molted 6 times. 5 molted
7 times and 11 shrimps molted 8 times. A one-way analysis ofvariance indicated that there was no significant difference (P> 0.05) in molting frequency between the shrimps exposed to 2
mg/L nitrite-N and the controls.
Mean intermolt period of the shrimps exposed to 8 mg/L
nitrite-N was significantly less (P < 0.05) than those
exposed as controls for 2nd-3rd molting. The MATC was 2 mg/L
nitrite-N from the molting frequency and intermolt period.

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Test condition:

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MATC means NOEC.
TEST ORGANISMS:
Size: The shrimps used were 6.03+/-0.07 cm average body lengthand 1.40+/-0.05 g wet weight
Age: Juveniles
Pretreatment: Aclimated for one week
Supplier: Private nursery located in Iilan, Taiwan
DILUTION WATER:
Source: Seawater pumped from the Keelung coast adjacent to
the University was diluted with municipal water to 25 ppt andfiltered through sand and gravel filters by air-lift pumping.
Chemistry: no data
Temperature: no data
STOCK AND TEST SOLUTION AND THEIR PREPARATION:
Vehicle/solvent and concentration: None used
Preparation: Nitrate test solutions were prepared using 43.3 gof sodium nitrite in 1 litre of distilled water to make
10,000 mg/L nitrite-N (nitrite as nitrogen) and then diluted
with salt-water
STABILITY OF THE TEST CHEMICAL SOLUTIONS: No data
REFERENCE SUBSTANCE: None
TEST SYSTEM:
Concentrations: 2, 4, 8 and 20 mg/L
Renewal of test solution: Daily (semi-static test)
Exposure vessel type: 60 x 30 x 36 cm tank containing 30 L ofsolution. Each tank contained 10 cylindrical plastic cages(10 cm diameter, 30 cm high, 2x3 mm net size).
Number of replicates, fish per replicate: Triplicate, 10
fish/tank/concentration
Water parameters: water temperature, pH and dissolved oxygen
was 29 +/- 1.4 degree C, 8.14 +/- 0.13 and 5.91 +/- 0.23mg/L,
respectively.
Intensity of irradiation:
Photoperiod:
Feeding: Shrimps were offered commercial shrimp ration(Trairoun Product Co., Taipei) three times a day (9:00, 15:00
and 21:00) at a rate of 9% of body weight per day.
Aeration:
TEST PARAMETER: Mortality

Test substance:
Conclusion:

MONITORING OF TEST SUBSTANCE CONCENTRATION:
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Supplier: Merck
1. Survival or Penaeus monodon juveniles (1.40 +/- 0.05 g;
6.30 +/- 0.07 cm) reared in control, 2, 4, 8 and 20 mg/L
nitrite-N by a static renewal method after 80 days was 100,
100, 96.7, 86.7 and 70%, respectively.
2. Growth of the shrimps reared at 4, 8 and 20 mg/L
nitrite-N was significantly lower (P < 0.05) than control
animals and those reared at 2 mg/L nitrite-N after 20 days.

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3. EC50 (concentration that reduced growth by 50% or thatof the controls) rot weight gain was 17.41 and 22.45 mg/L
nitrite-N. and EC50 for length increase was 16.14 and26.20mg/L nitrite-N after 20, and 60 days, respectively.
4. Nitrite decreased the ratio of carapace length to total
length, and enhanced molting frequency of the shrimps.
Average molting frequency of shrimps reared as control andat 2, 4, 8 and 20 mg/L nitrite-N was 6.27, 6.30, 6.34, 6.92
and 7.14 times, respectively.
5. The NOEC [MATC (maximum acceptable toxicant
concentration)] was estimated to be 2 mg/L nitrite-N fromthe growth and molting.

Reliability:
Flag:
26-MAY-2005

NOEC := 2 (Growth Inhibition)
EC50 := 23.31 (Growth inhibition)
LC50 :> 20 (mortality)(2) valid with restrictions
Critical study for SIDS endpoint(36)

TERRESTRIAL ORGANISMS
4.6.1 Toxicity to Sediment Dwelling Organisms
Species:
Endpoint:
Expos. period:
Unit:
LC50 (lower) :Lumbriculus
Mortality
96 other:hour(s)other: mg/L
= 20

Method:
Year:

other
1986

Method:Effect: mortality
Fresh water
Age/Weight: juvenile, 0.006 grams
LC50 > 20 mg/L
LC50 = 20 mg/L

Result:

Test condition:

The lower value was = 20 mg/L.
Latin name: Lumbriculus variegatus-Water parameters:
Temperature; 20 degree C
Dissolved O2; >40%
pH; 6.5-8.5

Test substance:
Reliability:
27-MAY-2005
Species:
Endpoint:
Expos. period:

Food was withheld for the 24 preceding start of the test.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable(57)
other: Corbicula manilensis
Mortality
96 other: hours
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Unit:
LC50:

other: mg/L
= 51

Method:
Year:

other
1979

Method:StaticEffect: mortality, increasing
Fresh water
Weight: 1.0-2.7 grams-Water parameters:
Temperature; 16 degree C
Hardness (mg/L CaC03); 16-26
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Technical grade(4) not assignable

Test condition:
Test substance:
Reliability:
27-MAY-2005(34)

4.6.2 Toxicity to Terrestrial Plants
4.6.3 Toxicity to Soil Dwelling Organisms
Species:
Endpoint:
Exposure period:
Unit:
LC50:

other: Eisenia fetida (earthworm)
mortality
48 hour(s)other: micro-g/cm2= 100 - 1000

Method:Year:

OECD Guide-line 207
1984

Method:Result:Filter paper method
48-h LC50 range 100 - 1,000 micro-gram/cm2 (moderately
toxic)-Test animals
E. foetida were purchased as needed from Bert's Bait Farm,
Irvine, KY. The earthworms were housed in Nalgene boxes
filled with moist peat moss and rabbit manure, and stored at
18 degree C. Cornmeal was added as an additional food source
and calcium carbonate was added as necessary to maintain asoil pH, above 5.5. Mature worms showing a developed
clitellum and weighing 370 to 450 mg each were used for the
toxicity experiments.

Test condition:"Earthworm, Acute Toxcity Test"-Contact toxicity test
The testing protocol used for evaluating chemical toxicity
against earthworms involves exposing individual E. foetida
to concentrations of chemicals in paper-lined glass vials
for 48 h in the dark.
Glass shell vials (22 mm x 85 mm) (Research ProductsInternational, Mt. Prospect, IL) were lined with Whatman No,
1 filter paper strips (9.5 cm x 6.8 cm; surface area, 65cm2) and placed in cardboard scintillation vial trays.
Chemical concentrations used in the contact toxicity tests
were expressed in ug/cm2. After the vials had been under
the stream of warm air for 3 min, they were air-dried for an
additional 2 h to remove all remaining solvent. Then, 1 mL
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Test substance:
Reliability:
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of water was added to each vial to moisten the paper and one
earthworm was placed into each vial.
After the earthworms were placed in the vials, thecontainers were capped and kept stored in the dark in thehorizontal position for 48 h. Death was recorded if the worm
did not respond to gentle probing of its anterior end. Worms
that were severely morbid, even having lost their posterior
half but still responding to the probe, were considered
alive. The approximate range of acute toxicity wasdetermined with five exposure concentrations, using 10 worms
per exposure and chemical concentrations that increased
logarithmically from 0.1 to 1,000 fig/cm2.
The approximate lethal concentration was considered to be
the lowest exposure that killed 50% or more of theearthworms. LC50 values were then determined for certain
chemicals by exposing earthworms to a geometric series offive to seven exposure concentrations, including theapproximate lethal dose. This series was replicated so thata minimum of 100 earthworms were used for determining each
LC50 Value. The dose-lethality data provided a slope andLC50 values with 95% confidence intervals when calculated by
the Litchfield-Wilcoxon log dose-effect probit
transformation method.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Technical or analytical grade(4) not assignable(146)

4.6.4 Toxicity to other Non-Mamm. Terrestrial Species
Species:
Endpoint:
Expos. period:
Unit:
LC50:

other: Ambystoma texanum
other: equilibrium, behavior
96 hour(s)other: mg/L
= .33

Method:
Year:

other
1980

Method:StaticFresh water
Life stage/weight: larvae, 0.45 grams

Result:
Test condition:

Test substance:
Reliability:
27-MAY-2005
Species:
Endpoint:
Expos. period:
Unit:
LC50:

Loss of equilibrium, i.e. ecological death, was thecriterion for lethality.
LC50 = 0.33 (0.15 - 0.76) mg/L
-Water parameters:
Temperature; 25 degree C
Hardness (mg/L CaC03); 140
pH; 7.0
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable(80)
other: Ramshorn snail (Helisoma trivolvis)
mortality
24 hour(s)other: mg/L
= 552
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Method:Year:
Test substance:

other
1986
other TS

Method:StaticEffect: mortality
Fresh water
Age/Weight: 0.07-0.11 grams, 3 wk tadpole-Water parameters:
pH; 6.9-7.4
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analar grade(2) valid with restrictions

Test condition:
Test substance:
Reliability:
27-MAY-2005(198)

4.7 Biological Effects Monitoring
4.8 Biotransformation and Kinetics
4.9 Additional Remarks

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5.0 Toxicokinetics, Metabolism and Distribution
In Vitro/in vivo:
Type:
Species:Route of administration:
Year:
GLP:
Method:In vivo
Absorption
rat
gavage1980
no
Aqueous solutions of sodium nitrite were administered orally
by gavage to rats which were fasted overnight.
Blood samples were obtained either by decapitation of from
caudal veins.
Methaemoglobin and total haemoglobin were determined by the
Evelyn and Malloy's (Evelyn et al, 1938) andcyanomethaemoglobin (Van Assendelft, 1970) methods,
respectively.
The nitrosyl haemoglobin content was estimated from the peakheights of electron spin resonance spectra obtained at 77K
with a Varian E-12 X-band ESR spectrometer.
Evelyn KA & Malloy HT (1938) Microdetermination of
Oxyhemoglobin, Methemoglobin, and Sulfhemoglobin in a Single
Sample of Blood. J. Biol. Chem. 126, 655-662

Result:Van Assendelft OW (1970) Spectrophotometry of Haemoglobin
Derivatives. Assen: Royal Vangorcum.
The methemoglobin level increased to 45-80% one hour after theadministration of the LD50 dose and returned to the normal
level after 24 hours if the animals survived. The dose-maximum
methemoglobin concentration curve was found to be S-shaped.
Formation of nitrosyl hemoglobin preceded that ofmethemoglobin, its maximum concentration being a quarter thatof the latter derivative.

Reliability:
Flag:

The concentration of nitrite anion reached a maximum (about
1mM) 20-30 min after administration, and disappeared withhalf-life period of approximately 70 min, while theconcentration of nitrate anion remained at a high level (1.0 1.5mM) for more than 5 hours.
Test Species: Sprague-Dawley rat
Age/weight: 4 months/200 g
Dosage: 0, 10, 25, 50, 100, 150 mg/kg bw
Animals/dose: 5
Chemical Name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(2) valid with restrictions
Critical study for SIDS endpoint

26-APR-2005(85)

Test condition:

Test substance:

In Vitro/in vivo:
Type:
Species:

In vivo
Absorption
mouse
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Method:SODIUM NITRITE
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1972
Time course of in vivo disappearance of sodium nitrite frommouse stomach:
Sodium nitrite (150 µg) was administered to each mouse bygavage in 0.1 mL aqueous solution. Animals, in groups of
13-18, were then killed by cervical dislocation within aminute and at 10, 20 and 30 minutes after administration.
Stomachs, together with attached 5 mm segments of theesophagus and duodenum, were removed and assayed individuallyfor sodium nitrite.
Effect of ligation of gastroduodenal junction on rate of invivo disappearance of sodium nitrite from mouse stomach:
Groups of 5-8 mice were anesthetised by intraperitoneal
injection of 150 mg/kg sodium hexobarbital. The
gastroduodenal junction was ligated in some groups, while incontrols the ligature was left loose. The stomachs were theninjected intraluminally with 150 µg sodium nitrite in 0.1 mLof water. The abdominal wall was then sutured. Mice were
killed by cervical dislocation 10 or 30 min later and stomachs
were removed and assayed individually for sodium nitrite.
Nitrite determination:

Result:Individual stomachs were placed in 20 mL distilled water,
buffered with 0.25 mL of 0.67M NH4Cl/NH4OH at pH 9.6-9.7 andsliced open. Activated charcoal was added and the flasks wereagitated for 15 min at room temperature. Then 0.2 mL of 1.04
M ZnSO4 was added and the flasks were agitated for a further 5
min. Contents of each flask were centrifuged at 2000 ppm for
15 min. Aliquots were taken for colorimetric determination of
sodium nitrite.
Following oral administration, sodium nitrite diasappeared
rapidly from the mouse stomach. 85 and 95% losses were seen at
10 and 30 minutes, respectively.
The rate of sodium nitrite disappearance from the mousestomach in vivo was not significantly reduced by ligature at
the gastroduodenal junction. Although there was consistently
more gastric sodium nitrite lost in mice not having thegastroduodenal junction ligated, this difference was notstatistically significant and did not represent a major
pathway of nitrite loss.

Test condition:
Test substance:
Conclusion:
Reliability:
26-APR-2005
147

Test animals: Swiss ICR/Ha miceSex: Male
Weight: 20-25 g
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: No data
The authors concluded that the major pathway of loss
available gastric nitrite is absorption directly from thestomach into the bloodstream.
(2) valid with restrictions(62)

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Type:
Species:Year:
Method:Metabolism
other: cat, rabbit, rat

1988
In vivo study:
Animals were dosed by intravenous injection with 0.30 mmol/kg
sodium nitrite. Prior to dosing, animals were anaesthetisedwith either 30 mg/kg i.v. pentobarbitol (rabbits), 60 mg/kg
chloralose by gastric tube (cats) or ether in a glass tube
(rats). All animals were allowed to breath spontaneously.
The anaesthetics were repeatedly administered as required.
Heparin was always give to the anaesthetised animals (500
I.U./kg i.v.). Blood samples were taken via a catheter fromthe femoral vein.
In vitro study:
Heparinised blood samples were taken from the animals via acatheter from the femoral vein. Human PPL erythrocyte
concentrate was delivered from a blood bank.
For the preparation of the erythrocyte suspensions, the humanand animal samples were centrifuged at 4000 rpm for 10
minutes. After removing the supernatant, the cellular sediment
was washed three times with 0.15 M saline and centrifuged
before resuspension in 0.2 M phosphate buffer, pH 7.4, with 5mM glucose.
Purified human haemoglobin was prepared by chromatography.
Ferrihaemoglobin formation was followed in tightly capped HPLC
vessels containing 1.5 mL of the red blood cell suspension.
Sodium nitrite, diluted in 0.15 M saline, was added in
microquantities (<= 5 µL) from a Hamilton syringe through therubber membrane of the vessel cap. The incubates were shaken
intensively in a water bath at 37°C.
Ferrihaemoglobin was determined photometrically at 550 nm
after addition of KCN to haemolysate samples. Blood or washederythrocytes (0.1mL) were haemolysed in ice-cold deionised
water (10 mL) during 10 minutes and adjusted to pH 6.6 with
0.2 M phosphate buffer (1.0 mL) before centrifugation at 4000
rpm for 5 minutes.

Result:For ferrihaemoglobin determinations in solutions of purified
haemoglobin, 0.1 mL of the solution was likewise diluted in a
total volume of 11.0 mL. Total haemoglobin was assayed after
oxidation of ferrohaemoglobin to ferrihaemoglobin withpotassium hexacyanoferrate (III) (10 g/dL).
In vivo study:
Sodium nitrite induced ferrihaemoglobin formation with maxima
of 47.7+/-1.3% at 90 min in cats, 7.5+/-1.0% at 10 min in
rabbits and 18.4+/-0.0% at 30 min in rats. Despite the fivetimes greater ferrihaemoglobin maxima due to treatment withsodium nitrite in cats compared to rabbits, respiratory rateincreased three times less. Total haemoglobin was not
influenced by nitrite.

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
In vitro study:
Human erythrocytes: The haemoglobin content in the sealed test
tubes averaged 12.2+/-0.2 g/dL (n=17). In the presence of 1.4
mM sodium nitrite the gain in FE3+ was 1.97=/-0.06 mmol/mol
NaNO2.

Test condition:

Erythrocytes from different animal species: in the presence of
2.5 mM sodium nitrite, ferrihaemoglobin maxima were notreached by 60 minutes except for rabbit erythrocytes. The
courses of the rate of formation curves were similar for theerythrocytes of cats, oxen, dogs and humans. The initial rateof ferrihaemoglobin production in canine red blood cells washigher than in the cells of the other species. Half the maxima
were attained within less that five minutes in theerythrocytes from dogs or rabbits and within approximately 20
minutes or greater in human, bovine and cat erythrocytes. In
the rabbit cells, the ferrihaemoglobin content did not varysignificantly between 30 and 60 minutes.
In vivo study:
Test animals:
Chinchilla rabbits
Weight: 4.4+/-0.2 kg
No. of animals: 6
Cats
Weight: 2.5+/-0.2 kg
No. of animals: 4

Test substance:
Reliability:

Sprague-Dawley rats
Weight: 295+/-8.7 g
No. of animals: 3
Chemical Name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Purest grade
Supplier: Merck (Darmstadt, Germany)(2) valid with restrictions

29-APR-2005(104)

In Vitro/in vivo:
Type:
Species:Year:
Method:149

In vitro
Metabolism
other: human, rat, sheep

1983
Preliminary testing established a concentration of sodium
nitrite (3 mM) which produced evidence of an approximately 50%
increase in methaemoglobin levels in human blood cells. This
amount of sodium nitrite was administered in 10 µL aliquots/mLof whole blood. This amount of blood and oxidant was thenincubated with increasing levels of ascorbic acid (1.0 - 9.0mM) for a 2-hour exposure at 37°C. An incubated control withno ascorbic acid addition was employed. Additional controls
employing ascorbic acid (1.0 - 9.0 mM) were run to assess thepotential effects of ascorbic acid acting by itself.

UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Blood samples were taken from six normal humans obtained via
venipuncture of the brachial vessels, six female adult sheepof the Dorset strain obtained via puncture of the jugularvein, and six male Sprague-Dawley rats aged approximately 3months obtained via cardiac puncture. The blood was collectedin heparinised tubes on the morning of testing, held in an ice
bath until use in the experiment that day. Methaemoglobin wasmeasured according to the method of Brown (1973) using
potassium ferricyanide and potassium cyanide as reagents andmeasuring changes in optical density at 630 nm.

Result:Brown BP (1973) Hematology: Principles and Procedures, 1st ed,
Lea & febiger, Philadelphia, USA
Rats: Treatment of rat erythrocytes with 3 mM sodium nitrite
produced 14.2% methaemoglobin compared to 1.7% in the control.
This level of methaemoglobin was reduced in a dose-dependantmanner when incubated in the presence of ascorbic acidadditions.
Sheep: The formation of methaemoglobin in sheep erythrocytes
increased substantially (48.7% compared with control mean of2.2%) upon incubation with 3 mM sodium nitrite. Ascorbic acidtreatment, however, did not alter this level of methaemoglobin
formation significantly.

Test substance:
Conclusion:

Reliability:
Flag:
26-APR-2005

Humans: Incubation of normal human erythrocytes with 3 mM
sodium nitrite produced a methaemoglobin level of 48.6%
compared to 1.8% in the incubated controls. Ascorbic acidtreatment significantly (p<0.001) reduced methaemoglobin
levels in a dose-dependant manner.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
The 2-hour incubation of whole blood with 3mM of sodium
nitrite produced an approximately 50% methaemoglobin level forboth sheep and normal humans. However, rats were considerably
less susceptible to nitrite induced methaemoglobin formation,with the same dose producing only 14% methaemoglobin. The
difference in sensitivity is probably due to the fivefold
difference in erythrocyte methaemoglobin reductase activity
between humans and rats [Smith and Beutler, 1966].
(2) valid with restrictions
Critical study for SIDS endpoint(30)

In Vitro/in vivo:
Type:
Species:Year:
Method:In vitro
Toxicokinetics
other: human, goats, sheep, horse, cattle, pig
1966All blood samples were collected from mature individuals of
the various species into ACD solution to which sodium chloride
had been added to the extent of 0.25% to increase the osmotic
strentgh to a level more nearly isotonic with RBCs. The blood
samples were stored at 4°C for up to 7 days prior to use. The
rate of oxidation of oxyhaemoglobin to methaemoglobin wasdetermined by the method of Betke et al. Erythrocytes fromthe various species were washed three times with 1.5% sodium
chloride solution and hemolysed by dilution with distilledwater. The hemolysate was mixed with 4-5 vol colloidal
aluminium hydroxide and filtered. The haemoglobin
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
concentration was determined by the cyanmethaemoglobin method,
adjusted to 105 mg/100 mL, and 1/20 vol of 2.8 M phosphatebuffer, pH 6.8 was added. The reaction was started by theaddition of 0.02 mL freshly prepared 0.073 M sodium nitrite
solution to 2.5 mL haemoglobin solution. The reaction rate wasfollowed at 630 mµ in a Gilford model 2000 multiple absorbancerecorder.
Methaemoglobin reduction was carried out in a system
previously described except that the volume of all reactants
was reduced by one third (Beutler & Beluda). Blood from thevarious species was centrifuged and the plasma and buffy coat
removed. The haemoglobin was converted to methaemoglobin by
incubating the erythrocytes with 2 vol 0.145 M sodium nitrite
solution for 20 min. The cells were then separated bycentrifugation and washed with 7-10 vol isotonic saline. The
reaction mixture contained: nitrite-washed erythrocytes, 29%;
potassium phosphate buffer, pH 7.4, 65 mM; glucose, 28 mM; andsodium chloride, 45 mM. Methylene blue, 0.017 mN, was used toactivate the triphosphopyridine nucleotide-linked system.
Methaemoglobin percentage was determined by the method of
Evelyn and Malloy at two hour intervals for a total of six
hours.
Betke K, Greinacher I and Hecker F (1956) Oxidation of Humanand Animal Oxyhemoglobin by Sodium Nitrite. arch. Exptl.
Pathol. Pharmakol. 229, 207-219
Beutler E and Baluda MC (1963) Methemoglobin Reduction.
Studies of the Interaction Between Cell Populations and of theRole of Methylene Blue. Blood, 22, 323-333

Result:Evelyn KA & Malloy HT (1938) Microdetermination of
Oxyhemoglobin, Methemoglobin, and Sulfhemoglobin in a Single
Sample of Blood. J. Biol. Chem. 126, 655-662
Methaemoglobin formation: The rate of oxidation of haemoglobin
to methaemoglobin occurred most rapidly in ruminants (sheep,goat and cow) and was slower in nonruminants (man, horse andpig).
Methaemoglobin reduction with glucose: When nitrite-treated,washed erythrocytes were incubated with glucose, the reductionof methaemoglobin was linear for the first six hours of
incubation. There was a marked difference between each of thespecies studied. With the exception of man, the animals withthe most rapid reduction rate were ruminants.

Test substance:
Reliability:
26-APR-2005
In Vitro/in vivo:
Type:
Species:151

Methaemoglobin reduction with glucose and methylene blue: The
rates of methaemoglobin reduction with methylene blue andglucose again showed marked differences between the various
species. Methylene blue produced an acceleration in the
reduction rate. This acceleration was most pronouned in man(six-fold) and cattle (four-fold).
Chemical name: Sodium nitrate (CAS No. 7632-00-0)(2) valid with restrictions(166)
In vivo
Metabolism
rat
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

No. of animals, males:
No. of animals, females:
Doses, males:
Route of administration:
Exposure time:Year:
Method:22
00, 10, 30, 100, 300, 1000 µmol/kg bw
infusion
5 minute(s)1997Male Wistar rats were anaesthetised with urethane (1.3 g/kg bw
ip). The trachea was canulated to avoid obstruction of the
airways by mucus secretion. The right femoral artery wascannulated for measurement of arterial blood pressure andheart rate, the left femoral vein was cannulated for taking
blood samples and the left jugular vein was prepared forinfusion of nitrite.
A solution of sodium nitrite (1.25 mL) was infused over 5
minutes into the left jugular vein. For each dose four animals
were used except for the control and high dose groups forwhich three animals were used.

Result:

Test condition:
Test substance:
Reliability:
26-APR-2005

Blood pressure and heart rate were recorded at time -5, 0, 5,
15, 30, 45 and 60 minutes. For measurement of plasma nitrateand nitrite, blood sampls (0.4 mL) were taken immediately
after infusion of sodium nitrite and collected in EDTA vials.
Body temperature was kept between 36 and 39°C by a heatingpad.
In urethane-anaesthetised rats infusion of NaNO2 [0 (n=3), 10(n=4), 30 (n=3), 100 (n=4), 300 (n=4) or 1000 (n=3)µmol/kg bw] over 5 minutes, resulted in a dose-dependent
increase in plasma levels of nitrite and a rapid conversion of
nitrite into nitrate. Mean arterial pressure (MAP) and heart
rate (HR) just prior to infusion of NaNO2 were 92.6+/-3.2 mmHg
and 396+/-6.9 beats/min, respectively. NaNO2 decreased MAP
dose dependently but no marked effects on HR were observed.
Test animals: Wister male rats
Weight: 275-350g
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade
Source: E Merck AG (Darmstadt, Germany)(2) valid with restrictions(188)

In Vitro/in vivo:
Type:
Species:No. of animals, females:
Route of administration:
Year:
Method:In vivo
Toxicokinetics
rat
21
gavage1984
21 rats were dosed with 30 mg/kg bw sodium nitrite by gavage.
Groups of three animals were exsanguinated at intervals from
2.5 to 360 minutes.
Plasma nitrite was determined photometrically according to themethod of Grau and Mirna with minor modification.
Methaemoglobin was determined photometrically using the methodof Evelyn and Malloy.

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Grau R and Mirna A (1957) Z. Anal. Chem. 158, 182

Result:Evelyn KA & Malloy HT (1938) Microdetermination of
Oxyhemoglobin, Methemoglobin, and Sulfhemoglobin in a Single
Sample of Blood. J. Biol. Chem. 126, 655-662
Oral treatment with NaNO2:

Test substance:
Reliability:
26-APR-2005

When starved rats received a single dose of 30 mg/kg bw ofNaNO2 in aqueous solution by gavage (10 - 15% of LD50), plasma
nitrite and methaemoglobin levels were already increased after
2.8 minutes and maximum effects were observed after 22.5
minutes. After three hours both parameters had returned tothe physiological range.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(76)

In Vitro/in vivo:
Type:
Species:Route of administration:
Year:
Method:Result:In vivo
Absorption
ratdermal1997
Male Wistar rats weighing about 480 - 500g were anesthetizedby intraperitoneal injection of 60 mg/kg pentobarbital. normal
and abraded skin were prepared as follows: Dorsal hair was
shaved with a razor (normal skin).
About 10 cm2 of epidermis
was scraped with a razor from this shaved area (abraded skin).
Indwelling cannulae were implanted in the left and rightfemoral artery. One catheter was used to monitor arterial
blood pressure. A 7 cm2 skin area was delimited by an open
circular cell fixed to the skin using cyanoacrylate glue. Eachliniment solution (120 µL) was applied to six animals for bothnormal and abraded skin. Heparinized blood samples wereplaced in a hematocrit tube from another cannula. The
arterial blood gas sample was analyzed for MetHb (OSM3Hemoximeter, Radiometer, Copenhagen, Denmark). Samples weretaken before application and at 5 and 10 min after applicationand every 10 min thereafter, up to 180 min.
Application of liniment solutions containing 30 g nitrite/L toabraded skin caused a gradual increase of MetHb which reacheda peak within 40-50 minutes and then decreased relatively
contantly throughout the observation period of 180 minutes.
Application of liniment solutions containing 140 g nitrite/L
to abraded skin caused a marked increase in MetHb
concentration. regardless of the application time, theconcentration of MetHb was consistently significantly higher
in abraded skin than in normal skin. rats with abraded skin towhich liniment solution B2 was applied died after about 170
minutes.
MetHb formation was significantly correlated with the skincondition at the same nitrite concentration.
Application of liniment solutions containing 30 g nitrite/L tonormal skin resulted in an immediate decline of arterial bloodpressure, followed by an increase. Application of liniment

153

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ID: 7632-00-00
DATE: 04-JAN-2006
solutions containing 140 g nitrite/L to normal and abradedskin significantly decreased the blood pressure.

Test substance:

Within 10 min after the application of liniment solutions
containing 140 g nitrite/L to abraded skin, cutaneous bloodflow dropped significantly to between 50.2+/-3.2% and41.6+/-6.0% of the pretreatment values. This decrease
continued to the end of the experiment. Application ofliniment solutions containing 30 g nitrite/L to abraded skinalso significantly decreased the subcutaneous blood flow. In
normal skin, the subcutaneous blood flow was significantly
increased compared to the abraded skin.
Liniment solutions containing sodium nitrite, as follows:
Liniment A: Base of nonionic surfactant/oil containing 30 g
nitrite/L
Liniment A2: Base of nonionic surfactant/water containing 30 g
nitrite/L
Liniment A3: Base of water containing 30 g nitrite/L
Liniment B: Base of nonionic surfactant/water containing 140 g
nitrite/L

Reliability:
29-APR-2005

Liniment B2: Base of water containing 140 g nitrite/L(2) valid with restrictions
Not a standard test, but closely related to human data which
is an important hazard warning.
(155)

In Vitro/in vivo:
Species:Year:
Remark:In vivorat
1975
Adaptation of rats following sodium nitrite induced
methemoglobinemia. The effect of repeated intraperitoneal
injections of sodium nitrite on methemoglobin, hemoglobin
and blood sugar level, on leucine aminopeptidase activity inplasma and methemoglobin reductase activity in red blood
cells was investigated in rats.
Repeated methemoglobinemia produced gradual disappearance ofhyperglycemia, changes of hemoglobin content in blood andincrease of methemoglobin reductase activity in red blood
cells.

Test substance:
Reliability:

The enzyme methemoglobin reductase catalyzes the reductionof methemoglobin to hemoglobin and protects red cells
against oxidative damage. Along with methemoglobin
concentrations, methemoglobin reductase activities increased
after nitrite administration to rats.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

29-APR-2005
Type:
Year:

(142)
Metabolism
1996
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Remark:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Reduction of nitrate to nitrite in vivo may be effected byboth enteric bacteria and mammalian nitrate reductase
activity. Many species of micro-organisms resident in theoro-gastrointestinal tract possess nitrate reductase activity
and this enzyme has been detected in rat liver and intestinal
mucosa.
From comparitive studies in germ-free and conventional rats
the author concluded that of the 40-50% of a dose of nitrate
reduced to nitrite in conventional animals, approximately half
was effected by mammalian nitrate reductase. The major site ofconversion of nitrate to nitrite varies with species and isdependent on the sites of microbial colonisation andabsorption of nitrate.

Reliability:
22-JUL-2005

The presence of nitrite in the oral cavity of humans is
attributed to a stable population of nitrate reducing bacteria
established at the base of the tongue. On th ebasis of the(highly variable) salivary levels of nitrate and nitrite after
oral ingestion of nitrate by humans, it has been estimatedthat, of the 25% of ingested ntirate secreted in saliva, 20%
is reduced to nitrite (i.e. about 5% of the oral dose). and it
appears that oral reduction of nitrate is the most importantsource of nitrite for man and most species that possess anactive salivary secretory mechanism.
(2) valid with restrictions
(191)

Type:
Year:
Remark:22-JUL-2005

Metabolism
2001
Infants under 3 months old are particularly sensitive tonitrite. A large proportion of haemoglobin in these infants
is in the foetal haemoglobin form, which is more readilyoxidised to methaemoglobin than adult haemoglobin. Further,
reduced nicotinamide-adenine dinucleotide (NADH)-dependent
methaemoglobin reductase, the enzyme responsible for reductionof methaemoglobin back to normal haemoglobin, has only about
half the activity present in adults(3)

5.1 Acute Toxicity
5.1.1 Acute Oral Toxicity
Type:Species:
Strain:Sex:
No. of Animals:
Doses:
Value:
Year:
Remark:
155

LD50
mouse
other: White
male/female
100
100, 150, 200, 250, 300 mg/kg= 214 - 216 mg/kg bw
1950
Route; oral

UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
LD50(mg/kg) = 214 (male)
LD50(mg/kg) = 216 (female)-Male
Dose (mg/kg) - Proportion killed
300 - 10/10
250 - 8/10
200 - 7/10
150 - 2/10
100 - 0/10
LD50 = 214 mg/kg-Female-Male
Dose (mg/kg) - Proportion killed
300 - 10/10
250 - 8/10
200 - 8/10
150 - 1/10
100 - 0/10
LD50 = 216 mg/kg

Test substance:
Reliability:
Flag:
31-MAY-2005

All animals that died were found to have methaemoglobin in
their blood, although the levels are not reported. Micereceiving the larger doses died within a few minutes and allother mice (except one) that died did so within 24 hours.
Animal: about 20 g
Substance was given in a 0.5-2% aqueous solution.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint
(144)

Type:
Species:
Strain:
Vehicle:Doses:
Value:LD50
rat
Sprague-Dawley
no data
10, 50, 100, 150 mg/kg bw= 150 mg/kg bw

Test condition:

Year:
Remark:Result:

Test substance:
Reliability:
22-JUL-2005
Type:
Species:
Strain:No. of Animals:
Value:Year:
Result:1980
fasted before dosing
The oral LD50 of NaNO2 for rats was found to be 150 mg/kg
bw. The methemoglobin level increased to 45-80%, 1h after
the administration of the LD50 dose and returned to thenormal level after 24 h.
Chemical name: Sodium nitrite (CAS No 7632-00-0)
Purity: Reagent grade(4) not assignable
(85)
LD50
rabbitother: New Zealand24= 124 mg/kg bw
1974
Oral LD50 = 124 mg/kg
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Test substance:
Reliability:
31-MAY-2005
Type:
Species:
Strain:Value:
Year:
Remark:Test substance:
Reliability:
22-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(95% C. I. = 114- 134 mg/kg)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(49)
LD50
rat
other: BD= 77 - 130 mg/kg bw
1963
Route; gavage
LD50(mg/kg) = 130
LD50(mg/kg) = 77 (fasted)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(50)

5.1.2 Acute Inhalation Toxicity
Type:Species:
Strain:Sex:
No. of Animals:
Vehicle:Doses:
Exposure time:
Value:

LC0
rat
Wistarmale/female
10water
10 and 100 mg/m3
4 hour(s)= .0951 mg/l

Method:
Year:
GLP:

other
1985
yes

Remark:Original report: McLean-Head L and Mould AP (1985). ICI
Unpublished Report CLT/T/2461
During exposure signs typically seen in restrained animals
were somewhat more severe in treated animals.
Methaemoglobin was significantly increased above concurrent
control values only in females exposed to 10 mg/m3.
However,the increase was judged to be not haematologicallysignificant as the value was within the range seen forcontrol animals of this age. Further there was no
significant increase in males. There were no
toxicologically significant effects on animals maintainedfor 14 days post-exposure.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Current controls of exposure of workers to sodium nitrite(ie at 10 mg/m3) was more than adequately protective for
acute hazards.
Groups of 10 male and 10 female Alpk:AP (Wistar) rats were
exposed nose only for 4 hours to Sodium nitrite aerosols,
generated from solutions in deionised water, at target
concentrations of 10 or 100 mg/m3. Aerosols dried rapidly
so animals were exposed to dry particulate test material.
Air humidity was approximately 60%. Mass mean aerodynamic
diameter was 1.7 and 2.0 µm for the low and high groups
respectively. Controls killed after exposure and blood

Result:

Test substance:
Conclusion:
Test condition:

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Reliability:
Flag:
31-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
taken for measurement of methaemoglobin, the remaining
animals were maintained for 14 days, and then subject to afull post-mortem examination.
(4) not assignable
Critical study for SIDS endpoint(56)

5.1.3 Acute Dermal Toxicity
5.1.4 Acute Toxicity, other Routes
Type:Species:
Strain:Route of admin.:Value:
Year:

LD50
rat
other: SBi.v.
= 65 mg/kg bw
1963

Result:
Test substance:
Reliability:
22-JUL-2005

Oral toxicity was conducted concurrently.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable

Type:
Species:
Strain:Sex:
Route of admin.:Value:

LD50
mouse
Swiss
male
i.p.
= 159.7 mg/kg bw

Year:

(50)

1963

Test condition:
Test substance:
Reliability:
31-MAY-2005

Animal: Swiss, Albino, male, 20-25g (BW)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable

Type:
Species:Route of admin.:Value:

LD50
rat
i.v.
= 65 mg/kg bw

Reliability:
31-MAY-2005

(3)

(132)

invalid(143)

5.2 Corrosiveness and Irritation
5.2.1 Skin Irritation
Species:Result:rabbitnot irritating

Method:Year:

OECD Guide-line 404
1985"Acute Dermal Irritation/Corrosion"

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GLP:
Method:Result:

Test substance:
Reliability:
Flag:
31-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
yes
Approximately 500 mg of sodium nitrite was applied to theshaved backs of 6 male New Zealand White rabbits and covered
with a semi-occlusive dressing for four hours. The animals
were examined one hour, one, two and three days after removalof the chemical.
Some slight irritation was observed one hour after removal of
the substance, but all signs had disappeared by the one day
observation and the substance is not considered to be a skinirritant.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint(168)

5.2.2 Eye Irritation
Species:Result:rabbitmoderately irritating

Method:Year:
GLP:

OECD Guide-line 405
1985
yes

Method:Test substance:
Reliability:
Flag:
31-MAY-2005

100 mg of substance was applied into the conjunctival sac ofthe left eye of six female New Zealand White Rabbits. Theeyes of three of the rabbits were irrigated with water for two
minutes 30 - 60 seconds after application of the substance.
Conjunctival effects were seen in all animals and consisted ofmoderate redness, mild chemosis and severe discharge. Allsigns of irritation had disappeared by twelve days. No corneal
effects were observed
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint(168)

Species:
Concentration:
Result:rabbit.1 other: mol/L
not irritating

Method:Year:
Test substance:other: see "test condition"1948
as prescribed by 1.1 - 1.4

Result:

Test Substance/Concentration/No. Eyes Tested/Severity ofReaction

Result:

Test condition:

159"Acute Eye Irritation/Corrosion"

NaNO2/0.08M/1/0
Cf:
H2O/0/-/0
NaCl/0.9%(0.16M)/-/0
H2O2/0.25%/1/95
In the course of the studies reported in the preceding
papers a great number of substances were injected into thecorneas of rabbits and the resulting reactions observed.
These experiments were performed, in part, as controls for awide variety of special studies, in part as a preliminary
UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
survey of the general toxicology of the corneal tissue. The
results are compiled.

Reliability:
31-MAY-2005

Unless otherwise noted, 0.1 mL. of the solution of test
substance was injected intracorneally, using a # 25-27 gauge
needle and tuberculin syringe. Occasionally the anteriorchamber was entered accidently,in some cases resulting in apersistent edematous bulging of the cornea which could be
identified clinically and the false positive corneal
reaction discarded. The exact quantity injected within
limits of 0.05 cc. -0.2 cc. was of less importance than theconcentration of the injected material. Secondary infection
was uncommon. Accidental injection of air into the cornea
did not increase the severity of the reaction produced.
The reactions following intracorneal injection weresimilar in severity to those following mechanical removal of
the corneal epithelium with a cotton toothpick swab,
followed by irrigation for 10 minutes with the test
solution.
The single numerical value represents the sum of the
maximum values of each symptom observed over a period of
7-14 days, expressed in percentage of the maximum possible
total.
(3) invalid
Method is too unique to used for evaluation.
(81)

5.3 Sensitization
Type:
Remark:other
No studies are available in animals investigating thesensitising potential of sodium nitrite. As this substance isendogenously generated, sensitisation potential is notexpected. No evidence of sensitisation in humans has beenreported.

31-MAY-2005
5.4 Repeated Dose Toxicity
Type:Sub-chronic
Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
14 weeks
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 375, 750, 1500, 3000, or 5000 ppm in drinking water
available ad lib.
Control Group:
yes, concurrent vehicle
Method:Year:
GLP:

other: FDA (21 CFR, Part 58)
2001
yes

Result:Exposure to 0, 375, 750, 1,500, 3,000 or 5,000 ppm in drinking
water was equivalent to approximate daily doses of 0, 30, 55,
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115, 200 or 310 mg/kg bw/day in males and 0, 40, 80, 130, 225
or 345 mg/kg bw/day in females.
NOAEL : not obtained (all doses showed methaemoglobin
formation)
LOAEL: Males = 115 mg/kg bw/day; Females = 225 mg/kg bw/day
TOXIC RESPONSE/EFFECTS BY DOSE LEVEL:
Clinical signs: Brown discoloration in the eyes and cyanosisof the mouth, tongue, ears, and feet of 200 and 310 mg/kg
bw/day males and of 130 mg/kg bw/day and higher females.
Bodyweight and food consumption: Body weights of 200 and 310
mg/kg bw/day males and 345 mg/kg bw/day females weresignificantly less than those of the controls. Water
consumption by 310 mg/kg bw/day males and 225 and 345 mg/kg
bw/day females was less than that by the controls at weeks 2
and 14.
Mortality and time to death: One 225 mg/kg bw/day female died
before the end of the study.
Urinary examination:
Clinical Pathology: Methaemoglobin levels were significantly
elevated in all treated groups compared to the controls by theend of the treatment period. For males, mean methaemoglobin
levels after 14 weeks were 0.03±0.01, 0.08±0.01, 0.12±0.02,
0.25±0.07, 0.71±0.20 and 3.38±0.80 g/dL at doses of 0, 30, 55,
115, 200, and 310 mg/kg bw/day. For females, mean
methaemoglobin levels after 14 weeks were 0.06±0.02,
0.14±0.02, 0.16±0.02, 0.48±0.05, 0.99±0.20 and 2.27±0.54 g/dL
at doses of 0, 40, 80, 130, 225 and 345 mg/kg bw/day.
Haematology: Reticulocyte counts were increased in 200 and 310
mg/kg bw/day males and 225 and 345 mg/kg bw/day females. The
erythron was decreased on day 19 but increased by week 14 in
310 mg/kg bw/day males and 345 mg/kg bw/day females.
Gross pathology incidence and severity: The incidences ofsquamous cell hyperplasia of the forestomach in 310 mg/kg
bw/day males and 345 mg/kg bw/day females were significantly
increased.
Organ weight changes: The relative kidney and spleen weightsof 200 and 310 mg/kg bw/day males and 225 and 345 mg/kg bw/day
females were significantly greater than those of the controls.
Histopathology: Increased erythropoietic activity in the bonemarrow of exposed males and females was observed.

Test condition:

Sperm Motility and Vaginal Cytology: Sperm motility in 115 and
310 mg/kg bw/day males was significantly decreased.
Study Laboratory:Microbiological Associates, Inc. (Bethesda,
MD)
Strain and Species: Rat F344/N

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DATE: 04-JAN-2006
Animal Source: Taconic Farms (Gemantown, NY)
Time Held Before Studies:14 days (males) or 15 days
(females)Average Age When Studies Began:7 weeks
Duration of Exposure:14 weeks
Average Age at Necropsy:20 weeks
Size of Study Groups: core study, 10 males and 10 females;clinical pathology study, 15 males and 15 females
Method of Distribution: Animals were distributed randomly
into groups of approximately equal initial mean body weights
Animals per Cage: 5Method of Animal Identification: Tail tattoo
Diet:NIH-07 open formula powdered diet (Zeigler Brothers,Inc., Gardners, PA), available ad libitum, changed weekly
Water: Charcoal-filtered deionized water via amber glass
bottles with stainless steel sipper tubes, available adlibitum and changed twice weekly
Cages: Solid-bottom polycarbonate
Bedding: Sani-Chips
Cage Filters: DuPont 2024 spun-bonded polyester filter (Snow
Filtration Co., Cincinnati, OH)
Racks: Stainless steel
Animal Room Environment:
Temperature: 72 degree +/-3 degree F
Relative humidity: 50% +/-15%
Room fluorescent light: 12 hours/day
Room air changes: Minimum 10/hour
Exposure Concentrations:0, 375, 750, 1,500, 3,000, or 5,000
ppm in drinking water, available ad libitum
Type and Frequency of Observation: twice daily. Core study
animals were weighed and clinical findings were recorded
initially, weekly, and at the end of the studies. Drinking
water consumption was measured daily.
Method of Sacrifice: CO2 asphyxiation
Necropsy: Necropsy was performed on all core study. Organs
weighed were heart, right kidney, liver, lung, spleen, righttestis, and thymus.
Clinical Pathology:
Blood for hematology and clinical chemistry was collected
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from the retroorbital sinus of anesthetized clinicalpathology study rats on days 5 and 19 and from core study
rats at the end of the study. Two blood samples each werecollected from the abdominal aorta of 15 male and 15 female
clinical pathology study rats on day 70 (2000 or 2200 hours)
or 71 (0900 hours) for hemoglobin, methemoglobin andnitrosamine concentrations; stomach contents were alsocollected for nitrosamine concentrations. Blood and stomach
contents were collected from five males and five females at
each time point.
Hematology: hematocrit; hemoglobin concentration;
erythrocyte, reticulocyte, and platelet counts; mean cellvolume; mean cell hemoglobin; mean cell hemoglobin
concentration; leukocyte count and differentials;
erythrocyte and platelet morphologic assessments;
methemoglobin concentration; reduced glutathione
concentration in erythrocytes; and Heinz body count.
Clinical chemistry: urea nitrogen, creatinine, total
protein, albumin, alanine aminotransferase, alkaline
phosphatase, creatine kinase, sorbitol dehydrogenase, andbile acids
Nitrosamine concentrations: serum and gastric nitrosamine
Histopathology: Complete histopathology was performed on 0
and 5,000 ppm core study animals. In addition to grosslesions and tissue masses, the following tissues were
examined: adrenal gland, bone and marrow, brain, clitoral
gland, esophagus, heart, large intestine (cecum, colon,
rectum), small intestine (duodenum, jejunum, ileum), kidney,
liver, lung, lymph nodes (mandibular and mesenteric), mammary
gland, muscle, nose, ovary, pancreas, parathyroid gland,
pituitary gland, preputial gland, prostate gland, salivary
gland, spleen, skin, stomach (forestomach and glandular),testis (and epididymis and seminal vesicle), thymus, thyroid
gland, trachea, urinary bladder, and uterus. The forestomachof 750 (males), 1,500, and 3,000 ppm animals were also
examined.

Test substance:

Conclusion:
163

Sperm Motility and Vaginal Cytology: At the end of thestudies, samples were collected for sperm motility orvaginal cytology evaluations from male rats in the 0, 375,
1,500, and 5,000 ppm groups and female rats in the 0, 375,
750, and 3,000 ppm groups. The left cauda, epididymis, andtestis were weighed. The following parameters were
evaluated: spermatid heads per gram testis, spermatid heads
per testis, spermatid count, motility, and concentration.
Vaginal samples were collected for up to 12 consecutive days
prior to the end of the studies for vaginal cytology
evaluations. The length of the estrous cycle and the lengthof time spent in each stage of the cycle were
evaluated.Statistical analyses were conducted about survivalrate, neoplasm and non-neoplastic lesion incidences.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Purity: >99%
Lot No: A42340 and H05714
NOAEL : not obtained (all doses showed methaemoglobin
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ID: 7632-00-00
DATE: 04-JAN-2006
formation)

Reliability:
Flag:

LOAEL: Males = 115 mg/kg bw/day; Females = 225 mg/kg bw/day(1) valid without restriction
Critical study for SIDS endpoint

18-JUL-2005

(134)

Type:
Sub-chronic
Species:mouse
Sex: male/female
Strain:B6C3F1
Route of administration: drinking water
Exposure period:
14 weeks
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 375, 750, 1500, 3000, or 5000 ppm in drinking water
available ad lib.
Control Group:
yes, concurrent vehicle
Method:Year:
GLP:

other: FDA (21 CFR, Part 58)
1989
yes

Result:Exposure to 0, 375, 750, 1,500, 3,000 or 5,000 ppm in drinking
water was equivalent to approximate daily doses of 0, 90,
190, 345, 750, or 990 mg/kg bw/day in males and 0, 120, 240,
445, 840, or 1,230 mg/kg bw/day in females.
NOAEL : not obtained (methaemoglobin levels not reported)
LOAEL: Males = 750 mg/kg bw/day; Females = 445 mg/kg bw/day
TOXIC RESPONSE/EFFECTS BY DOSE LEVEL:
Clinical signs: No clinical signs of toxicity
Bodyweight and food consumption: Body weights of 990 mg/kg
bw/day males were significantly less than those of thecontrols. Water consumption by males exposed to 1,500 ppm orgreater was slightly less than that by the controls at week
13.
Mortality and time to death: All mice survived until the endof the study
Urinary examination:
Clinical Pathology: Methaemoglobin levels were not reported.
Haematology:
Gross pathology incidence and severity: There were increased
incidences of squamous cell hyperplasia of the forestomach in
990 mg/kg bw/day males and 1230 mg/kg bw/day females.
Organ weight changes: Relative spleen weights of 750 and 990
mg/kg bw/day males and absolute and relative heart, kidney,
liver, and spleen weights of 840 and 1230 mg/kg bw/day females
females were greater than those of the control groups.

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Histopathology: There were increased incidences ofextramedullary hematopoiesis of the spleen in 750 and 990
mg/kg bw/day males and 445 mg/kg bw/day or greater females,and degeneration of the testis in 750 and 990 mg/kg bw/day
males.

Test condition:

Sperm Motility and Vaginal Cytology: Sperm motility wasdecreased in 990 mg/kg bw/day males, and the estrous cycles of
445 and 1230 mg/kg bw/day females were significantly longer
than in the controls.
Study Laboratory:Microbiological Associates, Inc. (Bethesda,
MD)
Strain and Species:Mice B6C3F1Animal Source:Taconic Farms (Gemantown, NY)
Time Held Before Studies:11 days
Average Age When Studies Began:6 weeks
Duration of Exposure:14 weeks
Average Age at Necropsy:19 weeks (males) and 20 weeks(females)Size of Study Groups:Mice: 10 males and 10 females
Method of Distribution:Animals were distributed randomly
into groups of approximately equal initial mean body weights
Animals per Cage:1
Method of Animal Identification:Tail tattoo
Diet:NIH-07 open formula powdered diet (Zeigler Brothers,Inc., Gardners, PA), available ad libitum, changed weekly
Water:Charcoal-filtered deionized water via amber glass
bottles with stainless steel sipper tubes, available adlibitum and changed twice weekly
Cages:Solid-bottom polycarbonate
Bedding:Sani-Chips
Cage Filters:DuPont 2024 spun-bonded polyester filter (Snow
Filtration Co., Cincinnati, OH)
Racks:Stainless steel
Animal Room Environment:
Temperature: 72 degree +/-3 degree F
Relative humidity: 50% +/-15%
Room fluorescent light: 12 hours/day
Room air changes: equal or more than 10/hour
Exposure Concentrations:0, 375, 750, 1,500, 3,000, or 5,000
ppm in drinking water, available ad libitum

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ID: 7632-00-00
DATE: 04-JAN-2006
Type and Frequency of Observation:twice daily. Core study
animals were weighed and clinical findings were recorded
initially, weekly, and at the end of the studies. Drinking
water consumption was measured daily.
Method of Sacrifice:CO2 asphyxiation
Necropsy:Necropsy was performed on all core study. Organs
weighed were heart, right kidney, liver, lung, spleen, righttestis, and thymus.
Clinical Pathology:Blood for hematology and clinicalchemistry was collected from the retroorbital sinus ofanesthetized clinical pathology study rats on days 5 and 19
and from core study rats at the end of the study. Two blood
samples each were collected from the abdominal aorta of 15
male and 15 female clinical pathology study rats on day 70(2000 or 2200 hours) or 71 (0900 hours) for hemoglobin,
methemoglobin and nitrosamine concentrations; stomach
contents were also collected for nitrosamine concentrations.
Blood and stomach contents were collected from five males
and five females at each time point.
Hematology: hematocrit; hemoglobin concentration;
erythrocyte, reticulocyte, and platelet counts; mean cellvolume; mean cell hemoglobin; mean cell hemoglobin
concentration; leukocyte count and differentials;
erythrocyte and platelet morphologic assessments;
methemoglobin concentration; reduced glutathione
concentration in erythrocytes; and Heinz body count.
Clinical chemistry: urea nitrogen, creatinine, total
protein, albumin, alanine aminotransferase, alkaline
phosphatase, creatine kinase, sorbitol dehydrogenase, andbile acids
Nitrosamine concentrations:serum and gastric nitrosamine

Histopathology:Complete histopathology was performed on 0
and 5,000 ppm core study animals. In addition to grosslesions and tissue masses, the following tissues were
examined: adrenal gland, bone and marrow, brain, clitoral
gland, esophagus, gallbladder, heart, large intestine(cecum, colon, rectum), small intestine (duodenum, jejunum,
ileum), kidney, liver, lung, lymph nodes (mandibular andmesenteric), mammary gland (female), muscle, nose, ovary,pancreas, parathyroid gland, pituitary gland, preputial
gland, prostate gland, salivary gland, spleen, skin, stomach(forestomach and glandular), testis (and epididymis andseminal vesicle), thymus, thyroid gland, trachea, urinary
bladder, and uterus. The forestomach, testis, and spleen of
all remaining mice were also examined.
Sperm Motility and Vaginal Cytology: At the end of thestudies, samples were collected for sperm motility orvaginal cytology evaluations from male and female mice inthe 0, 375, 1,500, and 5,000 ppm groups. The left cauda,
epididymis, and testis were weighed. The following
parameters were evaluated: spermatid heads per gram testis,
spermatid heads per testis, spermatid count, motility, andUNEP PUBLICATIONS

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Test substance:

Reliability:
Flag:
22-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
concentration. Vaginal samples were collected for up to 12
consecutive days prior to the end of the studies for vaginal
cytology evaluations. The length of the estrous cycle andthe length of time spent in each stage of the cycle were
evaluated.Statistical analyses were conducted about survivalrate, neoplasm and non-neoplastic lesion incidences.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Purity: >99%
Lot No: A42340 and H05714(1) valid without restriction
Critical study for SIDS endpoint
(134)

Type:
Chronic
Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
2 years
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 750, 1500, or 3000 ppm in drinking water available
ad lib.
Control Group:
yes, concurrent vehicle
Method:Year:other: NTP Protocol
2001

Result:Exposure to 0, 750, 1500 or 3000 ppm sodium nitrite indrinking water was equivalent to average daily doses ofapproximately 0, 35, 70 or 130 mg/kg bw/day for males and 0,40, 80 or 150 mg/kg bw/day for females.
NOAEL = 130 mg/kg bw/day (males), 150 mg/kg bw/day (females)
Clinical signs: None
Mortality: Survival of exposed groups was similar to that of
the controls (29/50, 38/50, 36/50 and 36/50 for males at doses
of 0, 35, 70 and 130 mg/kg bw/day, respectively and 33/50,
31/50, 36/50 and 33/50 for females at 0, 40, 80 or 150 mg/kg
bw/day, respectively).
Bodyweight/Food consumption: Mean body weights of 130 mg/kg
bw/day males and 150 mg/kg bw/day females were less than thoseof the controls throughout the study. Water consumption byhigh dose males and females was less than that by the controls
throughout the study and that by the other exposed groups was
generally less after week 14.

Test substance:

167

Clinical pathology: Methaemoglobin levels were measured at two
weeks and three months. At both 2 weeks and three months,
methaemoglobin levels were high at night when the rats wereactively feeding and drinking and low during the day when therats were less active. Methaemoglobin levels tended toincrease with increasing dosage.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Purity: >99%
Lot No: A42340 and H05714
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Reliability:
Flag:
31-MAY-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(1) valid without restriction
Critical study for SIDS endpoint
(134)

Type:
Chronic
Species:mouse
Sex: male/female
Strain:B6C3F1
Route of administration: drinking water
Exposure period:
2 years
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 750, 1500, or 3000 ppm in drinking water available
ad lib.
Control Group:
yes, concurrent vehicle
Method:Year:other: NTP protocol
1997

Result:Exposure to 0, 750, 1500 or 3000 ppm sodium nitrite indrinking water was equivalent to average daily doses ofapproximately 0, 60, 120 or 220 mg/kg bw/day for males and 0,
45, 90 or 165 mg/kg bw/day for females.
NOEL = 220 mg/kg bw/day (males), 165 mg/kg bw/day (females)
Clinical signs: none
Mortality: Survival of exposed groups was similar to that of
the controls (39/50, 45/50, 42/50 and 39/50 for males at doses
of 0, 60, 120 or 220 mg/kg bw/day, respectively and 40/50,
34/50, 37/50 and 41/50 for females at doses of 0, 45, 90 or
165 mg/kg bw/day, respectively).
Body weight/Food consumption: Mean body weights of 165 mg/kg
bw/day females were less than those of the controls throughout
the study. Exposed groups generally consumed less water thanthe control groups.

Test substance:

Reliability:
Flag:
31-MAY-2005

Clinical pathology: At 12 months, no significant increase inmethaemoglobin level was observed in either sex at any dose.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Purity: >99%
Lot No: A42340 and H05714(1) valid without restriction
Critical study for SIDS endpoint
(134)

Type:
Chronic
Species:rat
Route of administration: drinking water
Exposure period:
24 months
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 100, 1000, 2000, 3000 mg/L
Control Group:
yes, concurrent vehicle
Year:
Remark:Sex: male

1972
NOEL = 10 mg/kg bw/day (Focal degeneration and fibrosis of the
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heart, dilatation of the bronchi with infiltration oflymphocytes and alveolar hyperinflation in lungs) equivalent
to 6.7 mg NO2/kg bw/day.

Result:The Joint FAO/WHO Expert Committee on Food Additives (JECFA)
established an acceptable daily nitrite intake of 0 to 0.07 mg
NO2/kg bw/day by applying a safety factor of 100 to this NOEL.
Exposure to 0, 100, 1000, 2000 or 3000 mg sodium nitrite/L in
drinking water was equivalent to approximately 0, 10, 100, 250
or 350 mg/kg bw/day, respectively
There were no significant differences in growth, development,
mortality or total haemoglobin levels between the control andtreated groups. However, the methaemoglobin levels in thegroups receiving 100, 250 and 350 mg/kg bw/day sodium nitrite
were raised significantly throughout the study and averaged 5,
12 and 22% of total haemoglobin, respectively.

Test condition:

Test substance:
Reliability:
Flag:
02-JUN-2005

The main histopathological changes occurred in the lungs andheart. Focal degeneration and fibrosis of the heart muscle
were observed in animals receiving the highest dose of
nitrite. The coronary arteries were thin and dilated in these
aged animals, instead of thickened and narrow as is usuallyseen at that age. Changes in the lungs consisted of dilatationof the bronchi with infiltration of lymphocytes and alveolar
hyperinflation. Such changes were observed in rats receiving
100, 250 and 350 mg/kg bw/day sodium nitrite.
number of test animals per group: 8
Parameters measured:
Body weight; 1ce a month
Mortality;
Methemoglobin;
Blood chemistry; glucose, pyruvate, lactate
Pathology; heart, lungs, kidneys, liver, spleen, pancreas,
adrenals and some brains.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint
(163)

Type:
Sub-chronic
Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
6 weeks
Frequency of treatment: continuous
Post exposure period:noDoses:
0, 500, 1250, 2500, 5000, 10000 ppm in drinking water
Control Group:
yes, concurrent vehicle
Year:
Result:1982
Four female rats in the 10000 ppm group and one male and one
female in the 5000 ppm group died. None of the other control
or treated group rats died.
In all the experimental groups except the 10000 ppm group,
depression of body weight gain compared to the control group
was less than 10%.

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At autopsy, the abnormal colour of the blood and the spleen
due to methaemoglobin was marked in rats of the two highest
dose groups.

Test condition:

On the basis of these results it was determined that the
maximum tolerated dose of sodium nitrite in F-344 rats was2500 ppm in drinkin water.
Test Animals:
Age: 5 wk old
Source: Charles river Japan Inc. (Kanawaga)
Groups of 10 male and 10 female rats were given 20 mL ofwater each day containing the appropriate concentration of
sodium nitrite. Controls received 20mL water only.
All animals were observed daily; signs of toxicity andmortality were recorded and body weights were determined every
other week. Dead animals were completely autopsied.

Test substance:
Reliability:
22-JUL-2005

At the end of the study, all surviving animals were killed forgross and microscopic examinations.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 98.5%
Supplier: Koso Chemical Co. Ltd (Tokyo)(2) valid with restrictions
(116)

Type:
Chronic
Species:rat
Sex: male
Strain:Sprague-Dawley
Route of administration: drinking water
Exposure period:
14 months, 16 weeks
Frequency of treatment: continuous
Post exposure period:noDoses:
200 ppm (16 weeks) 2000 ppm (14 months)
Control Group:
yes, concurrent no treatment
Year:
Result:1980
Experiment 1 (14 months):during the 14 month treatment period, the blood of animals
receiving 2000 ppm sodium nitrite in drinking water had 1-35%
Methaemoglobin as compared with less than 2% in that ofanimals receiving water only. The methaemoglobin values of thenitrite-treated animlas fluctuated from time to time. the redcells of controls and treated animals had less than 5%
haemolysis throughout the entire experimental period.
Seven of 12 nitrite-treated and four of nine control animals
died of respiratory infection during the first six months ofthe experimental period. the difference was not statisticallysignificant.
At the time of sacrifice, the body weights of surviving
animals averaged 457 g for treated animals and 556 g forcontrols.
The nitrite-treated group had the lightest livers and heaviest
lungs; all the lungs in thsi group exhibited severe lesions.
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GSH level was significantly increased in the red cells andplasma vitamin E was significantly decreased in the
nitrite-treated group compared with controls.
Experiment 2 (16 weeks):
No animals died during this study.
The methaemoglobin content in the nitrite-treated groupaveraged from 0.5-3.1% and the values also fluctuated fromtime to time. The control group had less than 1.2%
methaemoglobin in the blood during the entire experimental
period.
At the end of the treatment period, the lungs ofnitrite-treated rats averaged 2.0 g compared with 2.5 g forthe controls. The weight of other tissues (liver, spleen,
heart and kidney) and the body weight were not altered bytreatment.

Test condition:

The levels of GSH in the red cells, of vitamin E in plasma andof GSH peroxidase in the red cells and in plasma were notsignificantly changed as a result of nitrite treatment.
Experiment 1 (14 months):
2 month old male rats maintained on a commercial diet (Purina
rat chow) were given water containing either none or 2000 ppm
sodium nitrite in drinking water.
Tail blood samples were collected every other week to measure
the level of methaemoglobin. Haemoglobin content wasdetermined using cyano-MHb reagent at 540 nm. The degree of
red cell haemolysis was also measured.
At the end of 14 months, surviving animals from each groupwere killed and examined for tissue abnormalities. Hemolysate
from heparinized blood samples were analysed for levels of
GSH, GSH peroxidase and haemoglobin. Vitamin E content andGSH peroxidase activity were also measured in plasma.
Experiment 2 (16 weeks):Groups of 1-month old male rats (8/group) were given drinking
water that contained either none or 200 ppm sodium nitrite for
16 weeks.
During the treatment period blood samples were taken
periodically to measure the level of methaemoglobin as inexperiment 1.
At the end of 16 weeks animals were killed, blood samples
collected and the animals examined for any tissue
abnormalities.

Test substance:
Reliability:
171

Blood samples were assayed for levels of GSH and GSH
peroxidase in red cells and of GSH peroxidase and Vitamin E inplasma.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
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DATE: 04-JAN-2006

02-JUN-2005

(41)

Type:
Sub-chronic
Species:rat
Strain:WistarRoute of administration: drinking water
Exposure period:
90 daysFrequency of treatment: daily ad libitum
Post exposure period:
up to 8 weeks
Control Group:
yes

Sex: male

Year:
GLP:
Test substance:

1996
yes
other TS

Result:LOEL = 12 mmol KNO2, equivalent to 54 mg NO2-/kg bw/day.
All rats survived the experimental period. Rats receiveing
nitrite appeared cyanotic during the first month of thetreatment period.
In both feed groups the body weights of the rats exposed to
the low and medium dose of nitrite did not differ
statistically significantly from the concurrent control rats.
In feed group A the body weight gain the the high dose groupwas statistically significantly retarded compared to thecontrol rats. During the recovery period the body weights ofthese rats remained lower than those in the concurrent control
group. The retardation of body weight gain in the dose groupfed with diet B was less prominent than of the rats on feed A
and recovery of weight gain was observed after withdrawal of
nitrite.
In both feed groups the liquid intake of the rats exposed to
the low and medium dose of nitrite did not differ
statistically from the concurrent control rats. The average
daily drinking water consumption per kg body weight of thehigh dose rats was, during the exposure period, always
statistically significantly decreased compared to the control
rats. The reduction was generally more pronounced in the rats
fed with diet A.
After 4 and 8 weeks of exposure to the high nitrite dose thehaemoglobin concentration in the blood of rats on feed A wasstatistically significantly lower than that of concurrent
controls. The haemoglobin concentration was lowest after 4
weeks, rose gradually afterwards and from week 13 nodifference between treatment groups could be seen. Thisdecrease of haemoglobin concentration was not seen in rats fed
on diet B.
The concentration (and fraction) of methaemoglobin in blood of
the control rats fed on diet A were statisticallysignificantly slightly higher than those of the control rats
on feed B. Exposure to the low or medium nitrite dose for 13
weeks caused no effects on theses parameters. In the high dosegroups, the methaemoglobin concentration (and fraction) inblood of rats of both feed groups was statisticallysignificantly increased (p<0.01, rank sum test) compared tothe control groups.
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Pathology:
Gross examination revealed no remarkable observation in mostof the rats.
Absolute and relative weights of the adrenal glands of thenitrite dosed rats did not differ significantly from controls.
All high nitrite dosed rats of both feed groups showed slight
hypertrophy of the adrenal zona glomerulosa. This hypertrophy
manifested from the first examination (after 4 weeks of
exposure) and on all subsequent examinations during theexposure period (after 8 and 13 weeks). After 90 days of
exposure, the incidence and intensity of the hypertrophy of
the adrenal zona glomerulosa was dose dependent. The low dosegroup showed minimal hypertrophy in 3/10 rats on feed A and
0/10 on feed B. In the medium dose groups very slight
hypertrophy was observed in the adrenals of 8/10 feed A and9/10 feed B rats.

Test condition:
Animal Source: National Institute of Public Health andEnvironmental Protection
Time Held Before Studies: 2 weeks
Average Age When Studies Began: no data
Size of Study Groups: Controls - 100 rats; low and medium dose
- 20 rats each; high dose - 100 rats
Method of Distribution: The animals were weighed and allocatedto 4 test groups (including the control group) matched byweight by a computer randomisation program.
Animals per Cage: 2/cage
Method of Animal Identification: no data
Diet: Feed A - semisynthetic diet prepared with purified
components (SSP-TOX, Hope Farms BV, Woerden, NL); Feed B Diet used in Til study (van Eck, Cothen, NL obtained from TNO,
Zeist)
Water: ad libitum
Cages: Macrolon cages (Type III)
Bedding: no data
Cage Filters: no data
Racks: no data
Animal Room Environment:
Temperature: 19-24°C
Relative humidity: 37-83%
Room fluorescent light: 12 hr light/dark cycle
Room air changes: about 10/hr
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Exposure Concentrations (administered in drinking water):
Controls - Potassium chloride (36 mmol/L = 2584 mg/L)
Low dose - Potassium nitrite (3.6 mmol/L = 306 mg/L)
supplemented with potassium chloride (32.4 mmol/L)
Medium dose - Potassium nitrite (12 mmol/L = 1021 mg/L)
supplemented with potassium chloride (24 mmol/L)High dose - Potassium nitrite (36 mmol/L = 3064 mg/L)
During the recovery period the drinking water contained
potassium chloride. The daily supply of potassium was thesame in all groups throughout the experimental period.
Type and Frequency of Observation:
Cage-site observations to check the general condition andbehaviour of all rats or to detect signs of ill health andreaction to treatment were conducted once daily.
The individual body weights of all rats were recorded at thestart of the experiments and then weekly. In addition, therats were weighed on the day of their scheduled sacrifice inorder to calculate the relative adrenal weight. Water intake
was recorded daily and food intake was measured over weekly
periods throughout the study. Liquid and food intake per kg
body weight were calculated over weekly periods using the
average weight of the 2 rats in each cage.
Autopsy:
Starting four weeks before termination the rats were handledindividually twice weekly. Sedated rats were sacrificed bydecapitation. Following exsanguination macroscopic examination
was performed. Adrenals were dissected, weighed and fixed in
4% w/v formaldehyde in 0.067 mol/L phosphate buffer.
Haematology and clinical chemistry:
Blood samples were collected at autopsy in plastic vials
containing EDTA. Samples were examined for haemoglobin andmethaemoglobin concentrations. Concentrations of nitrate andnitrite in plasma were also measured.
Histopathology:
The fixed adrenal glands were embedded in paraplast and slices
stained with haematoxylin-eosin for microscopical examination.
Morphometry:
Morphometry was performed on the stained slices o fthe
adrenals to quantitate the size of the zona glomerulosa.
Statistical methods:
data were transofrmed to their natural logarithm to achieve
homogeneity of variances and evaluated by analysis of varianceusing the STATA statistical analysis program. The Bonferroni
multicomparison test was used to calculate the significance ofthe differences. In case the variances were not homogenous
after log transformation and for the statistical evaluation of
the histopathology score of hypertrophy of the zona
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Test substance:
Reliability:
02-JUN-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
glomerulosa of the adrenals, the non-paramtetric
Wilcoxon-Mann-Whitney rank sum test was used to calculate thesignificance of the differences. p values < 0.05 wereconsidered statistically significant.
Chemical name: Potassium nitrite (CAS No. 7758-09-0)(2) valid with restrictions
(19)

Type:
Sub-chronic
Species:rat
Strain:WistarRoute of administration: drinking water
Exposure period:
90 daysFrequency of treatment: daily
Doses:
0, 100, 300, 1000, 3000 mg/L
Control Group:
yes, concurrent no treatment

Sex: male/female

Year:
GLP:
Test substance:

1988
no dataother TS

Result:LOEL = 100 mg KNO2/L, equivalent to 5.4 mg NO2/kg bw/day
There were no deaths and the rats appeared to be healthy
throughout the study. Ophthalmoscopic examination did notreveal any differences between the test rats and controls that
could be ascribed to treatment.
Body weight, food intake and food efficiency weredecreased at 3000 mg/L in males. Liquid intake wasdecreased at 3000 mg/L in males and females and 1000 mg/L
in males.
Methaemoglobin was increased at 3000 mg/L. Haemoglobin
associated parameters were depressed slightly at 1000 and 3000
mg/L, the changes being slight or very slight.
Hypertrophy of the adrenal zona glomerulosa was observed in
all test groups in a dose-dependent manner. The
incidence was not significally different from controls at
100 mg/L.

Test condition:
Strain and Species: Wistar derived SPF-bred rats
Animal Source: F. Winkelmann (Institute for the Breeding ofLaboratory Animals GmbH & Co. KG, Borchen, Germany)
Average Age When Studies Began:6 weeks
Acclimatisation: 13 days
Duration of Exposure: 90 days
Size of Study Groups: 10 rats/sex/dose
Method of Distribution: Animals were distributed randomly
into groups
Animals per Cage: 5Method of Animal Identification: no data
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Diet: Grain-based open formula diet (nitrite and nitratecontent 2 and 140 mg/kg, respectively) ad lib
Water: Tap water (nitrite and nitrate content <0.01 and 10
mg/L, respectively)
Cages: Stainless steel cages fitted with wire mesh front andfloor.
Animal Room Environment:
Temperature: 22+/-2°C
Relative humidity: 40-70%
Photoperiod: 12 hours light/dark cycle
Room air changes: Approximately 10/hour
Type and Frequency of Observation: Rats were weighed weekly
and observed daily for condition and behaviour. Ophthalmic
onservations were made in all rats of the control and top dosegroups prior to the administration of the test substance andduring week 13. Food and liquid intake were measured overweekly periods throughout the study.
Method of Sacrifice: Exsanguination from the abdominal aorta
whilst under light ether anaesthesia.
Necropsy: Rats were killed in wk 14 and a thorough autopsy was
performed. Immediately after evisceration, the adrenals,
brain, heart, kidneys, liver, ovaries, spleen, testes, thyroid
and thymus were weighed and the organ to body weight rations
calculated.
Clinical Pathology:
Hematology and clinical chemistry: Blood samples werecollected from the tip of the tail of all animals in wk 13 andwere examined for methaemoglobin concentration, haemoglobin
concentration, packed cell volume and erythrocyte, leucocyte
and thrombocyte counts and prothrombin times. Whole bloodtaken from each of the animals after an overnight fast was
examined for glucose. At autopsy, heparinised blood samples
collected fron the abdominal aorta of all rats were analysed
for alkaline phosphatase, aspartate aminotransferase, alanine
aminotransferase, total protein, albumin, total bilirubin,
urea, creatinine, glutathioneperoxidase,
gamma-glutamyltransferase and calcium, inorganic phosphate,chloride, sodium, potassium, nitrite, nitrate and vitamin E.
In week 4,8 and 13 nitrite was determined semiquantitatively
in the saliva from all rats of the 1000 and 3000 mg/L groups
and from the group receiving KCl instead of KNO2 in thedrinking water.
Clinical chemistry:
Histopathology: samples of the organs weighed and of thepituitary, lungs, aorta, parotoid salivary glands,
submandibular salivary glands, sublingual salivary glands,
oesophagus, forestomach, glandular stomach, small intestine,
pancreas, caecum, colon, rectum, urinary bladder,
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epididymides, prostate, uterus, mesanteric lymph nodes,
axillary lymph nodes and sciatic nerve were fixed in 10%
neutral buffered formalin embedded in paraffin wax, stainedwith haematoxylin and eosin and examined microscopically.

Test substance:
Reliability:
02-JUN-2005

Sperm Motility and Vaginal Cytology:
Test Substance: Potassium nitrite (CAS No. 7758-09-0)
Purity: >97%
Supplier: E. Merck, AG Darmstadt, Germany(2) valid with restrictions
(178)

Type:
Chronic
Species:rat
Strain:WistarRoute of administration: drinking water
Exposure period:
9 months
Frequency of treatment: continuous
Post exposure period:noDoses:
0, 0.2 % in drinking water
Control Group:
yes, concurrent vehicle
Result:

Test condition:

Test substance:
Reliability:
02-JUN-2005

The lipoperoxidation in the liver microsome was increased.
The free acid phosphatase was increased the total activity,
however degraded, which was similarly with that of lysosomal
enzyme Cathepsin. The superoxide dismutase activity waselevated in post-mitochondrial expulsion, while it reducedin mitochondria.
The hepatic microsomal lipoperoxidation activity, as
measured by malondialdehyde formation, was increased in male
Wistar rats given 0.2% sodium nitrite in drinking water.
Liver lysosomal enzyme (acid phosphatase and cathepsin) andsuperoxide dismutase activities were increased compared tothe controls. The data suggest that sodium nitrite
stimulates generation of superoxide radicals in the liverand causes damage to the cellular and subcellular membranes.
In this study the effect of sodium nitrite was investigatedon microsomal lipoperoxidation in the liver, for which
examines lysosomal enzyme activities in the liver and thecytosomal superoxide dismutase activity in the liver after
the treatment in vitro. Six animals per group were used.
Chemical name: Sodium ntirite (CAS No. 7632-00-0)(4) not assignable
(45)

Type:
Chronic
Species:rat
Strain:Long-Evans
Route of administration: oral feed
Exposure period:
21 days
Doses:
Dietary conc.= 0, 10, 25 g/kg
Year:
Remark:177

Sex: maleSex: female

1974
Sodium nitrite administered in feed at 10 or 25 g/kg tounilaterally ovariectomized Long-Evans rats for 21 days
inhibited body weight gain and caused a decrease in thecompensatory ovarian hypertrophy that follows
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

hemicastration. Decreased uterine, liver, and kidney weights
and increased spleen weights were also observed.
Test substance:
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Reliability:(4) not assignable
02-JUN-2005
(131)
Type:
Sub-chronic
Species:rat
Sex:
Strain:WistarRoute of administration: drinking water
Exposure period:
3 months
Frequency of treatment: daily
Doses:
0.3%
Remark:Test substance:
Reliability:
02-JUN-2005

The feeding sodium nitrite to male Wistar rats at 0.3% for 3
months did not affect relative liver weights or the
expression of hepatic c-Jun, c-Fos, or c-Myc oncogenes.
Chemical name: sodium nitrite (CAS No. 7632-00-0)(4) not assignable(79)

5.5 Genetic Toxicity 'in Vitro'
Year:

2001

Remark:Sodium nitrite is a direct-acting, base-pair substitution
mutagen in organisms ranging from bacteria to mammals. It
also has been shown to induce chromosomal effects in
mammalian cells in vitro and in vivo.
In an acidic environment, sodium nitrite reacts with amines toform nitrosamines or with amides to form nitrosamides. These
compounds are mutagenic in a variety of systems.
Nitrosamines require metabolic activation for expression ofmutagenic activity, but nitrosamides do not.
Positive results have been reported for sodium nitrite, withand without S9 metabolic activation enzymes, in Salmonella
gene mutation studies with strains that revert by base-pair
substitution. Genotoxicity of sodium nitrite is not often
detected in strains of S. typhimurium that mutate via
frameshift mechanisms. Gene reversion and DNA damage were also
observed in Escherichia coli WP tester strains after exposure
to sodium nitrite in the presence of S9.
Furthermore, sodium nitrite-induced gene mutations werereported in Saccharomyces cerevisiae, Candida utilis , andC. albicans.
In cultured mammalian cells, sodium nitrite was reported toinduce gene mutations, chromosomal aberrations and sister
chromatid exchanges (SCEs); in none of these experiments was
S9 required for the positive response. HeLa cells incubatedfor 1 to 36 hours had increased levels of unscheduled DNA
synthesis (DNA repair) at concentrations above 1 mM sodium
nitrite. In vivo, increased frequencies of micronuclei and8-azaguanine- and ouabain-resistant mutations, but not
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chromosomal aberrations, were seen in cells of Syrian golden
hamster embryos 24 hours after oral administration of 125,
250, or 500 mg/kg sodium nitrite to the dams. No increases inchromosomal aberrations were noted in lymphocytes of Wistar
rats 48 hours after a single gavage treatment of 300 mg/kg
sodium nitrite. However, positive results were reported for
induction of chromosomal aberrations in bone marrow cells ofpregnant female albino rats exposed to 210 mg/kg per day indrinking water for 13 days. In this same study, the liver
cells of embryos exposed trans- placentally for the first 13
days of gestation also showed increased numbers of chromosomal
aberrations. SCE induction increased with increasing dose inbone marrow cells of Swiss albino mice treated with 2.5 to 200
mg/kg sodium nitrite by intraperitoneal injection. In addition
to the demonstrated genotoxicity of sodium nitrite, concerns
about the effects of the compound arise from its ability totransform primary and secondary amines into N-nitroso
compounds, which are generally mutagenic after S9 activation.
Acid conditions facilitate the reaction of nitrite withamines, and this reaction is further catalyzed by alcohols andaldehydes, ultimately producing the actual nitrosating agent,nitrous anhydride.
There are numerous reports of mutagenic activity detected
after combined administration of sodium nitrite with amino
compounds. For example, sodium nitrite combined with the dyemetanil yellow induced dose-related increases in SCEs in thebone marrow of Swiss mice; the increase was significantly
greater than the increase in SCEs induced by sodium nitrite
alone. Amino acid derivatives in food stuffs (Amadori
compounds, <1 micro-M), when reacted with sodium nitrite (>1mM) under acidic conditions at normal body temperatures (37degree C), produced mutagenic nitrosated products and induced
high levels of unscheduled DNA synthesis in HeLa cells whenpresent in culture medium for 1 to 36 hours.
Transplacental exposure of cells of Syrian golden hamster
embryos to a combination of aminopyrine plus sodium nitrite,
administered to dams via gavage on days 11 or 12 of gestation,induced a significant increase in
8-azaguanine-resistant mutations compared to either compound
administered individually.
In a similar study, transplacental exposure to sodium nitrite
plus morpholine, administered simultaneously by gavage topregnant Syrian golden hamsters on days 11 or 12 of gestation,induced significant increases in 8-azaguanine- andouabain-resistant mutations, as well as micronuclei, inembryonic fibroblasts.
References cited:
Abe S and Sasaki M (1977) Studies on Chromosomal Aberrations
and Sister Chromatid Exchanges Induced by Chemicals. Proc.
Jpn. Acad. 53, 46-49
Alavantic D, Sunjevaric G, Cerovic D, Bozin D, Pecevski J(1988) Mutat. Res. 204, 609-701
Balimandawa M, de Meester C, Leonard A (1994) The Mutagenicity

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of Nitrite in the Salmonella/microsome Test System. Mutat.
Res. 321, 7-11
Brams A, Buchet JP, Crutzen-Fayt MC, De Meester C, Lauwerys R,
Leonard A (1987) A Comparative Study, with 40 Chemicals, ofthe Efficiency of the Salmonella assay and the SOS Chromotest(kit procedure). Toxicol. Lett. 38, 123-133
De Flora, S. (1981). Study of 106 Organic and Inorganic
Compounds in the Salmonella/microsome test. Carcinogenesis 2,283-298
De Flora S, Zanacchi P, Camoirano A, Bennicelli C, Badolati GS(1984) Genotoxic Activity and Potency of 135 Compounds in theAmes Reversion Test and in a Bacterial DNA-repair Test. Mutat.
Res. 133, 161-198
Ehrenberg L, Hussain S, Noor Saleh, M, Lundquist U (1980)
Nitrous esters - A Genetical Hazard from Nitrogen Oxides(NOx)? Hereditas 92, 127-130
El Nahas SM, Globus M, Vethamany-Globus S (1984) Chromosomal
Aberrations Induced by Sodium Nitrite in Bone Marrow of Adult
Rats and Liver Cells of Transplacentally Exposed Embryos. J.
Toxicol. Environ. Health 13, 643-647
Giri AK, Talukder G, Sharma A (1986) Sister Chromatid Exchange
Induced by Metanil Yellow and Nitrite Singly and in
Combination In Vivo on Mice. Cancer Lett. 31,
299-303
Grimmelikhuijzen CJP and Slater EC (1973)
Antimycin-insensitive Mutants of Candida Utilis. I. Isolation
and Characterization of Mutant 28. Biochim. Biophys. Acta 305,
67-79
Inoue K, Shibata T, Kosaka H, Uozumi M, Tsuda S, Abe T (1985)
Induction of Sister Chromatid Exchanges by N-nitrosocimetidine
in Cultured Human Lymphocytes and its
Inhibition by Chemical Compounds. Mutat. Res. 156, 117-121
Inui N, Nishi Y, Hasegawa MM, Taketomi M, Yamamoto M, Tanimura
A (1980) Induction of 8-azaguanine-resistant Mutation and
Neoplastic Transformation of Hamster Embryonic Cells by
Coadministration of Sodium Nitrite and Aminopyrine. J. Cancer
Res. Clin. Oncol. 97, 119-128
Inui N, Nishi Y, Mori M, Taketomi M, Yamamoto M, Tanimura A(1979) Detection of 8 Azaguanine Resistant Mutants ofEmbryonic Cells Induced by Products Formed in the Stomach on
Oral Administration of Sodium Nitrite plus Aminopyrine toPregnant Golden Hamsters. Proc. Jpn. Acad. 55, 286-289
Inui N, Nishi Y, Taketomi M, Mori M (1979) Transplacental
Action of Sodium Nitrite on Embryonic Cells of Syrian Golden
Hamster. Mutat. Res. 66, 149-158
Ishidate M Jr, Sofuni T, Yoshikawa K (1981) Chromosomal
Aberration Tests In Vitro as a Primary Screening Tool for
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ID: 7632-00-00
DATE: 04-JAN-2006
Environmental Mutagens and/or Carcinogens. Gann
Monogr. Cancer Res. 27, 95-108
Ishidate M Jr, Sofuni T, Yoshikawa K, Hayashi M, Nohmi T,
Sawada M, Matsuoka A (1984) Primary Mutagenicity Screening ofFood Additives Currently Used in Japan. Food Chem. Toxicol.
22, 623-636
Ishidate M Jr and Odashima S (1977) Chromosome Tests with 134
Compounds on Chinese Hamster Cells In Vitro-A Screening for
Chemical Carcinogens. Mutat. Res. 48, 337-353
Katz M, Kazmer S and Weinstein D (1980) An Analysis of Weak
Mutagens in the Ames Assay. J. Environ. Pathol. Toxicol. 3,
171-187
Kodama F, Umeda M, Tsutsui T (1976) Mutagenic Effect of Sodium
Nitrite on Cultured Mouse Cells. Mutat. Res. 40, 119-124
Kosako M and Nishioka H (1982) New Forward Mutation Assay
Using Low-Concentration Streptomycin Resistance Mutation in E.
Coli Strains with Plasmid pKM 101. Sci. Eng. Rev. Doshisha
Univ. 22, 239-249
Lilly LJ, Cobon AM, Newton MF (1979) Chromosomal Aberrations
Induced in Rat Lymphocytes by In Vivo Exposure to Chemicals. A
Short-term Method of Carcinogenicity Screening. Meth. Find.
Exp. Clin. Pharmacol. 1, 225-231
Toernqvist M, Rannug U, Jonsson A, Ehrenberg L (1983)
Mutagenicity of Methyl Nitrite in Salmonella Typhimurium.
Mutat. Res. 117, 47-54
Tsuda H and Kato K (1977) High Rate of Endoreduplications andChromosomal Aberrations in Hamster Cells Treated with Sodium
Nitrite In Vitro. Mutat. Res. 56,
69-74
Tsuda H, Inui N, Takayama S (1973) In Vivo Transformation of
Newborn Hamster Cells by Sodium Nitrite. Biochem. Biophys.
Res. Comm. 55, 1117-1124
Tsuda H, Kushi A, Yoshida D, Goto F (1981) Chromosomal
Aberrations and Sister-Chromatid Exchanges Induced by Gaseous
Nitrogen Dioxide in Cultured Chinese
Hamster Cells. Mutat. Res. 89, 303-309
Whong WZ, Long R, Ames RG, Ong TM (1983) Rule of Nitrosationin the Mutagenic Activity of Coal Dust: A Postulation for
Gastric Carcinogenesis in Coal Miners.
Environ. Res. 32, 298-304

Result:181

Zeiger E, Anderson B, Haworth S, Lawlor T, Mortelmans K (1992)
Salmonella Mutagenicity Tests: V. Results from the Testing of
311 Chemicals. Environ. Mol.
Mutagen. 19(21), 2-141
Sodium nitrite (100-10,000 ug/plate) was mutagenic in
Salmonella typhimurium strain TA100, with and without
Aroclor 1254-induced hamster and rat liver S9 enzymes; no
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Test condition:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
mutagenicity was observed in strain TA98. When sodium
nitrite was administered by intraperitoneal injection at
6.25 to 200 mg/kg to male rats three times at 24-hourintervals, no significant increase in the frequency of
micronucleated polychromatic erythrocytes was observed inany of the dose groups. The initial trial was judged to bepositive, based on the trend test (P=0.001); however,results of a repeat trial, in which 50 mg/kg was the highest
nonlethal dose tested, were negative, and the rat bonemarrow micronucleus test with sodium nitrite was judged tobe negative overall. A similar study in which male mice wereadministered 7.81 to 250 mg/kg also gave negative results. A
third in vivo study, a peripheral blood micronucleus test in
male and female mice administered sodium nitrite (375 to
5,000 ppm) for 14 weeks, showed no significant increase in
the frequency of micronucleated normochromatic erythrocytes
in either males or females. Thus, sodium nitrite
demonstrated mutagenic activity in a strain of S.
typhimurium that mutates via base-pair substitution, but no
indication of chromosomal damage was observed in three
micronucleus studies conducted in rats and mice in vivo.
The genetic toxicity of sodium nitrite was assessed by
testing the ability of the chemical to induce mutations invarious strains of Salmonella typhimurium and micronucleatederythrocytes in rat and mouse bone marrow and mouse
peripheral blood.
The genetic toxicity studies of sodium nitrite are part of alarger effort by the NTP to develop a comprehensive databasethat would permit a critical anticipation of a chemical's
carcinogenicity in experimental animals based on numerous
considerations, including the molecular structure of thechemical and its observed effects in short-term in vitro andin vivo genetic toxicity tests (structure-activity
relationships). These short-term genetic toxicity tests wereoriginally developed to clarify mechanisms ofchemical-induced DNA damage growing out of the earlier
electrophilicity/mutagenicity relationship proposed and thesomatic mutation theory of cancer. Therefore, theinformation obtained from these tests applies only tomutagenic carcinogens.
For mutagenic carcinogens, the combination of DNA reactivity
and Salmonella mutagenicity is highly correlated with theinduction of carcinogenicity in multiple species and gendersof rodents and at multiple tissue sites. Data from NTP
studies show that a positive response in Salmonella is themost predictive in vitro test for rodent carcinogenicity(89% of the Salmonella mutagens are rodent carcinogens) andthat there is no complementarity among the in vitro genetic
toxicity tests. That is, no battery of tests that included
the Salmonella test improved the predictivity of the
Salmonella test alone. Although other in vitro genetic
toxicity tests correlate less well with rodent
carcinogenicity compared with the Salmonella test, theseother tests can provide useful information on the types of
DNA and chromosomal effects induced by the chemical underinvestigation.
The predictivity for carcinogenicity of a positive response
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Test substance:
Conclusion:

Reliability:
01-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
in the acute in vivo bone marrow chromosome aberration testor micronucleus test appears to be less than that in the
Salmonella test However, clearly positive results inlong-term peripheral blood micronucleus tests are associatedwith high predictivity for rodent carcinogenicity; negative
results in this assay do not correlate well with either
negative or positive results in rodent carcinogenicity
studies. Because of the theoretical and observed
associations between induced genetic damage and adverse
effects in somatic and germ cells, the determination of invivo genetic effects is important to the overall
understanding of the risks associated with exposure to aparticular chemical. Most organic chemicals that are
identified by the International Agency for Research on
Cancer as human carcinogens, other than hormones, aregenotoxic. The vast majority of these are detected by boththe Salmonella assay and rodent bone marrow cytogenetics
tests.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Sodium nitrite was mutagenic in Salmonella typhimurium
strain TA100, with and without Aroclor 1254-induced hamster
and rat liver S9 enzymes; no mutagenicity was observed instrain TA98. Results of acute bone marrow micronucleus tests
with sodium nitrite in male rats and mice by intraperitoneal
injection were negative. In addition, a peripheral blood micro
nucleus assay conducted with mice from the 14-week study gave
negative results.
(2) valid with restrictions
(134)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Bacterial reverse mutation assay
Salmonella typhimurium TA1535, TA100, TA98, TA1537
25-2500 µg/platewith and without
positive

Method:Year:other: Ames et al (1975)
1980

Result:

The testing of 25, 250 and 2500 ug/plate with strain TA1535
resulted in definite mutagenic effects at 250 and 2500
ug/plate. A subsequent experiment indicated that aconcentration as low 80 ug/plate significantly increased
numbers of revertant colonies as compared to the appropriate
controls.

Test condition:

A definite mutagenic effect in observed with TA100 but notstrong as with TA1535. At lower limit of 250 ug/plate withthis strain for minimal detection in indicated. The
statistically significant elevation at 25 ug plus 3.125 mg
S9 is not substantiated since negative results are observed
at 80, 140 and 200 ug/plate. The completely negative effecton strains TA98 and TA1537 is observed.
DOSES IN ABSENCE AND PRESENCE OF ACTIVATION:
TA1535: Expt 1 - 0, 25, 250, 2500 µg/plate; Expt 2 - 0, 80,
140, 200 µg/plate
TA100: Expt 1 - 0, 25, 250, 2500 µg/plate; Expt 2 - 0, 80,
140, 200 µg/plate

183

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5. TOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
TA1537 and TA98: 0, 25, 250, 2500 µg/plate
METABOLIC ACTIVATION: S9 from rat liver, induced withphenobarbital and 5,6-benzoflavone
POSITIVE CONTROLS (+/-S9):
Cyclophosphamide (200 µg/plate): TA1535, TA100
Benzo(a)pyrene (10 µg/plate): TA98, TA1537

Test substance:
Reliability:
Flag:
03-JUN-2005

PLATES/TEST: 3
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Pfalz and Bauer, Inc.
(2) valid with restrictions
Critical study for SIDS endpoint
(101)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Year:
Method:Chromosomal aberration test
Syrian Hamster Embryo Cell
0, 5, 10, 20, 30, 50 mmol/Lwithout
positive

1977
Cells were ontained from a near-term whole embryo of a Syrian
hamster. In all the experiments the medium used was Eagle's
minimal essential medium supplemented with 10% fetal calf
serum, Neomycin (50 µg/mL) and Fungizone (1.25 µg/mL). Primarycultures of hamster cells were trypsinized and seeded in TD-40
flasks at a concentration of 1E+06 cells per flask. 24 hours
after seeding, the cells were exposed for 24 hours to a medium
containing the test substance at the rquired concentrations.
the cells were then washed twice with Hank's balanced solution
and maintained in a anormal complete medium for 24h. For thelast 3h, colcemid (0.3 µg/mL) was added. The chromosomes wereprepared by the method of Rothfels and Siminovitch.
Reference:

Result:Rothfels KH and Siminovitch L (1958) an air-drying techniquefor flattening chromosomes in mammalian cells grown in vitro.
Stain Technology, 33, 73-77
NaNO2 induced endoreduplications and chromosomal aberrations
as well as malignant transformation, in hamster cells in
vitro.
Concn Abnormal* Aberrations per 100 cells
NaNO2 Metaphase Gaps Chromatid Chromosome Exchange Minutes
(mM)
(%)
**
breaksbreaks
**
**
0
3
3
0
0
0
0
5
4
4
0
0
0
0
10
7
6
0
0
1
0
20
14
15
1
0
1
2
30
20
18
7
3
2
6
50
48
43
39
4
32
32
NaCl***
430
001*For control and treated cells, 100 metaphases were counted **UNEP PUBLICATIONS184

OECD SIDS
5. TOXICITY

Test substance:
Reliability:
Flag:
03-JUN-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
results represent the summation of chromatid type andchromosome type*** Cells were treated with 50 mM NaCl as an osmotic pressure
controlChemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Kanto Chemicals, Japan(2) valid with restrictions
Critical study for SIDS endpoint
(183)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Year:

Bacterial reverse mutation assay
Salmonella typhimurium TA92, TA1535, TA100, TA1537,
TA94, TA98
up to 10 mg/platewith and without
positive

1984

Result:Positive +/- metabolic activation in TA1535 and TA100

Test condition:
Test substance:

2800/plate at 10.0 mg/plate in TA1535 with S9 mix and2069/plate without S9 mix
465/plate in TA100 withS9 mix and 314/plate without S9 mix
Solvent; phosphate buffer
Chemcial name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 97.0%(2) valid with restrictions(93)

Reliability:
03-JUN-2005

Type:
System of testing:
Metabolic activation:
Result:Year:
Method:Result:DNA damage and repair assay
DNA repair test in Escherichia coli WP2, WP67, CM871
with and without
positive

1984
Liquid microethod procedure
Spot test-Liquid micromethod--MIC (ug) without S9 mix
WP2; 2500
WP67; 2500
CM871; 625--MIC (ug) with S9 mix
WP2; 3000
WP67; 3000
CM871; 1250--Potency (Delta MICs/nmol)
0.0003

Test substance:
Reliability:
06-JUN-2005
185-Spot test
Positive
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: reagent grade
Supplier: BDH(2) valid with restrictions(47)
UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Type:
System of testing:Concentration:
Result:Year:
Method:Bacterial forward mutation assay
Saccharomyces cerevisiae (diploid strain MP1)
0.058-0.43 mM
positive

1979
Media: Synthetic complete medium. The liquid complete medium
YEP is composed of 2% Bacto peptone (Difco No. 0118-01), 1%
yeast extract (Difco No. 0127-01) and 2% glucose.
Culturing of yeast cells: About 1000 yeast cells are
inoculated in a 300 mL Erlenmeyer flask containing 100 mL YEP,
set on a shaker and allowed to grow for 3 days at 25°C into
the stationary phase. For the detection of the spontaneous
frequency of interallelic recombination, the cultures ofstrains are stored at 4°C for 3-4 days. During this time
their spontaneous frequency is determined by spreading 0.1 mLfrom the YEP/yeast suspension on solid media selective forinterallelic recombinants. Only cultures with a low
spontaneous frequency are used for the experiments. The
cultures needed for one experiment are mixed together in orderto obtain a similar spontaneous frequency of genetic
alterations in both experiment and control.

Result:
Test substance:
Reliability:
07-JUN-2005

In vitro test: The cultured cells are washed twice with
distilled water and the cell titers are adjusted to 5E+08
cells per mL of 0.1 M phosphate buffer of pH 4.5. These cells
suspensions are incubated in a test tube on a shaker at 25°C
with different concentrations of the test substance. After 210
minutes treatments are stopped and 0.1 mL aliquots of thesuspensions (containing 5E+07 cells) are spread on four platesof solid media, selective for interallelic recombinants andmutants, respectively. Similarly, 0.1 mL aliquots of 1E-05
dilutions in distilled water (containing 5E+02 cells) areplated out on ten plates of complete medium to attain thenumber of survivors (white colonies) and intergenic
recombinants (red colonies or red sectors). These cultures
are incubated at 25°C and the survivor and recombinantcolonies are counted after 4 days. Actidione-resistantcolonies are incubated 8 days. The spontaneous frequency ofcolonies per plate is about 10 to 20 for the mutation system,
20 to 30 for the interallelic recombination system and 1-3 forthe intergenic recombination system.
Sodium nitrite shows weak toxic effects and accordingly thedose/effect curves are parallel for all three genetic
alterations (slope of about 1) only at the lower dose ranges.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 99%
Supplier: Schuchardt Munchen(2) valid with restrictions
(58)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Bacterial forward mutation assay
Escherichia coli WP2uvrA/pKM101
up to 10 mg/platewithpositive

UNEP PUBLICATIONS186OECD SIDS
5. TOXICITYYear:
Result:
Test condition:

Test substance:
Reliability:
06-JUN-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
1982
Dose response effect was seen in the SMr-5 mutagenicity of
NaNO2.
Mutagenicities of NaNO2 to streptomycin resistance at aconcentration of 5 uh/mL (SMr-5) were examined in E. coli
WP2 uvrA with plasmid pKM101 derived from S. typhimurium.
Solvent; water
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(108)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Bacterial reverse mutation assay
TA1530, TA1535, TA100, TA102, YG1024, DJ400, DJ460
1, 2.5, 5 mg/platewith and without
positive

Method:Year:

Directive 2000/32/EC, B.10
1994

Result:Nitrite is a direct mutagen in certain S. typhimurium hisstrains sensitive to base-pair substitutions (TA1530, TA1535
and TA100), whereas it is inactive in strain TA102 and inframeshift-sensitive strains containing increased
acetyltransferase activities (YG1024, DJ400 and DJ460).
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(13)

Test substance:
Reliability:
03-JUN-2005

Type:
System of testing:Concentration:
Metabolic activation:
Result:Bacterial reverse mutation assay
Salmonella typhimurium TA97, TA98, TA100
100 - 1000 µg/platewithpositive

Method:Year:other: Maron and Ames (1984)
1987

Result:TA97: negative
TA98: negative
TA100: positive (2.1= induced mutagenicity/solvent control)
DOSES IN ABSENCE AND PRESENCE OF ACTIVATION:
TA1535: Expt 1 - 0, 25, 250, 2500 µg/plate; Expt 2 - 0, 80,
140, 200 µg/plate

Test condition:

TA100: Expt 1 - 0, 25, 250, 2500 µg/plate; Expt 2 - 0, 80,
140, 200 µg/plate
TA1537 and TA98: 0, 25, 250, 2500 µg/plate
METABOLIC ACTIVATION: S9 from rat liver, induced with
Aroclor 1254
POSITIVE CONTROLS:-S9: 2-NF (TA97, TA98), NaN3 (TA100)+S9: 2-AA (TA97, TA98, TA100)
187

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Test substance:
Reliability:
03-JUN-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
PLATES/TEST: 3
REPLICATES: 2
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Merck(2) valid with restrictions
(22)

Type:
System of testing:Concentration:
Result:Year:
Test substance:
Reliability:
15-JUL-2005

Unscheduled DNA synthesis
HeLa S3 Carcinoma cells
0.0000001-0.006M
positive

1983
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade
Supplier: JT Baker Chemical Co. (Phillipsburg, NJ)(2) valid with restrictions
(115)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Year:
Result:Bacterial reverse mutation assay
Salmonell typhimurium TA98, TA100
0, 100, 333, 1000, 1666, 3333, 6666, 10000 ug/platewith and without
positive

1992
TA 100: Positive +/- S9
TA 98: Negative +/- S9
TA 100DOSE
NAµg/Plate MEAN SEM
0.000 171 5.5
100.000
333.333
1000.000 211 19.9
1666.666 224 10.6
3333.000 274 21.4
6666.000 376 7.5
10000.000 443 12.0
POS

878 22.7

30% HLI
MEAN
SEM
158
12.0
187
5.6
182
13.5
220
4.7

30%RLI
MEAN
SEM
173
6.2
199
14.7
233
6.4
230
11.8

309

11.7

312

10.4

451

20.1

353

5.4

894

24.1

555

18.3

TA 98
DOSE
NA
µg/Plate MEAN SEM
0.000
31 0.09100.000
27 0.6333.333
26 4.21000.000
30 3.51666.666
3333.000
25 2.6
6666.000
10000.000
26 2.830% HLI
MEAN
SEM
42
1.7
40
4.6
39
3.1
47
4.2

30%RLI
MEAN
SEM
40
4.8
33
3.6
41
3.8
29
1.0

42

2.1

33

2.8

30

5.2

21

5.0

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188OECD SIDS
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Test condition:
Test substance:
Reliability:
03-JUN-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
POS
432 19.0
539
6.1
155
14.3
METABOLIC ACTIVATION: S9 from rat liver, induced with
Aroclor 1254; S9 from hamster liver, induced with
Aroclor 1254
Chemical name: Sodium ntirite (CAS No. 7632-00-0)
Supplier: Pflaltz and Bauer, Inc(2) valid with restrictions
(206)

Type:
Bacterial reverse mutation assay
System of testing:
Salmonella typhimurium TA1530
Concentration:
0, 33.2, 66.5, 133 mmol/L
Cytotoxic Concentration: See RESULTMetabolic activation:
without
Result:positiveYear:
Result:

Test substance:
Reliability:
03-JUN-2005

1980-Cytotoxicity
Dose (mmol/L)/Survival (%)
0/100
33.2/100
66.5/100
133/79.5-Mutation frequency (X10E8)
0/2
33.2/666.5/8133/33Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(52)

Type:
System of testing:Concentration:
Metabolic activation:
Result:Year:
Result:

Chromosomal aberration test
CHL (Chinese Hamster Fibroblast cell line)
up to 1.0 mg/mL
without
positive

1984
Polyploid (%): 0.0%
Structural aberration; 71.0 (%)

Test condition:
Test substance:
Reliability:
03-JUN-2005

D20=0.41; TR=52
Positive at 24 hr (22%). Positive at 0.25 mg/mL at 24 hr(11.0%). Also positive at 0.5 mg/mL at 24 hr (16.0%) and at
48 hr (27.0%)
treatment hour; 24, 48 hours
Solvent; saline
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions

Type:
System of testing:189(91) (93)
Chromosomal aberration test
FM3A-Cell (Mammocarcinom-Cell line from C3H Mouse)
UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Concentration:
Metabolic activation:
Result:Year:
Result:

Test condition:
Test substance:
Reliability:
03-JUN-2005

10E-3 to 10E-1 mol/Lwithout
positive

1976
The chromosomal preparations demonstrated that severe
aberrations were induced in more than 80% of the mitotic
plates at 10(-2) M and in nearly 40% at 10(-25) M after 24
and 48 h treatment. According to the results of alkaline
sucrose gradient analysis sedimentation profiles of cell DNA
treated at as high as 10(-1) M for 24 h scarcely changed
from that of control cell DNA. Induction of
8-azaguanine-resistant mutation was demonstrated above
10(-3) M sodium nitrite.
Effect of sodium nitrite on cultured FM3A cells, a C3H mouse
mammary carcinoma cell line, was examined.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(106)

Type:
System of testing:
Metabolic activation:
Result:Bacterial reverse mutation assay
Salmonella typhimurium TA1535, TA1537, TA1538, TA98,
TA100
with and without
positive

Method:Year:other: Maron & Ames (1983)
1981

Result:-Reverted strains;
TA1535; positive
TA1537; negative
TA1538; negative
TA98; negative
TA100; positive-Range of activity (nmols/plate)
4-14.5X10E4-Muatgenic potency (revertants/nmol)
0.005-Effect of S9 mix (rat liver Aroclor)slight decrease

Test condition:
METABOLIC ACTIVATION: S9 from rat liver, induced with
Aroclor

Test substance:
Reliability:

PLATES/TEST: 3
REPLICATES: 3
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: reagent grade
Supplier: BDH(4) not assignable
Insufficient experimental detail

06-JUN-2005
Type:

(46)
other: Chromosomal aberration test, Sister-chromatid
exchanges
UNEP PUBLICATIONS

190

OECD SIDS
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

System of testing:Concentration:
Metabolic activation:
Result:Year:
Result:Chinese Hamster V79-H3-Cell0, 10, 50, 100 mmol/Lwithout
positive

1981-Chromosomal aberrations
Concentration (mmol/L)/Abnormal metaphases (%)
0/5
10/6
50/10
100/20-Sister-chromotid exchanges

Test substance:
Reliability:
03-JUN-2005

Concentration (mmol/L)/SCEs metaphases
0/5.6
10/5.350/8.0100/8.8
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(184)

Type:
System of testing:Concentration:
Result:Year:
Result:

Test substance:
Reliability:
03-JUN-2005

1977-Frequencies of Chromosomal aberration
Dose / Breaks cell(mL/mL)
1X10E-3 / 0.00
3X10E-3 / >0.24 (the presence of cells with 10 or more
breaks, more than 2-fold of control values)-Frequencies of SCEs
Dose / SCEs cell(mL/mL)
1X10E-3 / 5.53
3X10E-3 / 11.96 (more than 2-fold of control values)
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(1)

Type:
System of testing:Concentration:
Result:Year:
Result:191

other: Chromosomal aberration test, Sister-chromatid
exchanges
Chainese hamster cell line D-6
1, 3 mmol/L
positive

Sister chromatid exchange assay
Human peripheral blood lymphocytes
0, 0.0003, 0.003, 0.01, 0.03 mol/L
positive

1985
Concentration (mol/L)/No. of SCEs per cell
0/4.40
3X10E-4/4.24
3X10E-3/4.68
UNEP PUBLICATIONSOECD SIDS
5. TOXICITY

Test condition:
Test substance:
Reliability:
15-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
1X10E-2/8.94*
3X10E-2/No mitosis*; significantly different from control, p<0.001
Treatment time; 72 hours
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Merck(2) valid with restrictions
(87)

Type:
System of testing:Result:Year:other: Bacterial reverse mutation assay, Chromosomal
aberration test
Salmonella typhimurium TA98, TA100, TA1537, Chinese
hamster cell (CHL)
positive

1981

Result:-Ames test; Positive

Test condition:-Chromosomal aberration test; positive
D20 = 0.4 (mg/mL)
TR-value = 52 (mg/mL)-Ames test; without S9

Test substance:
Reliability:
15-JUL-2005-Chromosomal aberration test; with and without S9
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(92)

Type:
System of testing:Concentration:
Metabolic activation:
Result:
Test condition:
Test substance:
Reliability:

other
SOS Chromotest Kit; E. coli PQ37
6.9 ng/mL to 6.9 mg/mL
without
negative

Solvent; water
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Merck(4) not assignableNon-standard test method

06-JUN-2005(22)

5.6 Genetic Toxicity 'in Vivo'
Type:
Species:
Strain:Route of admin.:
Exposure period:
Doses:
Result:Micronucleus assay
rat
Sex: maleFischer 344
i.p.
3 days
6.25, 12.5, 25, 50, 100 or 200 mg/kg
negative

Method:Year:
GLP:

other: NTP method
2001
yes

Method:Male F344/N rats were injected i.p. (three times at 24-hourintervals) with sodium nitrite dissolved in phosphate-buffered
UNEP PUBLICATIONS

192

OECD SIDS
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
saline. Solvent control animals were injected withphosphate-buffered saline only. The positive control animals
received injections of cyclophosphamide. The animals were
killed 24 hours after the third injection and blood smears
were prepared from bone marrow cells obtained from the femurs.
Air-dried smears were fixed and stained. 2000 polychromaticerythrocytes (PCEs) were scored for the frequency of
micronucleated cells in up to 5 animals per dose group.

Test substance:
Reliability:
15-JUL-2005

The frequency of micronucleated cells among PCEs was analyzed
by a statistical software package that tested for increasing
trend over dose groups with a one-tailed Cochrane-Armitage
trend test followed by pairwise comparisons between each dosed
group and the control group.
200 mg/kg was found to be the lethal dose. No significant
increase in the frequency of micronucleated polychromaticerythrocytes was observed in any of the dose groups. The
initial trial was judged to be positive, based on the trend
test (P=0.001); however, results of a repeat trial, in which
doses of 0, 25 or 50 mg/kg bw were tested, were negative, andthe rat bone marrow micronucleus test with sodium nitrite wasjudged to be negative overall.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(134)

Type:
Species:
Strain:Route of admin.:
Exposure period:
Doses:
Result:Micronucleus assay
mouse
Sex: male
B6C3F1i.p.
3 days7.81, 15.63, 31.25, 62.5, 125, or 250 mg/kg
negative

Method:Year:
GLP:

other: NTP method
2001
yes

Method:Male B6C3F1 mice were injected i.p. (three times at 24-hourintervals) with sodium nitrite dissolved in phosphate-bufferedsaline. Solvent control animals were injected withphosphate-buffered saline only. The positive control animals
received injections of cyclophosphamide. The animals were
killed 24 hours after the third injection and blood smears
were prepared from bone marrow cells obtained from the femurs.
Air-dried smears were fixed and stained. 2000 polychromaticerythrocytes (PCEs) were scored for the frequency of
micronucleated cells in up to 5 animals per dose group.

Result:

Test substance:
Reliability:
15-JUL-2005

The frequency of micronucleated cells among PCEs was analyzed
by a statistical software package that tested for increasing
trend over dose groups with a one-tailed Cochrane-Armitage
trend test followed by pairwise comparisons between each dosed
group and the control group.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
(134)

Type:
Species:

Micronucleus assay
mouse

193

Sex: male/female
UNEP PUBLICATIONSOECD SIDS
5. TOXICITY
Strain:Route of admin.:
Exposure period:
Doses:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Result:

B6C3F1drinking water
14 weeks
0, 375, 750, 1500, 3000, or 5000 ppm in drinking water
available ad lib.
negative

Method:Year:
GLP:

other: NTP method
2001
yes

Method:At the end of the 14 week toxicity study, peripheral blood
samples were obtained from male and female mice. Smears wereimmediately prepared and fixed in absolute methanol. The
methanol-fixed slides were stained with acridine orange andcoded. Slides were scanned to determine the frequency of
micronuclei in 2000 normochromatic erythrocytes (NCEs) in eachof 10 animals per exposure group.
Exposure to 0, 375, 750, 1,500, 3,000 or 5,000 ppm in drinking
water was equivalent to approximate daily doses of 0, 90,
190, 345, 750, or 990 mg/kg bw/day in males and 0, 120, 240,
445, 840, or 1,230 mg/kg bw/day in females.

Result:

Test substance:
Reliability:
15-JUL-2005
Type:
Species:Route of admin.:
Exposure period:
Doses:
Result:Year:
Result:

Test condition:

There was no significant increase in the frequency of
micronucleated NCEs in either males or females.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(134)
other: micronucleus formation, chromosomal aberrations,morphological or malignant transformation and drug-resistantmutations in embyonic cells
hamster
Sex: female
gavageonce
125, 250, 500 mg/kg
positive
1979
Marked dose-dependant increases in micronucleus formation,induction of 8-azaguanine- and ouabain-resistant mutations andmorphological or neoplastic transformations in the embryo
cells were observed. However, there was no marked increase in
the frequency of chromosomal aberrations.
Animal; Syrian golden hamster, 150 +/- 30g on the 11th or
12th day of pregnancy
Source: Matsumoto Experimental Animal Lab., Chiba, Japan.
Solvent; saline solution
Sample; fetuses excised after dosing of NaNO2, for culture
Transplacental application of NaNO2:
The hamsters were given 0.5-1 mL of physiological saline
solution containing 0, 125, 250 or 500 mg NaNO2/kg bw by
gavage.The dose of 500 mg/kg bw NaNO2 proved to be above theLD50 dose within 24 h for pregnant hamsters. The hamsters were
fed standard laboratory chow (Clea Japan Ltd., Tokyo) andwater ad libitum just before and for 24 h after administrationof NaNO2. Their fetuses were then excised. The babies from
UNEP PUBLICATIONS

194OECD SIDS
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
mothers treated with 500 mg/kg bw NaNO2 and with DMN served as
negative and positive controls, respectively.
Primary cultures:
The fetuses were chopped up finely with scissors and digested
with 0.25% trypsin at room temperature for 45 min. Primarycultures of trypsinised cells were initiated by seeding
5-10E+05 cells into 10 mL of medium in 75 cm2 plastic flasks.
Most cells were grown in Eagle's minimal essential medium
supplemented with 10% fetal calf serum but some cells were
cultured in Dulbecco's modified Eagle's medium plus 20% FCS at
37°C under 5% CO2 in air.
Examination of chromosomes:
For examination of chromosomes within the first 24 h ofprimary culture, cells grown in MEM were treated with colcemid
at 0.3 µg/mL for 3 h. Mitotic cells in the first cell cycle
were then examined. Chromosome preparations were made by theusual air-drying method with a slight modification and stainedwith Giemsa. The numbers and types of chromosomal
abnormalities were assessed by examining 200 well-spead
metaphase plates. For examination of micronuclei, samples
were made by a modification of the method of Schmid: after
culture for 30 h, the cells were collected with 0.1% trypsin,smeared on slide glasses, fixed with methanol and stained with
Geimsa. In each experiment, over 5000 resting nuclei were
examined for micronuclei.

Test substance:
Reliability:
Flag:
01-JUL-2005

Induction of morphological transformation:
For determination of transformation, the cells were cultured
in DMEM plus 20% FCS for 3-5 days from primary culture andthen seeded in inocula of 5000/60 mm dish for studies oncolony formation and transformation. The dishes wereincubated for 8 days without change of medium then fixed andstained with Giesma solution. The number of colonies wasdetermined. Some transformed colonies were cloned by thecylinder-cup method and cultured in DMEM medium for 7-9 weeks.
Then 5-10E+06 cells from the transformed colonies were
implanted into the cheek pouches of young golden Syrian
hamsters weighing 80-110 g to test for malignant
transformation.
Name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions
Critical study for SIDS endpoint
(90)

Type:
Species:
Strain:Route of admin.:
Exposure period:
Doses:
Result:other: chromosomal aberration in bone marrow of rats
rat
Sex: male/female
other: albino
drinking water
day 0 to 18
mean 210 mg/kg/day
positiveYear:
Result:195

1984
Chromosomal aberrations comprising chromatid gaps, breaks(mainly chromatid, including fragments and deletions), centric
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fusions, and dicentrics were induced in the bone marrow ofadults and the liver of transplacentally exposed embryos. All
aberrant cells had one aberration, with the exception of a few
cells where two or more aberrations were found.
Pregnant and nonpregnant females treated with nitrite showed asignificant increase (p<0.01) in chromosomal aberrations ofbone marrow cells over the control. However there was nodifference between the two groups and their results werepooled.
In the liver of transplacentally exposed embryos, there wasalso a significant increase (p<0.001) in the number of cellswith chromosomal aberrations.
The number of cells with hypoploidy was not stasticallysignificant in maternal bone marrow and embryo liver oftreated and control groups. Cells with hyperploidy were rare
in both bone marrow and embryonic liver.
Adult bone marrow-control/3.31%
Adult bone marrow-treated/9.60%
ratio treated/control=2.90

Test condition:

Embryonic liver-control/1.75%
Embryonic liver-treated/8.62%
ratio treated/control=4.93
Animal;15-20 week old
Virgin female rats were mated with males. The day on which
sperm were found in the vaginal smears was designated as day 0of gestation.
Sodium nitrite (1.25 g/L) was given in the drinking water(deionized). The water was changed daily and the volume
consumed per rat was recorded. All adults were treated for aperiod of 13 days, from day 5-day 18 of gestation in the caseof pregnant animals. Untreated rats served as controls.

Reliability:
Flag:
01-JUL-2005

At the termination of treatment the rats were sacrificed and3-4 living embryos per litter were removed as quickly as
possible. The liver of each embryo was transferred to 5 mL MEM
supplemented with 10% fetal bovine serum and forced through astainless steel mesh yielding a cell suspension. The bonemarrow cells from the femur of the adult were also collected
in 5 mL culture medium. The cell suspensions, to which 0.5 mg
colchine was added, were then incubated for 2 h at 37°C in an
atmosphere of 5% CO2 in air. Maternal and embryo chromosomes
were prepared in accordance with standard cytogenetic
procedures. Slides were prepared and stained with giemsa. At
least 50 metaphase spreads wee examined for each adult rat andembryo for chromosomal aberrations.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Matheson, Coleman, Coleman and Bell)(2) valid with restrictions
Critical study for SIDS endpoint
(53)

Type:
Species:

Sister chromatid exchange assay
mouse

Test substance:

Sex: male

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Strain:Route of admin.:
Exposure period:
Doses:
Result:Year:
Result:

Test condition:

Reliability:
15-JUL-2005

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Swiss
i.p.
once
2.5, 5, 10, 20, 40, 100, 200 mg/kg
positive
1986
In vivo sister chromatid exchanges induced by metanil yellow(dye containing secondary amino group), sodium nitrite, anddye combination with nitrite following treatment with acutedoses were on mice. The incidence of SCEs was significantly
high in both dye- and nitrite-treated series. However, acombination of half the concentrations of dye and nitrite,when used together, gave a frequency of SCE higher than thatof either chemical, when given in full dose, indicating thestronger clastogenicity of the nitrosamine formed.
Animal: laboratory-bred Swiss albino male mice (Musmusculus), 30g, about 90-100 days old
7 animals/group
Solvent; water(2) valid with restrictions
(65)

Type:
Species:
Strain:Route of admin.:
Exposure period:
Doses:

Heritable translocation assay
mouse
C3H
gavage14 days60, 120 mg/kg/day

Method:
Year:
GLP:

other
1988
no dataResult:A lack of heritable translocations, sperm abnormalities, aswell as morphological changes, such as changes in eyes, coatcolour, testes and body weight, was demonstrated in F1 males
originating from treated P males. Significant effects intreated males were found with respect to:(1) sex-chromosomal univalency in the diakinesis-methaphaseI stage after the treatment of stem spermatogonia (thehigher dose of sodium nitrite),(2) sperm-head abnormalities after treatment ofdifferentiating spermatogonia (both doses of sodium nitrite)(3) fertility after treatment of spermatids (the higher doseof sodium nitrite).
In all experiments mature F1 male and female mice (10-12 weeksold) of the hybrid strain C3HX101 were used.

Test condition:

Sex: maleAnimals were housed in wire-topped polycarbonate cages understandard laboratory conditions (T=21°C, 60% RH, 12-h day-nightrhythm, water and food ad libitum).
Experimental doses were 60 and 120 mg/kg/day for 14 days.
Statistical processing of results was performed using
Student's t-test.
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Heritable translocation test:
Mice (25 males/group) were dosed by gavage with sodium nitrite
solution (0, 60 or 120 mg/kg bw) daily for 14 days.
Ten days
after the last treatment each male was mated with two virgin
females. The interval of mating was seven days after whichmales were taken out and left for later examination. Numbersof both fertile and sterile females, litter size per fertile
female, sex ratio and survival of offspring were noted. Three
weeks after birth F1 males were taken out and left until
maturation (10-12 weeks). Cytogenetic analyses were performedon spermatocytes (diakinesis-metaphase I) in all F1 males fromtreated males of the P generation (up to three males from eachlitter) and in 25 F1 males from controls.
Tests were performed for cytogentic analysis of P males andsperm abnormality tests on P males and F1 males. for all males
in the experiment both testes and body weight were determined
and changes in eyes and coat colour were noted.

Test substance:
Reliability:
01-JUL-2005
Type:
Species:Route of admin.:
Exposure period:
Doses:
Result:Result:

Test condition:

Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Yugoslav Institute for Meat Technology (Belgrade).
(2) valid with restrictions(5)other: 8-azaguanine-resistant mutation and neoplastictransformation
hamsterSex:
gavageonce
0, 25, 50, 100 mg/kg
positivea) 8-azaguanine-resistant mutation
Dose (mg/kg);Induced ratio (induced freq./sponteous freq.)25; 1.5
50; 1.3
100; 3.7b)Neoplastic transformation
Dose (mg/kg);Transformation rate (%)
Control; 0.22 +/- 0.23
25; 0.60 +/- 0.41
50; 0.79 +/- 0.26 (p<0.05)
100; 0.82 +/- 0.25 (p<0.05)
On the 11th and 12th days of pregnancy Syrian golden
hamsters weighing 150 +/- 40g, from a closed colony.
Solvent; water

Test substance:
Reliability:
01-JUL-2005
Type:
Species:
Strain:Examined tissue; embryonic cell
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
supplier: Wako Chemical Indust., Japan(2) valid with restrictions(88) (89)
Micronucleus assay
mouseother: NIH

Sex: male

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Route of admin.:Doses:
Result:Year:
Result:SODIUM NITRITE
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gavage0, 10, 15 or 20 mg/kg bw
positive
2002

Reliability:
15-JUL-2005

The treated animals showed a statistically significant
increase (p=0.05) in micronucleated polychromatic erythrocytes
at all doses compared with the 0h values ( MNPCE/1000 PCE =1.2+/-0.58 (0h), 4.8+/-0.37 (96h) at 10 mg/kg; 0.4+/-0.24(0h), 5.0+/-0.31 (96h) at 15 mg/kg; and 1.0+/-0.31 (0h),5.8+/-0.85 (96h) at 20 mg/kg). No statistical differenceswere observed in the PE/NE ratio when their results werecompared before and after treatment, suggesting that sodium
nitrite produced no significant influence on normal bonemarrow activity in this study.
0, 10, 15 or 20 mg/kg of sodium nitrite administered orally
four times at 24-hour intervals and peripheral blood samples
examined after 96 hours.
Chemical name: Sodium nitrite (CAS No 7632-00-0)
Supplier: Sigma Chemicals (St Louis MO, USA)(2) valid with restrictions
(48)

Type:
Species:
Strain:Route of admin.:
Exposure period:
Doses:
Result:other: chromosomal aberration
rat
Wistaroral unspecified
once
300 mg/kg
negative

Test condition:
Test substance:Year:
Result:
Test condition:

Test substance:
Reliability:
01-JUL-2005

Sex: female

1979
Total aberration (%) = 3
Significant difference was not observed.
Test flow
1)administration to rat2)rat lymphocytes
3)culture4)harvest5)scoreChemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(114)

5.7 Carcinogenicity
Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
2 years
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 750, 1,500, or 3,000 ppm in drinking water,
available ad libitum
Result:negative
Control Group:
yes, concurrent vehicle
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Method:Year:
GLP:

other: FDA (21 CFR, Part 58)
1997
yes

Result:Survival
Survival of exposed groups was similar to that of thecontrol groups.
Body Weights, Water and Compound Consumption, and ClinicalFindings
Mean body weights of males and females exposed to 3,000 ppm
were less than those of the control groups throughout the
study. Water consumption by males and females exposed to3,000 ppm was less than that by the controls throughout the
study, and that by the other exposed groups was generally
less after week 14. Drinking water concentrations of 750,
1,500, or 3,000 ppm sodium nitrite resulted in average daily
doses of approximately 35, 70, or 130 mg/kg body weight tomales and 40, 80, or 150 mg/kg to females. There were noclinical findings related to exposure to sodium nitrite; thebrown discoloration and cyanosis seen in the 14-week studies
were not observed.
Determination of Plasma Nitrite and Blood Methemoglobin
Concentrations
At 2 weeks and 3 months, no nitrite was detected in theplasma of control male or female rats. Plasma nitrite
concentrations tended to increase with increasing exposure
concentrations of sodium nitrite. Generally, plasma nitrite
concentrations were high at night when the rats wereactively feeding and drinking, and were low during the day
when the rats were less active. Blood methemoglobin
concentrations followed the same pattern.
In 18-month-old male and female rats administered a single
dose of 40 mg/kg sodium nitrite by gavage,
plasma nitrite and blood methemoglobin concentrations peakedat 30 minutes.
Pathology and Statistical Analyses
This section describes the statistically significant or
biologically noteworthy changes in the incidences ofneoplasms and/or nonneoplastic lesions of the forestomach,
mammary gland, liver, kidney, and skin and in the incidencesof mononuclear cell leukemia. Summaries of the incidences ofneoplasms and nonneoplastic lesions, individual animal tumor
diagnoses, statistical analyses of primary neoplasms that
occurred with an incidence of at least 5% in at least one
animal group.
Forestomach: The incidences of hyperplasia of the squamous
epithelium were significantly increased in males and females
exposed to 3,000 ppm. Hyperplasia was generally a minimalchange affecting the epithelium of the limiting ridge at thejunction of the forestomach and glandular stomach. In a few
cases, severe hyperplasia was seen both at and away from thelimiting ridge. Hyperplasia was characterized primarily by
variable degrees of folding of the squamous epithelium andwas usually accompanied by a variable degree of thickeningof the overlying keratin layer (hyperkeratosis). No
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forestomach neoplasms were observed following exposure to
sodium nitrite.
Mammary Gland: The incidence of fibroadenoma wassignificantly increased in females exposed to 1,500 ppm
sodium nitrite and exceeded the historical range for NTP
controls given NTP-2000 diet (all routes) or NIH-07 diet(drinking water route) (24%-58%). The incidences in the 750
and 3,000 ppm groups also exceeded the range for the NTP
controls given NTP-2000 diet; the incidence in the control
group was greater than in these exposed groups and equaled
the highest incidence in the NTP-2000 historical control
database. Also, when combined with adenomas, there were no
significant increases in the incidences of these neoplasms.
The incidences of carcinoma were not increased in the
exposed groups. The incidences of multiple fibroadenoma weregreater in females exposed to 750 ppm and 1,500 ppm than incontrols. Fibroadenomas are the most common benign neoplasmsthat occur in the mammary gland of female F344/N rats.
However, unlike benign neoplasms in other tissues thatusually progress to malignancy, fibroadenomas are generally
considered to represent an end-stage lesion, and progression
to carcinoma is rare. Microscopically, fibroadenomas in
exposed rats were similar to those in the controls and werecharacterized by collections of glandular epithelium
arranged in acini and ducts and surrounded by fibrousconnective tissue. The relative amounts of glandular andfibrous elements varied among neoplasms. Epithelial cells
were well differentiated and arranged in a single layer of
cuboidal epithelium, which was often vacuolated.
Liver: There were significant increases in the incidences ofchronic active inflammation in 1,500 and 3,000 ppm males (0ppm, 13/50; 750 ppm, 19/50; 1,500 ppm, 25/50, 3,000 ppm,
24/50). This was generally a minor lesion, characterized bya few to several scattered aggregates of mixed mononuclear
inflammatory cells, mainly lymphocytes and macrophages.
Chronic active inflammation of the liver is a common
spontaneous lesion in F344/N rats and may be obscured inrats with mononuclear cell leukemia. Because of the lower
incidences of mononuclear cell leukemia, this common
background lesion was more easily observed microscopically.
The marginally increased incidences of chronic active
inflammation in 1,500 and 3,000 ppm males were notconsidered to be related to sodium nitrite exposure.
Kidney: The incidence of nephropathy was marginally
increased in females exposed to 3,000 ppm (14/50, 16/50,
20/50, 23/50). It is unclear whether the slightly increased
incidences of nephropathy were directly related to sodium
nitrite exposure. Nephropathy is a common spontaneous renal
lesion in F344/N rats.
Skin: The incidence of fibroma of the subcutis was
significantly increased in males exposed to 1,500 ppm (0/50,
1/50, 6/50, 3/50). The incidence in this group slightly
exceeded the historical range for NTP controls (all routes)
given NTP-2000 diet. The lack of a dose response for fibroma
or a significant increase in the incidences of fibrosarcomas(1/50, 0/50, 0/50, 2/50) and the fact that the combined

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incidences of fibroma or fibrosarcoma (1/50, 1/50, 6/50,
5/50) are within the historical range for NTP controls given
NTP-2000 diet suggest that these neoplasms were not related
to sodium nitrite exposure. Fibromas and fibrosarcomas are
the most common neoplasms that occur in the skin of F344/N
rats.
Mononuclear Cell Leukemia: The incidences of mononuclear
cell leukemia were significantly decreased in males andfemales exposed to 1,500 or 3,000 ppm and were less than thehistorical ranges for NTP controls (all routes) given
NTP-2000 diet. These findings indicate that sodium nitrite
reduced the incidence of mononuclear cell leukemia in F344/N
rats, thereby resulting in increased survival.
-Male:
Concentrations in drinking water: 0, 750, 1,500, or 3,000
ppm
Body weights: 3,000 ppm group less than the control group
Survival rates: 29/50, 38/50, 36/50, 36/50
Nonneoplastic effects: Forestomach: epithelial hyperplasia(12/50, 9/50, 10/50, 44/50)
Neoplastic effects: None
Uncertain findings: None
Decreased incidences: Mononuclear cell leukemia: (17/50,
12/50, 7/50, 3/50)
Level of evidence of carcinogenic activity: No evidence

Test condition:-FemaleConcentrations in drinking water: 0, 750, 1,500, or 3,000
ppm
Body weights: 3,000 ppm group less than the control group
Survival rates: 33/50, 31/50, 36/50, 33/50
Nonneoplastic effects: Forestomach: epithelial hyperplasia(8/50, 6/50, 8/50, 40/50)
Neoplastic effects: None
Uncertain findings: None
Decreased incidences: Mononuclear cell leukemia: (15/50,
10/50, 1/50, 1/50)
Level of evidence of carcinogenic activity: No evidence
Study Laboratory:
Battelle Columbus Laboratories(Columbus, OH)
Strain and Species:
Rat F344/N
Animal Source:
Taconic Laboratory Animals and Services (Germantown, NY)
Time Held Before Studies:
11 days (males) or 12 days (females)
Average Age When Studies Began:
6 weeks
Duration of Exposure:
105 weeks
Average Age at Necropsy:
110 weeks
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Size of Study Groups:
Core study: 50 males and 50 females; special study, 10
males and 10 females; aged sentinel animal study, 15 males
and 15 females
Method of Distribution: Animals were distributed randomly
into groups of approximately equal initial mean body weights
Animals per Cage:core study, 2 or 3 (males) or 5 (females); special study, 2
or 3 (males) or 5 (females); aged sentinel animal study, 3
Method of Animal Identification:
Tail tattoo
Diet:
NTP-2000 pelleted diet, irradiated beginning 22 July 1996,
changed weekly
Water:
Tap water (Columbus, OH, municipal supply) via amber glass
bottles with stainless steel sipper tubes, available adlibitum and changed twice weekly.
Cages:
Solid-bottom polycarbonate
Bedding:Sani-Chips
Cage Filters:
DuPont 2024 spun-bonded polyester filter (Snow Filtration
Co., Cincinnati, OH)
Racks:
Stainless steel
Animal Room Environment:
Temperature: 72 degree +/-3 degree F
Relative humidity: 50% +/- 15%
Room fluorescent light: 12 hours/day
Room air changes: equal or more than 10/hour
Exposure Concentrations:0, 750, 1,500, or 3,000 ppm in drinking water, available adlibitum
Type and Frequency of Observation:
twice daily. Core study animals were weighed initially andclinical findings and body weights were recorded on day 8,
day 36, at 4-week intervals thereafter, and at necropsy.
Special study rats were weighed at 2 weeks and 3 months,
special study mice were weighed at 12 months, and aged
sentinel animal rats and mice were weighed at 18 months.
Drinking water consumption by the core study animals wasmeasured over a 1-week period at 4-week intervals, beginningduring the first week of the study.
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CO2 asphyxiation
Necropsy:
Necropsy was performed on all core study animals and fivemale and five female aged sentinel animals.
Histopathology:
Complete histopathology was performed on all core study
animals. In addition to gross lesions and tissue masses, thefollowing tissues were examined: adrenal gland, bone andmarrow, brain, clitoral gland, esophagus, heart, large
intestine (cecum, colon, rectum), small intestine (duodenum,
jejunum, ileum), kidney, liver, lung, lymph nodes(mandibular and mesenteric), mammary gland, nose, ovary,pancreas, parathyroid gland, pituitary gland, preputial
gland, prostate gland, salivary gland, spleen, skin, stomach(forestomach and glandular), testis (and epididymis andseminal vesicle), thymus, thyroid gland, trachea, urinary
bladder, and uterus.
Plasma Nitrite and Blood Methemoglobin Concentrations:
Blood was collected from the retroorbital sinus of 10 maleand 10 female special study rats at 2 weeks and 3. Blood
was collected from two animals per group per time point(0600, 1200, 2100, 2400, and 0300 hours).
Blood was collected from the retroorbital sinus of 15 maleand 15 female aged sentinel animals after a single gavage
dose of 40 mg/kg at 18 months. Two or three animals were
sampled at each time point (2, 5, 10, 30, or 60 minutes
after dosing). Plasma nitrite and blood methemoglobin
concentrations were determined.

Test substance:

Conclusion:

Reliability:
Flag:
18-JUL-2005

Statistical analyses were conducted about survival rate,
neoplasm and non-neoplastic lesion incidences.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: >99%
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Lot No. A42340 and H05714
Under the conditions of this study there is no evidence of
carcinogenic activity of sodium nitrite in F344/N rats at
approximate doses of up to 130 mg/kg bw/day in males and 150
mg/kg bw/day in females over a two year period.
(1) valid without restriction
Critical study for SIDS endpoint(134)

Species:mouse
Sex: male/female
Strain:B6C3F1
Route of administration: drinking water
Exposure period:
2 years
Frequency of treatment: continuous
Post exposure period:
none
Doses:
0, 750, 1,500, or 3,000 ppm in drinking water,
available ad libitum
Result:ambiguous
Control Group:
yes, concurrent vehicle
Method:Year:
GLP:

other: FDA (21 CFR, Part 58)
1997
yes
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Test substance:other TS

Result:Survival
Survival of exposed groups was similar to that of thecontrols.
Body Weights, Water and Compound Consumption, and ClinicalFindings
Mean body weights of exposed groups were generally similar
to those of the controls throughout the study, except mean
body weights of 3,000 ppm females were consistently lessthan those of the controls. Water consumption by the exposedgroups was generally less than that by the control groups.
Drinking water concentrations of 750, 1,500, or 3,000 ppm
resulted in average daily doses of approximately 60, 120, or
220 mg/kg for males and 45, 90, or 165 mg/kg for females.
There were no clinical findings related to exposure to
sodium nitrite.
Determinations of Plasma Nitrite and Blood Methemoglobin
Concentrations
At 12 months, no nitrite was detected in the plasma ofcontrol or 750 ppm male mice or in any group of female mice.
In general, there was an exposure concentration-related
increase in plasma nitrite in the 1,500 and 3,000 ppm male
mice; peak plasma nitrite concentrations occurred around
midnight. Blood methemoglobin concentrations were similar
among exposed groups of males and females.
Pathology and Statistical Analyses
This section describes the statistically significant or
biologically noteworthy changes in the incidences ofneoplasms and/or nonneoplastic lesions of the forestomach,glandular stomach, lung, and skin. Summaries of theincidences of neoplasms and nonneoplastic lesions,individual animal tumor diagnoses, statistical analyses ofprimary neoplasms that occurred with an incidence of atleast 5% in at least one animal group.
Forestomach: The incidences of squamous cell papilloma or
carcinoma (combined) in female mice occurred with a positive
trend, and the incidence in 3,000 ppm females exceeded thehistorical range for NTP controls given NTP-2000 diet (allroutes) or NIH-07 diet (drinking water route) (range 0%-4%).
Because both of these historical databases are rather small,the historical incidences of forestomach squamous cell
papilloma or carcinoma (combined) in NTP controls given NIH07 diet in studies with other routes of chemical
administration were evaluated, such as feed controls andinhalation controls.The incidence of squamous cell papilloma
or carcinoma (combined) in the 3,000 ppm females exceeded
these historical incidences with the exception of corn oil
gavage studies, where as many as five papillomas, but nocarcinomas, were observed in one control group. Hyperplasiaof the squamous epithelium was observed more frequently in
3,000 ppm females than in the controls. Forestomach
neoplasms were not observed in male mice exposed to sodium
nitrite. Proliferative lesions involving the squamous
epithelium represent a continuum, progressing from focal
hyperplasia to papilloma to squamous cell carcinoma.
Hyperplasia was generally a mild change affecting the205

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squamous epithelium of the limiting ridge at the junction of
the forestomach and glandular stomach. Papillomas consistedof a solitary stalk of lamina propria protruding into thelumen with multiple finger-like projections arising from thestalk. The epithelium covering the projections was
hyperplastic. In carcinomas, there was a focal invasion of
the squamous epithelium into the lamina propria; however,there was no infiltration of neoplastic cells through theserosa of the forestomach, and there was no metastasis.
Glandular Stomach: The incidence of epithelial hyperplasia
was significantly greater in 3,000 ppm males than in thecontrols. Hyperplasia of the glandular stomach epithelium
was focally extensive and was characterized by a distorted
and irregular arrangement of the glandular elements of thegastric mucosa. In the hyperplastic areas, the proportion of
the gastric glands with mucus-secreting cells was reduced to25% compared to 50% in the normal area. In addition, theparietal cells in the mid portion of the gastric glands wereless distinct in the hyperplastic areas. Instead of large,
cuboidal cells with eosinophilic cytoplasm (characteristicof normal parietal cells), the parietal cell area tended tobe composed of smaller, elongated, basophilic cells withvesiculated, fusiform nuclei and relatively scant cytoplasm
consistent with chief cells. There were no neoplasms of theglandular stomach.
Lung: The incidences of alveolar/bronchiolar adenoma or
carcinoma (combined) in exposed groups of females wereslightly greater than that in the control group. (1/50,
6/50, 5/50, 6/50). However, the incidences of these lesions
were within the historical range for controls (all routes)
given NTP-2000 diet [17/250 (6.8% +/- 5.6%), range 0%-12%].
The increased incidences were not statistically significant
or exposure concentration related and were not accompanied
by increased incidences of preneoplastic lesions; therefore,
the lung neoplasms in exposed females were not considered tobe related bitrite exposure.
Skin: The incidence of fibrosarcoma in 750 ppm females was
significantly greater than that in the controls (0 ppm,
0/50; 750 ppm, 5/50; 1,500 ppm, 1/50; 3,000 ppm, 2/50). The
incidence exceeded the historical range for NTP controls(all routes) given NTP-2000 diet [3/250 (1.2% +/- 1.8%),
range 0%-4%]. The lack of a dose response for fibrosarcomas
and the fact that the combined incidence of fibroma or
fibrosarcoma (0/50, 5/50, 1/50, 3/50) fell within thehistorical range for NTP controls given NTP-2000 dietsuggest that these neoplasms were not related to sodium
nitrite exposure. The most frequent spontaneous mesenchymal
neoplasms of the subcutaneous skin in female mice in theorder of occurrence were fibrosarcomas, sarcomas, andlipomas.
-Male:
Concentrations in drinking water: 0, 750, 1,500, or 3,000
ppm
Body weights: Exposed groups similar to the control group
Survival rates: 39/50, 45/50, 42/50, 39/50
Nonneoplastic effects: Glandular stomach: epithelial
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hyperplasia (0/50, 0/50, 2/50, 10/50)
Neoplastic effects: None
Uncertain findings: None
Decreased incidences: None
Level of evidence of carcinogenic activity: No evidence

Test condition:-FemaleConcentrations in drinking water: 0, 750, 1,500, or 3,000
ppm
Body weights: 3,000 ppm group less than the control group
Survival rates: 40/50, 34/50, 37/50, 41/50
Nonneoplastic effects: None
Neoplastic effects: None
Uncertain findings: Forestomach: squamous cell papilloma or
carcinoma (1/50, 0/50, 1/50, 5/50)
Decreased incidences: None
Level of evidence of carcinogenic activity: Equivocal
evidence
Study Laboratory: Battelle Columbus Laboratories(Columbus,
OH)
Strain and Species:Mice B6C3F1Animal Source:Taconic Laboratory Animals and Services(Germantown, NY)
Time Held Before Studies:13 days (males) or 14 days
(females)Average Age When Studies Began:6 weeks
Duration of Exposure:104 to 105 weeks
Average Age at Necropsy:110 weeks
Size of Study Groups:Core study: 50 males and 50 females;
special study, 10 males and 10 females; aged sentinel animal
study, 15 males and 15 females
Method of Distribution: Animals were distributed randomly
into groups of approximately equal initial mean body weights
Animals per Cage:core and special studies, 1 (male) or 5
(females); aged sentinel animal study, 1 (male) or 3
(females)Method of Animal Identification:Tail tattoo
Diet:NTP-2000 pelleted diet, irradiated beginning 16 July
1996, changed weekly (males), or twice weekly (females)
Water:Tap water (Columbus, OH, municipal supply) via amberglass bottles with stainless steel sipper tubes, available
ad libitum and changed twice weekly (female) or weekly(male)
Cages:Solid-bottom polycarbonate
Bedding:Sani-Chips

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Cage Filters:DuPont 2024 spun-bonded polyester filter (Snow
Filtration Co., Cincinnati, OH)
Racks:Stainless steel
Animal Room Environment:
Temperature: 72 degree +/- 3 degree F
Relative humidity: 50% +/- 15%
Room fluorescent light: 12 hours/day
Room air changes: equal or more than 10/hour
Exposure Concentrations:0, 750, 1,500, or 3,000 ppm in
drinking water, available ad libitum
Type and Frequency of Observation:twice daily. Core study
animals were weighed initially and clinical findings andbody weights were recorded on day 8, day 36, at 4-weekintervals thereafter, and at necropsy. Special study rats
were weighed at 2 weeks and 3 months, special study mice
were weighed at 12 months, and aged sentinel animal rats andmice were weighed at 18 months. Drinking water consumption
by the core study animals was measured over a 1-week period
at 4-week intervals, beginning during the first week of thestudy.
Method of Sacrifice:CO2 asphyxiation
Necropsy: Necropsy was performed on all core study animals
and five male and five female aged sentinel animals.
Histopathology:Complete histopathology was performed on all
core study animals. In addition to gross lesions and tissue
masses, the following tissues were examined: adrenal gland,bone and marrow, brain, clitoral gland, esophagus,
gallbladder, heart, large intestine (cecum, colon, rectum),small intestine (duodenum, jejunum, ileum), kidney, liver,lung, lymph nodes (mandibular and mesenteric), mammary gland(female), nose, ovary, pancreas, parathyroid gland,
pituitary gland, preputial gland, prostate gland, salivary
gland, spleen, skin, stomach (forestomach and glandular),testis (and epididymis and seminal vesicle), thymus, thyroid
gland, trachea, urinary bladder, and uterus.

Test substance:

Plasma Nitrite and Blood Methemoglobin Concentrations:Blood
was collected from the retroorbital sinus of 10 male and 10
female mice at 12 months. Blood was collected from two
animals per group per time point (0600, 1200, 2100, 2400,
and 0300 hours).
Blood was collected from the retroorbital sinus of 15 maleand 15 female aged sentinel animals after a single gavage
dose of 62.5 mg/kg at 18 months. Two or three animals were
sampled at each time point (2, 5, 10, 30, or 60 minutes
after dosing). Plasma nitrite and blood methemoglobin
concentrations were determined. Statistical analyses wereconducted about survival rate, neoplasm and non-neoplastic
lesion incidences.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: >99%
Supplier: J.T. Baker, Inc. (Phillipsburg, NJ)
Lot No. A42340 and H05714
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Conclusion:

Under the conditions of this study there is no evidence of
carcinogenic activity of sodium nitrite in male B6C3F1 mice atdoses up to approximately 220 mg/kg bw/day over a two year
period. There is equivocal evidence of carcinogenic activity
in female mice, based on the positive trend of squamous cell
papilloma or carcinoma (combined) in the forestomach.
(1) valid without restriction
Critical study for SIDS endpoint(134)

Reliability:
Flag:
18-JUL-2005

Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
2 years
Frequency of treatment: continuous
Post exposure period:noDoses:
0, 0.125, 0.25 % in drinking water
Result:negative
Control Group:
yes, concurrent vehicle
Year:
Result:

Test condition:

Test substance:
Reliability:
18-JUL-2005

1982
Dose (%)-0.125%; equivalent to 19 mg/rat for male, 15 mg/rat for
female-0.25%; equivalent to 34 mg/rat for male, 25 mg/rat for
femaleThere were no significant differences in the incidence oftumours between control and test groups, apart from a lowere
incidence of mononuclear cell leukaemia amongst the test
groups compared with controls. This was attributed to slightatrophy of the haematopoietic organs.
Animals; 50 animals/sex/groupAge: 8 weeks at start of study.
The carcinogenicity of sodium nitrite was examined in F-344
rats. Sodium nitrite was administered in the drinking-waterfor 2 yr at levels of 0.125 or 0.25%.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: 98.5%
Supplier: Koso Chemical Co Ltd(2) valid with restrictions(116)

Species:rat
Strain:Fischer 344
Route of administration: drinking water
Exposure period:
2 weeks
Frequency of treatment: ad libitum
Post exposure period:
24 weeks
Doses:
0.3% in drinking water
Result:negative
Control Group:
yes
Year:
Result:209

Sex: male

1993
NaNO2 itself had no carcinogenic potential.

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Test condition:

Test substance:
Reliability:
15-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
In a multi-organ model in which rats were initiated withvarious carcinogens, 0.3% sodium nitrite in drinking waterstrongly enhanced the development of forestomach lesions but
inhibited the development of glandular stomach lesions whenthese animals were given catechol or 3-methoxycatechol, withor without prior carcinogen exposure.
In a multi-organ model in which rats were initiated withvarious carcinogens (4 weeks)
15 animal/group
Starting 3 days after the completion of these carcinogentreatments, animals were given diet containing test
chemicals, or basal diet either alone or in combination with
0.3% NaNO2 for about 24 weeks, when complete autopsy was
performed.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade(4) not assignable(77)

Species:other: rat and hamster
Sex: male/female
Strain:other: Sprague-Dawley and Syrian golden
Route of administration: oral feed
Exposure period:rat; F1+F2 generations (F1 + F2 at 125 weeks), hamster;
110 weeks
Frequency of treatment: continuous
Post exposure period:
nonDoses:
1000 ppm
Result:positive
Control Group:
yes
Year:
GLP:
Result:

Test condition:
Test substance:
Reliability:
15-JUL-2005
Species:
Strain:1976
noMost combinations of the two chemicals induced a highincidence of hepatocellular carcinoma in rats and lower
incidence in hamster. The highest level of nitrite andmorphpline (1000 ppm of each) had a stronger potential for
carcinogenesis in both rats and hamsters than did a dietarylevel of 50 ppm of preformed N-nitrosomorpholine. Nitrite
and morpholine also induced angiosarcoma in both species,
most frequently in the liver, with the lung as the next mostcommon site. The nitrite concentration in the diet seemed tohave a greater effect on the incidence of hepatocellular
carcinoma and angiosarcoma in the rat than did theconcentration of morpholine. Dietary concentrations of 5 ppm
each of nitrite and morpholine induced hepatocellular
carcinoma and angiosacroma in some rats.
High concentrations of sodium nitrite alone associated witha relatively high incidence (27%) of lymphoreticular tumor,
control (6%).
Concentration;
various dietary concentrations of nitrite and morphine (upto 1000 ppm of each) or N-nitro-somorpholine (5 or 50 ppm).
Chemical name: sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(159)
rat
Fischer 344

Sex: male

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Route of administration: drinking water
Exposure period:
Expeiment-1; 4 weeks, Experiment-2; 52 weeks
Post exposure period:noDoses:
0.3% in drinking water
Control Group:
yes
Year:
GLP:
Result:

Test condition:

Test substance:
Reliability:

1994
no data
Experiment-1;
It was noteworthy that the heights of the mucosa in animals
treated with NaNO2 alone were more than in those receiving
basal diet alone, and these were further increased by theadditional with sodium ascorbate without phenolicanti-oxidants.
Experiment-2;
In MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) treatedanimals, incidences of forestomach papilomas and carcinomas
were significantly enhanced in the NaNO2 alone group (84 and
47%, respectively) as compared with the basal diet group (30and 10%), with further significant increase in carcinomas
occurring with additional sodium ascorbate (79%, p<0.05) andascorbic acid (85%, p<0.05) treatment. In animals without
MNNG, all animals in the NaNO2 group demonstrated mild
hyperplasia, additional administration of sodium ascorbate
or ascorbic acid remarkably enhancing the grade ofhyperplasia, and resulting in 53% and 20% incidences,respectively, of papillomas. Thus NaNO2 was demonstrated toexert promoter action for forestomach carcinogenesis, withsodium ascorbate and ascorbic acid acting as co-promoters.
The results strongly indicate that combined treatment withsodium ascorbate or ascorbic acid and NaNO2 may induce
forestomach carcinomas in the long term.
Experiment-1;
120 rats were divided into 24 groups, each one of fivephenolic compounds in the diet, basal as a control, or
additional treatment 1% sodium ascorbate in diet and/or 0.3%
NaNO2 in drinking water for 4 weeks.
Experiment-1;
120 rats in groups were given 150 mg/kg bw of MNNG
(N-methyl-N'-nitro-N-nitrosoguanidine) in vehicle (DMS:water= 1:1) by stomach tube after 16h starvation. Starting 1 week
later, animals were divided into 6 groups. And another 6groups of 15 animals each were treated as pretreated groups.
Sodium ascorbate and ascorbic acid were mixed in powderedbasal diet at a dose of 1%, and NaNO2 was dissolved in tap
water at dose of 0.3% for the end of test period (52 week).
Chemcial name: Sodium nitrite (CAS No. 7632-00-0)
Purity: food grade(4) not assignable

15-JUL-2005(205)

Species:rat
Sex: male/female
Strain:Fischer 344
Route of administration: other: Exp-1; oral feed, Exp-2; drinking water
Exposure period:
106 weeks
Frequency of treatment: ad libitum
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Post exposure period:
Doses:
Result:Control Group:

until death
0.2% in feed, drinking water (2000 ppm)
positive
yes, concurrent no treatment

Method:
Year:
GLP:

other
1984
no dataResult:2000 ppm;
drinking waterequivalent to 27 mg/animal/day (male and female)oral feed
equivalent to 57 mg/animal/day (male)equivalent to 38 mg/animal/day (female)
There was little or no life-shortening effect in any
treatment group. None of the four amines administered alone
induced an increase in the incidence of any tumour incomparison with the untreated control groups. In the malerats given diphenhydramine, chlorpheniramine orN,N-dimethyldodecylamine-N-oxide concurrently with nitrite
there was a significant increase in the incidence of liver
neoplasms (hepatocellular carcinomas and neoplastic
nodules). In the groups given untreated feed or
drinking-water there were, respectively, five and three malerats that had liver tumours. In contrast the number of malerats with liver tumours was ten in the group given
dimethyldodecylamine-N-oxide plus nitrite, 11 in that given
diphenhydramine plus nitrite and 14 (eight with carcinomas)
in the group given chlorpheniramine plus nitrite.

Test condition:

Test substance:
Conclusion:

Reliability:
15-JUL-2005

These results suggest that the ingestion ofdimethyldodecylamine-N-oxide, diphenhydramine hydrochloride
or chlorpheniramine under conditions when they could be
nitrosated with nitrite in the stomach might present anincreased carcinogenic risk.
Feed containing 0.2% allantoin or diphenhydramine (as thehydrochloride) or 0.1% chlorpheniramine (as the maleate),with or without 0.2% sodium nitrite, was given ad lib. togroups of 20 or 24 male and 20 or 24 female F344 rats for
106 wk. Groups of 24 male and 24 female F344 rats were given
drinking-water that contained
N,N-dimethyldodecylamine-N-oxide at a concentration of 0.1%,
with or without 0.2% sodium nitrite, for 93 wk. Control rats
were given untreated feed or drinking-water andnitrite-treated controls were given sodium nitrite at aconcentration of 0.2% in feed or drinking-water. At the endof the treatment period the rats were given untreated feed
and water and observed until death.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Fisher Scientific Co., Pittsburgh, PA, US.
In female rats given nitrite alone the incidence of liver
neoplasmas (carcinomas plus neoplastic nodules) was
significantly increased (P=0.015; nitrite in feed) and
P=0.060; nitrite in drinking water vs untreated control),but in male.
(4) not assignable(111)
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Species:mouse
Sex: male/female
Strain:ICR
Route of administration: drinking water
Exposure period:
109 weeks
Frequency of treatment: continuous
Post exposure period:noDoses:
0, 0.125, 0.25, 0.5 % in drinking water
Result:negative
Control Group:
yes, concurrent no treatment
Year:
Result:

Test condition:

Test substance:
Reliability:
18-JUL-2005

1979
Dose (%)-0.125%; equivalent to 702 mg/kg/day for male, 471 mg/kg/day
female-0.25%; equivalent to 429 mg/kg/day for male, 244 mg/kg/day
female-0.5%; equivalent to 241 mg/kg/day for male, 173 mg/kg/day
femaleAs a result, development of various tumors, including thymic
lymphoma, nonthymic lymphoid leukemia, pulmonary adenoma andcarcinoma, and benign and malignant tumors in soft tissue,
was seen in these mice. However, as to the incidence oftumors as well as the developmental time of eachhistologically classified tumor, no apparent difference was
detected between those in the experimental groups and thecontrol group.
Sodium nitrite has been widely used as one of the mosteffective food additives to tinge color on cured meat.
However, it has been elucidated that this chemical is not
merely a precursor of N-nitroso compounds, many of which arestrongly carcinogenic, but also a mutagenic substance inbiological tests. In order to ascertain the possible
tumorigenicity of sodium nitrite itself, chronic toxicity of
the agent in mice, by means of daily oral administration as
drinking water for more than 18 months, in the concentrationof 0.5 (maximum tolerated dose), 0.25, and 0.125%, wastested.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4)

not assignable(86)

Species:rat
Sex: male
Strain:Fischer 344
Route of administration: oral feed
Exposure period:
Continued on diets for 115 weeks, or until sacrificemoribund.
Frequency of treatment: continuous
Doses:
0.2 or 0.5% (w/w)
Result:negative
Control Group:
yes, concurrent vehicle
Year:
Result:213

1989
Increased frequency of focal or diffuse interstitial cellhypoplasia. Appeared to increase with increasing dose, but
not statistically significant.
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DATE: 04-JAN-2006
Significant reductions in RBCs, resolved by 52 weeks.
Reduced MCV, Hct, and Hb in highconcentration group.
Concentration-related decrease in body weight gain,
statistically significant at the high concentration.
Evidence of impaired feed utilization.
Better survival rate for treated than control animals, but
not statistically significant.
Significantly lower incidences of lymphomas, leukemias, andtesticular interstitial cell tumors.
Sodium nitrite exposure was associated with RBC (red blood
corpuscle) count reduction over the first eight weeks oftreatment. RBC's remained low until at least week 28 of thestudy, and then gradually rose to reach normal levels byapproximately week 52. The reductions in RBC's seen in thehigh-concentration group were associated with reductions in
the MCV (mean red cell volume), Hct (hematocrit), and Hb(hemoglobin concentration).
Body weight gain in treated rats showed a dose-related
reduction, which was statistically significant at the higher
sodium nitrite concentration. The body weight reductions
relative to the pattern of feed intake, indicated that feed
utilization was impaired by sodium nitrite exposure.
Mortality data, on the other hand, showed a more favorable
survival rate for treated animals, as compared to controls.
This difference, however, was not statistically significant.
Compared to controls, treated animals suffered significantly
lower incidences of lymphomas, leukemias, and testicularinterstitial cell tumors. The authors suggested that the
reduced weight gain of treated animals might have reduced
susceptibility to tumor formation, and exerted a positive
influence on life span.

Test condition:

On the other hand, findings of focal or diffuse testicularinterstitial cell hypoplasia were more frequent among
treated animals. While these changes appeared to increase
with increasing dose, statistical significance was notreported. The study authors postulate that the hyperplasia
might have been a function of hormonal imbalance related togeriatric changes in older animals.
5-6 week old male rats fed low-protein diets containing
sodium nitrite at 0, 0.2, or 0.5% (w/w).
50 animals/treatment group. 20 controls.
Continued on diets for 115 weeks, or until sacrificemoribund.
Groups of 5-6-week old, male, F344 rats were fed
reduced-protein diets contain sodium nitrate atconcentrations of 0.2 or 0.5% (w/w). Fifty rats were
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Test substance:
Conclusion:

Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
assigned to each treatment group, and 20 control rats were
given the reduced-protein diet without added sodium nitrite.
Animals were continued on their diets until they weresacrificed as moribund, or after 115 weeks of treatment.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: BDH Ltd, Dagenham Essex
There was no evidence of carcinogenicity in a detailed
examination of a wide range of tissues from 50 male rats
given up to 5000 ppm sodium nitrite (about 260 mg/kg/day) in alow protein diet, for up to 115 weeks.
(4) not assignable(68)

Species:rat
Strain:WistarRoute of administration: oral feed
Exposure period:
646 daysFrequency of treatment: continuous
Post exposure period:noDoses:
0, 800, 1600 ppm
Control Group:
yes, concurrent vehicle
Year:
Result:

Test condition:
Test substance:
Conclusion:
Reliability:
18-JUL-2005

1989
The first tumor was found on day 441 in the liver of a rat
given a diet containing 800 ppm sodium nitrite. On day 646,
liver tumors were found in 1 of 22 rats (4.5%) on an 800-ppm
sodium nitrite diet and in 5 of 19 rats (26.3%) on a
1,600-ppm sodium nitrite diet. The incidence of liver tumors
in the rats fed 1,600 ppm sodium nitrite was significantly
different from that in controls as judged by the t-test (P <0.05).
A hepatocellular carcinoma and a hemangioendothelial sarcomaof the liver were found on day 646 in 2 rats fed 1,600 ppm
sodium nitrite. One mammary tumor but no liver tumors were
found in the 19 control rats. The concentration of sodium
nitrite decreased after preparation of the pellet diet, but
it was still at least 70% of the initial amount when thepellets were given to the rats.
Sodium nitrite was given to male noninbred Wistar rats at
levels of 800 ppm and 1,600 ppm in a pellet diet for 646
experimental days.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade
Supplier: Wako Pure Chemical Company, Japan
Liver tumors (incidences 5/19 or 26%) were induced in Wistar
rats given 1,600 ppm in pelleted feed.
(4) not assignable(10)Species:mouse
Strain:Swiss
Route of administration: drinking water
Exposure period:
40 weeks
Frequency of treatment: continuous
Post exposure period:noDoses:
1.0 g/liter (concentration)
Control Group:
yes
Year:
215

Sex: male

1971
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Result:

Test substance:

Conclusion:

Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Compound/Control/NaNO2
Dose/None/1.0g per liter
Initial No. of mice (females;males)/80;80/40;40
Effective No. of mice (females/males)/71;73/38;36
Total adenoma-bearing mice (%)/14/19
Adenoma per mouse/0.18/0.2
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Analytical grade
Supplier: J.T. Baker Chemical Company, Phillipsburg, New
JerseyTreatment with sodium nitrite alone produced no effect.
This study suggested that the induction of lung adenomas inanimals treated with secondary amins (piperazine, morphineand so on) and nitrite is due to in vivo nitrosation(presumably in the stomach) with the formation ofcarcinogenic nitrosamines.
(4) not assignable(71)

Species:mouse
Strain:Strain A
Route of administration: drinking water
Exposure period:
20-25 weeks
Frequency of treatment: continuous
Doses:
1.0 g/liter (concentration)
Control Group:
yes
Year:
Result:

Test substance:

Conclusion:
Reliability:
18-JUL-2005

1973
CompoundControl
NaNO2
Dose (g/L)
0
1.0
Initial No. of mice40
40
Effective No. of mice
37
37
Total adenoma-bearing mice (%)
32
30
Adenoma per mouse
1.4
1.2
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Practical grade
Supplier: J.T. Baker Chemical Company, Phillipsburg, New
JerseyNegative result was obtained with NaNO2 alone.
(4) not assignable(70)

Species:mouse
Strain:Swiss
Route of administration: drinking water
Exposure period:
26 weeks
Frequency of treatment: continuous
Post exposure period:
12 weeks
Doses:
0.65 g/mouse
Result:negative
Control Group:
yes
Year:
Result:Sex: maleSex: male/female

1972
Compound
Dose (g/mouse)
Initial No. of mice (F/M)

Control
030;30

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0.65
30;30
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Test substance:
Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Autopsied No. mice (F/M)
27;26
30;30
Total adenoma-bearing mice (%)
13.2
8.3
Adenoma per mouse
0.15
0.08
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(69)

Species:other: rat and mouse
Strain:other: F344 and C57BL/6
Route of administration: oral feed
Exposure period:
365 daysFrequency of treatment: continuous
Post exposure period:
120 days
Doses:
0.5%
Control Group:
yes, concurrent vehicle
Year:
Result:Sex: male/female

1979
Days in study and incidence of neoplasms-RatGroup/Effective No. of animals/Days in study/Animals withneoplasms
Control (stock diet);Male/ 50 / 472 / 30 (60 %)Female / 44 / 473 / 20 (45 %)0.58% butylurea;
Male/ 16 / 396 / 7 (44 %)Female / 16 / 437 / 5 (31 %)
0.50% sodium nitrite;Male/ 16 / 432 / 8 (50 %)Female / 16 / 447 / 6 (37 %)0.50% sodium nitrite and 0.58% butylurea;Male/ 46 / 262 / 43 (93 %)Female / 45 / 233 / 44 (98 %)-MouseGroup/Effective No. of animals/Days in study/Animals withneoplasms
Control (stock diet);Male/ 95 / 475 / 8 (8 %)Female / 92 / 457 / 17 (18 %)
0.58% butylurea;Male/ 26 / 480 / 7 (27 %)Female / 24 / 418 / 4 (17 %)0.50% sodium nitrite;Male/ 11 / 430 / 2 (18 %)Female / 12 / 418 / 2 (17 %)Test condition:

0.50% sodium nitrite and 0.58% butylurea;Male/ 39 / 325 / 35 (90 %)Female / 40 / 293 / 27 (67 %)Number of Animals used
-Rat
Control (stock diet); male/female = 50/55

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0.58% butylurea; male/female = 50/50
0.50% sodium nitrite; male/female = 20/20
0.50% sodium nitrite and0.58% butylurea; male/female = 50/50

Test substance:
Reliability:
18-JUL-2005-MouseControl (stock diet); male/female = 100/100
0.58% butylurea; male/female = 50/50
0.50% sodium nitrite; male/female = 20/20
0.50% sodium nitrite and0.58% butylurea; male/female = 50/70
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(110)

Species:rat
Strain:Sprague-Dawley
Route of administration: drinking water
Exposure period:
104 weeks
Frequency of treatment: continuous
Post exposure period:
until death
Doses:
0.2%
Control Group:noYear:
Result:

Test condition:

Test substance:
Reliability:
18-JUL-2005

Sex: male/female

1975
Most of the animals given heptamethyleneimine hydrochloride
or sodium nitrite alone survived 2 years or more after the
beginning of the treatment, and no tumors attributable tothe treatment were seen at death; tumors appearing were
those of endocrine origin found commonly in untreatedcontrols. In the group receiving the combined treatment,
most females were dead at 50 weeks and most males were deadat 80 weeks, 27 of 30 having tumors not seen in either
control group. A total of 16 had squamous carcinomas in thelung; 25 had tumors of the oropharynx, tongue, esophagus,
and forestomach; and there were a few animals with tumors in
the nasal cavity and trachea. The expericment showed thatsquamous tumors of the lung could be induced by ingestion anamine and sodium nitrite.
NaN02, 0.2% - Nonendcrine tumor-bearing rats/total no. of
rats
Male
- 0/27
Female- 0/26 (4 animals were still alive at 140 wks.)
Groups of 15 males and 15 females Sprague-Dawley rats were
given 20 ml of drinking water solution containing either
0.2% heptamethyleneimine hydrochloride or this salt together
with 0.2% sodium nitrite, 5 days a week for 28 weeks.
Another group of 17 male and 30 female rats was given 0.2%
sodium nitrite solution for 104 weeks.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(175)

Species:rat
Strain:WistarRoute of administration: drinking water
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Exposure period:
Frequency of treatment:
Post exposure period:
Doses:
Control Group:Year:
Remark:Result:

Test substance:
Reliability:
18-JUL-2005
Species:219

94 weekscontinuous
no0, 0.1, 0.3%
yes, concurrent no treatment

1989
The carcinogenic activity of endogenously synthesized
N-nitrosobis(2-hydroxypropyl)amine (BHP) was investigated inmale Wistar rats administered bis(2-hydroxypropyl)amine(BHPA) mixed in powder diet at a concentration of 1%, andsodium nitrite (SN) dissolved in distilled water atconcentrations of 0.15 and 0.3%, for 94 weeks. Urinary
excretion of BHP was detected in rats given 1% BHPA and 0.3%
SN but not in the groups receiving either of theseprecursors alone. Nasal cavity, lung, esophagus, liver andurinary bladder tumors were found in animals treated withcombinations of 1% BHPA and 0.15 or 0.3% SN, suggesting thatthe target organs of the endogenously synthesized BHP are
similar to those affected when the carcinogen isadministered exogenously. The incidences of nasal cavity andlung tumors reached 74 and 58% in rats given 1% BHPA and
0.3% SN, respectively. Tumors at sites other than target
organs were only found at levels similar to those previously
reported for spontaneous tumors in male Wistars. The present
results clearly indicated the tumor inducibility of anitrosatable amine, BHA, through an endogenous nitrosation
by feeding to rats in conjunction with nitrite, and provide
further suggestive evidence that endogenous nitrosations ofenvironmental nitrosatable amines can be a potential risk
factor in human cancer development.
(Treatment)/(No. of rats-initial;effective)/(Bodyweight-initial;final)/(Daily intake per rats as sodium
nitrite (mg))
Non-treated / 20; 19 / 189.5; 404.7/ 0.0
0.15% NaNO2 / 20; 18 / 189.5; 401.3/ 29.6
0.30% NaNO2 / 20; 16 / 185.6; 358.9/ 51.3
Incidence of tumors (%)/Non-treated/0.15% NaNO2/0.30% NaNO2
Nasal cavity
/ 0
/ 0
/ 0
Lung
/ 0
/ 0
/ 0
Esophagus
/ 0
/ 0
/ 0
Liver
/ 0
/ 0
/ 0
Urinary bladder
/ 0
/ 0
/ 0
Thyroid
/ 15
/ 6
/ 13
Kidney/ 0/ 0/ 0
Stomach/ 0/ 6/ 0
Pancreas
/ 0
/ 11
/ 0
Adrenal gland
/ 21
/ 6
/ 31
Testis
/ 47
/ 56
/ 63
Pituitary gland
/ 5
/ 6
/ 0
Mammary gland
/ 5
/ 6
/ 0
Others/ 0/ 0/ 0
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Wako Pure Chemical Industry Ltd., Japan(4) not assignable
(203)
rat

Sex: male/female
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Strain:ICR
Route of administration: gavage
Exposure period:
10 weeks
Frequency of treatment: once a week
Post exposure period:
until 18 months after the first dose
Doses:
0, 70 mg/kg/week
Control Group:
yes, concurrent vehicle
Year:
Remark:Result:1993
Carcinogenic potential of ethylenethiourea (ETU) in
combination with sodium nitrite was investigated in ICR miceof both sexes. Groups of 30 males and 30 females each were
given 10 weekly oral administrations of ETU and sodium
nitrite with the following combinations of dosing (ETU vssodium nitrite, mg/kg/wk): 0 vs 0, 100 vs 0, 0 vs 70, 25 vs17.5, 50 vs 35, and 100 vs 70. Thereafter, the animals wereallowed to live without treatment up to 18 mo after the
first administration.
Cumulative incidence of tumors at 18 months-Male(Incidence of tumors)/ (Control) / (NaNO2-treated)
Malignant lymphoma/ (3/30)/ (4/30)
Lung adenoma, adenocarcinoma/ (9/30)/ (11/30)
Forestomach squamous cell papilloma, carcinoma/ (0/30)/ (0/30)
Harderian gland adenoma/ (3/30)/ (1/30)-Female(Incidence of tumors)/ (Control) / (NaNO2-treated)
Malignant lymphoma/ (6/30)/ (12/30)
Lung adenoma, adenocarcinoma/ (3/30)/ (5/30)
Forestomach squamous cell papilloma, carcinoma/ (0/30)/ (0/30)
Harderian gland adenoma/ (0/30)/ (4/30)
Uterine adenocarcinoma/ (0/30)/ (0/30)

Test substance:
Conclusion:
Reliability:
18-JUL-2005

Concurrent administration of ETU and sodium nitrite caused
earlier development of tumors and/or dose-dependent increases
in the incidences of tumors in the lymphatic tissue, lung,forestomach, Harderian gland, and uterus, whereas treatment
with either ETU or sodium nitrite
failed to show carcinogenic activity. In addition,
carcinomas in the forestomach and uterine horn were limited
to mice receiving concurrent administrations of ETU andsodium nitrite.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Wako Pure Chemical Industry Ltd., Japan
These results indicate that ETU is most probably converted invivo into N-nitroso ETU and that the N-nitroso ETU has agreater carcinogenic potential in mice than ETU alone.
(4) not assignable(204)

Species:mouse
Strain:Swiss
Route of administration: drinking water
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Exposure period:
Doses:
Control Group:Year:
Result:

Test substance:
Reliability:
18-JUL-2005

6 months
1 g/liter (concentration)yes
1972
Compound/Control/NaNO2
Dose
/None
/1.0g per liter
Initial No. of mice /144
/74
Adenoma per mouse
/0.2
/0.2
Chemical name: Sodium ntirite (CAS No. 7632-00-0)(4) not assignable(125)

Species:rat
Strain:Sprague-Dawley
Route of administration: other: various
Exposure period:
26 months or until death
Frequency of treatment: continuous
Doses:
0, 250, 500, 1000, 2000 ppm
Control Group:
yes, concurrent vehicle
Year:
Remark:Result:Sex:

1979
Rats were exposed to sodium nitrite in food or water atconcentrations of 0, 250, 1000, and 2000 ppm.
-Treatment/Dose(ppm)/Proportion (%) Malignant
lymphomas;Immunoblastic cell proliferation
Semipurified diet (agar gel)/
0/ 3.7 ;7.3
Semipurified diet (agar gel)/ 250/ 7.3 ;6.6
Semipurified diet (agar gel)/ 500/ 8.1 ;16.9
Semipurified diet (agar gel)/1000/ 8.1 ;10.3
Semipurified diet (agar gel)/2000/ 10.3;13.4
In water (agar diet)In water (agar diet)/1000/ 11.8 ;12.5/2000/ 10.3 ;13.4

Commercial lab chow (purina)/
0/ 6.8 ;3.8
Commercial lab chow (purina)/1000/ 10.4 ;8.9
Commercial lab chow (purina)/2000/ 9.0 ;8.3
Casein diet
Casein diet

Test substance:
Reliability:
18-JUL-2005

Lymphoma was increased in all groups fed nitrite; theoverall combined incidence was 5.4 percent in 573 control
rats and 10.2 percent in 1383 treated rats. The mechanism ofcancer induction did not appear to be through the formation of
nitrosamines but through a more direct effect of nitrite on
the lymphocyte.
Chemical name: Sodium ntirite (CAS No. 7632-00-0)(4) not assignable(130)

Species:
Doses:
Control Group:
Year:
221

/
0/ 7.4 ;7.4
/1000/ 13.2 ;8.0

mouse
50 micro-gram/gm
yes, concurrent no treatment
1982
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Result:

Test condition:

Test substance:
Reliability:
18-JUL-2005
Year:
Remark:Reliability:
18-JUL-2005

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Histopathlogical examination of liver revealed that mice
given DEA-HCl and NaNO2 had significantly more liver tumors
compared to mice given only NaNO2 or DEA-HCl. This study
suggested the formation of a potent carcinogen in vivo by
the interaction of DEA-HCl and NaNO2.
(Treatment)/(Dose)/(No of mice with tumors-No of examined)
Distilled water/ / 2 - 17
NaNO2
/ 50
/ 3 - 11
DEA-HCl/ 50/ 5 - 15
DEA-HCl + NaNO2/ 50+50 / 17 - 23
To investigate the in vivo interaction of DEA-HCl and NaNO2
infant C57BL X C3H F1 male mice were given these substances(50 micro-gram/gm BW) intragastrically either singly or in
combination. There were from 30 to 35 mice per group.
Animals were sacrificed periodically up to 110 weeks.
Chemical Name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(145)
1980
Incidences of malignant lymphoma were significantly
increased in all exposed groups compared to the controls,
and immunoblastic cell proliferation was observed in someanimals in each exposed group. However, these results were
not confirmed by a committee specially formed to review thedata.
(4) not assignable(59)

Species:Year:
Remark:Test substance:
Reliability:
18-JUL-2005

mouse
1997

A study of the effect of sodium nitrite (SN) on leukemia
development in mice induced by Rauscher Leukemia virus (RLV)(Balb/c mice), Mazurenko leukemia virus (MaLV) (CC57Br
mice), and Gross leukemia virus (GLV) (AKR/J mice) was
performed. SN was administered in water (at concentrationsof 5.0, 50.0, 500.0, and 2000.0 mg/l, by NaNO2). A moderate,
yet statistically significant acceleration of leukemia
development was observed in some groups of SN-treated mice.
Our findings and the literature provide evidence that SN has
the capacity to enhance the carcinogenic effect of leukemia
viruses in vivo.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(84)

Species:
Strain:Year:
Remark:

Sex:

mouse
Balb/cSex: male/female

1975
The spontaneous incidence of pulmonary tumors in intact
virgin BALB/c mice of both sexes was 9 % in males and 11 %in females.
Ethambutol and sodium nitrite administered singly did not
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Test substance:
Reliability:
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tumors. However, when administered together they increased
the adenoma and carcinoma incidence to 67 % in males and to
76 % in females and that of lymphomas (lymphocytic,
histiocytic and mixed) to 22 % in males and to 14 % infemales.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(17)

Species:rat
Strain:Fischer 344
Route of administration: oral feed
Exposure period:
104 weeks
Frequency of treatment: continuous
Post exposure period:
sacrified at 130-week
Doses:
0, 2000 ppm
Control Group:
yes, concurrent vehicle
Year:
Result:

Test substance:
Conclusion:
Reliability:
18-JUL-2005

1984
Simultaneous feeding to rats of thiram with sodium nitrite
was carried out to assess the possibility of formation ofcarcinogenic N-nitroso derivatives in vivo. Following theadministration of feed containing 500 ppm thiram plus 2000
ppm sodium nitrite for 104 w, a high incidence of tumors of
the nasal cavity was found in both sexes, 18 of 24 males and
15 of 24 females. No nasal-cavity tumors were seen in
untreated rats, or those given 500 ppm of thiram or 2000 ppm
of sodium nitrite alone. A 20% incidence of papillomas of
the forestomach was also seen in the rats of both sexes
given the combined treatment. The other significant
difference in incidence of tumors between the rats given
thiram with or without nitrite was a decreased number ofanimals with monocytic leukemia, which is a common neoplasm
in untreated F344 rats.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
No nasal-cavity tumors were seen in untreated rats, or 2000
ppm of sodium nitrite alone.
(4) not assignable(112)

Species:rat
Strain:Fischer 344
Route of administration: oral feed
Exposure period:
78 weeks
Frequency of treatment: continuous
Post exposure period:
until death
Doses:
0.2%
Control Group:
yes
Year:
Remark:223

Sex: male/female

Sex: male/female

1980
A mixture of 0.1% disulfiram together with 0.2% sodium
nitrite in powdered rat diet was fed to 20 male and 20
female Fischer 344 rats for 78 wk, after which the animals
were observed until death. Ten of the males and 12 of thefemales died with tumours of the oesophagus, tongue,squamous stomach and nasal cavity. None of these tumours wasobserved in rats fed either disulfiram or sodium nitrite
alone at similar doses. The tumours were attributed to the
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reaction of disulfiram and nitrite in the stomach, with theformation of nitrosodiethylamine, which has given rise tothese tumours in Fischer rats from the same colony.

Test substance:
Reliability:
18-JUL-2005

Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(113)

Species:
Strain:Year:
Remark:Test substance:
Reliability:
18-JUL-2005

rat
Wistar1980

Large doses of dimethylnitramine (DMNM), N-nitroso-L-proline(NPRO), and sodium nitrite were administered in the drinking
water to MRC Wistar rats for at least 1 year, and the rats
were maintained for life. DMNM (total dose, 20 g/kg)
produced liver tumors in 25 (69%) of the 36 rats and nasal
cavity tumors in 9 (25%) of the rats. NPRO (total dose, 36g/kg) induced no tumors in 37 treated rats. In the group
receiving NaNO2 (3.0 g/liter drinking water; total dose, 63g/kg), 8 (18%) of 45 rats had forestomach squamous
papillomas. The tumor incidence in the NaNO2-treated groupwas significantly greater than that of 2% in a control group
started 11 months earlier, which suggested that the NaNO2
was tumorigenic in this experiment.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(124)

Species:Year:
Remark:Sex: male/female

rat

Sex:

1983

Test substance:

Administration to rats of ascorbate with morpholine andnitrite was previously shown to inhibit the liver tumor
production and to enhance the induction of forestomach
tumors, as compared to treatment with morpholine andnitrite. In a repetition of this experiment, 10 g
morpholine/kg in the diet and 2 g sodium nitrite/liter inthe drinking water were administered for life to male
MRC-Wistar rats without (group 1) or with (group 2) 22.7 g
sodium ascorbate/kg in the diet. Group 3 was untreated.
Group 2 showed a lower liver tumor incidence with a longer
latency than group 1, indicating a 78% inhibition byascorbate of in vivo N-nitrosomorpholine (NMOR) formation.
The incidence of forestomach papillomas was 3% in group 1,
38% in group 2, and 8% in group 3. The difference between
groups 1 and 2 was not significant due to the shorter
life-span of group 1. Group 1 and especially group 2 hadmore forestomach hyperplasia and hyperkeratosis than group
3. Ascorbate might have enhanced induction of these lesions
because of an action synergistic with that of NMOR. However,
it is most likely that the lowered NMOR dose andconcomitantly increased survival produced by the ascorbate
were solely responsible for the increased incidence offorestomach papillomas and other lesions in group 2.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)

Reliability:(4)

not assignable
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(126)

Year:
Remark:Reliability:
18-JUL-2005

1990
Presented are the literature data as well as the results of
our own investigations on the genotoxic and carcinogenic
effects of sodium nitrite (SN). The carcinogenicity of SN
detected in animal experiments appears to be related to theformation of nitroso compounds from endogenous nitrosable
precursors. Sodium nitrite possesses transforming andpromoting effects in cell cultures, as well as mutagenic
effects in the bacterial systems, where the predominant
effect of SN was compared to that of N-nitrosodimethylamine(NDMA). Prolonged pretreatment with SN amplifies the liver
DNA damage in rats in case of NDMA endogenous synthesis.
(4) not assignable(151)

Species:rat
Strain:WistarRoute of administration: drinking waterYear:

Sex: male

1995

Remark:Cancers and precancerous lesions of the esophagus were
efficiently induced in rats by the simulation of aclinico-epidemiological setting; that is, the administrationof precursors of nitrosamine. Six week old non-inbred male
Wistar rats were given 2g/kg bodyweight of sarcosine ethyl
ester hydrochloride (SEEH) and concurrently 0.3g/kg
bodyweight of sodium nitrite (NaNO2), precursors of
N-nitrososarcosine ethyl ester (NSEE), in 2% sucrose as
drinking water. Group 1 received the precursors twice a week
for 6 weeks followed by 8 weeks observation, and group 2,
once every 3 days for 7 weeks followed by 26 weeks
observation. At the end of treatment, no tumor had developedin the esophagus of rats in group 1, but the [3H]-thymidine
labeling indices in both basal and superficial layer cells
were higher than in the control group. On subsequent
observation, papillomas appeared in group 1 (33.3%), andcarcinomas in group 2 (33.3%), within 4 weeks. The tumors
induced in group 1 were mostly papillomas and rarely
carcinomas. When the observation was prolonged in group 2,
100% of the animals had cancer in week 20. The pathologicalchanges of the lesions paralleled the sequential developmentof human squamous cell carcinoma of the esophagus. Our
system has the advantages in that papillomas and cancers canbe induced in rats in a short time and the agents used areless toxic than preformed nitrosamines administeredpreviously by gastric intubation. It would serve as a usefulexperimental tool to study premalignant lesions and cancersof the esophagus.

Reliability:
18-JUL-2005(2)

valid with restrictions(201)

5.8.1 Toxicity to Fertility
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See section 5.8.2 and 5.8.3

5.8.2 Developmental Toxicity/Teratogenicity
Remark:Data available in the published literature included studiesof the effects of pre- and/or postnatal exposure to sodium
nitrite on mice, guinea pigs, and rats. Additional relevant
information on the developmental toxicity of compounds
related to sodium nitrite is also discussed below.
Studies conducted in mice have not provided clear andconsistent evidence for adverse effects of in utero exposure
to sodium nitrite on measures of fetal viability, weight,
sex ratio, or the frequencies of external or skeletal
malformations. Nor did the study provide clear,dose-dependent evidence for adverse effects of prenatal
exposure on parameters of postnatal growth or viability.
Treatment protocols used in all three of these studies
covered at least a major portion of the organogenesis phaseof development, and oral doses of sodium nitrite ranged from20 mg/kg/day to 243 mg/kg/day.
The study was aimed primarily at detecting sodium
nitrite-induced changes in fetal erythropoiesis in CD-1
mice. From the commencement of gestation until sacrifice,according to a time course schedule, pregnant animals were
given a daily dose of 20 mg sodium nitrite/kg bw by gavage.
Treatment was associated with evidence for alterations in
the proportions of hepatic erythroblasts at distinct stagesof maturation. The authors interpreted the observed changes
as indicative of a treatment-dependent increase in embryonicproduction of erythroid cells. No increase in peripheral red
blood cell counts could be demonstrated, however, hence thefunctional significance of these findings remains unclear.
In pregnant guinea pigs, administration of 45 mg sodium
nitrite/kg bw by s.c. injection during the last week ofgestation resulted in spontaneous abortion of litters, but
only in ascorbic acid-deficient females. Neither ascorbic
acid deficiency alone, nor sodium nitrate in the presence ofsufficient ascorbic acid, was associated with excess
abortions. No gross abnormalities were noted in any living
or aborted fetuses. In another study using guinea pigs, allpregnant sows given a dose of 70 mg sodium nitrite/kg bw bys.c. injection died within 60 minutes of treatment. All
animals given a lower dose of 60 mg/kg bw aborted theirlitters. Co-administration of methylene blue, a MetHb
antagonist, exerted a protective effect on fetuses.
Guinea pigs were also adversely affected by prenatal
exposure to potassium nitrite in maternal drinking water.
The percentage of fetal loss was higher in all treatedlitters than in controls, and appeared to generally increase
with increasing dose (ranging from approximately 110 to 3520
mg potassium nitrite/kg bw/day), but no statistical analysis
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was provided. At the two highest doses, all fetuses and one
dam died. Placental degeneration, and inflammation of the
reproductive tract were noted in females having resorbed or
mummified fetuses.
There were no studies available from the publishedliterature which used rats in a standard
developmental-toxicity protocol involving prenatal-only
administration of sodium nitrite. There are, however, aseries of studies which exposed pregnant rats to sodium
nitrite during the latter half of gestation, and evaluatedpostnatal effects on behavior and neurological development.
In other studies, sodium nitrite was administered topregnant and lactating rats; in some cases, the weaned
offspring were then exposed directly. Reported effects ofsuch treatment have included increased postnatal mortalityand depressed postnatal growth, as well as decreases inopen-field locomotor activity, and effects on pup organ
weights and iron status.
Simple learning in response to either a reward or anaversive stimulus was not affected in two month old maleoffspring of female rats exposed to sodium nitrite in thelatter half of gestation. Discriminatory learning of bothvisual and auditory cues, however, was impaired in the
nitrite-exposed animals, as was long-term retention of aconditioned passive-avoidance response. Effects of prenatal
nitrite exposure did not diminish as the animals aged; at 24
months, nitrite-exposed animals were unable to discriminate
between light and dark areas of the test cage in response to
avoidance training. Open-field activity levels, social
behavior, and corticosterone levels in response to stresswere also all affected in adult rats prenatally exposed tonitrite. Upon necropsy at 28 months of age, absolute andrelative adrenal weights were found to be significantly
higher in treated animals than in controls.
A study of cholinergic and serotonergic nerve fiber
outgrowth in the hippocampus and neocortex of neonatal rats
found significant delays associated with prenatal exposure
date: 04-JAN-2006
to sodium nitrite. The authors attributed their findings tonitriteinduced prenatal hypoxia, leading to retarded
development of certain neurotransmitter pathways, in turncausing long-lasting dysfunctions in the developing rat
brain. In the histopathological study, as in the behavioral
studies, co-adminsitration of the Ca2+ channel-blocking
drug, nimodipine, prevented the adverse effects associatedwith nitrite exposure alone. The protective effects ofnimodipine were attributed to its antihypoxic activity, as
it would be expected to block increases in intracellular
Ca2+ concentrations associated with perinatal brain damageof hypoxic/ischemic origin.
Pre- and postnatal exposure of rats to sodium nitrite has
been reported to have adverse effects on hematologicalparameters, including dose-dependent decreases in Hb
content, RBC counts, and MVC values. A later study by thesame group investigated the possible role of iron deficiency
in producing the adverse postnatal effects associated with

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sodium nitrite exposure. In the absence of supplemental
iron, sodium nitrite-treated pups developed severe
microcytic anemia by the second week of postnatal life. The
anemia was associated with significant depressions inhematological parameters, as well as with depressed growthand increased pup mortality. Iron supplementation mitigatedor eliminated all of these adverse effects.
No adverse effects on pup weights or mortality were observedin a rat multigeneration study, in which animals were fed ona sodium nitrite-containing, cured-meat diet providing daily
sodium nitrite doses of approximately 5, 20, or 100 mg/kg
bw.
Two of the studies in which rats were exposed to sodium
nitrite both pre- and post-natally presented data on
parameters evaluated at birth. A paper described the resultsof a cross-fostering experiment, in which offspring were
exposed during either, both, or neither the pre- andpost-natal periods. Although data were not presented, theauthors stated that prenatal-only exposure led to no
statistically significant differences in body weights fromcontrol pups, but there was an apparent effect of prenatal
exposure evident on postnatal days one through eight.
Additionally, offspring exposed only prenatally to sodium
nitrite showed a significant reduction in MCV on postnatal
day 21. In a later study by the same group, pup sex ratio
and litter size at birth were found to be unaffected byprenatal exposure to sodium nitrite, but birth weights weresignificantly lower (by an ANOVA test of sex and treatment
as sources of variation) in treated than in control animals.
The U.S. FDA summarized the results of submitted data fromteratogenicity studies on sodium and potassium nitrate,
which were performed in rats, mice, hamsters, and rabbits.
The Agency concluded that none of these studies demonstrated
adverse effects of either compound on development.
Conversely, the same N-nitroso compounds which can induce
transplacental carcinogenicity in experimental animals when
given late in pregnancy, may also induce a teratogenic
response when given early in pregnancy
References cited:Nyakas C, Buwalda B, Markel E, Korte S, Luiten P (1994b).
Life-spanning behavioural and adrenal dysfunction
induced by prenatal hypoxia in the rat is prevented by thecalcium antagonist nimodipine. Eur. J. Neurosci. 6(5),746-53
Nyakas C, Markel E, Bohus B, Schuurman T, Luiten P (1990).
Protective effect of the calcium antagonist nimodipine on
discrimination learning deficits and impaired retention
behavior caused by prenatal nitrite exposure in rats. Behav.
Brain Res. 38, 69-76
Olshan A and Faustman E (1989). Nitrosable drug exposure
during pregnancy and adverse pregnancy outcome. J. Epi.
18(4), 891-899

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Roth A and Smith MK (1988). Nitrite-induced irondeficiency in the neonatal rat. Toxicol. Appl. Pharmacol.
96, 43-51
Roth A, Herkert G, Bercz J, Smith M (1987). Evaluation of thedevelopmental toxicity of sodium nitrite in long evans rats.
Fundam. Appl. Toxicol. 9(4), 668-677
Shimada T (1989). Lack of teratogenic and mutagenic
effects of nitrite. Arch. Environ. Hlth. 44(1), 59-63
Shiobara S (1987). Effects of sodium nitrite (NaNO2)
administration on pregnant mice and their fetuses. Jpn. J.
Hygiene 42, 836-846
Shuval HI and Gruener N (1972). Epidemiological andtoxicological aspects of nitrates and nitrites in theenvironment. Am. J. Public Health 62, 1045-1052
Sinha DP and Sleight SD (1971). Pathogenesis of abortion inacute nitrite toxicosis in guinea pigs. Toxicol. Appl.
Pharmacol. 18, 340-347
Vorhees CV, Butcher RE, Brunner RL, Wootten V (1984).
Developmental toxicity and psychotoxicity of sodium
nitrite in rats. Food Chem. Toxicol. 22, 1-6
FDA (Food and Drug Administration) (1972). GRAS (Generally
Recognized As Safe) Food Ingredients. Nitrates and Nitrites(Including Nitrosamines). Washington, D. C.: U.S. FDA;
Report No.: NTIS PB-221-220.
Globus M and Samuel D (1978). Effect of maternallyadministered sodium nitrite on hepatic erythropoiesis infetal CD-1 mice. Teratology 18, 367-378
Kociba RJ and Sleight SD (1970). Nitrite toxicosis in theascorbic acid-deficient guinea pig. Toxicol. Appl. Pharmacol.
16, 424-429
Nyakas C, Buwalda B, Kramers RJ, Traber J, Luiten PG (1994a).
Postnatal development of hippocampal andneocortical cholinergic and seotonogeric innervation in rat:
effects of nitrite-induced prenatal hypoxia and imodipine
treatment. Neuroscience 59(3), 541-59

Test substance:
Conclusion:229

WHO (World Health Organization) (1996). Toxicologicalevaluation of cetain food additives and contaminants infood: Nitrite. WHO Food Additives Series; 35, 269-323
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Studies conducted in mice have not provided clear andconsistent evidence for adverse effects of in utero exposure
to sodium nitrite on standard parameters of developmental
toxicity. Administration of sodium nitrite to pregnant
guinea pigs, particularly ascorbic acid deficient guinea
pigs, has resulted in abortion of litters. Behavioral andneurodevelopmental studies conducted in rats have indicatedlife-long consequences of prenatal exposure to sodium
nitrite. These effects have been attributed tonitrite-induced prenatal hypoxia. Fetal, as well as
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Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
maternal, methemoglobinemia has been reported in guinea pigs
and dairy cows, following administration of sodium nitrite
to the maternal animal. In dairy cows, mean fetal PO2 levels
were found to be decreased following maternal infusion withsodium nitrite.
(2) valid with restrictions
Reliable review of exsisting literature data.
(29)

Species:Route of administration:
Exposure period:
Control Group:Year:
Remark:guinea pig
s.c.
During last week of gestation
otherSex: female

1970
Three experiments were performed in an attempt to clarify
the relationship between ascorbic acid deficiency andsensitivity to sodium nitrite toxicity. Guinea pigs were fed
on a diet lacking in ascorbic acid, until their plasma
ascorbic acid decreased to a level considered to be"subnormal." In the experiment A, administration of 50 mg/kg
sodium nitrite by subcutaneous (s.c.) injection produced
significantly higher MetHb levels in 12 ascorbic aciddeficient guinea pigs than in 6 controls. Higher MetHb
levels were found at all time points tested: 60, 90, and 120
min post injection. No control animals died, while mortality
was 83.3% in treated/deficient animals.
The experiment B and C; See TC and RS

Result:

The authors attributed the more severe effects of sodium
nitrite on ascorbic-acid deficient guinea pigs to: "(1) arelative decrease in ascorbic acid available as a reducing
substance, and (2) decreased hemoglobin and PCV values,
which increased the ratio of nitrite per erythrocyte."
Experiment B;-Fetal Effects
No gross abnormalities.
All litters aborted in sodium nitrite treated, ascorbic
acid-deficient animals.
No abortions in non-deficient, treated animals, or in
deficient animals not given sodium nitrite.
-Maternal Effects
No deaths in non-deficient group; 83.3% mortality indeficient group.
Higher MetHb levels in deficient than in non-deficient dams.
Experiment C;-Fetal Effects
Fetal MetHb levels did not differ between deficient andnon-deficient groups.

Test condition:-Maternal Effects
Maternal Hb, PCV, and plasma ascorbic acid lower in ascorbic
acid-deficient dams than in their offspring.
MetHb levels significantly higher in deficient than in
non-deficient dams.
Experiment B;
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Test substance:
Conclusion:
Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
11 pregnant sows given 45 mg sodium nitrite/kg bw, s.c.
Ascorbic acid status of animals varied.
Experiment C;
8 pregnant sows, 5 having low ascorbic acid status, were
given 40 mg sodium nitrite/kg bw, s.c.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
These data indicated that the fetal deaths were related tohigher levels of methemoglobin in maternal blood of ascorbic
acid-deficient guinea pig.
(2) valid with restrictions(105)

Species:
Strain:Route of administration:
Exposure period:
Control Group:Year:
Result:guinea pig
other: not specifieds.c.
Last 15 days of pregnancy
yes

Sex: female

1971
Experiment-1:
All guinea pigs given 50 mg/kg NaNO2 as well as the controls
gave birth to normal littles.
All 3 guinea pigs given 60 mg/kg NaNO2 aborted 1-4 days after
treatment.
The four given 70 mg/kg died within 60 minutes.
Experiment-2:
There was 96% mortality of fetuses from nitrite-treated dams
examined at 3 or more hours after nitrite administration. All
fetuses of control animals were alive.
Methemoglobin was present in maternal and fetal blood up to 6
hr after administration, with maternal concentrations being
much higher. Plasma NO2-N was detected at low concentrations
at 1/4 and 11/2 hr in both maternal and fetal blood but was
not detected at 3 hr or later. Heinz bodies were not seen.
Experiment-3:
Methemoglobin concentrations increased significantly during
the experiment in both dams and fetuses. Fetal methemoglobin
levels were significantly lower than corresponding maternal
values. fetuses from dams were viable at 20 and 40 min, but
fetuses in 4/6 litters were dead by 60 minutes.
Experiment-4:
fetuses were apparently protected by administration of
methylene blue to the dams at the time of nitrite
administration. Thoses gives nitrite alone aborted 3-4 days
after treatment.

Test condition:
231

Experiment-5:
In guinea pigs given NaNO2 (60 mg/kg) there was acorresponding reduction in maternal and fetal PO2 values with
the increases in methemoglobin values.
Experiment-1:

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DATE: 04-JAN-2006
Four pregnant guinea pigs were each given an s.c. injection of
sodium nitrite (2% solution) at a dose of 50 mg/kg, three were
given 60 mg/kg and 4 were administered 70 mg/kg. Two controls
were given 2% NaCl, 50 mg/kg and one 60 mg/kg. The number oflitters born alive, the number aborted and the number of dams
killed was recorded.
Experiment-2:
A group of nine guinea pigs was injected s.c. with sodium
nitrite solution (2%) at a dose of 60 mg/kg. A control groupof nine guinea pigs was injected with sodium chloride (2%)
s.c. at a dose of 60 mg/kg. One nitrite-treated and one
control guinea pig eac hwere killed at the followingintervals following administration of the sodium nitrite or
sodium chloride: 0.25, 1.5, 3, 6, 18, 24, 24.5, 48 and 56
hours. Hysterotomies were performed and the fetuses removed
and examined. Maternal blood samples were collected as were
blood samples from live fetuses. Hemoglobin, methemoglobin andplasma nitrite levels were determined on all blood samples.
Blood samples were stained with 1% methylene blue and examined
for the presence of Heinz bodies. At necropsy samples ofadrenal, brain, heart, intestine, kidney, liver, lung,pancreas, placenta, spleen and uterus were examined.
Experiment-3:
To determine maternal and fetal values of methemoglobin andplasma nitrite following sodium nitrite administration, 18
pregnant guinea pigs were each given sodium nitrite (60 mg/kg)
and a hysterotomy was performed on 6 each at 20, 40 and 60
minutes. Maternal and fetal blood samples were obtained andanalysed. The viability of fetuses was ascertained andrecorded.
Experiment-4:
Methylene blue (10 mg/kg) was administered i.p. to 6 pregnant
guinea pigs during the last 15 days of pregnancy. Three were
simultaneously given NaNO2 (60 mg/kg, s.c.). One
nitrite-treated animal and 1 given only methylene blue wereanesthetised and hysterotomies were performed 3, 24 and 100 hr
after treatment. Six pregnant guinea pigs wre selected. Two
were given methylene blue (10 mg/kg) and NaNO2 (60 mg/kg). Two
were given only methylene blue (10 mg/kg) and the remaining 2
guinea pigs were given NaNO2 (60 mg/kg). Toxicity for the
fetuses was evaluated as in prior experiments.
Experiment-5:

Test substance:

Six pregnant guinea pigs at approximately day 60 of gestation
were used. Three were given a s.c. injection of NaNO2 (60
mg/kg). Blood samples wre then collected 30, 60 and 90 min
after the injection. Maternal blood was drawn from uterine
blood vessels and the fetal blood from umbilical bloodvessels. Maternal and fetal blood samples were also collectedfrom the 3 untreated guinea pigs. A Radiometer was used todetermine PO2.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
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Reliability:
18-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(2)

valid with restrictions(164)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:Year:
Remark:mouse
Sex: female
CD-1
gavagefrom 0 to 14, 16, or 18 days of gestation
daily
20mg/kg bw/day (ca 0.5 mg/mouse/day)
yes, concurrent vehicle

1978
Although the dose level is only one, this study can be used
as a key study because the protocol is similar toguideline-study.
CAL/EPA (California Environmental Protection Agency) (2000).
Evidence on Developmental and Reproductive Toxicity of
Sodium Nitrite, Reproductive and Cancer Hazard Assessment
Section (RCHAS), Office of Environmental Health Assessment(OEHHA) evaluated this study as follows:

Result:A study of erythropoiesis in fetal CD-1 mice following
maternal exposure to sodium nitrite was conducted. The study
was intended to test a working hypothesis that sodium
nitrite-induced fetal methemoglobinemia would be expected toresult in increased fetal erythropoietic activity.
No differences were found between treated and control
animals, at any of the time points evaluated, for litter
size, mean litter weight, mean embryo weight, mean number ofresorption sites, or percentages of dead implants. There
were no statistically significant differences between
treated (n=42) and control (n=37) animals in the frequenciesof skeletal abnormalities or variations, but the authors
noted a tendency toward talipomanus and talipes in the
nitrite-treated group. No data were provided to support thistendency.
Hepatic hematopoeisis was evaluated as percentages of total
hepatic erythroblasts which were at various distinct stagesof maturation. The overall frequency of red blood cells was
significantly increased in treated animals at 14 and 16 daysof gestation, but not at 18 days. The percentage of matureerythrocytes in hepatic tissue was reduced in treatedanimals on gestation days 14 and 16, but not on gestation
day 18. The percentages of pro- and basophilic erythroblasts
were significantly decreased in treated animals of 14 and 16
days gestation age, but not on gestation day 18.
Polychromatophilic erythroblasts were significantly more
frequent in treated than control animals on gestation day
14, and significantly less frequent on gestation day 16,
with no difference between treated and control animals ongestation day 18. Orthochromatophilic erythroblasts werealso found at a higher percentage in treated than control
animals on gestation day 14, and to be unchanged fromcontrols on gestation day 18. This cell type, however, wasfound to be more frequent in treated than in control animals
on gestation day 16.

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The overall frequency of white blood cells was slightly, but
not significantly, reduced at all three time points. The
proportion of neutrophil granulocytes was significantly
increased in treated animals at day 18, but was unchanged
from control values at the other time points.

Test condition:

Test substance:
Conclusion:

Reliability:
19-JUL-2005

The authors interpreted their results as indicating atreatment-dependent increase in embryonic hepatic productionof erythroid cells. The lack of a sustained increase inmature red blood cells in the livers of day 18 fetuses wasconsidered to be due to a normal developmental shift in themain site of erythropoesis from the liver to the bone marrowand spleen. The authors acknowledge, however, that noincrease in red blood cell counts could be demonstrated in
the peripheral circulation. Hence the functionalsignificance of their findings remains unclear.
CD-1 mice were time-mated, and the day of plug detection wasconsidered to be day one of gestation. Treated animals were
given 0.5 mg sodium nitrite per mouse, by intubation, daily
throughout gestation, until sacrifice on gestation day 14,
16, or 18. For an approximate average body weight of 25 mg,
this provided a dose of 20 mg/kg/day. Control animals were
given distilled water, also by gavage. Twenty-three control
and 23 treated litters were sacrificed for examination ongestation day 14; 12 control and 9 treated litters were
examined on day 16; and four control and four treatedlitters were evaluated on gestation day 18.
Litter size, the number of resorption sites and dead
implants, and embryo/fetal weights were recorded at the timeof sacrifice. Embryos/fetuses were examined for grossanatomical defects, and, following removal of the livers foranalysis, their carcasses were prepared for skeletal
examinations. Parameters of erythropoiesis were determinedfor hepatic tissues, as the liver is the main site oferythrocyte production between gestation days 12 and 19 in
the mouse.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Supplier: Matheson, Coleman and Bell
-Fetal Effects
No significant differences between groups for: litter size,
weight, resorptions, fetal death, or skeletal abnormalities
or variations.
Significant changes in hepatic erythropoiesis.
No sustained increase in hepatic mature red blood cells on
day 18.
(2) valid with restrictions(66)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:

mouse
Sex: male/female
CD-1
gavagegestation days 6-15, dosing started after
implantation.
daily
0, 20, 40, 80, or 120 mg sodium nitrite given togroups of 25 pregnant mice on gestation days 6 - 15.
yes

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Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
1987
One maternal death occurred in the 40 mg/kg/day group; noother dams died. No clinical symptoms of toxicity werereported during the course of the study. Maternal bodyweights on gestation day 17, and maternal body weight gains
over the gestation period, were significantly reduced at thetwo highest doses of 80 and 120 mg/kg/day. Kidney and liver
weights showed significant decrements from controls at somedoses, but there was no evidence for a dose-response
relationship. Furthermore, when considered relative to bodyweights, organ weights were found not to differ between
groups. There were no differences between groups inhemoglobin or hematocrit values.
There were no differences between groups in the frequency of
pregnancy among mated females, nor were there any incidents
of total litter loss or premature delivery. The number of
implantations per litter was significantly reduced in thehigh-dose group, as was mean litter size. As it is likelythat implantation preceded or coincided with the beginningof treatment, the observed changes in implantation frequency
are unlikely to have resulted from treatment. In turn, thechange in litter size on gestation day 17 may have been an
artifact of non-treatment related variation in implantation
frequency.
The percentage of living fetuses at each dose wassignificantly reduced at both 20 and 120 mg sodium
nitrite/kg bw, but not at the intervening doses of 40 and 80
mg/kg. The total number of dead fetuses, and the number of
early fetal deaths was significantly increased at the highdose. At the low dose, the total number of dead fetuses was
significantly decreased. Fetal weights were significantly
increased over controls at all doses of sodium nitrite, with
no apparent relationship to administered dose.
Isolated incidences of cleft palate were observed in allgroups (treated and control), with no evidence for atreatment-related effect. No other external abnormalities
were observed. There were some significant differences
between treated and control fetuses in the pattern ofossification of skeletal elements, but there was no
consistent treatment related pattern of skeletal retardation
or advancement. As compared to controls, the frequency of a
14th rib was significantly lower in the fetuses of animals
given 20 or 80 mg sodium nitrite, but significantly higher
in fetuses of the 40 or 120 mg/kg/day groups. No differenceswere observed between groups in the frequency of litters
having at least one fetus with 14 ribs.
For the five females in each dose group who delivered theirfetuses normally, only the high-dose group showedsignificant reductions in body weight, relative to controls,on gestation day 17. There were no significant differences
between groups in the rate of body weight gain during
gestation. When these dams were necropsied subsequent toweaning of their offspring, uterine weights weresignificantly reduced in the 20 and 120 mg/kg groups, but
not in the two intervening dose groups. Hemoglobin was

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ID: 7632-00-00
DATE: 04-JAN-2006
significantly increased in the 40 mg/kg dose group, andhematocrit was significantly decreased in the 120 mg/kg dosegroup.
Litter size at postnatal day 70 was significantly reduced
from control levels in the 40 and 80 mg/kg groups. No
offspring deaths were reported for the first 14 days
following birth. During the interval between postnatal day
14 and postnatal day 70, one pup died in each of the control
and low-dose groups, and two pups died in the high-dosegroup.
Pup body weights on postnatal day 14 were significantly
reduced in the 20 and 120 mg/kg dose groups, but not in the
40 or 80 mg/kg/day dose groups. Hence, the dose-response
pattern for body weight reductions mirrors that observed forlitter size. In other words, the data suggest that pups inthe smaller litters of the 40 and 80 mg/kg dose groups had
less competition for milk, and thus were able to maintain anormal body weight.

Test condition:

Test substance:
Conclusion:

Reliability:
19-JUL-2005
Species:

By postnatal day 70, there were no differences between dosegroups in the mean weights of male or female pups. Somesignificant differences in mean organ weights were foundbetween dosed groups and the control group, but thesedifferences were not apparent when organ weights wereconsidered relative to body weights.
Compared to controls, hematocrits were significantly reduced
in all groups of sodium nitrite-exposed female pups.
Hemoglobin content was also reduced in treated animals,reaching statistical significance for males in the 20 and 80
mg/kg groups, and for females in the 40 mg/kg group.
Groups of 25 time-mated female Crj:CD-1 mice (10 wk-old)
were exposed to sodium nitrite by gavage, at doses of 0, 20,
40, 80, or 120 mg/kg/day, on gestation days 6-15. On
gestation day 17, 20 pregnant mice from each group weresacrificed for examination of their uterine contents. The
five remaining mice in each group were allowed to deliver
their offspring normally for postnatal observations.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Reagent grade-Fetal Effects
Significant decreases in: implantation frequency and meanlitter size at 120 mg/kg/day; living fetuses at 20 and 120(not 40) mg/kg/day; dead fetuses at 20 mg/kg/day.
Significant increases in: dead fetuses and early fetal
deaths at 120 mg/kg/day; increased fetal weights at all
doses, with no dose response.
-Maternal Effects
1 maternal death at 40 mg/kg
No clinical symptoms of toxicity.
Body weights on day 17, and gestational weight gainsignificantly reduced at 80 and 120 mg/kg/day.
Some decreases in absolute, but not relative, liver andkidney weights.
(2) valid with restrictions
(161)
mouse

Sex: female
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:
NOAEL Maternal Toxity:
NOAEL Teratogenicity:
Year:
Result:ICR
drinking water
gestation day 7-18
continuous
0, 100, 1000 mg/L = appl. 0.27, 243 mg/kg bw/day
yes, concurrent vehicle> 1000 mg/l
> 1000 mg/l

1989
There were no statistically significant changes in water
consumption or gestational weight gain of treated dams. Nor
were there any significant changes in the numbers of corpora
lutea, live fetuses per litter, or resorbed or dead fetuses
per litter. No significant differences were reported between
groups for sex ratio, the frequency of runting, fetal bodyweights, or the frequencies of external or skeletal
malformations. No significant changes were noted in thefrequency of chromosomal gaps or breaks in maternal bonemarrow cells, or in fetal liver cells.
Although the numbers of corpora lutea had been predetermined
before dosing, the result is consistent-Fetal Effects
No significant changes in: live fetuses per litter, fetal
weights, sex ratio; or in frequencies of resorptions, deadfetuses, runting, or external or internal malformations.
No significant changes in the frequency of chromosomal gaps
or breaks in liver cells.

Test condition:

Test substance:
Conclusion:
Reliability:
19-JUL-2005-Maternal Effects
No significant changes in: water consumption, gestational
weight gain, or frequency of chromosomal gaps or breaks inbone marrow cells.
Animal; sexually mature virgin female ICR mice (25-33g)
Females were sacrificed, and their uterine contents
evaluated on gestation day 18.
Chemical name: Sodium ntirite (CAS No. 7632-00-0)
Teratogenic and mutagenic effects of NaNO2 were absent inmice at the dose of 100 and 1000 mg/L.
(2) valid with restrictions(160)

Species:
Strain:Route of administration:
Exposure period:
Duration of test:
Doses:
Control Group:
Year:
GLP:
Method:237

rat
Sex: female
Wistardrinking waterfrom gestation day 13 to parturation
Two months postnatal
2g/L
yes, concurrent no treatment

1990
no dataBehavioral testing of male offspring at 2 months postnatal
age.
Male offspring were divided into test groups, and subjected
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
to either discrimination or passive avoidance testing.
Auditory discrimination for a drinking water reward(conducted following 23 hours of water deprivation) wastested, as well as visual discrimination in a (footshock)active avoidance situation. The passive avoidance test
system consisted of avoiding footshock by learning not toenter a darkened compartment. Extinction and retention ofthese behaviors were also evaluated. Five to nine animals
were subjected to each testing series.

Result:Number animals/group not stated.
Not standard test, single dose level, number of the dam notreported, but noteworthy.
Acquisition of the initial phase of all three tasks showedno significant differences between treatment groups. For all
animals, performance of the auditory conditioned responsewas "almost errorless" within four training sessions.
Acquisition of the visually cued, one-way avoidance response
was also comparable between groups (F2,13 = 0.1; P = 0.9).
More than 50% of the animals from all groups showed maximal
passive avoidance following the first footshock experience.
Animals exposed prenatally to nitrite, however, were foundto be impaired both in discrimination learning behavior(both auditory and visual), and in long-term retention of
the passive-avoidance response. In the discrimination phaseof the auditory test, the nitrite-treated rats made moreerrors than did either the controls or the nitrite plus
nimodipine -treated group in response to the non-reinforced
stimulus (F1,12 = 21.26; P<0.001 and F1,16 = 10.68; P<0.01,
respectively). A similar pattern was found for the error
rate in response to the reinforced stimulus (F1,16 = 5.89;
P<0.05 and F1,16 = 6.32; P<0.05, for differences from thecontrol and nimodipine plus nitrite groups, respectively).
Impairment of long-term retention of the passive avoidance
response (intertrial intervals of 3 or 4 days) was shown for
nitrite-exposed animals compared to the control group (U =33; P = 0.02). The effect of nitrite was at least partiallyreversed by nimodipine, as no difference was found between
the controls and the nitrite plus nimodipine group (U = 75;
P = 0.6). However, there was no significant difference
between the nitrite only group, and the nitrite plus
nimodipine group (U = 43; P = 0.09). In the first two
sessions of the retention test, significantly moreindividuals of the nitrite plus nimodipine group showed the
avoidance response as compared to the nitrite treated group(X2 = 4.53; P<0.05; and X2 = 4.11; P<0.05, respectively).
Differences between the nitrite-only group and the control
group were also significant (X2; P<0.05). By the third
trial, the extinction process was too far advanced in allgroups to reveal any between-group differences.
-Offspring Effects
No changes in initial acquisition of learned responses.
Nitrite-exposed animals significantly impaired fordiscrimination learning behavior, and for long-term
retention of passive-avoidance.
Co-administration of nimodipine prevented these effects.
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Test condition:

Test substance:
Conclusion:
Reliability:
19-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Pregnant Wistar rats were given 2 g/L sodium nitrite indrinking water, from gestation day 13 until parturition.
Apart from untreated controls, other experimental groups
were given either the calcium antagonist nimodipine, at adose of 10 mg/kg bw, by gavage, from gestation day 11
through parturition, or both nimodipine and sodium nitrite.
The number of animals assigned to each treatment group was
not stated in the paper.
At two months postnatal age, male offspring were divided
into test groups, and subjected to either discrimination or
passive avoidance testing. Auditory discrimination for adrinking water reward (conducted following 23 hours of water
deprivation) was tested, as well as visual discrimination ina (footshock) active avoidance situation. The passive
avoidance test system consisted of avoiding footshock bylearning not to enter a darkened compartment. Extinction andretention of these behaviors were also evaluated. Five tonine animals were subjected to each testing series.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
The results support the hypothesis that Ca++ homeostasis ofneurons is important factor for normal development of brain
behavior.
(2) valid with restrictions(137)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Duration of test:
Doses:
Control Group:
Result:rat
Sex:
Wistardrinking waterfrom gestation day 13 to parturationad libitum
10 days post natal
2 g/L
yes, concurrent no treatment-Offspring Effects: Significant effects of sodium
nitrite on ingrowth of cholinergic and serotonergic
nerve fibers into the hippocampal dentate gyrus andthe parietal neocortex.

Method:Year:other: brain histopathology on days 1, 3, 5, 7, 10 postnatal
1994

Result:Detail are as follows:
Brains of male pups were processed for histopathologicalstaining of acetylcholinesterase (AchE) and serotonin(5-hydroxytryptamine: 5-HT)-positive fibers. Brains were
sampled on each of post-natal days 1, 3, 5, 7, 10, and 20.
From each litter group, only a single pup was assigned to oneof the age-groups, to avoid possible litter-based confounding
effects.
Prenatal nitrite exposure was shown to modulate thedevelopment of AchE and 5-HT positive fiber ingrowth into
the hippocampal dentate gyrus (DG) and parietal neocortex
during the first week of postnatal life. Fiber densities
were evaluated from serial sections. Effects on both fiber
types were region-specific in the hippocampus, andrestricted to the DG. Based on an ANOVA test of treatment
effects, nitrite was found to significantly influence

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cholinergic fiber density in the DG (F1,39 = 3.92, P <0.05). The number of fiber crossings in the DG region was
also decreased in nitrite-treated postnatal day 5 and 7
animals. Co-administration of nimodipine prevented theseeffects.
In the parietal cortex, the delay in cholinergic fiber
ingrowth was more pronounced in deep than in superficial
layers, while the serotonergic innervation was influenced
more evenly. By postnatal day 10, the differences between
nitrite-treated and control rats were no longer apparent.
ANOVAs carried out for postnatal days 3-10, revealed atreatment effect on cholinergic fibers restricted to thedeeper layers (F2,66 = 3.71, P < 0.05), with a specificeffect of nitrite (without nimodipine) on lowering fiber
density (F1,39 = 5.67, P < 0.02). On postnatal day 7, 5-HT
fiber density was significantly lower in nitriteexposed
animals than in controls, in both layers of the parietal
cortex. Again, the effect of nitrite was reversed in thepresence of nimodipine.
The authors concluded that the impact of prenatal nitrite
exposure was most evident during the early postnatal period,
when rapid fiber proliferation normally takes place.

Test condition:

Test substance:
Conclusion:

Reliability:
19-JUL-2005

They attributed the effects of nitrite to prenatal hypoxia,
and the mitigating effects of nimopidine to its
neuroprotective or antihypoxic action. Nimopidine would be
expected to block increases in intracellular Ca2+
concentrations associated with perinatal brain damage ofhypoxic/ischemic origin. They postulated that the transitory
effects of prenatal hypoxia on fiber ingrowth could, in turn,result in long-lasting functional deficits in the rat brain.
2 g sodium nitrite/liter drinking water from gestation day
13 through birth. 1000 ppm nimodipine in food pellets to someanimals (with or without sodium nitrite), from gestation day
11 through birth.
Number animals/group not stated. Brain histology of male pups
on post-natal days 1, 3, 7, 10, and 20.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
The results indicated that prenatal hypoxia evokes atemporary delay in the cholinergic and serotonergic fiber
outgrowth in cortical target areas in a region-sepecificmanner. The hypoxia-induced growth inhibition is prevented
by the calcium antagonist nimodipine, which supports theimportance of the intracellular Ca++ homeostasis of cells
and growth cones in regulating axonal proliferation.
(2) valid with restrictions
Not standard test, single dose level, number of the dam notreported, but noteworthy.
(135)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Duration of test:
Doses:

rat
Sex:
Wistardrinking waterfrom gestation day 13 to parturation
daily
28 months postnatal
2g/L
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Control Group:
Method:Year:
Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
yes, concurrent no treatment
other: Behavioral testing of male offspring at 26 months
postnatal age.
1994
-Offspring Effects
Details are as follows: Pregnant Wistar rats were given 2
g/L sodium nitrite in drinking water, from gestation day 13
until parturition. Apart from untreated controls, otherexperimental groups were given either the calcium antagonist
nimodipine, at a dose of 10 mg/kg bw, by gavage, fromgestation day 11 through parturition, or both nimodipine andsodium nitrite. All treatments ceased at parturition. There
were eight to ten dams in each treatment group, and no
significant differences in litter size or pup birth weight
were noted.
Behavioral testing was performed on adult male offspring at
the ages of 5 months, 19 months, and 23-26 months.
Spontaneous behaviors, such as open-field activity andsocial behavior, were measured repeatedly. Learning tests
were applied only during old age, in order to avoid repeateduse of footshock. Plasma corticosterone responses were
measured at 28 months of age.
By 2-way ANOVA, both age and treatment-dependent effects
were apparent on measures of open-field activity (latency tostart locomotion and number of crossings of lines marking
the test arena). A statistically significant interaction
between these two factors (F2,128 = 2.44; P<0.05) indicatedthat the effect of prenatal nitrite exposure on startlatency was more profound at advanced ages. Line-crossing
activity also decreased with age (F2,128 = 46.75; P<0.001).
Nitrite-only exposed rats were less active than controls at
both 5 and 19 months of age (P<0.05), but not at 23 months.
Total duration of social interactions, as measured byrecording the duration of activities such as inspection,
mounting, grooming, and play fighting, showed a marked
effect of treatment (F2,43 = 76.31; P<0.001). The number ofsocial interactions occurring during the five minute
observation periods also varied between treatment groups(F2,43 = 3.42; P<0.05); this was attributed primarily to thehigh activity levels of nitrite plus nimodipine-exposed
animals at 23 months, as compared to the nitrite-only group.
At 24 months of age, rats exposed prenatally to nitrite
showed no evidence of ability to discriminate between lightand dark areas of the test cage, following avoidance
training by administration of footshocks in the dark area.
The vehicle controls, and nitrite plus nimodipine-exposed
animals showed dark-avoidance behavior in initial trials, aswell as extinction of this response in later trials, in
response to withdrawal of the aversive stimulus. Nearly 60%
of nitrite-exposed animals showed an extreme response to thefootshock stimulus, and vocalized, jumped, and/or bit thegrid floor. This was a significant increase over thefrequency of such reactions in vehicle controls, or inanimals prenatally exposed to nitrite plus nimodipine

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(P<0.02, by X2).

Test condition:

Test substance:
Conclusion:

Reliability:
19-JUL-2005

At the age of 28 months, plasma corticosterone levels were
measure 15, 30, and 90 minutes after test animals were
subjected to a novel stress. Compared to basal
corticosertone levels, determined from samples taken at one
minute prior to application of the novel stressor, an
increased corticosterone response was induced in all threegroups (F3,42 = 9.53; P<0.001). The shape of thestress-response curve depended on the nature of prenatal
treatment (F3,42 = 2.71; P<0.02). For vehicle control andnitrite plus nimodipine-exposed rats, corticosterone levels
had returned to baseline levels by 90 minutes following thestress incident. In the nitrite-only exposed animals, plasma
corticosterone was still significantly elevated above
baseline levels at 90 minutes poststress (P<0.05). Upon
necropsy, adrenal weights, and adrenal weights relative tobody weights were found to be significantly (P<0.05) higher
in rats prenatally exposed to nitrite alone, as compared tocontrol animals. Animals exposed to nitrite plus nimodipine
had higher adrenal weights, but also higher body weights
than controls, hence relative adrenal weights werecomparable between the latter two groups.
2 g sodium nitrite/liter drinking water from gestation day
13 through birth.
10 mg nimodipine/kg bw by gavage to some animals (with orwithout sodium nitrite), from gestation day 11 throughbirth.
8-10 dams/group.
Behavioral testing of male offspring at 5, 19, and 23-26
months.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)-Offspring Effects
Age and treatment had significant effects on measures ofopen field activity.
Impaired discrimination learning at 24 months of age (nottested at earlier time points). Hyperreactivity tofootshock.
Significantly prolonged(2) valid with restrictions(136)

Species:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:
Year:
GLP:
Result:rat
drinking water
From pregnancy to lactation
continuous
2000, 3000 mg/L
yes, concurrent vehicle

Sex: female

1972
noReported effects for pups included: increased mortality,
decreased weight gain, and poor appearance of the fur. Meanlitter size (presumably at birth) was 10 for controls, 9.5
at the low dose, and 8.5 at the high dose. No statisticalanalysis was provided. Mortality was reported as 6% forcontrols, 30% for the low-dose group, and 53% for thehigh-dose group. It is not stated, however, during what
period that mortality occurred. Birthweights were similar
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
for treated and control animals, but growth rates were
substantially slower for treated animals. At weaning, themean weight of control pups was 51.5 g, while the mean
weights of low and high-dose group pups were 29.5 and 18.5
g, respectively. Subsequent to weaning, growth rates of thedosed groups improved. No evidence was found of abnormallyhigh MetHb in pups, but mean Hb levels were approximately
20% lower in treated than control animals.

Test condition:

Conclusion:
Reliability:
22-JUL-2005-Offspring Effects
Mean litter sizes lower in treated than control animals; nostatistical analysis.
Birthweights similar between groups.
0, 2000, or 3000 mg sodium nitrite/L drinking water togroups of 7-12 rats during gestation and lactation.
Groups of 12 pregnant rats were given sodium nitrite indrinking water at concentrations of either 2000 or 3000
mg/L. A group of seven controls was given plain tap water.
While the experimental details are not provided, it appears
that litters were delivered normally and remained with theirdams until weaning. Treatment of the dams' drinking watercontinued during the lactation period. At weaning, the pups
were put on plain drinking water.
Rats born of dam chronically exposed to nitrites in drinking
water bduring gestation period showed high mortality rates
and poor growth and development as compared to controls.
(2) valid with restrictions(163)

Species:
Strain:Route of administration:
Exposure period:

Frequency of treatment:
Duration of test:
Doses:
Control Group:
Method:Year:
GLP:
Remark:Result:rat
Sex: male/female
Sprague-Dawleyoral feedfor 14 days prior to mating, throughout the breeding
period (1-14 days), and throughout gestation andlactation. Weaned offspring were continued on thesame diets for the duration of the study
continuous
same as exposure period to day 90 post-natal
0, 0.0125, 0.025, or 0.05% (w/w) equivalent to 0,
10.75, 21.5 or 43 mg/kg bw/day
yes, concurrent vehicle

other: reproductive performance and behavioral test on
offsprings
1984
noAlthough offsprings were fed with test substance containing
feed for 90 days post-natal, and manifested effects areindiscriminative from pre- or pat-natal effect, study iscomprehensive and well described.
NOAEL (Reproduction) = 43 mg/kg bw/day
NOAEL (Development) = 10.75 mg/kg bw/day
Parental observations:
There were no significant reductions in food consumption or
body weight in treated animals before breeding or in treated

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ID: 7632-00-00
DATE: 04-JAN-2006
animals before breeding or in treated females during gestationor lactation. Sodium nitrite had no significant effect on
reproductive performance (Table 1) and no malformations were
seen.
Table 1: Reproductive Performance of rats fed 0-43 mg/kg
bw/day sodium ntirite in the diet----------------------------------------------------------Values of reproductive
performance parameters
Negative
Positive
Parameter
Control
Control----------------------------------------------------------No. females w/ sperm
35
32
Females delivering (%)
77.1
78.1
No. litters < 8 live pups
2
15
Gestation length (days)
22.2+/-0.2 22.3+/-0.2
No. born/litter
11.0+/-0.4 8.5+/-0.7
Total No. offspring delivered 297
212
Mean male/female ratio
1.25
0.71
No. litters tested after birth 25
10--------------------------------------------------------------------------------------------------------------------Sodium nitrite groups(mg/kg bw/day)
10.75
21.5
43
----------------------------------------------------------22
24
28
68.2
79.2
64.3
0
5
3
21.9+/-0.2
22.4+/-0.2
21.9+/-0.2
10.9+/-0.4
11.0+/-0.9
10.9+/-0.7
163
209
196
1.08
0.91
1.21
15
14
14
----------------------------------------------------------Preweaning observations:
Mortality: Sodium nitrite produced significant increases inoffspring mortality in the 43 mg/kg bw/day group during thepreweaning period but not at birth or after day 24, and in the21.5 mg/kg bw/day group at birth but not thereafter. The 10.75
mg/kg bw/day group exhibited no significant increase inmortality.
Body weight: Sodium nitrite decreased preweaning body weights
in the 21.5 and 43 mg/kg bw/day groups compared with negative
controls.
Behaviour:
The preweaning appearances of surface righting, pivoting,negative geotaxis, and auditory startle behavior were all
unaffected by exposure to sodium nitrite. Control ofswimming direction and control of head height whileswimming, however, were delayed in sodium nitrite exposed
preweaning pups. These effects were more pronounced at the
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
two higher sodium nitrite concentrations. Open-field
activity was decreased in preweaning females of the middle
concentration group (P<0.05). The effect is considered thebasis of NOEL of offsprings.
Open field activity on postnatal days 40-45 wassignificantly reduced in both males and females of the highand low-sodium-nitrite concentration groups, but not in the
mid-concentration group. As compared to controls, thelow-concentration group also showed significantly longer
response latencies on the first day of post-weaning testing.
Body and organ weights:
At necropsy on postnatal day 90, there wereno significant reductions in body or brain weights withsodium nitrite treatment. Females of the 10.75 and 21.5 mg/kg
bw/day groups showed a 4-5% reduction in eye weights (P<0.05).
Toxicological meaning of the finding is unknown.

Test condition:

Due to the lack of a clear dose-response relationship, theauthors considered that interpretation of responses at the
low and mid-concentrations of sodium nitrite wasproblematical. They concluded, however, that the effects
observed in the high-concentration group gave evidence that
sodium nitrite is capable of inducing moderate decreases inopen-field locomotor activity.
Animals: Sprague-Dawley rats
Sex: male/female
Weight: 200-220 g
Fed 0 (two control groups), 0.0125, 0.025 or 0.05 w/w sodium
nitrite in diet (equivalent to 0, 10.75, 21.5 or 43 mg/kg
bw/day, respectively).
Negative control dams received no treatment. Positive control
dams were given two i.p. injections of 2 mg 5-azacytidine/kg
on day 16 of gestation.
Dietary treatments were given continuously to both males andfemales for 14 days before mating and for 1-14 days during
breeding, and to females only during gestation (22 days) andlactation (21 days).
After weaning, offspring were given dietary sodium nitrite at
the level their parents had received throughout the remainderof the experiment (up to 90 days of age for most animals andlonger for those in avoidance testing).
Litters with fewer than eight live offspring were not kept
beyond day 1 after birth. Litters of more than 12 were reduced
to 12 by a random selection procedure that balanced the sex
distribution as much as possible.
Parental bodyweights were measured weekly except during
breeding and food consumption was measured on selected rats
during all phases of the experiment.
Date of birth and length of gestation recorded for all

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Test substance:
Reliability:
19-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
litters. On the day following birth all litters were examinedand data collected on litter size, sex distribution, weightand number of dead and/or malformed offspring
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Purity: Food grade
Supplier: EI du Pont de Nemours & Co.
(2) valid with restrictions(189)

Species:Route of administration:
Year:
Method:rat
gavageSex: female

1982
Virgin female rats (170-200 g) were paired overnight withproven breeders. The orning that a positive vaginal smear wasobserved was noted as day 1 of pregnancy.
Postnatal study (exp 1): Five to 12 mated females wererandomnly assigned to each experimental group. On day 15 ofgestation two groups of rats were given an orally intubateddose of 40 or 60 mg/kg ETU/kg followed immediately by a doseof 80 mg NaNO2/kg or two successive doses of distilled water.
The dams were allowed to deliver normally and progeny were
examined at birth and frequently thereafter, the animals being
maintained for 140 days to assess survival and development.
pups that died while on test were autopsied to determine causeof death.
Prenatal studies (expt 2): All test chemicals wereadministered to dams (12-17 dams/group) orally on day 13 ofgestation. All the dams were autopsied on the last day ofpregnancy. Uteri were searched for resorptions and for deadand live fetuses. All live fetuses were weighed and examinedfor external malformations and after appropriate processing
2/3 of them wee studied for gross visceral changes and theremainder for skeletal anomalies using standard procedures.

Result:

Test substance:
Reliability:
22-JUL-2005

In expt 2 the effects of NaNa2 on the ETU-induced
teratogenicty were assessed. An oral dose of 60 mg ETU/kg wasfolllowed immediately by an oral dose of 80, 100 or 120 mg
NaNO2/kg. Control groups received either 60 mg ETU/kg or 100
or 120 mg NANO2/kg or distilled water alone.
Expt 1: No treatment related adverse effects were observed on
pregnancy or parturition in any test or control group.
Expt 2: Two of the 17 dams in the group given distilled waterplus 120 mg/kg NaNO2 died. Periodic weight measurements during
pregnancy failed to show any significant treatment related
effects. No foetal effects were observed in rats dosed with
100 or 120 mg NaNO2/kg.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(2) valid with restrictions(103)

Species:
Strain:Route of administration:
Exposure period:

rat
Sex:
Long-Evansdrinking water
Day 0 gestation to day 20 of lactation
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Frequency of treatment:
Doses:
Control Group:

daily
0, 2.0, 3.0 g NaNO2/lyes, concurrent vehicle

Method:Year:
GLP:

other: Effect of ion to the manifestation of nitrite toxicity.
1988
noRemark:A series of three experiments was performed to evaluate thepossible role of iron deficiency in the etiology of sodium
nitrite-mediated developmental toxicity.
Results of experiment I included the finding that fluid
consumption was significantly reduced in treated animals
over the period of gestation, but maternal gestational
weight gain was not significantly affected. At birth, pup
sex ratio and litter size were unaffected by treatment, but
pup weights were significantly lower in treated than control
litters. Birth weights were analyzed by 2-way ANOVA,
examining the contributions of sex and treatment.

Result:By the second week postpartum, pups not supplemented withiron developed severe microcytic anemia. These pups showed
reduced postnatal weight-gain, and significantly increased
mortality before day 20 postpartum. Hemoglobin, RBC counts,
and MCV values were all significantly lower in treated thanin control pups; iron supplementation ameliorated oreliminated all of these effects.
As in experiment I, treated experiment II females (bothpregnant and unmated) consumed significantly less water thantheir respective controls. At the same time, weight gains
over 22 days (the gestation period in the pregnant animals)
were unaffected by treatment. Mean lactational weight gain
in experiment II was significantly reduced in treated dams,
relative to controls. As evaluated on postnatal day 15,
treated dams showed significant reductions in MCV,
hemoglobin, and plasma iron levels. RBCs were unchanged fromcontrol values. In unmated females, nitrite treatment did
not affect hematological parameters or plasma iron levels.
Litter size and sex ratio were unaffected in thisexperiment. Birth weights were reduced in treated male andfemale pups, relative to controls, but these differenceswere not statistically significant. Postnatal pup growth wassignificantly depressed. By postnatal day 15, pups oftreated dams were demonstrably anemic, and had significant
reductions in MCV, RBC, and hemoglobin levels.
In experiment III, the pattern of results for maternal fluid
consumption and weight gain during gestation and lactation
was similar to that seen in the other two experiments.
Litter size was significantly increased in sodium
nitrite-exposed pups, and pup weights were significantly
decreased. While the decrease in birth weight may have been
an artifact of the larger mean litter size, the ANOVA used
to evaluate these data is stated to have examined only sex
and treatment as sources of variation in birth weight.
Litter size was evidently not incorporated into theanalysis.
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Test condition:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
As in the previous experiments, postnatal pup growth wasadversely affected by sodium nitrite exposure, as were
hematological variables. On gestation day 15, heart weights
relative to body weights were found to be significantly
increased in treated pups. Relative spleen weights of thesesame pups were significantly decreased. Liver iron content
was significantly decreased, and liver copper content
significantly increased following sodium nitrite exposure.
Milk from sodium nitrite-treated dams was found to have asignificantly lower iron content than the milk of control
animals. The authors postulate that sodium nitrite
exposed-dams suffered from iron deficiency, and hence
produced iron-deficient milk, which in turn was responsible
for the adverse effects observed on their offspring.
In experiment I;
Pregnant Long-Evans rats were assigned to either control ortreated conditions, with six animals in each group. Control
animals were given plain tap water, while treated animals
were given drinking water containing 3 g sodium
nitrite/liter. Treatment began on gestation day 0, andcontinued throughout lactation. Litters were delivered
normally, and culled to ten pups. Half the pups in eachlitter were given supplemental iron by i.p. injection, on
postnatal days 0, 7, and 14. On each of postnatal days 7,
14, and 21, selected pups were sacrificed for hematologicaland histopathological analysis.
In experiment II;
Four groups of animals were delineated: ten pregnant
controls, five virgin controls, 13 pregnant treated animals,
and four virgin treated animals. Treated animals were given
2.0 g sodium nitrite/liter drinking water. All animals weresacrificed on postnatal day 15 for analysis of hematologicalparameters.

Test substance:
Conclusion:

Reliability:
19-JUL-2005

In experiment III;
Pregnant females were maintained throughout gestation andlactation on drinking water containing 0 (n=7) or 2.0 (n=8)
g sodium nitrite/liter drinking water. All pups and dams
were sacrificed for evaluation on postnatal day 15.
Chemical name:Sodium nitrite (CAS No. 7632-00-0)
It appears that nitrite-consuming dams have a reduced
capacity to transfer iron to their pups. The
nitrite-associated toxicities in the pups are actually aresult of an iron deficiency.
(4) not assignable(148)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:
Method:
Year:
GLP:

rat
Sex: female
Long-Evansdrinking water
Day 0 gestation to day 20 of lactation
daily
0, 0.5, 1.0, 2.0, 3.0 g NaNO2/lyes, concurrent vehicle

other: Three studies in three methods are reported.
1987
no data

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Remark:Result:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
Postnatal endpoints were investigated in Long-Evans rats
following exposure to sodium nitrite in drinking water
during pregnancy and lactation.
Three related experiments were reported in a single paper: I- pilot dose-response; II - dose-response; and III crossfostering.
No effects on maternal gestational weight gain were found inexperiments I or II; data on maternal weight gain were notpresented for experiment III. In some instances, maternal
fluid consumption was significantly reduced in treatedanimals as compared to controls: at both doses in experimentI, and in the high concentration group in experiment II.
Treatment had no effect on litter size, sex ratio, or mean
pup weights in any of the three experiments.
Postnatally, adverse effects became manifest for both dams
and pups. In experiment I, maternal water consumption andweight gain in the treated groups were significantly
depressed during the lactation period. A dose-response trend
for reduced maternal body weight was also apparent inexperiment II, although the differences from controls did
not reach statistical significance. Fluid consumption inexperiment II was not significantly decreased by treatment.
In experiment I, pup growth was significantly depressed, andpup mortality was increased, both in a dose-dependent
fashion. Affected pups were described as "pale, weak, and ingenerally poor condition with distended bellies." Inexperiment II, only the high-concentration group pups showedsignificant growth impairment. Pups from the lowest
concentration group were significantly heavier than controlson postnatal days 3 and 6. There was no postnatal pup
mortality in experiment II
In experiment III, the strongest effects on postnatal weight
were seen for pups exposed to sodium nitrite during both
gestation and lactation. Pups exposed during lactation alone
were also affected, although to a lesser degree. Pups
exposed only during the prenatal period showed nosignificant differences from controls in postnatal bodyweights, although there was an apparent influence of
prenatal exposure on pup growth between postnatal days 1 and
8.
Hematological parameters were significantly affected intreated animals in all three experiments. In experiment I,
hemoglobin content and red blood cell counts (RBCs) weresignificantly decreased in a dose-dependent manner on
postpartum days 9 and 16. Maximum corpuscular volume (MCV)
was significantly reduced at both concentrations of sodium
nitrite, when measured on postnatal day 16. MVCs were also
reduced in treated, relative to control, animals on
postnatal day 9, but the differences were not statisticallysignificant. Methemoglobin levels were not significantly
different from controls at either sodium nitrite
concentration, or on either day.
Methemoglobin levels were not determined in experiment II,
but hemoglobin levels for the high concentration group (2.0g NaNO2/liter) were significantly lower than controls

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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
starting from postnatal day 7. RBCs for this group weresignificantly reduced relative to controls by postnatal day
9. Hematological effects were also seen in the lower
concentration groups, but only at later timepoints. The mostsensitive endpoint was MCV, which was significantly reduced,
in a concentration-dependent fashion, at all three
concentrations on postnatal day 16.

Test condition:

The cross-fostering experiment (experiment III) demonstrated
that the observed anemia was predominantly postnatal inorigin. The prenatal-exposure-only group, however, did show
a significant reduction in MCV on postnatal day 21.
Methemoglobin was not measured in this experiment.
In experiment I, three groups of 8-10 pregnant females were
given 0, 2.0, or 3.0 g sodium nitrite/liter drinking water.
According to the study authors, these concentrations
resulted in total sodium nitrite consumption, over 18 daysof gestation, of 3.94 and 5.40 mg/g bw (219 and 300 mg/kg
bw/day, respectively). Lactating dams given the samedrinking water solutions had higher sodium nitrite intakesof 420 and 514 mg/kg/day. Litters were delivered normally,
and culled to eight pups on postnatal day 1. Hematologicalparameters were determined on postnatal days 9 and 16.
In experiment II, four groups of 5-8 pregnant animals were
given 0, 0.5, 1.0, or 2.0 g sodium nitrite/liter drinking
water. These concentrations were reported to result in total
sodium nitrite consumption, over 18 days of gestation, of
1.3, 2.14, and 3.6 mg/g bw (72.2, 119, 200 mg/kg bw/day,
respectively). Litters were culled to ten pups on postnatal
day 2, and blood samples were taken on postnatal days 7, 9,
13, 16, and 20.

Test substance:
Conclusion:
Reliability:
22-JUL-2005

In experiment III, pregnant females were given either plain
tap water, or tap water containing sodium nitrite at aconcentration of 2.0 g/liter. All pups were fostered atbirth, such that four groups were created: control(prenatal)/control (postnatal); control (prenatal)/treated(postnatal); treated (prenatal)/control (postnatal); treated(prenatal)/treated (postnatal). Each litter consisted of ten
pups, and there were 5-6 litters per group. Pups weresacrificed for hematological and histological assessment on
postnatal days 7, 14, or 21.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Administration of 1g NaNO2/Liter resulted in hematologicaleffects but did not affect growth or mortality. NaNO2(0.5g/liter) was at or near the no observed effect level.
(4) not assignable(149)

Species:Route of administration:
Exposure period:

Frequency of treatment:
Doses:

rat
Sex: male/female
oral feed
Treated diets were provided to F0 animals from ten
weeks prior to mating, and continued until animals
were terminated on the study. Subsequent to weaning,groups of 60-100 F1 animals were continued on therespective F0 diet.
continuous
fed cured meat to which 0, 200, 1000, or 4000 mg/kg
expressed as sodium nitrite had been added. After
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Control Group:
NOAEL Maternal Toxity:
NOAEL Teratogenicity:
Result:processing the food, contents may have changed. See"remarks".
other: One control group received casein as aprotein source; another control group was given>= 100 mg/kg bw>= 100 mg/kg bw
see "remarks"

Method:Year:
GLP:

other: see "remarks"
1984
noRemark:Study protocol is somewhat similar to one generation feeding
study. The spiked diet were processed supposedly to cause
potential nitrosoamine formation in food.
A cohort of 70 male and 140 female rats was divided into
groups and fed cured meat to which 0, 200, 1000, or 4000 mg
sodium nitrite/kg had been added. One control group received
casein as a protein source; another control group was given
fresh chopped pork. Treated diets were provided to F0 animals
from ten weeks prior to mating, and continued until animals
were terminated on the study. Subsequent to weaning, groups of
60-100 F1 animals were continued on the respective F0 diet.

Test substance:
Reliability:
19-JUL-2005
Year:
Remark:Following canning, autoclaving, and storage prior toexperimental use, the treated diets were determined to havenitrite contents of 6, 47, or 580 mg/kg. Data on feed
consumption were not provided in the paper, but the doses of
sodium nitrite consumed in the form of treated diets have been
estimated at 5, 25, or 100 mg/kg bw. No differences were noted
between treated and control F0 animals in appearance or
behavior, nor were effects noted on reproductive parameterssuch as pregnancy rate, litter size, mean pup weight, or pup
survival. No morphologicalabnormalities were observed in F1 offspring. There were no
significant differences in the rate of postnatal mortality
between treated and control pups.
Chemical name: Potassium nitrite (CAS No. 7758-09-0)(4) not assignable
(138)
1989
Another information of N-nitroso compounds
Recent investigations have suggested that drugs that areamines can undergo endogenous or exogenous nitrosation
reactions to form N-nitroso compounds. These compounds havebeen extensively characterized in animal models as
carcinogens, mutagens and teratogens. In order to examine
the possible effects of exposure to nitrosatable drugs
during gestation on pregnancy outcome, data were utilized
from the Collaborative Perinatal Project of the National
Institute of Neurological and Communicative Disorders andStroke. Pregnancy outcomes for 6061 pregnancies in which themother ingested a drug known to undergo nitrosation werecompared with 6921 randomly sampled pregnancies without such

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Reliability:
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ID: 7632-00-00
DATE: 04-JAN-2006
exposure. The major outcome factors of interest were birthdefects, fetal, neonatal and infant death and birthweight.
Our findings suggest that no significant increases in riskof fetal, neonatal and infant death or low birthweight wereassociated with nitrosatable drug exposure during pregnancy.
However, the risk of a tumour in the offspring of exposed
mothers was increased (relative risk, RR = 2.29; 95% Cl
0.99-5.26). Increases in relative risk of major
malformations was also observed and this increase wasgreater when exposure during the first four months ofpregnancy was examined separately (RR = 1.33; 1.11-1.58).
There were specific individual malformations that wereobserved to have increased relative risks (for example: eyemalformations, hydrocephaly, craniosynostosis andmeningomyelocoele/meningocoele) but interpretation was
difficult due to multiple comparisons and some of theseobservations were associated with wide confidence intervals.
These types of adverse pregnancy outcomes were consistent
with animal study outcomes.
(4) not assignable(139)

Species:Route of administration:
Year:
Remark:Result:

Test condition:
Test substance:
Reliability:
19-JUL-2005

Sex: female

1968
Concentrations of 0, 300, 1000, 2000, 3000, 4000, 5000 ro
10000 mg/L (ppm) estimated to provide doses of 0, 110, 270,
940, 1110, 1190, 1490 or3520 mg/kg bw/day.
Reproduction in the female was impaired by 30,000 ppm of
KNO3 with reproductive performance only 8% of that of thecontrols. Fetal losses were 100% in females given 5000 and
10,000 ppm of KNO2. Reproduction was maintained at lower
levels of treatment. Male fertility was apparently not
impaired since conception took place at all levels oftreatment. Food and water consumption and weight gains werenormal except for a diminished rate of gain at 10,000 ppm of
KNO2. Uterine and cervical inflammatory lesions anddegenerative placental lesions were present in females inwhich the fetuses had been aborted, mummified, or absorbed.
Guinea pigs were given KNO3 in doses ranging from 300 to
30,000 ppm in the water and KNO2 in amounts from 300 to
10,000 ppm for periods ranging from 100 to 240 days.
Test Substance; Potassium nitrite (CAS No. 7758-09-0)(4) not assignable(165)

Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:
Control Group:
Result:
Method:Year:guinea pig
drinking water

mouse
Sex:
C57BL
drinking water
Parents, after mating to 21 days post-natal.
Offsprings from partulation to 21 days p-n.t
continuous
1 g/L
yes, concurrent vehicle
Aggression score increased

other: Aggression test
1974
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GLP:
Remark:Test substance:
Reliability:
19-JUL-2005

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DATE: 04-JAN-2006
noFive mated pairs of C57Bl6J mice were given sodium nitrite
in their drinking water at a concentration of 1 g/L. Fiveadditional pairs served as controls. When young were born,
the adult males were removed. Litters were left with theirdams for 21 days; treatment of the sodium nitrite exposed
females was continued during this time. At weaning (21 days
postnatal), 12 male offspring were chosen at random fromeach group and removed to isolation cages. Males from thesodium nitrite-treated group were continued on the 1 g
sodium nitrite/L drinking water solution. Aggression testing
was commenced following an eight week isolation period. Eachanimal was placed in a "fighting cage" with another animal
for a period of ten minutes, once each week, for six weeks.
Four of the sessions were with other males from the samegroup (treated or control), and two sessions were with males
from the other group. The level of aggression was scoredaccording to a predetermined scale having a maximum score of
20. Following this first round of aggression testing, thetreated animals were switched to plain tap water, and after
a break of two weeks, aggression testing was repeated.
For the first round of testing, aggression scores weresignificantly elevated for the treated animals. Aggression
scores were higher for treated males paired with control
males (mean=12.95), than for treated males paired with othertreated males (mean=10.88). These differences disappeared
following a two-week recovery period after withdrawal of
sodium nitrite.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(3) invalid
Method is not popular. Reporting is poor and down graded.
(72)

5.8.3 Toxicity to Reproduction, Other Studies
Remark:Integrative Evaluation
There were no available data on the potential of sodium
nitrite to cause reproductive toxicity in humans. Among theavailable animal studies, none were conducted under astandard multi-generation reproductive toxicity study
protocol, and only a limited number included the treatmentof both sexes during the mating period. None of thepair-based studies provided evidence for an effect of sodium
nitrite on fertility, or on other reproductive parameters
evaluated. A study of the effects of potassium nitrite inguinea pigs also reported no effect of treatment on
fertility.
Two studies have provided some evidence of testicularchanges at the histopathological level in male rats, but theobserved effects could not be confidently attributed tosodium nitrite exposure. No evidence of testicular pathology
was identified in animals subjected to a 3-day regimen of
sodium nitrite injections.
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DATE: 04-JAN-2006
No evidence for adverse effects of sodium nitrite on female
reproduction was obtained from the studies reviewed. In
addition to fertility, relevant endpoints addressed by atleast one of these studies included: mean live litter size,
pup birthweight and viability, post-delivery estrous cycle
parameters, gross and histopathological evaluation of theovaries and uterus, and timing of vaginal opening in exposed
female offspring. There is some suggestion that sodium
nitrite might affect milk production, as postnatal weightgain was reduced in the offspring of dams given
approximately 245 mg sodium nitrite/kg/day during pregnancy
and lactation. Alternatively, this might have been theindirect result of poor palatability of sodium
nitrite-treated water leading to reduced water consumption(and hence to reduced milk production), or due to a direct
effect on the pups of sodium nitrite secreted in the dams'
milk.
A study on the effects of potassium nitrite in pregnant
guinea pigs reported that fertility was retained, althoughfetal loss appeared to increase with increasing dose ofpotassium nitrite. It is not known whether the difference inresults from the studies using sodium nitrite is due to theuse of the potassium salt, or to the generally higher doses
given, or to a greater sensitivity of the guinea pig ascompared to the rat and mouse
References cited:
Anderson, L. M., Giner-Sorolla, A., Haller, I. M., Budinger,
J. M. (1985). Effects of cimetidine, nitrite, cimetidine plus
nitrite, and nitrosocimetidine on tumors in mice following
transplacental plus chronic lifetime exposure. Cancer Res. 45,
3561-3566
Chapin, R., Sloane, R. (1997). Reproductive assessment bycontinuous breeding: evolving study design and summaries ofninety studies. Environ. Health Perspect. 105(1), 199-395
FDA (Food and Drug Administration) (1972). GRAS (Generally
Recognized As Safe) Food Ingredients. Nitrates and Nitrites(Including Nitrosamines). Washington, D. C.: U.S. FDA;
Report No.: NTIS PB-221-220.
Grant, P. and Butler, W. (1989). Chronic toxicity of sodium
nitrite in the male F344 rat. Fd. Chem. Toxic. 27(9),565-571
Van Logten, M., Tonkelaar, R., Kroes, R., Berkvens, J.,
Esch, G. (1972). Long-term experiment with canned meat
treated with sodium nitrite and glucono-gamma-lactone inrats. Fd. Cosmet. Toxicol. 10, 475-488
NTP (National Toxicology Program) (1990). Final Report on
the Reproductive Toxicity of Sodium Nitrite (CAS No.
7632-00-0). Research Triangle Park, NC: National Toxicology
Program. Report No.: NTP 90-266
Olsen, P., Gry, J., Knudsen, I., Meyer, O., Poulsen, E.
(1984). Animal feeding study with nitrite treated meat. IARC
Scientific Publication 57, 667-675
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DATE: 04-JAN-2006
Vorhees, C. V., Butcher, R. E., Brunner, R. L., Wootten, V.
(1984). Developmental toxicity and psychotoxicity of sodium
nitrite in rats. Food Chem. Toxicol. 22, 1-6

Conclusion:-Male Reproductive Toxicity
There were no available data on the potential of sodium
nitrite to cause male reproductive toxicity in humans. Amongthe available animal studies, none were conducted under astandard multi-generation reproductive toxicity study
protocol, and only a limited number included the treatmentof both sexes during the mating period. None of thepair-based studies provided evidence for an effect of sodium
nitrite on fertility, or on other reproductive parameters
evaluated. Two studies provided some evidence of testicularchanges at the histopathological level in male rats, but theobserved effects could not be confidently attributed tosodium nitrite exposure. No evidence of testicular pathology
was identified in animals subjected to a 3-day regimen of
sodium nitrite injections.
-Female Reproductive Toxicity
There were no available data on the potential of sodium
nitrite to cause female reproductive toxicity in humans.
With regard to the available animal toxicity studies, noevidence for adverse effects of sodium nitrite on female
reproduction was obtained. In addition to fertility,
relevant endpoints addressed by at least one study included:
mean live litter size, pup birthweight and viability,
post-delivery estrous cycle parameters, gross andhistopathological evaluation of the ovaries and uterus, andtiming of vaginal opening in exposed female offspring. Thereis some suggestion that sodium nitrite might affect milk
production, as postnatal weight gain was reduced in theoffspring of dams given approximately 245 mg sodium
nitrite/kg/day during pregnancy and lactation.
Alternatively, this might have been the indirect result ofpoor palatability of sodium nitrite-treated water leading to
reduced water consumption (and hence to reduced milk
production), or due to a direct effect on the pups of sodium
nitrite secreted in the dams' milk.

Reliability:
22-JUL-2005
Remark:255

A study on the effects of potassium nitrite in pregnant
guinea pigs reported that fertility was retained, althoughfetal loss appeared to increase with increasing dose ofpotassium nitrite. It is not known whether the difference
from the studies using sodium nitrite is due to the use of
the potassium salt, to the generally higher doses given, orto a greater sensitivity of the guinea pig as compared to
the rat and mous
(2) valid with restrictions(29)
There is evidence for placental transfer of sodium nitrite
to rat and mouse fetuses. Sodium nitrite administered byoral intubation to pregnant mice (0.5 mg/mouse per day) did
not cause fetal mortality or resorption or changes in embryoweight or incidence of skeletal malformation. The treatment
did stimulate fetal hepatic erythropoiesis, probably related
to fetal methemoglobinemia.
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ID: 7632-00-00
DATE: 04-JAN-2006
Nitrite and methemoglobin were detected in fetal blood after
pregnant rats were given a single dose of 2.5 to 5.0 mg
sodium nitrite/kg body weight.
References cited:
Anderson, L. M., Giner-Sorolla, A., Haller, I. M., Budinger,
J. M. (1985). Effects of cimetidine, nitrite, cimetidine plus
nitrite, and nitrosocimetidine on tumors in mice following
transplacental plus chronic lifetime exposure. Cancer Res. 45,
3561-3566
Bond, J.A., Chism, J. P., Rickert, D. E., Popp, J. A.
(1981). Induction of hepatic and testicular lesions inFischer-344 rats by single oral doses of nitrobenzene.
Fundam. Appl. Toxicol. 1, 389-394
Chapin, R., Sloane, R. (1997). Reproductive assessment bycontinuous breeding: evolving study design and summaries ofninety studies. Environ. Health Perspect. 105(1), 199-395
Globus, M. and Samuel, D. (1978). Effect of maternallyadministered sodium nitrite on hepatic erythropoiesis infetal CD-1 mice. Teratology 18, 367-378
Sinha, D. P. and Sleight, S. D. (1971). Pathogenesis ofabortion in acute nitrite toxicosis in guinea pigs. Toxicol.
Appl. Pharmacol. 18, 340-347
Shuval, H. I. and Gruener, N. (1972). Epidemiological andtoxicological aspects of nitrates and nitrites in theenvironment. Am. J. Public Health 62, 1045-1052

Reliability:
22-JUL-2005

Vorhees, C. V., Butcher, R. E., Brunner, R. L., Wootten, V.
(1984). Developmental toxicity and psychotoxicity of sodium
nitrite in rats. Food Chem. Toxicol. 22, 1-6(2) valid with restrictions
Reliable evaluation
(134)

Type:
In Vitro/in vivo:
Species:
Strain:Route of administration:
Doses:
Control Group:

other: reproductive
In vivomouse
CD-1
Sex: male/female
drinking water
0, 0.06, 0.12, 0.24% w/v. (approximate doses of 125,
260, 425 mg/kg/day)
yes, concurrent vehicle

Method:Year:other: RACB protocol
1997

Remark:Swiss CD-1 mice were subjected to the National Toxicology
Program's (NTP) Reproductive Assessment by Continuous
Breeding (RACB) protocol. Forty mating pairs served ascontrols, and 20 mating pairs were assigned to each dosegroup. Sodium nitrite was given in the drinking water atconcentrations of 0, 0.06, 0.12, and 0.24% w/v. As
calculated from water consumption and body weight data,
these concentrations resulted in approximate doses of 125,
260, and 425 mg/kg/day.
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Nine animals died during the 14-week breeding period: 3, 4,0, and 1, in the control through high dose groups,
respectively. These deaths were not considered to betreatment related. The experiment revealed notreatment-related effects on the mean number of litters perpair, cumulative days to deliver each litter, mean litter
size, or pup birth-weight or viability.
The males were removed after 14 weeks of continuous
breeding, and the females allowed to deliver and rear theirlast litters. Exposure of dams was continued through thelactation period. Postnatal mortality was not affected bytreatment, but weights of the high-dose group pups werereduced by 12-17% from postnatal day 7 to postnatal day 21.
The authors were unsure whether this was a direct effect of
sodium nitrite exposure, or an indirect result of reduced
maternal water consumption, and hence reduced milk
production.

Result:Only the high-dose and control group pups were carriedthrough to breed a second generation. Following weaning,these (F1) animals were exposed to sodium nitrite in theirdrinking water, at the same dose their parents had received.
Non-siblings were mated within their treatment group at
approximately 74 days of age, and the females allowed tocarry and deliver their first litters. No effects oftreatment on fertility or reproductive success were noted.
Post-delivery estrous cycle and sperm parameters were notaltered by treatment. The number, weight and viability of F2
young were also unaffected, as were F1 terminal body andorgan weights.
No treatment-related effects on: mean number oflitters/pair, cumulative days to deliver each litter, meanlitter size, birth weight, or pup viability.
No effect on postnatal mortality of pups exposed duringlactation.
Reduced body weights of nursing pups.
No effects on reproduction of high-dose F1 animals, or on
viability and weight of F2 offspring.
No effects on post-delivery estrous cycle or sperm
parameters.
9 deaths during the study period were not considered to betreatment related.

Test condition:

No effect on F1 terminal body and organ weights.
Continuous breeding protocol.
Swiss CD-1 mice.
20 mated pairs/dose group; 40 mated pairs as controls.
Sodium nitrite in drinking water to doses of 0, 125, 260,
and 425 mg/kg/day.
High dose and control pups were continued on to breed a 2d

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Test substance:
Conclusion:

Reliability:
Flag:
25-JUL-2005
Year:
Remark:Result:

Test condition:

Reliability:
22-JUL-2005
Year:
Remark:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
generation.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)
Affected sex: Unclear
Study confounder: NoneNOAEL reproductive toxicity: 0.24% (425 mg/kg/day)NOAEL general toxicity: 0.12% (260 mg/kg/day)F1 more sensitive than F0?: No
Postnatal toxicity: Unclear(2) valid with restrictions
Critical study for SIDS endpoint(35) (133)1996
A cohort of 70 male and 140 female rats was divided into
groups and fed cured meat to which 0, 200, 1000, or 4000 mg
sodium nitrite/kg had been added. One control group received
casein as a protein source; another control group was given
fresh chopped pork. Treated diets were provided to F0
animals from ten weeks prior to mating until animals were
terminated on the study. Subsequent to weaning, groups of 60- 100 F1 animals were continued on the respective F0 diet.
Following canning, autoclaving, and storage prior toexperimental use, the treated diets were determined to havenitrite contents of 6, 47, 580 mg/kg. Data on feed
consumption were not provided in the paper, but the doses of
sodium nitrite consumed in the form of treated diets havebeen estimated at 5, 25, or 100 mg/kg bw. No differenceswere noted between treated and control F0 animals in
appearance or behavior. Nor were effects noted on
reproductive parameters such as pregnancy rate, litter size,
mean pup weight, or pup survival. No morphologicalabnormalities were observed in F1 offspring. There were no
significant differences in the rate of postnatal mortality
between treated and control pups.
No effects of treatment noted on pregnancy rate, litter
size, mean pup weight, pup survival, or malformation
frequency.
No differences noted in appearance of behavior of treated F0
animals.
70 male and 140 female rats (total) fed on meat containing
sodium nitrite to doses of 0, 5, 25, or 100 mg/kg bw.
Diets given from 10 weeks prior to mating, throughout
gestation and lactation, and to weaned F1 offspring.
(4) not assignable(138) (197)1963
In a multigeneration study of teratogenesis andtransplacental carcinogenesis, groups of 30 to 37 rats were
given sodium nitrite in drinking water to achieve doses of 0
or 100 mg/kg bw. The study was continued for three
generations, with F1 and F2 animals being fed 500 mg
diethyamine/kg bw, as well as sodium nitrite. Mean lifespan
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Test substance:
Reliability:
19-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
was lower for treated than control animals, for all three
generations (730 days for controls; and 630, 625, and 610
days for nitrate exposed animals of successive generations),
but the authors concluded that nitrite alone, or in
combination with diethylamine, at the doses used, had no
carcinogenic or teratogenic effects. Reproductive parameters
were only noted in passing, but it is noted that 15 matingsof the P0 generation resulted in 94 offspring (an average of
6.3 pups/litter), and that 22 matings of the F1 generation
resulted in 149 offspring (an average of 6.7 pups/litter).
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable
(50)

Type:
In Vitro/in vivo:
Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Duration of test:
Doses:
Control Group:Year:
Remark:Result:other: a study of transplacental and chronic
carcinogencity
In vivomouseother: see TC
Sex:drinking water
until natural death
ad libitum
until natural death0, 0.184, or 1.84 g/L (equivalent to to 0, 30.7 or
310 mg/kg bw/day)
yes, concurrent vehicle

1985
The authors state that these doses were chosen as equivalent
to common human exposure levels (the low dose), and to alevel ten times higher than that amount (the high dose).
Other treatments investigated included: cimetidine (CM),nitrocimetidine (NCM), and CM plus nitrite.
The authors state that data were collected on: the number offemales becoming pregnant, the average time fromintroduction of the male until birth of a litter, average
gestational weight gain, number of stillborn litters, meanlitter sizes at birth and at weaning, and the numbers ofmale and female offspring. While the data are not provided
in the paper, it is stated there were no significant
differences between groups for these parameters. Twenty
litters were born to the control group, and 14 and 15
litters to the low and high-dose sodium nitrite-treatedgroups, respectively. Sodium nitrite treatment did notaffect survival times or body weights in this experiment.
Common non-neoplastic lesions included cystic seminal
vesicles and preputial glands in males, and cystic uteri,
ovaries, and mammary glands in females. Incidences of theselesions were not correlated with chemical treatment.
No significant changes in measures of fertility, oroffspring viability or sex ratio.
No effect on survival times, body weights, or gestational
weight gain.

Test condition:
259

Incidences of non-neoplastic lesions were not correlatedwith chemical treatment.
In a study of transplacental and chronic carcinogencity,
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ID: 7632-00-00
DATE: 04-JAN-2006
treatment was initiated in 7 to 8-week old C57BL/6 female,and BALB/c male mice. Sodium nitrite was provided indrinking water, at concentrations of 0, 0.184, or 1.84 g/L.
Mice were bred after two weeks of treatment, producing ageneration of B6CF1 progeny.
These progeny were weaned at four weeks postnatal age, andcontinued on treated drinking water until their natural
deaths. (Animals were bred after 2 weeks; P0 dams and F1progeny continued on treatment.) Treatment of the dams was
also continued.

Test substance:
Conclusion:
Reliability:
22-JUL-2005

The concentrations of sodium nitrite used were determined tohave provided doses of 0, 30.7 mg/kg, or 0.31 g/kg,
respectively.
Chemical name: Sodium Nitrite (CAS No. 7632-00-0)
None of NaNO2 had large effects on reproductive parameters,
survival, or incidence of non-neoplastic lesions.
(2) valid with restrictions
(9)

Type:
In Vitro/in vivo:
Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Duration of test:
Doses:
Control Group:
Result:Year:
Remark:other: reproductive and carconogenicity
In vivorat
WistarSex: male/female
other: diet containing 40% meat
29 months (max.)diet
29 months (max.)
0, 0.02, 0.5% in dietyes
No effect to reproductive toxicity andcarcinogenicity

1972-Female Reproductive Toxicity
The authors fed groups of 30 male and 30 female rats on a
cured meat diet containing 0, 0.02 or 0.5% sodium nitrite.
The 40% meat diet, in theabsence of sodium nitrite, resulted in mean body weights
which were higher than those of standard-diet controls. Meatwith added sodium nitrite resulted in lower body weights.
These changes appear to have been dose-related, and were
statistically significant in many cases. Mean feed
consumption, however, was not reported to be different
between any of the meat-fed groups. There were nodifferences between groups in mortality. Organs evaluated at
the gross and histopathological levels included the ovaries
and uterus. No treatment-related changes were found.
-Male Reproductive Toxicity
The authors fed groups of 30 male and 30 female rats on a
cured meat diet containing 0, 0.02 or 0.5% sodium nitrite.
The study was terminated after 29 months. The 40% meat diet,in the absence of sodium nitrite, resulted in mean bodyweights which were higher than those of standard-diet
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Result:

Test substance:
Reliability:
22-JUL-2005

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
controls. Meat with added sodium nitrite resulted in lower
body weights.
These changes appear to have been dose-related, and were
statistically significant in many cases. Mean feed
consumption, however, was not reported to be different
between any of the meat-fed groups. There were nodifferences between groups in mortality. Organs evaluated at
the gross and histopathological levels included the testes
and prostate. No treatment-related changes were found.
No treatment-related changes in gross or histologicalappearance of testes and prostate, or ovaries and uterus.
Reductions in mean body weights appeared to be dose-related.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(187)

In Vitro/in vivo:
Species:
Strain:Route of administration:
Exposure period:
Frequency of treatment:
Doses:Year:
Result:In vivorat
Fischer 344
i.p.
3 daysevery 3 hours for 3 days.
15 mg/kg

Sex: male1981
At sacrifice 1 hr following final injection, no evidence ofhistopathological damage to testes.
Treatment supported a steady MetHb level of 2-40%.
At sacrifice 1 hr following final injection, no evidence ofhistopathological damage to brain or liver.

Test condition:

Test substance:
Reliability:
22-JUL-2005

This regimen supported a steady MetHb level of 2-40%.
Sodium nitrite-treated animals were sacrificed one hour
following the final injection, and histopathologicalexaminations were made of the brain, liver, and testes. No
evidence of pathology was found.
male rats given 15 mg sodium nitrite/kg bw, i.p., every 3
hours for 3 days.
In a study of the effects of nitrobenzene (NB) exposure on
male Fischer-344 rats, sodium nitrite was used as a positive
control for induction of methemoglobinemia. Animals exposed
to a single dose of NB developed hepatic and testicularlesions, as well as elevated levels of methemoglobin. In
order to distinguish the effects of methemoglobinemia fromother potential mechanisms of NB toxicity, five additional
male rats were given sodium nitrite by i.p. injection, at adose of 15 mg/kg, every three hours, for three days.
Chemical name: Sodium nitrite (CAS No. 7632-00-0)(4) not assignable(20)

5.9 Specific Investigations
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Endpoint:
Remark:Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006
other: CANCER
No adequate epidemiology studies of sodium nitrite and humancancer were found in the literature. A study was reported noassociations between nitrite intake and risk of laryngeal ororal cancer. In epidemiological studies, it was reported a
direct association between nitrite intake and stomach cancer
risk. As comparing subjects with low methionine (<1.5mg/day) and low nitrite (<2.7 mg/day) intake with subjects
with high methionine (>1.9 mg/day) and high nitrite (>2.7
mg/day) intake, it was reported an association between
nitrite intake and stomach cancer risk. Another study
reported a significantly elevated risk for stomach cancer
for users of well water compared with those who used central
water supplies in Germany. The study did not reportmeasurements of nitrate in the water but assumed that well
water contained considerable amounts of nitrate. An
increased death rate from gastric cancer among the residentsof the English town of Worsop was thought to be related tothe high concentration of nitrate (90 mg/L) in the public
water supply. In Columbia, where gastric cancer is common,
the high intake of nitrate is reflected in the high urinary
excretion rate of nitrate. Patients with precancerous
gastric lesions had high nitrite concentrations in theirgastric juice.
A study demonstrated that nitrate intake resulted in asignificant rise in mean salivary nitrate and nitrite
concentrations and that N-nitrosodimethylamine andN-nitrosopiperidine were detected in the urine samples.
(2) valid with restrictions
Reliable evaluation

22-JUL-2005
Endpoint:
Remark:(134)
other: DEVELOPMENTAL TOXICITY
Auxiliary Information: THE INTEGRATED EVALUATION BY
CALIFORNIA ENVIRONMENTAL PROTECTION AGENCY (2000)
Two epidemiological studies conducted in Australia examined
the possible relationship between birth defects andhigh-nitrate concentrations in drinking water. Statisticallysignificant results from these studies indicated thatelevated risk for congenital malformations, particularly
malformations of the CNS, was associated with maternal
consumption of drinking water containing sodium nitrate atconcentrations in excess of 5 ppm. Findings from acase-control study conducted in Canada were far lessstriking than the Australian data. Nitrate content of thewater was generally associated with source (spring, tap, orwell), with well water tending to have the highest nitratecontent (26.03 ppm at the 87.5 percentile). For women who
drank spring or tap water during pregnancy, the nitratelevel, per se, was not shown to be associated with increased
risk for birth defects. A moderate, non-statisticallysignificant increase in risk for CNS malformations was
associated with maternal consumption of well water having
nitrate levels of 26 ppm or more.
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Conclusion:

Reliability:
22-JUL-2005

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ID: 7632-00-00
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N-nitroso compounds, which are known to be teratogenic
and/or carcinogenic in experimental animals, have also been
implicated as potentially responsible for the increased
frequency of major malformations observed in offspring of
women given nitrosatable drugs during pregnancy. Nitrite isa precursor of N-nitroso compounds, but it has not been
directly established that the necessary reactions occur intoxicologically significant quantities in vivo, under normal
food intake conditions. However, the association between
frequent consumption of hot dogs and/or other cured meatproducts during pregnancy, and an increased risk forchildhood brain tumors in offspring suggests that suchreactions might occur.
Epidemiological studies support an association between
maternal consumption of nitrite containing cured meats
during pregnancy and childhood cancers, particularly brain
tumors. While these data cannot implicate sodium nitrite inisolation from other dietary components, they are consistent
with the results of transplacental carcinogenicity studies
in which sodium nitrite, in combination with amine or amide
precursors of N-nitroso compounds, were given toexperimental animals.
(2) valid with restrictions
Reliable evaluation(29)

Endpoint:

other: ADI (2003)

Remark:

ADI = 0.07 mg/NO2/kg/day (JECFA) (2003)
The Committee concluded that the pivotal observed toxic
effects of nitrate are consequent on its conversion tonitrite in vivo. The Committee at its present meeting
established an ADI of 0-0.07 mg/kg bw for nitrite. As the
new data on nitrite would not provide a basis for asignificant change in the previous ADI for nitrate, theCommittee retained the ADI of 0-5 mg/kg bw expressed as
sodium nitrate, or 0-3.7 mg/kg bw, expressed as nitrate ion,established at its forty-fourth meeting.
-RATIONALE
The few new studies on the toxicokinetics and metabolism of
nitrate in animals that have become available since theforty-fourth meeting of the Committee confirm that the rat
is not a good surrogate species for humans in this respect,
as it does not show salivary transport of nitrate andtherefore has limited conversion of nitrate to nitrite.
In a study of the conversion of nitrate to nitrite inhumans, in which sodium nitrate was administered indrinking-water at a single dose of 7.3 mg/kg bw, expressed
as nitrate ion, neither blood pressure nor methaemoglobin
concentration was affected. The nitrite concentration of thegastric juice was approximately six times higher afteradministration of nitrate in combination with pretreatment
with omeprazole at 40 mg/day (which increased the gastricpH) than after nitrate alone. Nitrate was absorbed rapidly,
the concentration in plasma increasing within 10 min, and

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the half-life of nitrate in plasma was about 6.5 h; about
70% of the dose was excreted in urine within 10 h of dosing.
The plasma concentration of nitrite did not change after
nitrate administration. About 8% of the total nitrateadministered was converted to nitrite in saliva, as found inother studies. The Committee at its forty-fourth meetingconcluded that the range of nitrate conversion is 5-7% fornormal individuals and 20% for individuals with a high rateof conversion.
The results of studies in humans on the potential of a highnitrate intake to cause methaemoglobinaemia were equivocal.
Some of the studies showed an association between a highnitrate concentration in drinking-water andmethaemoglobinaemia, and others indicated that
gastrointestinal infections, inflammation and the ensuing
overproduction of nitric oxide are major factors in
infantile methaemoglobinaemia. No increase in methaemoglobin
concentration was seen in volunteers after a single
administration of sodium nitrate in drinking-water providing
a dose of 7.3 mg/kg bw, expressed as nitrate ion.
A study in humans showed that nitrate in vegetable matrices
and from other sources, such as drinking-water, is almost
totally bioavailable.
As nitrate shares a common transport mechanism with iodide,studies were conducted to determine whether nitrate affects
thyroid function. A 28-day study with volunteers given
sodium nitrate in drinking-water at a concentrationequivalent to 15 mg/kg bw per day (11 mg/kg bw per day
expressed as nitrate ion) showed no effects on thyroid
function and no increase in the per cent ofmethaemoglobinaemia. A 90-day study of toxicity in rats
showed that sodium nitrate at a dose of 50 mg/kg bw per day
did not affect the thyroid or the zona glomerulosa of theadrenals.
In studies in humans, consumption of drinking-watercontaining sodium nitrate at a concentration of 2800 mg/l
concomitantly with volatile N-nitrosatable amines in thediet (in cod, salmon or shrimp) led to a two- to threefold
increase in urinary excretion of N-nitrosodimethylamine andN-nitrosopiperidine.
Several studies were reviewed on the effect ofadministration of nitrate on the release of nitric oxide at
the junction of the oesophagus and the stomach in humans,
which, it was speculated, might be associated with anincreased incidence of cancer at this site. However, no such
association has been observed in epidemiological studies.
A number of epidemiological studies have been publishedsince the forty-fourth meeting of the Committee on therelationship between nitrate intake and cancer risk. At its
present meeting, the Committee ranked the study designs
according to their capacity to provide evidence of a
relationship. In the descriptions below, relative risk
estimates are given for those studies in which levels of
intake of nitrate were provided.
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SODIUM NITRITE
ID: 7632-00-00
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Six ecological (correlation) studies were reported on
nitrate in drinking-water and mortality from or incidence ofcancer. Elevated risks were found for prostate cancer andfor brain tumours (each in one study), but the results ofsix studies on gastric cancer were conflicting. The resultsof ecological studies (in which populations are the units ofmeasurement) cannot be extrapolated to the individual level.
Furthermore, most of the ecological studies were based onlimited data on nitrate concentrations and on cancer
mortality rates (rather than incidence rates), and none took
an induction period for cancer into account.
Three of the studies were cross-sectional, involving
measurement of, e.g., salivary nitrate in cancer patientsand healthy subjects. Because cross-sectional studies do nottake into account the time between exposure and disease, any
observed differences in biomarkers of exposure might also be
a consequence of the disease; therefore these studies cannot
contribute to a causal interpretation of the results ofstudies of nitrate intake and cancer risk.
Seven case-control studies on nitrate in drinking-water
and/or food and cancers at various sites were reviewed. In
the studies on nitrate in drinking-water, conflicting
results were reported with regard to an association with
non-Hodgkin lymphoma, and no association was found withbrain tumours. In the studies on dietary nitrate, noassociation was found with oral, oesophageal, gastric or
testicular cancer. No other cancer sites have been studied.
Three prospective cohort studies have been conducted on
nitrate intake and cancer risk. A cohort study in the
Netherlands, with 6 years of follow-up, found no significant
association between the incidence of gastric cancer andintake of nitrate from food or drinking-water, with relative
risks for increasing quintiles of total nitrate intake of
1.0 (reference quintile), 1.2, 0.7, 0.9 and 0.9 for mean
intakes of 60, 85, 100, 120 and 180 mg/day, respectively.
Neither the relative risks nor the trend across relative
risks was significant. A further analysis of the effect ofnitrate within tertiles of vitamin C intake also did notreveal a positive association between nitrate intake andgastric cancer. A Finnish cohort study on dietary nitrate,with 24 years of follow-up, reported no association with therisks for tumours of the stomach, colorectum or head andneck. The average nitrate intake in this cohort was reported
to be 77 mg/day. A cohort study in Iowa, USA, with 11 years
of follow-up, revealed no consistent association between
intake of nitrate from drinking-water and the risks forcancers at many sites, and an inverse association wasreported with cancers of the uterus and rectum. Positive
associations with nitrate intake were observed only forcancers of the ovary and urinary bladder, although it was
not possible to determine whether other factors indrinking-water were responsible for these associations. In
addition, no evidence of a dose-response relationship was
found for any of the cancer sites addressed in the study in
Iowa. The cohort studies included control for various
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smoking.
Overall, the epidemiological studies showed no consistently
increased risk for cancer with increasing consumption of
nitrate. These data, combined with the results of theepidemiological studies considered by the Committee at its
forty-fourth meeting, do not provide evidence that nitrateis carcinogenic to humans.

Reliability:
22-JUL-2005

A number of studies were performed to determine whether
there are associations between nitrate intake indrinking-water and insulin-dependent diabetes mellitus,
neural tube defects or sudden infant death syndrome. In noneof these studies was a hypothesis proposed for the mechanismof an association. Two studies were conducted on theincidence of insulin-dependent diabetes mellitus and nitrateintake via drinking-water. One study in Yorkshire, United
Kingdom, suggested a positive association, but the authors
considered that the finding required confirmation. A study
in the Netherlands with a larger number of subjects did notshow a positive association. The two studies on nitrateintake and neural tube defects also showed no association.
In a recent ecological study in Sweden, a correlation wasreported between the nitrate concentration in drinking-waterand the occurrence of sudden infant death syndrome; however,no confounding factors were taken into account. The
Committee considered that it would be premature to include
these observations in its safety assessment.
(2) valid with restrictions
Reliable evaluation. Based on cumulative information andthe newest.
(97)

Endpoint:

other: Special studies, Effects on adrenal andthyroid glands
rat
WistarSex: male
See "remark".

Species:
Strain:Result:Year:
Remark:1996-Effects on adrenal and thyroid glands
Hypertrophy of the zona glomerulosa of the adrenals of rats
was reported after administration of low doses of nitrite
for 90 days; the effect was considered to be due to its
conversion to nitrate. A study was therefore conducted tocompare the effects of nitrate and nitrite on the zona
glomerulosa. Three groups of 10 male Wistar rats were given
drinking-water containing potassium chloride (control),potassium nitrite or potassium nitrate at a concentration of
36 mmol/l for 90 days. The body-weight gain of rats given
nitrite or nitrate was slightly slower than that ofcontrols, but no differences in food intake per kilogram
body weight were observed between the three groups. The
water intake of the group given nitrite was statisticallysignificantly lower than that of the other two groups. The
rats receiving nitrite appeared cyanotic during the firstmonth of treatment but not thereafter, perhaps because thewater intake was greater during the first month. At the end
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SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006of the observation period, the concentrations ofmethaemoglobin and nitrite in blood were significantly
increased; the nitrate concentration in plasma in the groups
given nitrite or nitrate groups were similar but were higher
than those of controls. Treatment with nitrite or nitrate
had no consistent effect on the concentrations of thyroxin,
free thyroxin, thyroid stimulating hormones,
adrenocorticotrophic hormone, corticosterone or aldosteronein blood. Microscopic examination revealed slight
hypertrophy of the adrenal zona glomerulosa in all rats
given nitrite and minimal hypertrophy in 2/10 rats given
nitrate. The results of morphometric analyses of theadrenals were in line with those of microscopic examination.
In the rats given nitrite, the fraction of the surface areaof the zona glomerulosa in median sections was significantly
greater than that in the controls or rats given nitrate. The
minimal hypertrophy of the adrenal zona glomerulosa observed
occasionally in rats given nitrate was barely detectable bymorphometric analysis. It was concluded that nitrate ion
does not play a role in the etiology of hypertrophy of thezona glomerulosa of the adrenal glands in rats.
Auxiliary information: THE INTEGRATED EVALUATION BY JECFA(2003)JECFA (FAO/WHO Joint Expert Committee on Food Additives)(2003). Food Additives Series 50 has determined that nitrate
ion does not play a role in the etiology of hypertrophy ofthe zona glomerulosa of the adrenal glands in rats (Boink etal., 1996). Based upon the determination, ADI was revised.
This paper confirmed the determination.

Reliability:
22-JUL-2005

This conclusion implies that safety evaluation should not bederived from the NOEL for minimal hypertrophy of the adrenalzona glomerulosa, used by the committee at its forty-forth
meeting, but on NOELs for other end-points.
(2) valid with restrictions
Based on a comprehensive study. Lately revised.
(97)

Endpoint:
Year:
Remark:other: ADI (1995)
2003
ADI = 0.06 mg/NO2/kg/day (JECFA) (1995)
Nitrite (and potential endogenous formation of N-nitroso
compounds)
Nitrite was reviewed at the sixth, eighth, seventeenth andtwentieth meetings of the Committee. At its sixth meeting,
the Committee allocated an ADI of 0-0.4 mg per kg of bodyweight to this substance, expressed as sodium nitrite. This
ADI was based on a marginal reduction in body-weight gain at
a dose level of 100 mg per kg of body weight per day in along-term study in rats. At its seventeenth meeting, theCommittee lowered the ADI to 0-0.2 mg sodium nitrite per kg
of body weight and made it temporary. At that time, theCommittee used a safety factor higher than normal (500)
because a marginal effect level was considered and there wasa possibility of the endogenous formation of N-nitroso
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present together in food and the gastrointestinal tract. At
its twentieth meeting, the Committee considered the reports
of a WHO task group and of a working group of theInternational Agency for Research on Cancer on N-nitroso
compounds, but concluded that they did not provide
sufficient evidence to revise the temporary status of the
ADI. Since the previous evaluation of nitrite, numerous
toxicological and epidemiological data have become
available.
The toxic effects of nitrite are of the following three
types: the formation of methaemoglobin; hypertrophy of theadrenal zona glomerulosa in rats; and genotoxicity.
Methaemoglobinaemia is seen particularly after acute andsubacute exposure. However, it is not the sole determinantof the NOEL. In a 2-year oral toxicity study in rats, theNOEL was 6.7 mg nitrite per kg of body weight per day (67mg/l of drinking-water per day), expressed as nitrite ion.
At the next higher dose level of 67 mg nitrite per kg ofbody weight, methaemoglobin accounted for 5 % of total
haemoglobin; in addition, dilatation of coronary arteries
and of the bronchi with infiltration of lymphocytes andalveolar hyperinflation were also seen.
Methaemoglobin is particularly important where it exceeds 10% of total haemoglobin, leading to toxic effects such as
cyanosis. Young infants (below the age of 3 months) seem
especially vulnerable to methaemoglobin. There is also
evidence that fetal haemoglobin is more readily oxidized tomethaemoglobin. and that in the neonate methaemoglobin
reductase is less effective in the reduction of
methaemoglobin to normal haemoglobin.
In a 90-day toxicity study in Wistar rats, the incidence anddegree of hypertrophy of the adrenal zona glomerulosa
observed at a dose level of 5.4 mg per kg of body weight perday, expressed as nitrite ion, were not significantly
different from those among controls, whereas at higher doselevels the hypertrophy was both significant anddose-related.
In another 90-day toxicity study carried out by otherinvestigators with a different Wistar substrain, slight
hypertrophy of the adrenal zona glomerulosa was seen from 28
days onwards, but only at dose levels three times as high.
The NOEL for hypertrophy in these studies was 5.4 mg per kg
of body weight per day, expressed as nitrite ion.
Nitrite both with and without nitrosatable precursors wasfound to be genotoxic in several in vitro and in vivo test
systems. However, DNA repair was not affected by nitrite.
Carcinogenicity studies with nitrite were negative, with the
exception of those in which extremely high doses of both
nitrite and nitrosatable precursors were administered. In
addition, there was no evidence for an association between
nitrite and nitrate exposure in humans and the risk ofcancer. The Committee noted that few epidemiological studies
were available in which cancers other than gastric cancer
were investigated.
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Although it has been shown in several controlled laboratory
studies that, when both nitrite and N-nitrosatable compounds
are present together at high levels, N-nitroso compounds areformed endogenously, there are quantitative data only on
those N-nitroso compounds which are readily formed
endogenously, such as N-nitrosoproline, which is not
carcinogenic. As there was no quantitative evidence of theendogenous formation of carcinogenic N-nitroso compounds at
intake levels of nitrite and nitrosatable precursors
achievable in the diet, a quantitative risk assessment of
nitrite on the basis of endogenously formed N-nitroso
compounds was not considered to be appropriate. The safety
evaluationwas therefore based on the toxicity studies on
nitrite.
As previously mentioned, the NOEL was 5.4 mg per kg of bodyweight per day (expressed as nitrite ion) in 90-day toxicity
studies in rats in which hypertrophy of the adrenal zona
glomerulosa was observed and 6.7 mg per kg of body weightper day (expressed as nitrite ion) in a 2-year toxicity
study in rats in which toxic effects in the heart and lungs
were observed. On the basis of these results and a safety
factor of 100, the Committee allocated an ADI of 0-0.06 mg
per kg of body weight to nitrite, expressed as nitrite ion.
This ADI applies to all sources of intake. Nitrite should
not be used as an additive in food for infants below the ageof 3 months. The ADI does not apply to such infants.

Reliability:
22-JUL-2005

A toxicological monograph summarizing both relevant
information from the previous monograph and the informationthat has become available since the previous evaluation was
prepared. The existing tentative specifications forpotassium nitrite and sodium nitrite were revised, and the"tentative" designation was deleted.
(4) not assignable(96)

5.10 Exposure Experience
Type of experience:other: NTP assessment

Remark:Auxiliary information: THE INTEGRATED EVALUATION BY NTP(2001)
HumansIn humans, sodium nitrite causes smooth muscle relaxation,methemoglobinemia, and cyanosis. Fatal poisonings ofinfants
resulting from ingestion of nitrates in water or spinach
have been recorded. Longterm ingestion of water containing
high levels of nitrate may increase the risk of gastriccancer. However, prospective cohort study did not support
anassociation between the intake of nitrate and nitrite andgastric cancer risk. The LD50 value for sodium nitrite has
been estimated to be about 1 g in adults; a 17-year-old
woman died after taking a single 1-g tablet. Fatal
methemoglobinemia was reported after ingestion of a

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Reliability:
19-OCT-2004

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laxative
solution contaminated with 15 g/L sodium nitrite.
(2) valid with restrictions(134)

Type of experience:other: National Institute of Public Health andEnvironmental Hygiene, Netherlands.

Remark:Auxiliary Information: National Institute of Public Healthand Environmental Hygiene, Netherlands (1986)
The lowest acute oral lethal dose of nitrite reported for
man varied from 27-255 mg/kg b.w., in which the lowest
figures applied for children and elderly people. Nitrite
is also more toxic to young infants (3 months) than adults
giving rise to relatively higher methaemoglobin levels inthe blood. The lowest toxic dose reported was 1 mg NO2/kg
b.w., whereas in another study 0.5-5 mg NO2/kg b.w. did notcause any toxic effect.
No information on short-term or long-term toxicity in man
is available except for the epidemiological studies on therelation between nitrate or nitrite intake and tumour
incidences.
No firm relationship was found between the estimatednitrate uptake and gastric cancer in normal healthy
individuals, although in several studies an association was
indicated. In occupational situations no increased gastriccancer incidences were found. The populations studiedwere,
however, small.
Individuals with stomach lesions or disorders, especiallythose with atrophic gastitis, PA-patients and persons on
cimetidine and other antacid medication present special
risk
groups in which a correlation between nitrate or nitrite
intake and incidence of gastric cancer cannot be excluded.

Reliability:
22-JUL-2005

Both for healthy individuals and those of the special risk
groups, the possible correlation between the nitrate or
nitrite intake and gastric cancer is based on the formationof carcinogenic N-nitroso compounds. Combining the facts
that for N-nitroso formation also amine or amide have to bepresent in relevant concentrations and that both nitrateand nitrite were not carcinogenic in animal studies underwell-defined conditions, it can be concluded that nitrateand nitrite itself have no carcinogenic properties.
(2) valid with restrictions(129)

Type of experience:

Direct observation, poisoning incidents

Result:A four year old boy was treated with two liniment solutions
containing sodium nitrite at 30 g/L (Liniment A) and 140
g/L (Liniment B). Liniment A was applied all over the boy's
body, causing listlessness and vomiting. Liniment B wasapplied all over the boy's body a few days later. The boy
went into shock and suffered severe cyanosis. He washospitalised immediately, but died after two hours in
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Reliability:
Flag:
22-JUL-2005

SODIUM NITRITE
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intensive care. The boy's blood methemoglobin level was
found to be 76%.
(2) valid with restrictions
Critical study for SIDS endpoint(155) (156)Type of experience:other: recurrent urticaria: clinical investigation of 330
patients

Remark:-Provocation tests
The patients were recommended a diet free from salicylates
and dyes for at least 4-5 days prior to admission. No
antihistamines were given. For safety reasons and to allow
close examination, all the provocations were performed in
the wards. A challenge test battery with several controls,
was used from 1974-1978. Changes in the schedule were often
made. The tests could only be done in patients with no orslight symptoms. The chemicals were given in titanium
dioxide-whitened gelatin capsules with lactose added tocomplete the fillings and the patients were unaware of thetype of compound tested. If the patients reacted tolactose,wheat starch was used instead as filling material. The
firstdose was given at 8 o'clock in the morning and additionaldoses at1-h intervals. Only one type of additive was given
per day. If the test was positive, it was necessary to waitwith the next provocation until the reaction had subsided.
Provocation tests are judged as positive when the patientsdevelop clear signs of urdcaria or angio-oedema within 24h.
About half of the patients reacted within 6 h. Judging
whether a reaction is positive or negative is not always
easy. When in doubt,the doctor should therefore can thereaction uncertain and repeat the test later. One or morepositive reactions were found in 31%. of the patients
testedand totally negative tests in 36%. In 33% one or several
tests were uncertain. They are those reported by thedoctors
on the questionnaire for provocation tests. Some patients
reacted to more than one drug. Patients reacting to lactose
were tested again With starch¥ In five patients therepeated
test with lactose was positive but the test with starch was
negative. The tests with other chemicals were then donewithstarch as filling. In four other lactose-positive
patients,the repeat tests with lactose were negative.
Several patients with ongoing urticaria had questionable
tests to both lactose and starch. Further tests then had tobe postponed until the patient was in a more stable phase.
Questionable tests to other chemicals were often repeated.
@Patients with positive or questionable tests were always
recommended a diet free from the additive:they had reacted
to. In patients with positive reactions to additives whichhave not before been known to provoke urticaria, repeatedtests with two placebo capsules were done within a year.
The

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Result:SODIUM NITRITE
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additive tested and the number of patients reacting out of
the number provoked were as follows: nitrateand nitrite 1of
2. The patients had often found flare-ups of their weals
when they had ingested by mistake the additive they shouldhave avoided.
Provocation test in patients with recurrent urticaria.
Test period 1974-1978
Result

Test substance:
Reliability:

No. of patients tested: 60
Positive (%); 6
Uncertain (%); 12
Negative (%); 82
a mixture of 100 mg sodium nitrite and 100 mg sodium
nitrate.
(3) invalid
Down graded because test material is a mixture.

24-NOV-2004(98)

Type of experience:other: food antigens and additives

Remark:Oral challenge with an unstated amount of sodium nitrite
cited un specified allergic response in two of 15 subjects
suffering from an underfined food allergy.

Result:Reliability:

Challenges were performed the additive and placebo.
Oral challenges with the food additive in 15 patients withallergy to various foods.
No. of patients; 15
Negative; 13
positive; 2(4) not assignable
Down graded because of too small number of subjects.

24-NOV-2004(127)

Type of experience:

Human - Exposure through Food

Remark:Reliability:
22-JUL-2005

A risk assessment was made on nitrate, nitrite andN-nitroso compounds encountered in the human diet. Mean
estimates of nitrate intake range from 31 - 185 mg/day invarious European countries, with vegetables supplying
80-85%. The intake of nitrite is much lower in various
European countries and averages 0.7 - 8.7 mg/day, with bothvegetables and cured meats being the major sources.
(2) valid with restrictions(63)

Type of experience:

Human - Exposure through Food

Remark:Reliability:
22-JUL-2005

Nitrite occurs in plants at low concentrations, normally
between 1-2 mg/kg fresh weight and rarely over 10 mg/kg,
although potatoes have been reported to contain 2-60 mg/kg,
with a mean concentration of 19 mg/kg(2) valid with restrictions(121)

Type of experience:

Human - Exposure through Food
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Remark:SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006

Reliability:
22-JUL-2005

Diet constitutes an important source of exposure to both
nitrite and nitrate. The major dietary source of nitrate isvegetables. Lettuce, spinach, celery and beetroot commonly
contain more than 1g nitrate/kg fresh weight and may reach
3-4 g/kg(2) valid with restrictions(190)

Type of experience:

Direct observation, poisoning incidents

Remark:Reliability:
22-JUL-2005

Report of the fatal case of a nurse who probably ingested a
1g tablet of sodium nitrite (670 mg NO2-). Death occurred
two hours after admission to hospital. Post mortem
methaemoglobin level was 35%, implying a much higher levelon admission. Serum nitrite level was 13 mg/L.
(2) valid with restrictions(67)

Type of experience:

Direct observation, poisoning incidents

Remark:Reliability:
22-JUL-2005

Report of a case of methaemoglobinaemia associated withthree previously healthy children (two four year old boys
and a two year old girl). One of the children had mistaken
a bag of sodium nitrite crystals for sugar and added it tocups of tea at concentrations of 5100, 5000 and 4900 mg/L.
Methaemoglobin levels of 77% and 38% were measured for twoof the children.
(2) valid with restrictions(60)

Type of experience:

Direct observation, poisoning incidents

Remark:Reliability:
22-JUL-2005

Report of two cases of methemoglobinaemia attributable tonitrite contamination of potable water through boiler fluid
additives. In the first of these, 49 schoolchildren wereaffected after eating soup which had been diluted with hotwater from the tap. The soup was found to contain 459 ppm
nitrite. Methaemoglobinaemia was diagnosed in 59% of thechildren, with levels between 3 - 47%. In the second case,six workers were found to have methaemoglobin levels of
between 6 - 16% after drinking coffee contaminated with 300
ppm nitrite.
(2) valid with restrictions(33)

Type of experience:

Direct observation, poisoning incidents

Remark:A case of nitrite poisoning after ingestion of spinach in a
2 year old boy is reported. He developed severe
methaemoglobinaemia of 53%. In 100 g of the spinach, which
had been stored in a refrigerator after preparation for 3days, 150 mg of nitrite ion was found. He had been fed in
unusually great amount because of obstipation.
A congenital methaemoglobinaemia (haemoglobin-anomaly or
deficiency of reducing enzymes) was excluded. Afterinjection of Thionin there was quick recovery and the levelof methaemoglobin returned to normal.

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22-JUL-2005(157)

Type of experience:

Human - Exposure through Food

Remark:Spinach often contains a high concentration of nitrate.
Nitrate is non-toxic but nitrite, into which nitrate isconverted, is toxic. Nitrite poisoning after the
consumption of spinach occurs virtually exclusively inchildren younger than 1.5 years. For purposes of
prevention, spinach intended for consumption by children
younger than 1.5 years should have a low nitrateconcentration.
(74)

22-JUL-2005

5.11 Additional Remarks
Type:

Neurotoxicity

Remark:Auxiliary information: THE INTEGRATED EVALUATION BY NTP(2001)
After a single subcutaneous dose of 55 mg sodium nitrite/kg
body weight, locomotor, exploratory, and grooming activities
were suppressed in 3-month-old male rats; complete recovery
was observed after 24 hours. Exposure of rats to sodium
nitrite at 100 to 2,000 mg/L in drinking water for 2 months
produced changes in the pattern of brain electricalactivity.

Reliability:

The electroencephalogram pattern of four dosed rats differedfrom those for controls and remained different after sodium
nitrite withdrawal.
(2) valid with restrictions

25-JUL-2005

(134)

Type:

other: Toxicological Effects

Remark:Auxilary information: THE INTEGRATED EVALUATION BY NTP(2001)The primary acute effect of sodium nitrite in rats and miceis methemoglobinemia. A study was reported methemoglobin
concentrations ranging from 9.5% to 72.1% in female CD-1
mice following intraperitoneal injection of 0.5 to 2.8
nmol/kg (35 to 193 mg/kg). Methemoglobin concentrations inSprague-Dawley rats increased to 45% to 80% 1 hour after anoral dose of 150 mg/kg and returned to normal within 24
hours in surviving rats. Sodium nitrite administered indrinking water at 1,000 to 3,000 mg/L (1,000 to 3,000 ppm)
for 2 years elevated methemoglobin concentrations in malerats (unspecified strain) throughout the 2-year period.

Reliability:

The secondary effects of acute nitrite intoxication in
animals are vasodilation, relaxation of smooth muscle, andlowering of blood pressure and a decrease in D-xylose
absorption in the intestinal mucosa. Other nitrite-induced
toxic effects include abdominal pain, diarrhea, atrophiedintestinal villi, and apoptotic cell death in the intestinal
crypts.
(2) valid with restrictions

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25-JUL-2005
Type:
Remark:Reliability:

SODIUM NITRITE
ID: 7632-00-00
DATE: 04-JAN-2006(134)
other: species difference in vitro
Sodium nitrite of 0.3 mmol/kg was given i.v. to rats,
rabbits and cats. In cats the ferric hemoglobin formationstrongly increased with a maximum with 90 min. In rats theinduction of the ferric hemoglobin formation was only half
as much and after 30 min the maximum had exceeded, withrabbit only a very weak induction had been measured andafter few (5-10) minutes their maximum had already. In
vitro test with erythrocyte of different animals, thehighest ferric hemoglobin formation was observed in cattle
and cats with 2.5 mmol/l at the initiaton of incubation,
followed by those by with the erythrocyte of dogs. The
ferric hemoglobin formation with erythrocyte of humans
corresponded about that from cats. Also in this attempt the
ferric hemoglobin formation was only moderate witherythrocyten of rabbits. Sodium nitrite is given as antidotewith cyanide poisonings due to the ferric hemoglobin
formation.
(4) not assignable

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(104)

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(1) Abe S and Sasaki M (1977). Studies on Chromosomal
Aberrations and Sister Chromatid Exchanges Induced by
Chemicals. Proc. Jpn. Acad. 53, 46-49.
(2) ACGIH (American Conference of Governmental Industrial
Hygienists) -Threshold Limit Values (1993-1994)(3) Agency for Toxic Substances and Disease Registry (ATSDR)(2001). Nitrate/Nitrite Toxicity. US Department of Healthand Human Services. Atlanta.
(4) Alabaster JS (1969). Survival of Fish in 164 Herbicides,
Insecticides, Fungicides, Wetting Agents and Miscellaneous
Substances. Int. Pest Control 11(2), 29-35(5) Alavantic D, Sunjevaric I, Pecevski J, Bozin D and Cerovic G(1988) In Vivo Genotoxicity of Nitrates and Nitrites in Germ
Cells of Male Mice. I. Evidence for Gonadal Exposure andLack of Heritable Effects. Mutation Research, 204, 689-695(6) Alcaraz G and Espina S (1994). Effect of Nitrite on theSurvival of Grass Carp, Ctenopharngodon idella (Val.), withRelation to Chloride. Bull. Environ. Contam. Toxicol. 52,
74-79.
(7) Alcaraz G, Chiappa-Carrara X, Vanegas C (1997).
Temperature Tolerance of Penaeus setiferus Ppostlarvae
Exposed to Ammonia and Nitrite. Aquat. Toxicol. 39, 345-353(8) Almendras JME (1987). Acute Nitrite Toxicity andMethemoglobinemia in Juvenile Milkfish (Chanos chanos
forsskal). Aquaculture 61(1), 33-40(9) Anderson LM, Giner-Sorolla A, Haller IM, Budinger JM (1985).
Effects of Cimetidine, Nitrite, Cimetidine plus Nitrite, andNitrosocimetidine on Tumors in Mice Following Transplacental
plus Chronic Lifetime Exposure. Cancer Res. 45, 3561-3566.
(10) Aoyagi M, Matsukura N, Uchida E, Kawachi T, Sugimura T,
Takayama S, Matsui M (1980). Induction of Liver Tumors in
Wistar Rats by Sodium Nitrite given in Pellet Diets. JNCI65, 411-414(11) Armstrong DA, Stephenson MJ, Knight AW (1976). Acute
Toxicity of Nitrite to Larvae of the Giant Malaysian Prawn,
Macrobrachium rosenbergii. Aquaculture 9, 39-46.
(12) Ary RDJ and Poirrier MA (1989). Acute Toxicity of Nitrite to
the Blue Crab (Callinectes sapidus). Prog. Fish. Cult. 51,
69-72.
(13) Balimandawa M, de Meester C, Leonard A (1994). The
Mutagenicity of Nitrite in the Salmonella/Microsome Test
System. Mutat. Res. 321, 7-11.
(14) BASF AG reported data
(15) BCT-INSERM (1999). Prevention des Risques Chemiques, Product
Number 004

UNEP PUBLICATIONS

276

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(16) Bianchini A, Wasielesky W Jr, Miranda Filho KC (1996).
Toxicity of Nitrogenous Compounds to Juveniles of Flatfish
Paralichthys orbignyanus. Bull. Environ. Contam.Toxicol. 56,
453-459.
(17) Biancifiori C, Montesano R, Bolis GB (1975). Indagini sulla
Cancerogenesi da Sodio Nitrito e/o Etambutolo in topi
Balb/c/Cb/Sc. Lav. Ist. Anat. Istol. Patol. Perugia
35, 45-56(18) Blanck H, Wallin G, Wangberg S (1984).
Species-dependent Variation in Algal Sensitivity to Chemical Compound.
Ecotoxicol. Environ. Saf. 8, 339-351(19) Boink ABTJ, Beekhof PK, Dormans JAMA, Speijers GJA (1996).
On the Etiology of Nitrite Induced Hypertrophy of the Zona
Glomerulosa of Rat II. National Institute of Public Healthand Environmental Hygiene, Netherlands. Report 235802 004.
(20) Bond JA, Chism JP, Rickert DE, Popp JA (1981). Induction of
Hepatic and Testicular Lesions in Fischer-344 rats by Single
Oral Doses of Nitrobenzene. Fundam. Appl. Toxicol. 1,
389-394(21) Bortz BM (1977). The Administration of Tetramethylthionine
Chloride as a Treatment for Nitrite-Induced
Methemoglobinemia in Rainbow Trout (Salmo gairdneri). MS.
Thesis, American University, Washington, D.C., 54.
(22) Brams A, Buchet JP, Crutzen-Fayt MC, De Meester C, Lauwerys
R, Leonard A (1987). A Comparative Study, with 40 Chemicals,of the Efficiency of the Salmonella Assay and the SOS
Chromotest (Kit Procedure). Toxicol. Lett. 38, 123-133.
(23) Bringmann G and Kuhn R (1960) Results of Water-toxicological
Tests of Insecticides. Gesundh. Ing. 81, 243-244(24) Bringmann G and Kuhn R (1977) Limiting Values for theDamaging Action of Water Pollutants to Bacteria (Pseudomonas putida) andGreen Algae (Scenedesmus quadricauda) in Cell Multiplication Inhibition
Test. Z.Wasser Abwasser Forsch. 10, 87-98(25) Bringmann G and Kuhn R (1977). The Effects of Water
Pollutants on Daphnia magna. Z. Wasser Abwasser Forsch. 10,
161-166.
(26) Bringmann G and Kuhn R (1978) Limiting Values for the
Noxious Effects of Water Pollutant Material to Blue Algae(Microcystis aeruginosa) and Green Algae (Scenedesmus
quadricauda) in Cell Propagation Inhibition Test. Vom Wasser 50, 45-60(27) Brownell CL (1980). Water Quality Requirements forFirst-Feeding in Marine Fish Larvae. I. Ammonia, Nitrite,
and Nitrate. J. Exp. Mar. Biol. Ecol. 44(2-3), 269-283(28) Buhl KJ and Hamilton SJ (2000). Acute Toxicity ofFire-Control Chemicals, Nitrogenous Chemicals, andSurfactants to Rainbow Trout. Trans. Am. Fish. Soc. 129,408-418.
277

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(29) CAL/EPA (California Environmental Protection Agency) (2000).
Evidence on Developmental and Reproductive Toxicity of
Sodium Nitrite, Reproductive and Cancer Hazard Assessment
Section (RCHAS), Office of Environmental Health Assessment(OEHHA).
(30) Calabrese EJ, Moore GS, McCarthy MS (1983). The Effect ofAscorbic Acid on Nitrite-induced Methemoglobin Formation in
Rats, Sheep, and Normal Human Erythrocytes. Regul. Toxicol.
Pharmacol. 3, 184-188.
(31) Cavalli RO, Wasielesky W Jr, Franco CS, Filho KM (1996).
Evaluation of the Short-Term Toxicity of Ammonia, Nitrite
and Nitrate to Penaeus paulensis (Crustacea, Decapoda)
Broodstock. Arq. Biol. Tecnol. 39, 567-575.
(32) Centeno MDF, Persoone G, Goyvaerts MP (1995).
Cyst-based Toxicity Tests. IX. The Potential ofThamnocephalus Platyurus as Test Species in Comparison With
Streptocephalus Proboscideus (Crustacea; Branchiopoda
Anostraca). Environ. Toxicol. Water Qual. 10(4), 275-282(33) Centers for Disease Control (1997). Methemoglobinemia
Attributable to Nitrite Contamination of Potable Water
Through Boiler Fuid Additives - New Jersey, 1992 and 1996.
Morbidity and Mortality Weekly Report 46(09), 202 - 204.
(34) Chandler JHJ and Marking LL (1979). Toxicity of Fishery
Cchemicals to the Asiatic Clam, Corbicula manilensis.
Prog. Fish-Cult. 41(3), 148-151(35) Chapin R and Sloane R (1997). Reproductive Assessment by
Continuous Breeding: Evolving Study Design and Summaries ofNinety Studies. Environ. Health Perspect. 105, 199-395.
(36) Chen J-C and Chen S-F (1992). Effects of Nitrite on Growthand Molting of Penaeus monodon Juveniles. Comp. Biochem.
Physiol. 101C, 453-458.
(37) Chen J-C and Nan F-H (1991). Lethal Effect of Nitrite on
Metapenaeus ensis Larvae. J. World Aquacult. Soc. 22, 51-56.
(38) Chen J-C, Liu P-C, Lei S-C (1990a). Toxicities of Ammonia
and Nitrite to Penaeus monodon Adolescents. Aquacult. 89,
127-137.
(39) Chen J-C, Ting Y-Y, Lin J-N, Lin M-N (1990b). Lethal Effectsof Ammonia and Nitrite on Penaeus chinensis Juveniles. Mar.
Biol. 107, 427-431.
(40) Chen JC and Chin TS (1988). Acute Toxicity of Nitrite to
Tiger Prawn, Penaeus monodon, Larvae. Aquacult. 69, 253-262.
(41) Chow CK, Chen CJ, Gairola C (1980). Effect of Nitrate andNitrite in Drinking Water on Rats. Toxicology Letters 6,
199-206.
(42) Colt J and Tchobanoglous G (1976). Evaluation of the
Short-term Toxicity of Nitrogenous Compounds to Channel
Catfish, Ictalurus Punctatus. Aquaculture 8, 209-224
UNEP PUBLICATIONS

278

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(43) Crawford RE and Allen GH (1977). Seawater Inhibitionof Nitrite Toxicity to Chinook Salmon. Trans. Am. Fish. Soc. 106(1),105-109(44) Daniels HV, Boyd CE and Minton RV (1987). Acute
Toxicity of Ammonia and Nitrite to Spotted Seatrout. Prog.
Fish-Cult. 49(4), 260-263(45) Darad R, De AK, Aiyar AS (1983). Toxicity of
Nitrite and Dimethylamine in Rats. Toxicol. Lett. 17,
125-130(46) De Flora S (1981). Study of 106 Organic and Inorganic
Compounds in the Salmonella/Microsome Test. Carcinogenesis
2, 283-298.
(47) De Flora S, Zanacchi P, Camoirano A, Bennicelli C, Badolati
GS (1984). Genotoxic Activity and Potency of 135 compounds
in the Ames Reversion Test and in a Bacterial DNA-repair
Test. Mutat. Res. 133, 161-198.
(48) Diaz-Barriga Arceo S, Hernandez-Ceruelos A,
Madrigal-Bujaidar E (2002) Inhibitory Effect ofChlorophyllin on the Frequency of Micronuclei Induced by
Sodium Nitrite in Mice. Phytother Res. 16(8), 754-7(49) Dollahite JW and Rowe LD (1974). Nitrate and Nitrite
Intoxication in Rabbits and Cattle. Southwest. Vet. 27,
246-248(50) Druckery VH, Steinhoff D, Beuthner H, Schneider H, Klarner P(1963). Screening of Nitrite for Chronic Toxicity in Rats.
Arzneimittelforschung 13, 320-323.
(51) Eddy FB, Kunzlik PA, Bath RN (1983). Uptake andLoss of Nitrite from the Blood of Rainbow Trout, Salmo
Gairdneri Richardson, and Atlantic Salmon, Salmo Salar L. in Fresh Water.
J. Fish Biol. 23(1), 105-116(52) Ehrenberg L, Hussain S, Noor Saleh M, Lundquist U (1980).
Nitrous Esters-A Genetical Hazard from Nitrogen Oxides(NOx)? Hereditas 92, 127-130.
(53) El Nahas SM, Globus M, Vethamany-Globus S (1984).
Chromosomal Aberrations Induced by Sodium Nitrite in Bone
Marrow of Adult Rats and Liver Cells of Transplacentally
Exposed Embryos. J. Toxicol. Environ. Health 13, 643-647.
(54) Enichem S.P.A. Milan, Manufacturer's data(55) Epifanio CE and Srna RF (1975). Toxicity of Ammonia, Nitrite
Ion, Nitrate Ion, and Orthophosphate to Mercenaria
mercenaria and Crassostrea virginica. Mar. Biol. 33,
241-246.
(56) European Chemicals Bureau (ECB) (2000). IUCLID CD-ROM 2000
(57) Ewell WS, Gorsuch JW, Kringle RO, Robillard KA, Spiegel RC(1986). Simultaneous Evaluation of the Acute Effects of
279

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Chemicals on Seven Aquatic Species. Environ. Toxicol. Chem.
5(9), 831-840(58) Fahrig R (1979). Evidence that Induction and Suppression of
Mutations and Recombination by Chemical Mutagens in S.
cerevisiae During Mitosis are Jointly Correlated. Mol. Gen.
Genet. 168, 125-139.
(59) FDA (Food and Drug Administration) (1980). Re-Evaluation of
the Pathology Findings of Studies on Nitrite and Cancer:
Histologic Lesions in Sprague-Dawley Rats. Final Reportsubmitted by the Universities Associated for Research and
Education in Pathology to the Food and Drug Administration,
Public Health Service, U.S. Department of Health and Human
Services, Washington, D. C.
(60) Finan A, Keenan P, O'Donavan F, Mayne P, Murphy J (1998)
Methaemoglobinaemia Associated with Sodium Nitrite in Three
Siblings. British Medical Journal 317, 1138 - 1139.
(61) Frame JR, Rhodes E, Ubbelohde A (1959). Trans. Faraday Soc.
55, 2039-2047(62) Friedman MA, Greene EJ and Epstein SS (1972) Rapid GastricAbsorption of Sodium Nitrite in Mice. Journal of
Pharmaceutical Sciences, 61(9), 1492-1494(63) Gangolli SD, van den Brandt PA, Feron VJ, Janzowsky C,
Koeman JH, Speijers GJA, Spiegelhalder B, walker R, andWishnok JS (1994) Assessment: Nitrate, Nitrite and N-nitroso
Compounds. European Journal of Pharmacology: Environmental
Toxicology and Pharmacology Section 292, 1-38.
(64) Gillette LA, Miller DL, Redman HE (1952). Appraisal of a
Chemical Waste Problem by Fish Toxicity Tests. Sewage Ind.
Wastes 24, 1397-1401(65) Giri AK, Talukder G, Sharma A (1986). Sister Chromatid
Exchange Induced by Metanil Yellow and Nitrite Singly and in
Combination In Vivo on Mice. Cancer Letters 31, 299-303.
(66) Globus M and Samuel D (1978). Effect of MaternallyAdministered Sodium Nitrite on Hepatic Erythropoiesis in
Fetal CD-1 Mice. Teratology 18, 367-378.
(67) Gowans WJ (1990). Fatal Methaemoglobinaemia in a Dental
Nurse: A Case of Sodium Nitrite Poisoning. Br. J. Gen.
Pract. 40, 470-471.
(68) Grant P and Butler W (1989). Chronic Toxicity of Sodium
Nitrite in the Male F344 Rat. Fd. Chem. Toxic. 27(9),565-571(69) Greenblatt M and Lijinsky W (1972). Failure to Induce
Tumors in Swiss Mice after Concurrent Administration of
Amino Acids and Sodium Nitrite. J. Natl. Cancer Inst. 48,
1389-1392(70) Greenblatt M and Mirvish SS (1973). Dose Response Studies
with Concurrent Administration of Piperazine and Sodium
UNEP PUBLICATIONS

280

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Nitrite to Strain A Mice. J. Natl. Cancer Inst. 50,
119-124(71) Greenblatt M, Mirvish S, So BT (1971). Nitrosamine
Studies: Induction of Lung Adenomas by Concurrent
Administration of Sodium Nitrite and Secondary Amines in
Swiss Mice. J. Natl. Cancer Inst. 46, 1029-1034(72) Gruener N (1974) The Effect of Nitrites on
Isolation-Induced Aggression in Mice. Pharmacol. Biochem.
Behav. 2, 267-269(73) Gutzmer, M. P. and Tomasso, J. R. (1985). Nitrite toxicity
to the crayfish Procambarus clarkii. Bull. Environ. Contam.
Toxicol. 34(3), 369-376(74) Hack W and Dowes AVA (1983). Spinach: A Source of Nitrite
Poisoning in Young Children. Ned Tijdschr Geneekd 127,
1428-1431.
(75) Hawley's p. 1067. Leduc Chemie B.V. Amersfoort(76) Hirneth H and Classen HG (1984). Inhibition of
Nitrate-Induced Increase of Plasma Nitrite and Methemoglobin in Rats by
Simultaneous Feeding of Ascorbic Acid or Tocopherol.
Arzneimittelforschung 34(II), 988-991(77) Hirose M, Tanaka H, Takahashi S, Futakuchi M, Fukushima S,
Ito N (1993). Effects of Sodium Nitrite and Catechol,
3-Methoxycatechol, or Butylated Hydroxyanisole in
Combination in a Rat Multiorgan Carcinogenesis Model. Cancer
Res. 53, 32-37(78) Hommel (1987). Handbuch der Gefaerlichen Gueter;
Springer-Verlag Heidelberg(79) Hsu JD, Hsu CL, Chou FP, Wen PH, Wang CJ (1997). Potential
Effect of Sodium Nitrite on the Expression of Nuclear
Proto-oncogenes During 2-Acetyl Aminofluorene-Induced
Hepatocarcinogenesis in rats. Chem-Biol. Interact. 108, 1-18(80) Huey DW and Beitinger TL (1980). Toxicity of Nitrite
to Larvae of the Salamander Ambystoma texanum. Bull. Environ. Contam.
Toxicol. 25(6), 909-912(81) Hughes WF Jr (1948). The Tolerance of Rabbit Cornea for
Various Chemical Substances. Bull. Johns Hopkins Hosp. 82,
338-349(82) ICI, reported data(83) ICSC (2000). Sodium Nitrite: International Chemical Safety
Cards No. 1120
(84) Ilnitsky AP and Kolpakova AS (1997). The Enhancing
Effect of Sodium Nitrite on Virus-Induced Leukemia in Mice.
Cancer Detect. Prev. 21, 312-318(85) Imaizumi K, Tyuma I, Imai K, Kosaka H, Ueda Y (1980) In Vivo
Studies on Methemoglobin Formation by Sodium
281

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Nitrite. International Archives of Occupational andEnvironmental Health, 45, 97-104(86) Inai K, Aoki Y, Tokuoka S (1979). Chronic Toxicity of
Sodium Nitrite in Mice, with Reference to its
Tumorigenicity. Gann 70, 203-208(87) Inoue K, Shibata T, Kosaka H, Uozumi M, Tsuda S, Abe T(1985). Induction of Sister Chromatid Exchanges by
N-nitrosocimetidine in Cultured Human Lymphocytes and its
Inhibition by Chemical Compounds. Mutat. Res. 156, 117-121.
(88) Inui N, Nishi Y, Hasegawa MM, Taketomi M, Yamamoto M,
Tanimura A (1980). Induction of 8-Azaguanine-Resistant
Mutation and Neoplastic Transformation of Hamster Embryonic
Cells by Coadministration of Sodium Nitrite and Minopyrine.
J. Cancer Res. Clin. Oncol. 97, 119-128(89) Inui N, Nishi Y, Mori M, Taketomi M, Yamamoto M, Tanimura A(1979). Detection of 8 Azaguanine Resistant Mutants ofEmbryonic Cells Induced by Products Formed in the
Stomach on Oral Administration of Sodium Nitrite Plus
Aminopyrine to Pregnant Golden Hamsters. Proc. Jpn. Acad.
55, 286-289(90) Inui N, Nishi Y, Taketomi M, Mori M, (1979b). Transplacental
Action of Sodium Nitrite on Embryonic Cells of Syrian Golden
Hamster. Mutat. Tes. 66, 149 - 158.
(91) Ishidate M Jr, and Odashima S (1977) Chromosome tests
with 134 Compounds on Chinese Hamster Cells In Vitro-A
Screening for Chemical Carcinogens. Mutat. Res. 48, 337-353(92) Ishidate M Jr, Sofuni T, Yoshikawa K (1981) Chromosomal
Aberration Tests In Vitro as a Primary Screening
Tool for Environmental Mutagens and/or Carcinogens. Gann
Monogr. Cancer Res. 27, 95-108(93) Ishidate M Jr, Sofuni T, Yoshikawa K, Hayashi M, Nohmi T,
Sawada M, Matsuoka A (1984) Primary Mutagenicity Screeningof Food Additives Currently Used in Japan. Food Chem.
Toxicol. 22, 623-636(94) Japan Fertilizer and Ammonia Producers Association (JAFA)(2005) Sodium Nitrite: Algal Inhibition Test. SafepharmLaboratories Ltd., Report No. 2104/001. Unpublished Data
(95) Japan Industrial Safety and Health Association (JISHA)(2004) Inspection Report of Worker's Exposure for the OECDSIDS Programme.
(96) JECFA (FAO/WHO Joint Expert Committee on Food Additives)(1995). Food Additives Series 35(97) JECFA (FAO/WHO Joint Expert Committee on Food Additives)(2003). Food Additives Series 50(98) Juhlin L (1981). Recurrent Rrticaria: Clinical
Investigation of 330 Patients. Br. J. Derm. 104, 369-381

UNEP PUBLICATIONS

282

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(99) Juhnke I and Luedemann D (1978). Results of theInvestigation of 200 Chemical Compounds for Acute Fish
Toxicity with the Golden Orfe Test. Z. Wasser
Abwasser-Forsch. 11, 161-164(100) Kamstra A, Span JA, van Weerd JH (1996). The Acute Toxicity
and Sublethal Effects of Nitrite on Growth and Feed
Utlization of European Eel, Anguilla anguilla (L.).
Aquacult. Res. 27, 903-911.
(101) Katz M, Kazmer S, Weinstein D (1980). An Analysis of Weak
Mutagens in the Ames Assay. J. Environ. Pathol. Toxicol. 3,
171-187.
(102) Keith, L. H. and Walters, B. (1989).Compendium of Safety
Data Sheets for Research and Industrial Chemicals, Part-VII,
VCH Verlagsgesellsch.mbH, Weinheim(103) Khera KS (1982). Reduction of Teratogenic Effects ofEthylenethiourea in Rats by Interaction with Sodium Nitrite
In Vivo. Food Chem. Toxicol. 20, 273-278.
(104) Klimmek R, Krettek C, Werner HW (1988). Ferrihaemoglobin
Formation by Amyl Nitrite and Sodium Nitrite in Different
Species In Vivo and In Vitro. Arch. Toxicol. 62, 152-160.
(105) Kociba RJ and Sleight SD (1970). Nitrite Toxicosis in the
Ascorbic Acid-Deficient Guinea Pig. Toxicol. Appl.
Pharmacol. 16, 424-429.
(106) Kodama F, Umeda M, Tsutsui T (1976). Mutagenic Effect of
Sodium Nitrite on Cultured Mouse Cells. Mutat. Res. 40,
119-124.
(107) Konikoff M (1975). Toxicity of Nitrite to Channel Catfish.
Prog. Fish-Cult. 37, 96-98.
(108) Kosako M and Nishioka H (1982). New Forward Mutation Assay
using Low-Concentration Streptomycin Resistance Mutation in
E. coli Strains with Plasmid pKM 101. Sci. Eng. Rev.
Doshisha Univ. 22, 239-249.
(109) Krebs F (1991). Bestimmung der Biologischen Schadwirkung
Wassergefahdender Stoffe im Assimilations-Zehrungs-Test(A-Z-Test). Deutsche Gewasserkundliche Mitteilungen 35(5/6), 161-170(110) Krishna Murthy AS, Baker JR, Smith ER, Zepp E(1979).
Neoplasms in Rats and Mice Fed Butylurea and Sodium
Nitrite Separately and in Combination. Int. J. Cancer 23,
253-259(111) Lijinsky W (1984). Induction of Tumours in Rats by
Feeding Nitrosatable Amines Together with Sodium Nitrite.
Food Chem. Toxicol. 22, 715-720(112) Lijinsky W (1984b). Induction of Tumors of the Nasal
Cavity in Rats by Concurrent Feeding of Thiram and Sodium
Nitrite. J. Toxicol. Environ. Health 13, 609-614(113) Lijinsky W and Reuber MD (1980). Tumours Induced in
283

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Fischer 344 Rats by the Feeding of Disulfiram Together with
Sodium Nitrite. Food Cosmet. Toxicol. 18, 85-87(114) Lilly LJ, Cobon AM, Newton MF (1979). Chromosomal
Aberrations Induced in Rat Lymphocytes by in vivo Exposure
to Chemicals. A Short-term Method of Carcinogenicity
Screening. Meth. Find. Exp. Clin. Pharmacol. 1, 225-231(115) Lynch SC, Gruenwedel DW, Russell GF (1983). Mutagenic
Activity of a Nitrosated Early Maillard Product: DNA
Synthesis (DNA Repair) Induced in HeLa S3 Carcinoma Cells by
Nitrosated 1-(NL- tryptophan)-1-deoxy-D-fructose. Food Chem.
Toxicol. 21, 551-556.
(116) Maekawa A, Ogiu T, Onodera H, Furuta K, Matsuoka C, Ohno Y,
and Odashima S (1982). Carcinogenicity Studies of Sodium
Nitrite and Sodium Nitrate in F-344 rats. Food Chem.
Toxicol. 20, 25-33.
(117) Mazik PM, Hinman ML, Winkelmann DA, Klaine SJ, Simco BA,
Parker NC (1991). Influence of Nitrite and Chloride
Concentrations on Survival and Hematological Profiles ofStriped Bass. Trans. Am. Fish. Soc. 120(2), 247-254(118) Meade ME and Watts SA (1995). Toxicity of Ammonia, Nitrite,
and Nitrate to Juvenile Australian Crayfish, Cherax
quadricarinatus. J. Shellfish Res. 14, 341-346.
(119) MERCK (2004). Sodium Nitrite MSDS according to EC Dir.
91/155/EEC.
(120) Merck Index (2001). Budavari S (ed.), The Merck Index-An
Encyclopedia of Chemicals, Drugs, and Biologicals.
Whitehouse Station, NJ, Merck and Co., Inc., No. 8721.
(121) Ministry of Agriculture, Fisheries and Food (MAFF) (1992)
Nitrate, Nitrite and N-Nitrosocompounds in Food: Food
Surveillance Paper No. 32, Her Majesty's Stationary Office,London(122) Ministry of Economy, Trade and Industry in JAPAN (2003).
Briefing paper(123) Ministry of Health, Labour and Welfare, Japan (2003).
(124) Mirvish SS, Bulay O, Runge RG, Patil K (1980). Study of the
Carcinogenicity of Large Doses of Dimethylnitramine,
N-nitroso-L-proline, and Sodium Nitrite Administered in
Drinking Water to Rats. JNCI 64, 1435-1442(125) Mirvish SS, Greenblatt M, Kommineni VR (1972). Nitrosamide
Formation In Vivo: Induction of Lung Adenomas in
Swiss Mice by Concurrent Feeding of Nitrite and Methylurea
or Ethylurea. J. Natl. Cancer Inst. 48, 1311-1315(126) Mirvish SS, Salmasi S, Cohen SM, Patil K, Mahboubi E (1983).
Liver and Forestomach Tumors and Other
Forestomach Lesions in Rats Treated with Morpholine andSodium Nitrite, with and without Sodium Ascorbate. JNCI 71,
81-85
UNEP PUBLICATIONS

284

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(127) Moneret-Vautrin DA (1986). Food Antigens and Additives.
J. Allergy Cli. Immun. 78, 1039-1046(128) Nalecz-Jawecki G and Sawicki J (1998). Toxicity of Inorganic
Compounds in the Spirotox Test: A Miniaturized Version of
the Spirostomum ambiguum Test. Arch. Environ. Contam.
Toxicol. 34, 1-5(129) National Institute of Public Health and Environmental
Hygiene, Netherlands (1986). Nitrate: Basis Document
Effects. Project Number 840820(130) Newberne PM (1979). Nitrite Promotes Lymphoma Incidencein Rats. Science 204, 1079-1081(131) Noel ME, Vaubel JE, Goldman M (1974). The
Influence of Sodium Nitrite on Spleen, Liver, Kidney,
Adrenal, Ovary, and Uterus of the Rat. Proc. S.D. Acad. Sci. 53, 232-235(132) Nofre C, Dufour H, Cier A (1963). Toxicite Generale
Comparee des Anions Mineraux chez la Souris. Comp Rend
Hebdom, Seanc. Acad. Sci., Paris, 257, 791-794(133) NTP (1990). Final Report on the Reproductive Toxicity of
Sodium Nitrite (CAS No. 7632-00-0) in CD-1 Swiss Mice.
National Toxicology Program Report No. NTP 90-266.
(134) NTP (2001). Toxicology and Carcinogenesis Studies of Sodium
Nitrite (CAS No. 7632-00-0) in F344/N Rats and B6C3F1 Mice
(Drinking Water Studies). National Toxicology Program Report
No. NTP TR 495. NIH Publication No. 01-3954.
(135) Nyakas C, Buwalda B, Kramers RJ, Traber J, Luiten PG(1994a). Postnatal Develoment of Hippocampal and Neocortical
Cholinergic and Seotonogeric Innervation in Rat: Effects of
Nitrite-Induced Prenatal Hypoxia and Imodipine Treatment.
Neuroscience 59, 541-559.
(136) Nyakas C, Buwalda B, Markel E, Korte S, Luiten P (1994b).
Life-spanning Behavioural and Adrenal Dysfunction Induced byPrenatal Hypoxia in the Rat is Prevented by the Calcium
Antagonist Nimodipine. Eur. J. Neurosci. 6, 746-753.
(137) Nyakas C, Markel E, Bohus B, Schuurman T, Luiten P (1990).
Protective Effect of the Calcium Antagonist Nimodipine on
Discrimination Learning Deficits and Impaired Retention
Behavior Caused by Prenatal Nitrite Exposure in Rats. Behav.
Brain Res. 38, 69-76.
(138) Olsen P, Gry J, Knudsen I, Meyer O, Poulsen E (1984). Animal
Feeding Study with Nitritetreated Meat. IARC
Scientific Publication 57, 667-675(139) Olshan A and Faustman E (1989). Nitrosable Ddrug Exposure
During Pregnancy and Adverse Pregnancy Outcome. J. Epi.
18(4), 891-899(140) Ostrensky A and Lemos D (1993). Effects of Ammonium andNitrite on Growth of the Marine Microalgae Tetraselmis
285

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

chuii. Actas IV Congreso Nac. Acuicult. 485-489.
(141) Palachek RM and Tomasso JR (1984). Toxicity of Nitrite to
Channel Catfish (Ictalurus punctatus), Tilapia (Tilapia
aurea), and Largemouth Bass (Micropterus salmoides). Can. J.
Fish. Aquat. Sci. 41, 1739-1744.
(142) Pankow D, Ponsold W, Liedke MD, Gessner G, Pfordte A (1975)
Zur Anpassung von Ratten an Natriumnitrit-induzierte
Methamoglobinamie (Adaptation of Rats Following Sodium
Nitrite-Induced Methemoglobinemia). Acta Biol. Med. Germ.
34, 1205-1209(143) Radian Hazardous Materials Library zitiert in NTIS. (1990).
PB91-132027(144) Riemann H. (1950). On the Toxicity of Hydroxylamine. Acta.
Pharmacol. 6, 285-292(145) Rijhsinghani KS, Abrahams C, Krakower C, Swerdlow M, Ghose T(1982). Tumor Induction in C57BL ~ C3HF1 Mice Following
Single Oral Administration of Diethylamine Hydrochloride
Sodium Nitrite (NaNO2). Cancer Detect. Prev. 5, 283-290(146) Roberts, B. L. and Dorough, H. W. (1984). Relative
toxicities of chemicals to the earthworm Eisenia foetida.
Environ. Toxicol. Chem. 3(1), 67-78(147) Rodriguez-Moreno PA and Tarazona JV (1994). Nitrite-induced
Methemoglobin Formation and Recovery in Rainbow Trout(Oncorhynchus mykiss) at High Chloride Concentrations. Bull.
Environ. Contam. Toxicol. 53, 113-119.
(148) Roth A and Smith MK (1988). Nitrite-induced Iron
Deficiency in the Neonatal Rat. Toxicol. Appl. Pharmacol.
96, 43-51(149) Roth A, Herkert G, Bercz J, Smith M (1987). Evaluation of
the Developmental Toxicity of Sodium Nitrite in Long Evans
Rats. Fundam. Appl. Toxicol. 9(4), 668-677(150) Rouse DB, Kastner RJ, Reddy KS (1995). Toxicity of Ammonia
and Nitrite to Hatchling Redclaw Crayfish, Cherax
quadricarinatus. Freshw. Crayfish 10, 298-303.
(151) Rubenchik BL, Osinkovskaya ND, Mikhailenko VM, Furman MA,
Boim TM (1990). The Carcinogenic Danger of Nitrite Pollutionof the Environment. J. Environ. Pathol. Toxicol. Oncol. 10,
290-296(152) Russo RC and Thurston RV (1977). The Acute Toxicity of
Nitrite to Fishes. In: R. A. Tubb (Ed.), EPA-600/3-77-085,
Recent Advances in Fish Toxicol., 118-131 (U.S.NTIS
PB-273500)(153) Russo RC, Smith CE, Thurston RV (1974). Acute Toxicity of
Nitrite to Rainbow Trout (Salmo gairdneri). J. Fish. Res.
Board Can. 31(10), 1653-1655(154) Russo RC, Thurston RV, Emerson K (1981). Acute Toxicity of
UNEP PUBLICATIONS

286

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Nitrite to Rainbow Trout (Salmo gairdneri): Effects of pH,
Nitrite Species, and Anion Species. Can. J. Fish. Aquat.
Sci. 38, 387-393.
(155) Saito T, Taseichi S, Nakajima Y, Yukawa N, Osawa M (1997).
Experimental Studies of Methemoglobinemia Due to
Percutaneous Absorption of Sodium Nitrite. Clinical
Toxicology 35(1), 41-48.
(156) Saito T, Taseichi S, Yukawa N, Osawa M (1996). Fetal
Methemoglonemia Caused by Liniment Solutions Containing
Sodium Nitrite. J. Forensic Science 41, 169-171.
(157) Sander C and Jacobi H (1967). Methemoglobinemia Poisoning ina Two Year Old Boy After Eating Spinach. Z. Kinderheilkd 98,
222-226.
(158) Scarano G, Saroglia MG, Gray RH, Tibaldi E (1984).
Hematological Responses of Sea Bass Dicentrarchus labrax toSublethal Nitrite Exposures. Trans. Am. Fish. Soc. 113,360-364.
(159) Shank RC and Newberne PM (1976). Dose Response Studyof the Carcinogenicity of Dietary Sodium Nitrite andMorpholine in Rats and Hamsters. Food Cosmet. Toxicol. 14,
1-8(160) Shimada T (1989). Lack of Teratogenic and Mutagenic
Effects of Nitrite. Arch. Environ. Hlth. 44(1), 59-63(161) Shiobara S (1987). Effects of Sodium Nitrite (NaNO2)
Administration on Pregnant Mice and Their Fetuses. Jpn. J.
Hygiene 42, 836-846(162) Showa Chemical Industry (2003). MSDS,1950-4250(163) Shuval HI and Gruener N (1972). Epidemiological andToxicological Aspects of Nitrates and Nitrites in theEnvironment. Am. J. Public Health 62, 1045-1052(164) Sinha DP and Sleight SD (1971). Pathogenesis of Abortion in
Acute Nitrite Toxicosis in Guinea Pigs. Toxicol. Appl.
Pharmacol. 18, 340-347.
(165) Sleight SD and Atallah OA (1968) Reproduction in the Guinea
Pig as Affected by Chronic Administration of Potassium
Nitrate and Potassium Nitrite. Toxicol Appl Pharmacol 12,
179-185(166) Smith JE and Beutler E (1966). Methemoglobin Formation andReduction in Man and Various Animal Species. Am. J. Physiol.
210, 347-350.
(167) Solbe JFD, Cooper VA, Willis CA, Mallett MJ (1985). Effectsof Pollutants in Fresh Waters on European Non-Salmonid Fish
I: Non-Metals. J. Fish Biol. 27(Suppl. A), 197-207.
(168) Southwood J (1985). ICI Unpublished Report No CTL/L/1003(169) SPIN (Substances in Preparations in Nordic Countries)
287

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(2003). [on line](170) Stoerfall-Verordnung vom (1991)(171) Stormer J, Jensen FB, Rankin JC (1996). Uptake of Nitrite,
Nitrate, and Bromide in Rainbow Trout, Oncorhynchus mykiss:
Effects of Ionic Balance. Can. J. Fish. Aquat. Sci. 53,
1943-1953.
(172) Sugiyama M, Tanaka H, Fukusho K (1991). Toxicity of Total
Ammonia and Nitrite Nitrogen to Young Yellowtail, Seriola
Quinqueradiata. Bull. Natl. Res. Inst. Aquacult. (Yoshoku
Kenkyusho Kenkyu Hokoku) 19, 31-33(173) Swanson HE, Fuyat R, Ugrinic G (1955). Natl. Bur. Std. (US)Circl. No 539. 1/75, 62(174) Takahama U, Oniki, T and Hirota, S (2002). Oxidation of
Quercetin by Salivary Components. Quercetin-Dependant
Reduction of Salivary Nitrite under Acidic Conditions
Producing Nitric Oxide. Journal of Agricultural and Food
Chemistry 50, 4317 - 4322
(175) Taylor HW and Lijinsky W (1975). Tumor Induction in
Rats by Feeding Heptamethyleneimine and Nitrite in Water.
Cancer Res. 35, 812-815(176) The Chemical Daily Co., Ltd. (2003). 14303 Chemical
Products, 1(177) Thurston RV, Russo RC, Smith CE (1978). Acute Toxicity ofAmmonia and Nitrite to Cutthroat Trout Fry. Trans. Am. Fish.
Soc. 107, 361-368.
(178) Til HP, Falke HE, Kuper CF, Williams M (1988). Evaluation of
the Oral Toxicity of Potassium Nitrite in a 13-Week Drinking
Water Study in Rats. Food Chem. Toxicol. 26, 851-859(179) Tomasso JR (1986). Comparative Toxicity of Nitrite toFreshwater Fishes. Aquat. Toxicol. 8, 129-137.
(180) Tomasso JR and Carmichael GJ (1986). Acute Toxicity ofAmmonia, Nitrite, and Nitrate to the Guadalupe Bass,
Micropterus treculi. Bull. Environ. Contam. Toxicol. 36,
866-870.
(181) Tomasso JR, Wright MI, Simco BA, Davis KB (1980). Inhibitionof Nitrite-Induced Toxicity in Channel
Catfish by Calcium Chloride and Sodium Chloride. Prog.
Fish-Cult. 42(3), 144-146(182) TRGS 900 (1993).
(183) Tsuda H and Kato K (1977). High Rate of Endoreduplications
and Chromosomal Aberrations in Hamster Cells Treated with
Sodium Nitrite In Vitro. Mutat. Res. 56, 69-74.
(184) Tsuda H, Kushi A, Yoshida D, Goto F (1981). Chromosomal
Aberrations and Sister-chromatid Exchanges Induced by
Gaseous Nitrogen Dioxide in Cultured Chinese Hamster Cells.
UNEP PUBLICATIONS

288

OECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006

Mutat. Res. 89, 303-309.
(185) UBE Industries Ltd (2005). Sodium Nitrite: EPIWIN v3.12
Calculations. Unpublished data.
(186) UBE INDUSTRIES, LTD (2004). merchandise information(187) Van Logten M, Tonkelaar R, Kroes R, Berkvens J, Esch G(1972). Long Term Experiment with Canned Meat
Treated with Sodium Nitrite and Glucono-gamma-lactone in
Rats. Fd. Cosmet. Toxicol. 10, 475-488(188) Vleeming W, Van de Kuil A, te Biesebeek JD, Meulenbelt J,
Boink AB (1997). Effect of Nitrite on Blood Pressure inAnaesthetized and Freemoving Rats. Food Chem. Toxicol. 35,
615-619(189) Vorhees CV, Butcher RE, Brunner RL, Wootten V (1984).
Developmental Toxicity and Psychotoxicity of Sodium Nitrite
in Rats. Food Chem. Toxicol. 22, 1-6.
(190) Walker R (1990). Nitrates, Nitrites and N-nitrosocompounds:
A Review of the Occurrence in Food and Diet and the
Toxicological Implications. Food Additives and Contaminants,
7(6), 717 - 768(191) Walker R (1996). The Metabolism of Dietary Nitrates andNitrites. Biochemical Society Transactions, 24, 780-785.
(192) Wallen IE, Greer WC, Lasater R (1957). Toxicity to Gambusia
affinis of Certain Pure Chemicals in Turbid Waters. Sewage
Ind. Wastes 29, 695-711.
(193) Wedemeyer GA and Yasutake WT (1978). Prevention andTreatment of Nitrite Toxicity in Juvenile Steelhead Trout(Salmo gairdneri). J. Fish. Res. Board Can. 35, 822-827.
(194) Weirich CR and Tomasso JR (1993). Toxicity of Ammonia andNitrite to Sunshine Bass in Selected Environments. J. Aquat.
Anim. Health 5(1),64-72(195) Westin DT (1974). Nitrate and Nitrite Toxicity to Salmonoid
Fishes. Prog. Fish-Cult. 36, 86-89.
(196) WHO (World Health Organization) (1996). Guideline for
Drinking-Water Quality 2nd ed. Vol.2, 313-324(197) WHO (World Health Organization) (1996). Toxicologicalevaluation of cetain food additives and contaminants infood: Nitrite. WHO Food Additives Series; 35, 269-323(198) Williams EM and Eddy FB (1986). Chloride Uptake inFreshwater Teleosts and its Relationship to Nitrite Uptake
and Toxicity. J. Comp. Physiol. B Biochem. Syst. Environ.
Physiol. 156, 867-872(199) Wise DJ and Tomasso JR (1989). Acute Toxicity of
Nitrite to Red Drum Sciaenops ocellatus: Effect of Salinity. J. World
Aquacult. Soc. 20(4), 193-198
289

UNEP PUBLICATIONSOECD SIDS
6. REFERENCES[SODIUM NITRITE]
ID: 7632-00-00
DATE: 04-JAN-2006(200) Wodzinski RS, Labeda DP and Alexander M (1978). Effects of
Low Concentrations of Bisulfite-Sulfite and Nitrite on
Microorganisms. Applied and Environmental Microbiology, 35,
718-723.
(201) Xiang YY, Wang DY, Tanaka M, Igarashi H, Kamo T, Shen Q,
Sugimura H, Kino I (1995). Efficient and Specific Inductionof Esophageal Tumors in Rats by Precursors of
N-nitrososarcosine Ethyl Ester. Pathol. Int. 45, 415-421(202) Yamagata Y and Niwa M (1979). Toxicity of Nitrite to Eels.
The Aquaculture (Suisan Zoshoku) 27, 5-11.
(203) Yamamoto K, Nakajima A, Eimoto H, Tsutsumi M, Maruyama H,
Denda A, Nii H, Mori Y, Konishi Y (1989). Carcinogenic
Activity of Endogenously Synthesized
N-nitrosobis(2-hydroxypropyl)amine in Rats Administeredbis(2-hydroxypropyl)amine and Sodium Nitrite. Carcinogenesis
10, 1607-1611(204) Yoshida A, Harada T, Maita K (1993). Tumor Induction
by Concurrent Oral Administration of Ethylenethiourea andSodium Nitrite in Mice. Toxicol. Pathol. 21, 303-310(205) Yoshida Y, Hirose M, Takaba K, Kimura J, Ito N (1994).
Induction and Promotion of Forestomach Tumors by
Sodium Nitrite in Combination with Ascorbic Acid or Sodium
Ascorbate in Rats with or without
N-methyl-N'-nitro-N-nitrosoguanidine pretreatment. Int. J.
Cancer 56, 124-128(206) Zeiger E, Anderson B, Haworth S, Lawlor T, Mortelmans K(1992). Salmonella Mutagenicity Tests: V. Results from theTesting of 311 Chemicals. Environ. Mol. Mutagen. 19, 2-141.

UNEP PUBLICATIONS

290