SUBJECT: 

FROM: 

THRU: 

TO: 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

September 24, 2012 

Product Chemistry, Environmental Fate, and Ecological Effects Scoping 

Document in Support of Registration Review of Ammonia and 

Ammonium Sulfate 

PC Codes: DP Barcodes: 

Ammonia: 005302 Ammonia: 404902 

Ammonium sulfate: 005601 Ammonium sulfate: 401476 

Decision Nos.: Registration Nos.: See Table 1 

Ammonia: 469069 

Ammonium sulfate: 464385 

Petition No(s).: NA Regulatory Action: Ecological 

Environmental Scoping Document 

for Registration Review 

Risk Assessment Type: Single chemical Case Nos.: 

Ammonia: 7 440 

Ammonium sulfate: 5073 

TXRNo.:NA CAS Nos.: 

Ammonia: 7664-41-7 

Ammonium sulfate: 7783-20-2 

MRID Nos.: See Tables 7. 11, 12 & 13 40 CFR: None 

William 

Srinivas Gowda, 

Erickson, 

M.S. 

Ph.D., 

Microbiologist/Science 

BiologistitA": .... 

Coordinator~ 2r1'~v ~ ~ 

Najm Shamim, Ph.D., Chemist .n JktU~v---J 

Risk Assessment and Science Support Branch (RASSB) 

Antimicrobials Division (7510P) . . ~ 

Steven Weiss, Acting Branch Chief %c 

Donna Randall, M.S. Ecological Risk Assessment Team Leader 

Risk Assessment and Science Support Branch (RASSB) 

Antimicrobials Division (7510P) 

Rebecca von dem Hagen, Chemical Review Manager 

Regulatory Management Branch II 

Antimicrobials Division (7 51 OP) 

Page 1 of 23 
Executive Summary 

Ammonia and ammonium sulfate are inorganic nitrogen compounds which are used on 

site to produce the oxidant and microbiocide, monochloramine, under controlled application 

conditions. Ammonia bromide is another inorganic nitrogen, ammonium salt compound that 

produces the oxidant and microbiocide, monochloramine, but it also produces hypobromous 

acid, another inorganic oxidant, so the Registration Review for ammonium bromide is addressed 

separately (Case Number 5002). Ammonia and ammonia sulfate are registered for use as 

microbiocides for controlling algal, bacterial and fungal deposits (slimes) in influent water 

systems, and all process water systems used for the manufacture of paper and paperboard 

products (food contact) and in industrial cooling towers, recirculating cooling water systems, 

evaporative condensers, brewery and food pasteurizers, industrial fresh water systems, air 

washers, seawater desalination and reverse osmosis systems, paint spray booth sumps, non-fish 

containing decorative fountains and ponds used for cooling purposes, and sewage and 

wastewater systems. They are also registered for the control of algae, bacteria, fungi and 

mollusks in both seawater and freshwater influent systems. The manufacturing and end use 

products have a declared ammonia content of7.59% total ammonia1 or a declared ammonium 

sulfate content ranging from 20% to 28% which is equivalent to a total ammonia (ammonia plus 

ammonium expressed as ionized ammonia) content ranging from 5.45% to 7.59%. The end use 

products are used in conjunction with an oxidant sodium hypochlorite (12.5-15%) to produce 

monochloramine. The Agency is conducting its fate and environmental assessment on the 

monochloramine formed during the application. 

The active ingredient ammonium sulfate is a strong oxidizing agent, the formation of 

monochloramine provides a slower acting, less aggressive oxidizing agent and biocide. The 

active ingredient ammonium sulfate has no pesticidal activity per se. The actual biocide, 

monochloramine is produced on-site by reacting the registered products with sodium 

hypochlorite. The monochloramine is generated and fed into water process systems using 

closed, automatic dosing/metering systems. Ammonium sulfate is reacted with an aqueous 

solution of sodium hypochlorite (1.0-1.5 to 1 molar ratio of ammonia and hypochlorite) under 

alkaline (pH ;:::8.5) conditions, as specified by some labels, to form monochloramine rather than a 

mixture of mono-, di-, and trichloramines. Monochloramine is added to the water to be treated 

immediately as it is formed. On one label, when the product is used to treat once-through 

industrial water system reduction of chloramine using sodium metabisulfite is required before 

discharge for effluents from these uses. 

Aqueous Ammonia was first registered in USA in 1971 for conventional uses. It was 

first registered as a microbiocide for use in pulp and paperboard process water systems in 2007. 

There are currently two active products, one of which is for formulation use only and the other is 

an end use product both have a declared total ammonia content of 7.59% which is equivalent to 

an ammonia sulfate content of 28%. Conventional uses are no longer active. 

Ammonium sulfate was first registered in the United States in 1987 for wood 

preservative uses. In 2011 two end-use ammonium sulfate products, Nalco 60620 and Fennosurf 

586 were registered by Nalco Company and Kemira Chemicals, Inc., respectively for use in pulp 

1 Sum of un-ionized and ionized ammonia content expressed as ionized ammonia. 

Page 2 of23 
and papermill water systems to control bacteria, algae and fungi. There are currently two active 

end use products, the declared ammonium sulfate content of one is 20% and the other is 28%. 

Use as a wood preservative is no longer active. 

Conventional fate data cannot be generated for aqueous ammonia, ammonium sulfate, 

and monochloramine as these are inorganic species. The environmental fate of these compounds 

is complex but is known based primarily on inorganic and oxidation/reduction chemistry. More 

recent fate data has established that monochloramine is not stable in the environmental media; it 

is considered biodegradable in water, and in sediments and possibly in soils. OPP's most recent 

exposure assessment (EPA 2011), conducting for the registration of the Nalco ammonium sulfate 

product, identified that the pulp and paper water use would not likely result in exposure or 

minimal exposure because of the reactivity of chloramine and retention of discharge water in 

holding ponds where any unreacted chloramine will react with organic matter prior to any release 

into the aquatic environment. However, there is uncertainty for once through industrial water 

system uses whether there is sufficient time for chloramine to dissipate completely before being 

discharged to surface waters. A field dissipation study is needed to refine exposure estimates 

and address this uncertainty. 

Ammonium sulfate is at most only moderately toxic to birds. Monochloramine generated 

from combining ammonium sulfate solution with sodium hypochlorite is highly to very highly 

toxic to aquatic plants and animals. These monochloramine data will be used to support the 

monochloramine requirements for ammonium sulfate uses. In addition to the available data, the 

following monochloramine environmental fate and ecological effects data are needed to conduct 

a risk assessment for once-through industrial water systems: aquatic field dissipation, chronic 

data for an estuarine/marine fish and shrimp species, chronic freshwater fish and invertebrate 

data, Tier II (dose response) seedling emergence- rice data, and aquatic plant growth (algal) 

Tier II (dose response) data for a marine diatom, freshwater diatom, and a blue-green algae. 

Environmental fate and ecological effects risk assessments, including an endangered 

species assessment, are anticipated to be conducted for the once-through industrial water 

systems. 

Introduction 

Ammonia and ammonium sulfate are inorganic nitrogen compounds registered for use as 

microbiocides for controlling algal, bacterial and fungal deposits (slimes) in influent water 

systems, and all process water systems used for the manufacture of paper and paperboard 

products (food contact) and in industrial cooling towers, recirculating cooling water systems, 

evaporative condensers, brewery and food pasteurizers, industrial fresh water systems, air 

washers, seawater desalination and reverse osmosis systems, paint spray booth sumps, non-fish 

containing decorative fountains and ponds used for cooling purposes, and sewage and 

wastewater systems. They are also registered for the control of algae, bacteria, fungi and 

mollusks in both seawater and freshwater influent systems. Ammonia and ammonium sulfate are 

used on-site in conjunction with sodium hypochlorite to produce the microbiocide, 

monochloramine within approved closed, feeder/delivery systems. Solution produced by the 

delivery system is immediately added to the process waters for which treatment is required. 

Page 3 of23 
Monochloramine is a slower-acting, less aggressive, oxidizing microbiocide than ammonia. The 

label requires trained personnel operate the system to maintain residual levels. Ammonia 

bromide is another inorganic nitrogen, ammonium salt compound that produces the oxidant and 

microbiocide, monochloramine, but it also produces hypobromous acid, another inorganic 

oxidant, so the Registration Review for ammonium bromide is addressed separately (Case 

Number 5002). 

Aqueous Ammonia was first registered in USA in 1971 for conventional uses. It was 

first registered as a microbiocide for use in pulp and paperboard process water systems in 2007. 

There are currently two active products, one of which is for formulation use only and the other is 

an end use product both have a declared total ammonia2 content of 7.59% which is equivalent to 

an ammonia sulfate content of 28% (Table 1). Conventional uses are no longer active. A 1.0-

1.5: 1 molar ratio of the end use product to sodium hypochlorite is mixed to produce 

monochloramine. The solution is applied at a rate to obtain at least 1 to 2 ppm in excess of 

system oxidant demand (maximum of 5 ppm) measured as total chlorine in the process water. 

When this product is used to treat sewage and wastewater systems, seawater, and freshwater 

influent systems for once-through industrial water systems, and seawater desalination and 

reverse osmosis systems, and the system water is not sent to a POTW, residual levels of 

chloramine in the effluent must be monitored and neutralized using on-line monitoring and 

control equipment. Detailed information on these registered products is provided in Table 1 and 

2. 

Ammonium sulfate was first registered in the United States in 1987 for wood 

preservative uses. In 2011 two end-use ammonium sulfate products, Nalco 60620 and Fennosurf 

586 were registered by Nalco Company and Kemira Chemicals, Inc., respectively for use in pulp 

and paper mill water systems to control bacteria, algae and fungi. There are currently two active 

end use products, the declared ammonium sulfate content of one is 20% and the other is 28%. 

Use as a wood preservative is no longer active. Detailed information on these registered 

products is provided in Table 1 and 2. The Nalco product is blended to achieve an approximate a 

molar ratio of 1.0-1.2 to 1.0 of Nalco 60620 to sodium hypochlorite (12.5%) to produce 

monochloramine on-site. The label requires the design, treatment, installation, calibration, and 

operation of the feeding system in all plants to be conducted only by authorized and trained 

personnel. The Fennosurf 586 (Kemira Chemicals, Inc.) product is blended to a minimum molar 

ratio of 1.5:1.0 product to sodium hypochlorite. 

A Reregistration Eligibility Decision (RED) was not issued by the Agency for 

ammonium sulfate because the initial registration date was after the November 1984, federal 

mandated cutoff for initiation of the RED process. An ecological risk screening assessment for 

cooling towers was conducted in 2008 (EPA 2008), and concluded that listed and nonlisted 

aquatic organisms may be at risk from exposure to monochloramine released from cooling 

towers, but additional data were needed to refine the assessment. Ecological risk for pulp and 

paper use was recently assessed by the Antimicrobials Division (EPA 2011). That assessment 

concluded minimal acute or chronic risks for listed and nonlisted species. Exposure was 

presumed to be minimal based on reactivity in the system and retention of discharge water in 

2 Sum of un-ionized and ionized ammonia content expressed as ionized ammonia. 

Page4 of23 
holding ponds where it is expected to react with organic matter prior to any release of the 

holding pond water into an aquatic environment. 

Table 1. Registered Products of Ammonia and Ammonium Sulfate 

EPA Product Company Active Ingredient Active Ingredient 

Registration Name Name Listed on Label - Expressed as Percent 

Number Percent A.l. A.l. Ammonium Sulfate 

9386-49 Fennosurf 586 Kemira Ammonia (total)1 - 7.59% Ammonium Sulfate- 28%2 

Chemicals, Inc. 

1706-240 Nalco 60620 Nalco Ammonium Sulfate- 20% Ammonium Sulfate- 20% Company 

Buckman 

1448-433 Busan 1215 Laboratories, Ammonia (total)1 -7.59% Ammonium Sulfate- 28%2 

Inc. 

Buckman 

1448-432 BCMW Laboratories, Ammonia (total)1 -7.59% Ammonium Sulfate- 28%2 

Inc. 

1 Total Ammonia (un-ionized ammonia (NH3) plus ammonium (NH/) content) as expressed as ionized ammonia 

(NH/). 

2 Conversion of total ammonia expressed as ionized ammonia content to ammonium sulfate equivalent content: 

(7.59 gas NH4 +) X (1 mole NH4 +) X (1 mole (NH4)zS04) X ( 132 g (NH4)zS04 ) = ZS% 

100 g of Solution 18 g NH4 + 2 mole NH4 + 1 mole (NH4)2S04 

Page 5 of23 
Table 2. Ammonia and Ammonium Sulfate Antimicrobial Use Summary 

Use Site (Treatment Site) Application Application Notes Method1 Rate 

Industrial Processes and Water Systems 

Industrial cooling towers, I 

recirculating cooling water I 

r 

systems, evaporative Nonauthorized, nontrained personnel 

condensers, influent water 

cannot operate system 

systems (freshwater and Residual levels of chloramine in the seawater), brewery and food Metering 0.5-5.0 ppm of effluent from treated sewage and pasteurizers, industrial fresh (Enclosed residual oxidant 

water systems, air washers, feeder/ demand in wastewater systems, seawater, and 

seawater desalination and delivery process or 

freshwater influent systems for oncereverse osmosis systems, paint system) water system2 through industrial water systems, and 

seawater desalination and reverse 

spray booth sumps, non-fish osmosis systems, where the system containing decorative 

water is not sent to a POTW, must be fountains and ponds used for monitored and neutralized. cooling purposes, sewage and 

wastewater systems 

Pulg and Pager Board Metering I 

Systems: Influent water (Enclosed 

systems (fresh and sea) and all feeder/ 

process water systems used for delivery 

the manufacturer of paper and system): 

paperboard products that Slug feed 0.5-10 ppm of 

contact food including method; residual oxidant Nonauthorized, nontrained personnel associated cooling water Intermittent demand in 

systems and wastewater feed method; process or 

cannot operate system 

treatment systems, pulp, paper Continuous water system2 

and paper board mill systems, feed method; 

nonpotable water systems, operated at pH 

starch slurries, and other >8.5 for 

process water that may contact OxiPro, ~12 

food for Fennosurf 

1 Product is applied in conjunction with sodium hypochlorite. 2 While the amount of ammonia and ammonia sulfate end use product and sodium hypochlorite solution to add to the 

feeder box is listed on the label, the amount actually applied per a given volume of process water is not specifically 

designated-operator adds sufficient dosage to maintain a designated residual (unreacted) monochloramine in the 

process water. 

A. Product Chemistry Summary 

Chemical identity and the physical and chemical properties of the ammonium sulfate 

technical grade (TGAI) are provided in Tables 3 and 4. The primary source of information for 

this assessment was Ammonium sulfate MSDS Science Lab and OECD SIDS October 2004. 

Page 6 of23 
T a e bl 3 . Ch em1ca ' I ld en t't l[Y 

Ammonium Sulfate TGAI (> 99 %) 

Chemical N arne Ammonium sulfate 

Common Name Ammonium sulfate 

Diammonium sulfate, 

Synonyms 

Diammonium sulphate, 

Mascagnite, 

Sulfuric acid, diammonium salt 

Classification Inorganic 

Sulfate 

PC Code 005601 

CAS No. 7783-20-2 

Molecular Formula NzHsS04 

(NH4)zS04 

Molecular Weight 132.14 g/mol 

0 o- f\JH+ 

~/ 4 

Molecular Structure: 

s 

~' NH+ o o- 4 

Ammonium sulfate 

Table 4. Product Chemistry Data Summary 

OPPTS Physical and Chemical Guideline Ammonium sulfate TGAI (> 99 %) 

No. Properties 

830.1550 Product identity and Refer to Table 3. composition 

830.1800 Enforcement analytical method Titration method 

830.6302 Color White crystals, granules or powder. White or brown 

orthorhombic crystals 

830.6303 Physical State crystals and lumps 

830.6304 Odor Odorless 

Stability to sunlight, normal and 

830.6313 elevated temperature, Stable. 

metals/metal ions 

Oxidation/Reduction: Chemical Contact with strong oxidizers may cause fire or 

830.6314 Incompatibility explosion. Incompatible with strong bases. Highly 

reactive with oxidizing agents. Reactive with alkalis. 

May be combustible at high temperature. Flammable in 

830.6315 Flammability-Flash point presence of oxidizing materials. Slightly flammable to 

flammable in presence of heat. Flash point: > 200 °F. 

830.6316 Explodability Explosive in presence of oxidizing materials 

830.6317 Storage Stability Stable under normal conditions of use and storage. 

830.6319 Miscibility Not applicable. The product is not an emulsifiable liquid. 

Com_IJletely miscible in water. 

Page 7 of23 
OPPTS Physical and Chemical Guideline Ammonium sulfate TGAI (> 99 %) 

No. Properties 

830.6320 Corrosion Characteristics Does not attack iron or aluminum I Ammoniacal 

solutions. Non-corrosive in presence of glass. 

830.6321 Dielectric breakdown voltage Not applicable. This product is an inorganic salt solution, 

not intended for use around electrical equipment. 

830.7000 pH 5.5 (0.1 M aqueous solution). 

5-6 (5% soln.) 

830.7050 UVNisible Abs~q>tion Does not adsorb in the UV-visible range. 

830.7100 Viscosity_ NA. 

830.7200 Melting point > 280 °C (decomposes) 

830.7220 Boiling point Solid. Decomposes before boiling. Decomposes upon 

heating above 250°C. 

830.7300 Density 1.77 g/mL at 25 oc 

830.7370 Dissociation Constant In aqueous media, ammonium sulfate dissociates in to 

ammonium and sulfate ions (NH/, SO/). 

830.7550 Partition coefficient (n- Not applicable. It is an inorganic salt. octanollwater) 

830.7840 Solubility in water 767 g/L at 25 °C 

830.xxxx Solubility in organic solvents Insoluble in acetone, ethanol, and ether 

830.7950 Vapor pressure 6.63E-022 mm Hg (EPI Suite version 4.0) - Non-volatile 

Henry's Law Constant 3.278E-027 atm-mj/mole (EPI Suite version 4.0). 

Physical and Chemical Properties of Monochloramines 

End use products of ammonia and ammonium sulfate are used in conjunction with 

sodium hypochlorite to produce monochloramine biocide in situ. Inorganic chloramines 

represent the stoichiometric reaction products resulting from the reaction of chlorine and 

ammonia in water; namely monochloramine, dichloramine, and trichloramine (Figure 1). 

Monochloramine (NH2Cl), dichloramine (NHCh) and trichloramine (NCb) are produced by 

either adding chlorine to a solution containing ammonia, by adding ammonia to a solution 

containing free residual chlorine or by adding premixed solutions of ammonia and chlorine to 

water. However, the production of monochloramine versus dichloramine and trichloramine is 

highly dependent upon pH, the ratio of chlorine to ammonia-nitrogen and, to a lesser extent, 

temperature and contact time. According to available literature, a pH between approximately 7.5 

and 9.0 is optimum for the formation of monochloramine; the ideal pH is 8.3. 

Monochloramine 

,,,N....._ 

H''''' I "'CI 

Cl 

Dichloramine 

_,..N,, 

cr' \ ·····c1 

Cl 

Trichloramine 

Figure 1. Chemical Structures of Inorganic Chloramines 

Page 8 of23 
When ammonium from ammonia and ammonium salt in the end use products reacts in 

1.0-1.5:1.0 molar ratio of product to a 12.5% aqueous solution of sodium hypochlorite, 

monochloramine is formed. Monochloramine is the preferred and expected form of chloramine 

in the industrial process system use for microbiocidal purposes. Summary of chemical and 

physical properties of monochloramine is presented in Table 5 (Source: Toxnet and EPI Suite 

v.4.0). 

Table 5. Summary of Chemical and Physical Properties of Inorganic Monochloramine 

Chemical VALUES Parameter 

CAS# 10599-90-3 

Molecular Formula NH2Cl 

Molecular Weight 51.48 

Solid form: Colorless crystals 

Color/Physical State Liquid form: Yell ow liquid 

Aqueous form: Colorless liquid 

Odor No data available 

Melting Point -66°C 

It may decompose violently above -66 °C 

Boiling Point No data available 

Water Solubility Soluble 

Other solubilities ETOH, ether, 

CC14, benzene < 

pH ----

Density -----

Partition coefficients -1.19 

Vapor pressure 1.16E-009 mm Hg at 25 °C (source: EPI Suite version 4.0) 

Henry's Law 7.857E-017 atm-m3/mole (source: EPI Suite version 4.0) constant 

Monochloramine is oxidized by ozone faster than ammonia 

Other 

Chemical/Physical Ultraviolet light depletes only free chlorine, whereas chloramines seem to be quite 

Properties stable in sunlight. Chloramine decay has been suggested to be at most 0.2 mg/liter 

per sunlight hour between 10 a.m. and 2 p.m. (latitude 30--40°N). 

B. Environmental Fate Summary 

Ammonia, as aqueous ammonia, and ammonium sulfate are registered for use as: a 

bactericide, bacteriostat, and microbicide. The Agency is presenting this scoping document on 

ammonia in solution, ammonium sulfate and monochloramine. Some chemical reactions are 

included to explain the chemistry of the products, and ammonium ion derived chemicals like 

monochloramine. 

Page 9 of23 
The central atom in ammonium ions and monochloramine is nitrogen. Nitrogen is a 

versatile element which forms compounds in various oxidation states from -3 to+ 5. In order to 

understand the fate chemistry of ammonium ions and monochloramine, it is important to know 

the basic chemistry of ammonia. The basic stoichoimetric reactions of ammonia in water and 

ammonia or ammonium sulfate with sodium hypochlorite in the closed system feeder/delivery 

system in industrial process water systems are described below. 

Basic Chemical Reactions of Ammonia and Ammonium Ions 

Ammonia (NH3) is a gas at room temperature, and is manufactured on a large scale as a 

liquid (liquid ammonia) at high pressure and reduced temperature. It is highly soluble in water 

but it actually reacts with water to form ammonium hydroxide: 

H2 0 ~ NH40H Equation 1 

Ammonia Water Ammonium hydroxide 

which in tum dissociates into: 

Ammonium hydroxide Ammonium cation Hydroxide anion Equation 2 

Reaction 2 is driven toward ammonium hydroxide and not toward ammonium ion and 

hydroxide ions. But as ammonium ions get removed in other chemical reactions, more 

ammonium hydroxide dissociates and so on. Aqueous solutions in reaction systems 1 and 2 are 

basic solutions. Ammonium ion is the only composite 'cation ion' (positively charged); all other 

cation ions are basically metal ions. Combining Equation 1 and Equation 2 and adjusting the 

water and hydroxide ion to allow expression in terms of the hydronium ion (log of the inverse 

concentration is solution pH) provides a way to determine the ratio between the un-ionized 

ammonia and ionized ammonia when the pH of a solution is known. Knowing the portion of unionized ammonia to ionized ammonia is important for both understanding which way reactions 

with ammonia are likely to occur and aquatic toxicity. 

Ammonia Hydronium ion Ammonium ion Water 

Equation 3 

EPA's Draft 2009 Ambient Water Quality Criteria document (EPA 2009) states the 

following: 

"The chemical form of ammonia in water consists of two species, the more abundant of 

which is the ammonium ion (N~ +) and the less abundant of which is the non-dissociated 

or un-ionized ammonia (NH3) molecule; the ratio of these species in a given aqueous 

solution is dependent upon both pH and temperature. In general, the ratio of un-ionized 

ammonia to ammonium ion in fresh water increases by 10-fold for each rise of a single 

pH unit, and by approximately 2-fold for each 10 °C rise in temperature from 0-30° C. 

Page 10 of23 
Table 6 below provides an example of the percent of un-ionized and ionized ammonia 

content at 20 °C. For aquatic organisms, the un-ionized ammonia content has been found to be 

most predictive of ammonia toxicity. 

T a e bl 6 P . ercen t o f ammomum Ions as f unc t' Ion o pJ a 

%of Total Ammonia as: pH Un-ionized Ammonia (NH3) Ionized Ammonia (N~ +) 

6.5 0.125 99.875 

7.0 0.395 99.605 

7.5 1.239 98.761 

7.7 1.95 98.05 

8.0 3.81 96.190 

8.5 11.15 88.85 .. Source: www.theaguanumwtki.com/Ammoma; AD amended table by addmg 10mzed ammoma content 

Note: There is a ten-fold increase in un-ionized ammonia content for a single rise in pH unit (e.g., at pH 6.5 unionized ammonia content is 0.125 and at pH 7.5 it is 1.239 which is approximately 10 times higher). 

Like other cations, ammonium ion is a reactive species, and reacts with many anions like 

chloride, bromide, sulfate, nitrate etc. to form salts. Hence all ammonium salts are 'ionic' in 

nature, that is, they will dissociate into cations and anions. The dissociation equation of concern 

for ammonium sulfate is provided in Equation 4. For registered ammonia and ammonium sulfate 

uses the primary reactions of concern are Equations 1, 2, 3, and 4. 

+ Equation 4 

Ammonium ion Sulfate anion Ammonium sulfate 

Most of the compounds ammonium ion form are ionic in nature; however some 

substitution reactions on ammonium do result in covalent compounds like monochloramine, 

dichloramine etc. 

Stoichiometric Reactions of Ammonium from Ammonia and Ammonium Sulfate Use 

In the presence of hypochlorite (ClO-) released from aqueous solutions of hypochlorous 

acid, the ammonium ion released from ammonia or ammonium sulfate (Equations 3 and 4) 

undergoes the following reaction: 

Ammonium cation Hypochlorite anion Monochloramine Water 

Equation 5 

If this reaction is not controlled, the formation of dichloramine, and trichloramine occurs. 

NH2Cl + HOCl ----+ NHCI2 + H2 0 Equation 6 

Monochloramine Hypochlorous acid Dichloramine Water 

Page 11 of23 
Dichloramine Hypochlorous acid Trichloramine Water 

Equation 7 

The controlled conditions of the system used for the registered uses (pH> 8, constant 

temperature, and molar ratios of ammonium ions and hypochlorite) will not likely produce 

dichloramine or trichloramine. 

Environmental Fate and Transport of Ammonium Sulfate Reaction Products 

In the feeder/delivery system under controlled conditions, monochloramine will be the 

primary reaction product. Thus the environmental fate of these moieties are central to this case. 

The conventional environmental fate test guidelines are not applicable for monochloramine 

because it is an inorganic substance. Monochloramine will oxidize and form intermediates. 

Unlike reactions with organics, typically inorganic reactions are much faster, and therefore not 

easy to keep tract of the intermediates. The intermediates cannot be classified as degradates in 

the classical sense. 

Ammonium sulfate is an inorganic substance, highly water soluble and has no 

measureable vapor pressure; because of its ionic nature, octanol/water coefficient cannot be 

measured. It is not likely to bioaccumulate in aquatic organisms. In literature some studies 

report bioaccumulation of ammonia in fish. In clay particles of soils, ammonium ions are 

adsorbed to the negative adsorption sites. A pH profile of ammonium (or ammonia) percentages 

at various pHs are known and are shown in Table 6. 

Ammonium ions are present naturally in various environmental media like water and 

soils. There is 1-5 ppb of ammonia present in the air and the estimated half-life is a few days. 

Because the central atom is nitrogen, ammonium ions are part of the nitrogen cycle (nitrogen 

fixation) and so it does not stay as ammonia, or ammonium, but goes through many oxidation 

and reduction steps forming different oxidized and reduced moieties along the way and recycled 

into the environment. Under aerobic aquatic conditions, ammonium ions are converted through 

nitrification process. No additional environmental fate data are required for ammonia or 

ammonium sulfate. 

Sulfate ions, in this case act as 'spectator ions': do not participate in chemical reactions. 

It is a powerful reducing agent, but needs strong reducing conditions to initiate chemical 

reactions. It is found in environmental media like soils and natural waters. Sulfate ions are likely 

to mineralize in soils over a period of time. 

Monochloroamine: Environmental Fate and Transport 

For monochloramine the Agency must take into account the physicochemical properties 

(Table 4), and environmental fate parameters. The environmental fate parameters of 

monochloramine, sourced primarily from EPI Suite (version 4.0, run September 4, 2012), a 

screening level environmental fate assessment, are summarized as follows: 

Page 12 of 23 
• Monochloramine is highly soluble in water and its vapor pressure and Henry's 

Law Constant are both low (1.16 x10-9 mm Hg, and 8.85 xl0-17 atm-m3/mole 

respectively). Therefore, it is not expected to volatilize from water surfaces 

quickly. 

• Low Kow (-1.19, estimated) therefore it is not expected to bioaccumulate. 

• Its Koc (13.2, estimated) indicates that it is mobile in soils and sediments. 

• Its half-life in aqueous media varies from a fraction of a day to about 40 days. 

(based on Health Canada study, 1998), depending upon temperature, pH, and 

salinity. This study and other Canadian studies for aqueous medium decay of 

chloramines show that in deionized water and seawater mixtures the half life 

varied from 0.68 days to 0.98 days. 

• Another Canadian study on the sediment of Grand River, in North Saskatchewan 

River and Downes Creek showed the half life of 1.4, 2.5 and 0.05 days. No 

concrete studies are known that provides data on the dissipation rate of 

chloramines from soil surfaces. 

• Monochloramine has been in use as a secondary disinfectant in the U.S. and 

internationally for over fifty years. Compared to hypochlorite ion, it degrades 

slowly and, hence, its disinfecting power in aqueous media is higher than 

hypochlorite. 

• All EPI Suite BioWIN (version 4.0) models estimate that monochloramine is 

quickly biodegraded and it can be classified as readily biodegradable. EPI Suite 

estimates the biodegradability to be 'very fast', which translates into minutes to 

days. See below for the experimental results from a hydrolysis study. 

• PMRA in its most recent Proposed Registration Decision (March 2012)3 on 

Ammonium bromide (Fuzzicide) has shown that monochloramine (referred to as 

bromide activated chloramine(BAC)) hydrolyses in water quickly and at pH 5, its 

half life is 15.9 minutes, while at pH 9, the half life was measured at 184 hours 

(12 days). 

• Pulp and paper use of ammonia and ammonium sulfate (and monochloramine) as 

the active is used in a closed system. Keeping in view the physical/chemical 

characteristics of monochloramine (short hydrolytic half life, readily 

biodegradable etc.), the high organic content of waste water, and holding time of 

wastes prior to any discharge to surface water, no detectable levels of residual 

monochloramine are expected in effluent prior to discharge to surface waters. 

• For once through industrial water systems there may be circumstances where 

residual monochloramine has not been reacted prior to discharge depending on 

the pH of the system and receiving waters, and organic content of water system. 

Field dissipation or monitoring data would provide a more refined exposure 

assessment for these uses. 

3 Pmra.publications @hc-sc.gc.ca 

Page 13 of23 
Dechlorination of Monochloramine 

For the product registered for use in once-through industrial water systems other than 

pulp and papermills before discharge to the wastewater streams residual monochloramine is 

measured and, if detected, treated with sodium metabisulfite (Na2S20 5), which immediately 

dissociates into sulfite ions (S03 -

2) which in tum reacts with monochloramine (NH2Cl) as 

follows 

so3 -z + 

Sulfite ion M onochloramine Water 

Equation 8 

Sulfate ion Chloride ion Ammonium ion 

cr + 

The amounts of these species produced are not huge, and the reaction of reformation of 

chloramine is not likely. In addition, the amount of sulfate formed under these conditions is not 

large enough to cause dissolved oxygen depletion of the waste water streams. 

Chloramine and Drinking Water 

Since monochloramine is used as a secondary disinfectant in wastewater treatments, it is 

likely to be found in surface and drinking water as a contaminant. Regardless of source, EPA has 

set a maximum drinking water limit for all contaminants. For chloramines the maximum 

contaminant limit goal (MCLG) is 4.0 ppm for chloramines in surface waters and 4.00 ppm 

maximum residual disinfectant level (MRDL). The water utilities are required to keep the 

chloramines at 4.0 ppm level. Excessive amount of chloramines, if present in water, can be easily 

boiled off. 

Water Quality 

Ammonium Sulfate is not identified as a cause of impairment for any water bodies listed 

as impaired under section 303(d) of the Clean Water Act, based on information provided at the 

Agency's National Pesticides Cause of Impairment of Waters website (searched September 6, 

2012)4. In addition, no Total Maximum Daily Loads (TMDL) have been developed ammonium 

sulfate, based on information rrovided at the Agency's National Pesticide TMDL web site 

(searched September 6, 2012) . However, ammonia was identified as a cause of impairment for 

584 water bodies (unionized (167), total ammonia (158), ammonia (66), and ammonia nitrogen 

(3)) under section 303(d) of the Clean Water Act. No Total Maximum Daily Loads (TMDL) 

have been developed for ammonia, based on information provided at the Agency's National 

Pesticide TMDL web site (searched September 6, 2012)6. 

More information on impaired water bodies and TMDLs can be found at 

http://www.epa.gov/owow/tmdll. The Agency invites submission of water quality data for this 

4 • http://iaspub.epa.gov/tmdl waters 10/attains nation cy.cause detail 303d?p cause group id=885 

5 

http://iaspub.epa.gov/tmdl waterslO/attains nation.tmdl pollutant detail?p pollutant group id=885&p pollutant 

roup name=PESTICIDES 

http://iaspub.epa.gov/tmdl waterslO/attains nation.tmdl pollutant detail?p pollutant group id=885&p pollutant 

group name=PESTICIDES 

Page 14 of23 
pesticide. To the extent possible, data should conform to the quality standards in Appendix A of 

the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water 

Quality Data in OPP's Registration Review Risk Assessment and Management Process (see: 

http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf ), in order to ensure 

they can be used quantitatively or qualitatively in pesticide risk assessments. 

C. Ecological Effects Summary 

The major oxidant, monochloramine, formed in the registered application method of 

ammonia and ammonium sulfate would be measured as chlorine residual. The Ambient Water 

Quality Criteria for Chlorine - 1984 document contains a review of public literature on effects 

of chlorine and based on the data derives freshwater and saltwater organism acute and chronic 

water quality criteria as total chlorine residual (TRC) for freshwater and total residual oxidant 

(TRO) for seawater. Current ambient water quality criteria for chlorine or total chlorine residual 

are based on the data in the 1984 document and the method for deriving water quality standards 

discussed in a 1986 Water Quality Document (USEPA, 1986). 

• Freshwater Criterion Maximum Concentration= 19 Jlg/L; 

• Freshwater Criterion Continuous Concentration= 11 J.tg/L; 

• Saltwater Criterion Maximum Concentration= 13 Jlg/L; and 

• Saltwater Criterion Continuous Concentration= 7.5 Jlg/L 

A review of toxicity effects data for ammonia, ammonium sulfate, and monochloramine 

is summarized in the following sections. 

a. Toxicity to Terrestrial Organisms 

Two studies conducted using formulated products are available to indicate the toxicity of 

ammonium sulfate to birds. Both products are practically nontoxic to birds on an acute oral basis 

(Table 7). Data are not available for the TGAI (the required test material for this guideline), but 

the tests with the two formulated products indicate that the TGAI would be only moderately 

toxic at most. No additional data are needed for the current uses. Mammalian toxicity data are 

not required, and data generated for the human health assessment are available in the human 

health scoping document. 

Page 15 of23 
Table 7. Summary of the Endpoints from Submitted Terrestrial Ecotoxicity Studies for 

Ammonium Sulfate 

Study Type Species Test material Toxicity Toxicity MRID& 

Classification Status 

464405-01 

Busan 1215 LD50: >2250 TGAI is not Acceptable 

(7.59% total mglk:g-bw/day more than for 

Acute- Northern ammonia*) [> 171 mg ailkg bw] moderately toxic formulated 

Bobwhite product Avian Oral (Colinus 483408-09 850.2100 virginianus) Nalco 60620 LDso: >2003 TGAI is not Acceptable 

(19.5% ai) mglk:g-bw/day more than for 

[>390 mg ai!kg bw] moderately toxic formulated 

product 

*7.59% total ammoma ts declared as acttve mgredtent on the label under the Active Ingredtent statement, and the 

term "Total Ammonia" refers to the sum of un-ionized ammonia and ionized ammonia (NH3(aq) +~"")expressed 

as the equivalent ionized ammonia content. 

b. Toxicity to Aquatic Animals 

There are National Ambient Water Quality Criteria (AWQC) for Ammonia (EPA 1989, 

1999, 2009). Ammonium sulfate is one of several ammonium salts (ammonium chloride; 

phosphoric acid, diammonium salt; ammonium bicarbonate; nitric acid ammonium salt; 

ammonium phosphate) in addition to testing with ammonia used to develop the water quality 

criteria. From these data, depending on the environmental pH and temperature conditions, 

ammonia toxicity can range from slightly toxic to highly toxic to aquatic organisms. 

The toxicity of ammonia is dependent on pH, and temperature; toxicity is also dependent 

on ionic strength but in fresh water this is minor compared to pH and temperature. Therefore 

water quality criteria values for ammonia are written in terms of pH and temperature for 

freshwater systems. The current freshwater A WQC for ammonia are expressed in terms of total 

ammonia nitrogen (TAN), concentration of NH3 plus N~ + expressed as nitrogen (N) 

concentration (note this differs from how the labels express total ammonia). The saltwater 

A WQC are expressed as total ammonia (TA), concentration of NH3 plus N~ expressed as total 

NH3 concentration. The following freshwater A WQC provided are the current criteria from the 

EPA 1999 A WQC document. When this risk assessment is performed, any updated ammonia 

criteria will be used in the assessment. 

Freshwater 

• Acute Criterion (Criterion Maximum Concentration (CMC) as mg TANIL): 

Wh 1 CMC 0.275 39.0 

o ere sa mon are present = 1+107.204-pH + 1+1 opH-7.2o4 

o Where salmon are absent CMC = 0"

411 + 58"

4 

1+107.204-pH 1+10PH-7.204 

Page 16 of23 
• Chronic Criterion (Criterion Continuous Concentration (CCC)) as mg TANIL: 

o Where fish early life stages are present 

_ 0.057 2.487 ( 0.028X(25-T)) CCC - 1 + 107.688-pH + 1 + 10PH-7.688 X MIN 2.85, 1.45 X 10 

o Where fish early life stages are absent 

CCC = 0.057 + 2.487 X 1.45 X 100.028x(25-MAX(T,7)) 

1 + 107.688-pH 1 + 10PH-7.688 

where temperature, T, is in degrees Celsius. 

Table 8. Examples of acute and chronic ammonia A WQC for freshwater, expressed as 

total ammonia nitrogen 

CMC,m2NIL1 CCC,m2NIL1 

pH Salmonids Salmonids Fish early life stages present Fish early life stages 

absent Present Absent 14 °C 22°C 30°C lS°C >lS°C 

6.5 32.6 48.8 6.67 4.12 2.46 6.46 

Same as fish 7.0 24.1 36.1 5.91 3.65 2.18 6.11 

7.5 13.3 19.9 4.36 2.69 1.61 4.51 early life 

8.0 5.62 8.40 2.43 1.50 0.897 2.52 stage 

8.5 2.14 3.20 1.09 0.672 0.401 1.13 present 

I• - + Total ammoma mtrogen -concentratiOn of NH3 plus concentration of N~ expressed as mtrogen (N). 

Saltwater 

The acute CCC and the chronic CMC for un-ionized ammonia (NH3) is 0.233 mg/L and 

0.035 mg/L, respectively. These criterion concentrations based on total ammonia are provided in 

Tables 1 and 2 of EPA's saltwater AWQC for ammonia document (1989); excerpts from these 

tables are provided for the acute CMC in Table 9 and the chronic CCC in Table 10. 

Table 9. Excerpt from EPA 1989 of acute CMC saltwater A WQC for ammonia expressed 

as total ammonia1 

Salinity 

pH 10Wk2 20Wk2 30Wk2 

Temperature Temperature Temperature 

S°C lS°C 2S°C S°C lS°C 2S°C S°C lS°C 2S°C 

7.0 191 92 44 200 96 44 208 102 48 

7.6 48 23 11 50 23 11 54 25 12 

8.0 19 9.4 4.6 20 9.8 4.8 21 10 5.0 

8.4 7.9 3.7 1.3 8.1 4.0 2.0 8.7 4.2 2.1 

9.0 2,1 1.1 0.67 2.3 1.2 0.69 2.3 1.2 0.71 I• - + Total ammoma mtrogen- concentration ofNH3 plus concentration ofN~ expressed as un-tomzed ammoma 

(NH3). 

Page 17 of23 
Table 10. Excerpt from EPA 1989 of chronic CCC saltwater A WQC for ammonia 

expressed as total ammonia1 

Salinity 

pH 10 g/kg 20 g/kg 30 g/kg 

Tem_l)_erature Temperature Temperature 

S°C lS°C 2S°C S°C lS°C 2S°C 5°C lS°C 2S°C 

7.0 29 14 6.6 30 14 6.6 31 15 7.2 

7.6 7.2 3.4 1.7 7.5 3.4 1.7 8.1 3.7 1.8 

8.0 2.9 1.40 0.69 3.0 1.5 0.72 3.1 1.6 0.75 

8.4 1.2 0.56 0.29 1.2 0.59 0.30 1.3 0.62 0.31 

9.0 0.31 0.17 0.10 0.34 0.18 0.10 0.34 0.19 0.08 + Total ammoma mtrogen = concentratiOn of NH3 plus concentration of N~ expressed as un-10mzed ammoma 

(NHJ). 

Table 11 provides a summary of ammonium sulfate specific data submitted by registrants 

and literature values reported in the 2009 draft freshwater A WQC for ammonia and the 1989 

saltwater AWQC for ammonia. However, this is a relatively small data set as compared to the 

more expansive and bridgeable ammonia toxicity data set used for setting ammonia criteria. 

Ammonium sulfate is one of several ammonium salts (ammonium chloride; phosphoric acid, 

diammonium salt; ammonium bicarbonate; nitric acid ammonium salt; ammonium phosphate) in 

addition to ammonia used to develop ammonia criteria. No additional ammonium sulfate or 

ammonia data are required for registration review. 

However, the Agency expects that under use application methods, exposure of aquatic 

organisms will not be to ammonia but rather to the monochloramine generated from combining 

the end-use products with sodium hypochlorite as specified on the product labels. Other data are 

available to categorize the toxicity of chloramines to aquatic animals. These data, generated for 

ammonium bromide mixed with sodium hypochlorite, categorize chloramines as being acutely 

highly to very highly toxic to freshwater and estuarine/marine animals (Table 12). To support 

the treatment of once-through industrial water system uses, acute toxicity data for 

monochloramine are needed for estuarine/marine fish and invertebrates and chronic data are 

needed for both freshwater and estuarine marine organisms. 

Table 11. Summary of the Endpoints from Fish and Aquatic Invertebrate Ecotoxicity 

Studies for Ammonium Sulfate. 

Study Type Species Test Exposure method, Toxicity1 Toxicity MRID& 

material pH, Temperature Classification Status 

Busan 1215 

(7.59% 96-hrLC50: >126 mg Practically 464351-06 

total a ilL nontoxic Acceptable 

Acute- Rainbow trout 

ammonia2) 

Nalco Freshwater (Oncorhynchus 60620 96-hr LC50: >140 mg Practically 483512-01 

Fish mykiss) (19.5% ai) a ilL nontoxic Acceptable 

Ammonium 96-hr LC5o: 51.06 mg Qureshi et al. 

sulfate S, 7.95, 15 °C NIL Slightly toxic 1982 cited in 

(46.46 mg NIL at pH=8) EPA2009 

Page 18 of23 
Test Exposure method, Toxicity MRID& Toxicity1 

Classification Status Study Type Species material pH, Temperature 

Thurston and 96-hr LC50: 36.73 mg 

Slightly toxic Ammonium Russo 1983 F, 7.9, 12.4 °C NIL sulfate cited in EPA (29.91 mg NIL at pH=8) 2009 

Thurston and 96-hr LC50: 39.25 mg 

Slightly toxic Ammonium Russo 1983 F, 7.94, 12.5 °C NIL sulfate cited in EPA (35.06 mg NIL at pH=8) 2009 

Busan 1215 

96-hr LC50: > 117 mg Practically 464351-05 Bluegill (7.59% 

total a ilL nontoxic Acceptable sunfish ammonii) (Lepomis Nalco 96-hr LCso: 62 Slightly toxic macrochirus) 483408-07 60620 

mg ai/L Acceptable (19.5% ai) 

Pink salmon Rice and 96-hr LC50: 230.5 mg 

Slightly toxic (Oncorhynchus Ammonium Bailey 1980 S, 6.4, 4.3 °C NIL gorbuscha), sulfate cited in EPA (38.33 mg NIL at pH=8) late alevins 2009 

Pink salmon 96-hr LC50: 277.7 mg 

Slightly toxic (Oncorhynchus Ammonium S, 6.4, 4.3 oc NIL gorbuscha), sulfate (46.18 mg NIL at pH=8) late alevins 

Atlantic Knoph 1992 Ammonium 16 Tests 20.45 to 69.49 mg NIL salmon (Salmo Slightly toxic cited in EPA sulfate S, 6.0 to 6.45, 1.8 atpH=8 salar) to 17.1 °C 2009 

Pacific tree Schuytema 96-hr LC50: 103.1 mg and Nebeker frog Ammonium R, 6.7, 22 °C NIL Slightly toxic 1999a cited (Pseudacris sulfate (19.45 mg NIL at pH=8) in EPA 2009 regilla), 

Embryo 

Pacific tree 

frog Schuytema 96-hr LC5o: 116.4 mg 

Slightly toxic (Pseudacris Ammonium and Nebeker R, 7.3, 22 °C NIL regilla), sulfate 1999a cited (37.3 mg NIL at pH=8) Gosner stage in EPA 2009 

26-27 

Schuytema Acute- Clawed toad 96-hr LC50: 33.2 mg Moderately and Nebeker Amphibian (Xenopus Ammonium R, 7.2, 22 °C NIL laevis), sulfate toxic 1999a cited (9.524 mg NIL at pH=8) embrvo in EPA 2009 

Clawed toad Schuytema 96-hr LC50: 60.71 mg 

Slightly toxic (Xenopus Ammonium and Nebeker R, 7.2, 24 oc NIL laevis), sulfate 1999 cited in ( 17.27 mg NIL at pH=8) embryo EPA2009 

Clawed toad Schuytema 96-hr LC50: 135.9 mg 

Slightly toxic (Xenopus Ammonium and Nebeker R, 7.15, 22 °C NIL laevis), Gosner sulfate 1999b cited (36.59 mg NIL at pH=8) stage 26-27 inEPA2009 

Acute- Water flea Busan 1215 

Freshwater 48-hrEC50: >120 mg Practically 464351-07 (Daphnia (7.59% 

Invertebrate total a ilL nontoxic Acceptable 

850.1010 magna) ammonia2) 

Page 19 of23 
Study Type Species Test Exposure method, Toxicity' Toxicity MRID& 

material pH, Temperature Classification Status 

Nalco 48-hr EC50: >789 mg Practically 483408-06 60620 

(19.5% ai) a ilL nontoxic Acceptable 

Acute- Water flea 48-hr EC50: 48.5 mg Manning et Freshwater Ammonium NIL 

Invertebrate ( Ceriodaphnia sulfate R, 7.4, 23 °C (15.06 mg NIL at pH =8 Slightly toxic al. 1996 cited 

dubia) and 25 °C) in EPA 2009 

Acute- Red drum S, 8.0-8.2, 25-26 Holt and 

Estuarine/ (Sciaenops Ammonium °C, 28-30 parts 96-hr LC50: 0.545 mg Highly toxic Arnold 1981 

Marine ocellatus), sulfate per thousand NH31L cited in EPA 

Fish embryo-larva salinity 1989 

Exposure method: S = static, R = static renewal, F = flow-through 

1 Acute values in the freshwater, ammonia ambient water quality criteria document are expressed as total ammonia 

nitrogen (mg NIL) and because ammonia toxicity is related to pH and temperature are normalized to pH 8 and 

temperature 25°C as per equations provided in the 1999 criterion document for comparison. 2 7.59% total ammonia is declared as active ingredient on the label under the Active Ingredient statement, and the 

term "Total Ammonia" refers to the sum of un-ionized ammonia and ionized ammonia (NH3(aq) +~+)expressed 

as ionized ~ +. 

Table 12. Summary of Endpoints from Submitted Fish and Aquatic Invertebrate Ecotoxicity 

Studies for Ammonia Bromide mixed with Hypochlorite to Form Monochloroamine. 

Study Type Species Test material Toxicity Value Toxicity MRID& 

Classification Status 

Rainbow trout Ammonium 

Very highly 447213-13 (Oncorhynchus bromide 96-hr LC50: 58 ~g Clz/L 

Acute- my kiss) (99.9% ai) toxic Acceptable 

Freshwater Fish Bluegill in 10% 

850.1075 sunfish hypochlorite 96-hr LCso: 290 ~g Clz/L Highly toxic 447213-12 

(Lepomis solution with Acceptable 

macrochirus) carbonate 

Acute- Sheepshead buffer 

Estuarine/marin minnow 96-hr LC50: 360 ~g Clz/L Highly toxic 447213-16 

eFish ( Cyprinodon Acceptable 

850.1075 variegatus) 

AcuteFreshwater Water flea 48-hr EC50: 23 ~g Clz/L Very highly 447213-14 

Invertebrate toxic Acceptable 

850.1010 

AcuteEstuarine/ Mysid Very highly 447213-15 marine (Mysidopsis 96-h LC50: 36 ~g Clz/L 

Invertebrate bahia) toxic Acceptable 

850.1035 

Acute- Eastern oyster Estuarine/marin Very highly 447213-17 

e Invertebrate ( Crassostrea 96-h ECso: 18 ~g Ch/L toxic Acceptable 

850.1025 virginica) 

Page 20 of23 
c. Toxicity to Aquatic Plants 

No aquatic plant toxicity data have been submitted for ammonia or ammonium sulfate. 

However, there is ammonia toxicity data with aquatic plants that has been reviewed for A WQC 

development (EPA 1989, 1999, 2009). While nitrogen is an important nutrient for plants, excess 

ammonia can be toxic to both freshwater and saltwater plants. No additional data is required for 

ammonia for this registration review assessment. 

Two studies are available to assess the effects of chloramines on duckweed and green 

algae. These studies indicate that chloramines adversely affect aquatic plants at low 

concentrations (Table 13). These data can be used to support ammonium sulfate as well. Data 

for monochloramine is also needed for a marine diatom, freshwater diatom, and blue-green algae 

to support the once-through industrial water system uses. 

Table 13. Summary of the Endpoints from Submitted Aquatic Plant Ecotoxicity Studies 

from Monochloramine. 

Study Type Species Test material Toxicity Value Toxicity MRID& 

Classification Status 

Aquatic 

Plants- Duckweed Ammonium 7-day EC50: 670 11g n/a 452052-02 

Vascular (Lemna gibba) bromide Ch!L Acceptable 

850.4400 (99.9% ai) 

Aquatic Green algae in 3% hypochlorite 

Plants- solution with 72-h ECso: 28 Jlg 452052-01 

Nonvascular (Pseudokirchneriella carbonate buffer Ch/L n/a Acceptable 

850.5400 subcapitata) 

Environmental Fate and Ecological Effects Data Gaps and Anticipated Work 

The Agency anticipates performing a refined risk assessment on the once-through 

industrial water system uses of ammonia and ammonium sulfate. To perform this assessment a 

field dissipation study is needed and additional monochloramine effects data with aquatic 

organisms are needed. No further risk assessment for the pulp and paper use of ammonia and 

ammonium sulfate is anticipated at this time. 

Environmental Fate Data Gaps 

There are no environmental fate data gaps for ammonia, ammonium sulfate or reaction 

product, monochloramine for the pulp and paper use scenario. However, to allow a refined risk 

assessment for use with once-through industrial water systems the following fate data is required 

to address the fate of monochloramine: 

835.6200: Aquatic Field Dissipation Study. 

Page 21 of 23 
Ecological Effects Data Gaps 

The following ecotoxicity guideline studies are needed with monochloramine to support 

the once-through industrial water system uses of ammonia and ammonium sulfate: 

850.1400 

850.1300 

850.1350 

850.4100 

850.4500 

850.4550 

Fish early-life stage: 1 freshwater species and 1 estuarine/marine 

species 

Aquatic invertebrate life-cycle: 1 freshwater species and 1 

estuarine/marine species 

Seedling emergence, Tier II - dose response, rice 

Aquatic plant growth (algal) Tier II (dose response): marine 

diatom, freshwater diatom, cyanobacteria (blue-green algae) 

Endangered Species Determination 

The Agency has determined that the use of ammonia and ammonia sulfate in oncethrough cooling towers has a potential to expose aquatic organisms to monochloramine. Because 

monochloramine is highly toxic, listed freshwater and estuarine/marine organisms may be at risk. 

An ecological risk assessment planned during registration review will allow the Agency to 

determine whether an antimicrobial pesticide's use has "no effect" or "may affect" federally 

listed threatened or endangered species (listed species) or their designated critical habitats. 

When an assessment concludes that a pesticide's use "may affect" a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service 

and/or National Marine Fisheries Service (the Services), as appropriate. 

REFERENCES 

Holt, G.J. and C.R. Arnold. 1983. Effects of ammonia and nitrite on growth and survival of red 

drum eggs and larvae. Trans. Am. Fish. Soc. 112:314-318. 

Knoph, M.B. 1992. Acute toxicity of ammonia to Atlantic salmon (Salmo salar) parr. Camp. 

Biochem. Physiol. Camp. Pharmacal. Toxicol. 10(2): 275-282. 

Manning, T.M., S.P. Wilson and J.C. Chapman. 1996. Toxicity of chlorine and other chlorinated 

compounds to some Australian aquatic organisms. Bull. Environ. Contam. Toxicol. 

56(6): 971-976. 

Qureshi, A.A., K.W. Flood, S.R. Thompson, S.M. Janhurst, C.S. Inniss and D.A. Rokosh. 1982. 

Comparison of a luminescent bacterial test with other bioassays for determining toxicity 

of pure compounds and complex effluents. In: Aquatic toxicology and hazard assessment, 

5th conference. Pearson, J.G., R.B. Foster and W.E. Bishop (Eds.). ASTM STP 766. 

American Society for Testing and Materials, Philadelphia, PA. pp. 179-195. 

Page 22 of23 
Rice, S.D. and J.E. Bailey. 1980. Survival, size and emergence of pink salmon, Oncorhynchus 

gorbuscha, alevins after short and long-term exposures to ammonia. Fish. Bull. 78(3): 

641-648. 

Schuytema, G.S. and A.V. Nebeker. 1999a. Comparative effects of ammonium and nitrate 

compounds on Pacific treefrog and African clawed frog embryos. Arch. Envion. Contam. 

Toxicol. 36: 200-206. 

Schuytema, G.S. and A.V. Nebeker. 1999b. Comparative toxicity of ammonium and nitrate 

compounds to Pacific treefrog and African clawed frog tadpoles. Environ. Toxicol. 

Chern. 18(10): 2251-2257. 

Thurston, R.V. and R.C. Russo. 1983. Acute toxicity of ammonia to rainbow trout. Trans. Am. 

Fish. Soc. 112: 696-704. 

United States Environmental Protection Agency (EPA). 1989. Ambient Water Quality Criteria 

for Ammonia (Saltwater)- 1989. Office of Water, Regulations and Standars Criteria and 

Standards Division, Washington, DC. EPA 440/5-88-004. 

United States Environmental Protection Agency (EPA). 1999. 1999 Update of Ambient Water 

Quality Criteria for Ammonia. Office of Water, Washington, DC. EPA-822-R-99-014. 

United States Environmental Protection Agency (EPA). 2008. Ecological Hazard and 

Environmental Risk Assessment of Aqueous Ammonia (Busan 1215) For the Proposed 

Use in Industrial Water Systems. Risk Assessment and Science Support Branch, 

Antimicrobials Division, March 20, 2008. 

United States Environmental Protection Agency (EPA). 2009. Draft 2009 Update. Aquatic Life 

Aquatic Life Ambient Water Quality Criteria for Ammonia- Freshwater. Office of 

Water, Washington, DC. EPA-822-D-09-001. 

United States Environmental Protection Agency (EPA). 2011. Ecological Risk Assessment for 

Nalco 60620 which is an end-use product containing ammonium sulfate. The proposed 

registration of this product is for use in controlling microorganisms using an in-situ 

generating system for use in pulp and paper mills. Risk Assessment and Science Support 

Branch, Antimicrobials Division, April 28, 2011. 

Page 23 of23