Page 2 of 23 

 

EXECUTIVE SUMMARY 

Dibromodicyanobutane (DBDCB) is registered for use in materials preservation, industrial 

recirculating cooling water treatment, oil production, and paper mill water treatment. The 

material preservation uses include adhesives, caulks, household cleaning solution, paints and 

coatings, metal working fluids and non-apparel textiles. The RED for DBDCB was completed in 

1996 and all of the existing uses were found to be eligible for registration. No additional uses 

have been added since the RED. There are 15 end use antimicrobial products that contain 

DBDCB as an active ingredient. 

Dietary (food) exposure to DBDCB is likely because it is used as a slimicide in food contact 

paper and paperboard production and to preserve paper-making chemicals. Migration of DBDCB 

from paper packaging to the food contents may occur. The material preservative uses of 

DBDCB are likely to result in waste water being discharged, which may lead to contamination of 

human and livestock drinking water. DBDCB and/or its degradation products could also 

potentially pass through wastewater treatment plants. Therefore, the Agency anticipates needing 

certain environmental fate data which will be used during the risk assessment stage of 

registration review to determine the potential for drinking water exposures. 

Occupational and residential dermal and inhalation exposures to DBDCB could occur during 

open pouring of liquids and wettable powders for material preservation and during the use of 

treated paints, metal working fluids, and household cleaners. Residential incidental oral 

exposures could occur for toddlers playing on floors cleaned with treated cleaning solutions.

The following toxicology studies will be needed for registration review: 

• 90 day Inhalation Toxicity Study in Rats 

• 2- Generation Reproduction Study in Rats 

The following exposure data will be needed for registration review: 

• Indoor exposure studies (dermal and inhalation) during open pouring of liquids and 

wettable powders for material preservation and during the use of treated paints, metal 

working fluids, and household cleaners.

• Surface residue dissipation studies on countertops and household floors cleaned with 

household cleaning solution. 

• Migration studies on paper packaging. 

• Product use information 

 
Page 3 of 23 

1.0 BACKGROUND 

1.1 Chemical Identity 

The chemical identity of 1,2-Dibromo-2,4-dicyanobutane (DBDCB) is listed in Table 1. 

Table 1 - Chemical Identity of 1,2-Dibromo-2,4-dicyanobutane (DBDCB) 

Chemical Name 1,2-Dibromo-2,4-dicyanobutane 

Common Name Dibromodicyanobutane (DBDCB) 

Synonym 1-bromo-1-(bromomethyl)-1,3-propanedicarbonitrile 

PC Code 111001 

CAS Registry Number 35691-65-7 

Case No. 2780 

Empirical Formula C6H6Br2N2

Structure 

 

1.2 Chemical and Physical Properties 

The physical and chemical properties of DBDCB that are relevant for human health risk 

assessment are listed in Table 2. 

Table 2 - Physical and Chemical Properties of DBDCB

Property Value Reference 

Molecular Weight 265.8 Based on formula 

Physical State Yellowish White Granular Solid US EPA, 1996 

Melting Point 52.2 – 53.2 C US EPA, 1996 

Water Solubility 0.212 grams per 100 ml US EPA, 1996 

Vapor Pressure 6.7 x 10-3 Pascal @ 25 C (5.0 x 10-5 mm hg) US EPA, 1996 

2.0 USE AND USAGE INFORMATION 

2.1 Product Types 

There are 15 end use antimicrobial products that contain DBDCB as an active ingredient (ai). 

The concentration of DBDCB in these products ranges from 10 to 99.9 percent. The liquid 

formulations include emulsifiable concentrates, ready to use solutions or soluble concentrates (11 

products), and the solid products include wettable powder (3 products) and pellets/tablets (1 
Page 4 of 23 

product). Only one wettable powder product (59106-2) is packaged in water soluble packaging 

(WSP) while the other two products (39967-32 and 67869-35) are not packaged in WSP. 

2.2 Summary of Registered Uses 

DBDCB is registered for a variety of antimicrobial uses as listed in Table 3. 

Table 3 – DBDCB Antimicrobial Uses 

Use Application Rate 

(In Terms of ai) 

Label with Highest 

Rate 

Materials Preservation 

Adhesives, Glues and Tackifiers 600 – 5900 ppm 67869-35 

Household Products (Cleaning Solutions) 600 – 1520 ppm 39967-39 

Joint Cements, Caulks and Plasters 480 - 3920 ppm 67869-35 

Latex Emulsions 240 -1960 ppm 67869-35 

Paints, Coatings and Stains 360 – 2940 ppm 67869-35 

Paper Additives 1700 ppm 67869-45 

Pigments 250-12000 ppm 39967-28 

Polymer dispersions and emulsions 600 ppm 67869-45 

Printing Fluids and Inks 380 – 1000 ppm 39967-40 

Textiles, Non– Apparel 

(Fiber Processing Solutions used for canvas) 

1440 – 11760 ppm 67869-35 

Waxes and Polishes 120-1000 ppm 39967-40 

Industrial Cooling Water and Process Preservation 

Cooling Water Systems, Industrial Recirculating 9.5 to 1898 ppm 39967-38 

Metal Working Fluids 50- 3920 ppm 67869-35 

Oil Production (Drilling Muds, Packer Fluids etc) 8.0-127 ppm 59106-2 

Paper Mill Water Systems 0.05 – 0.4 lbs/ton 39967-40 

The RED for DBDCB was completed in 1996 and all of the existing uses were found to be 

eligible for registration. No additional uses have been added since the RED. 

2.3 Usage Information 

According to the Kline Biocides Report for 2004/2005 (Kline, 2006), the most important uses for

DBDCB are adhesives and sealants (57% of DBDCB sales value), paints and coatings (33%) and 

synthetic latex polymers (11%). According to the report, DBDCB is not used in metal working 

fluids, oil production or paper production. 

3.0 TOXICOLOGY 

 

At the time of the RED, the toxicology database for DBDCB was considered to be complete and 

no additional studies were required. In addition to the studies that were included in the RED, 

several studies (MRID 48767301) have recently been conducted by the National Toxicology 

Program (NTP) to evaluate the hazards of DBDCB use in cosmetics. These include 2 week, 3 

month and 2 year dermal toxicity studies in mice and rats and genetic studies in Salmonella 

typhimurium, Escherichia coli, and mouse peripheral blood erythrocytes. 
Page 5 of 23 

3.1 Acute Toxicity 

A summary of the acute toxicity findings is included in Table 4. DBDCB is of low acute oral 

toxicity (Toxicity Category III), low dermal toxicity (Toxicity Category IV) and low inhalation 

toxicity (Toxicity Category IV). DBDCB is a severe dermal and eye irritant (Toxicity Category 

I). It is not a dermal sensitizer in animals but it is a dermal sensitizer in humans. 

Table 4 - Acute Toxicity Values for DBDCB 

Test (species) MRID (% ai) Result Toxicity 

Category 

81-1 Oral Toxicity (rat) 41885501 (99.9) LD50 (males) = 770 mg/kg 

LD50 (females) = 515 mg/kg 

III 

81-2 Dermal Toxicity (rabbit) 00027554 (98) LD50 (combined) > 5000 mg/kg IV 

81-3 Inhalation Toxicity (rat) 00025846 (98) 

42526401 (99.9) 

LC50 (combined) > 5.09 mg/l 

LC50 (combined) > 13.09 mg/l 

IV 

IV 

81-4 Eye Irritation (rabbit) 0025848 (98) Severe Irritant I 

81-5 Dermal Irritation (rabbit) 0025847 (98) 

41885502 (98) 

Severe Irritant I 

81-6 Dermal sensitization (guinea pig) 00105188 (98) Not a sensitizer N/A 

81-6 Dermal sensitization (human) 43183801 (98) A skin sensitizer. Tested at 2000 ppm 

using repetitive occlusive patchings. The 

effect was independent of UV exposure. 

N/A 

When conducting risk assessments in the past, EPA relied in part on some human studies, such 

as the human skin sensitization study mentioned above, which may have involved intentional 

exposure to pesticides. In the course of registration review, EPA will reconsider these studies, as 

well as any other research involving intentional exposure of human subjects to pesticides, such 

as DBDCB, brought to its attention. If EPA decides to rely on any of these studies, EPA will 

ensure that all applicable regulatory requirements are met, including but not limited to the 

requirements for EPA ethics review and Human Studies Review Board (HSRB) review of certain 

research involving intentional exposure of human subjects. 

3.2 Subchronic and Chronic Toxicity 

The following is a brief summary of the currently available toxicology studies for DBDCB. 

More detailed information is included in D397608. 

3.2a Subchronic Toxicity 

Oral Administration Route

Subchronic Oral Study in Dogs (MRID 43540501) - DBDCB was administered to beagle dogs 

(4-6/sex/dose group) in the diet at dose levels of 0, 10, 100, or 4000 ppm (0, 0.29, 3.1, or 100 

mg/kg/day for males and 0, 0.33, 3.1 or 120 mg/kg/day for females) for three months followed 

with a 3-month recovery phase using 2 dogs/sex at doses of 0, 100, or 4000 ppm of the test 

material. No mortality was reported; one male was euthanized in extremis on Day 40. 
Page 6 of 23 

No effects were observed at the 10 ppm dose level. At the 100 ppm dose level, the incidence of 

treatment-related clinical signs of toxicity were slightly increased, and these effects included 

diarrhea, soft stool, emesis, and thin appearance. These effects were observed more consistently 

in the females, and were only marginally increased in the males. No clear test compound-related 

effects were shown in body weight and/or food consumptions in this dose group. 

At the 4000 pm dose level, a treatment-related much higher and progressively increased 

incidence of decreased body mass, hindlimb ataxia, and pale oral mucosa was reported in both 

sexes. Treatment-related effects also included decreases in food consumption and body weights; 

changes in hematology, clinical chemistry, urological parameters, and gross and microscopic 

pathology. Treatment-related effects were also observed on the thyroid glands in both males and 

females. These effects included significantly decreased serum T4, T3, and reverse T3 at most or 

all of the monitoring time points, enlargement of the thyroid, increased absolute and relative 

thyroid weights, and hypertrophy (all males and females)/hyperplasia (all males and one female) 

in the thyroid glands. The severity of histopathological changes was greater in males than 

females. 

Additional findings at the 4000 ppm dose level were green discoloration of the kidneys; brown 

pigmentation in the liver; axonal degeneration in the brain and spinal cord; anemia triggered 

bone marrow response; seminiferous tubule degeneration in the testis with concurrent 

hypospermia and giant cell formation; prostatic atrophy; histopathological changes in spleen; and 

lymphoid depletion of the thymus. After the 3-month recovery period, a less severe form of 

axonal degeneration was seen; however, an increased thyroid/parathyroid/body weight ratio was 

found in the females. 

The NOAEL is 0.33 mg/kg/day (10 ppm) for females and 3.1 mg/kg/day (100 ppm) for 

males. The LOAEL is 3.11 mg/kg/day (100 ppm) for females and 102 mg/kg/day (4000 ppm, 

the highest dose tested [HDT]) for males based on treatment-related significant decreases in 

serum T4, T3, and reverse T3, enlargement of the thyroid, increased absolute and relative thyroid 

weights, and hypertrophy/hyperplasia in the thyroid glands, and gross and microscopic pathology 

changes in other system/organs including kidneys, liver, the brain and spinal cord, anemic bone 

marrow response, the testis, prostatic atrophy, spleen, and thymus, as well as treatment-related 

decreases in food consumption and body weights and changes in hematology, clinical chemistry, 

and urological parameters. 

Subchronic Oral Study in Dogs (MRID 92199020) - DBDCB was administered to beagle 

dogs, (4 dogs/sex/group) in the diet at 0, 4.8, 28.9, or 101.5 mg/kg/day for males and 0, 5.3, 37.7 

or 109.8 mg/kg/day for females for three months. Thyroid follicular cell hyperplasia was 

observed at the high dose in both sexes, in addition to decreased weight gains and food 

consumption; altered hematological parameters; decreased alkaline phosphatase; enlarged 

thyroid; marked increases in organ/body weight ratios for several organs and extramedullary 

hematopoiesis in spleen and liver. A NOAEL was not established. The LOAEL was 4.8/5.3 

mg/kg/day (the lowest dose tested [LDT]) based on a dose-related significant increase in 

absolute and relative thyroid weights in males (4.8 mg/kg/day) and in relative ovary 

weights in females (5/3 mg/kg/day). 
Page 7 of 23 

Thyroid Hormone Study in Dogs (MRID 41858401) - A special subchronic feeding study was 

conducted to determine the effect of the exposure to DBDCB on the thyroid hormones 

triiodothyronine (T3) and thyroxine (T4) in dogs. In this study, DBDCB was administered to 

beagle dogs (4/sex/group) in the diet at a single dose of 4.8 mg/kg/day for three months. The 

dose used in this study was the low dose of the 3-month dietary study in dogs (MRID 92199020). 

Both sexes of animals showed enlarged thyroids and increased levels of T3 and T4 after being 

stimulated with thyroid stimulating hormone (TSH). Thyroid weights and organ/body weight 

ratios were significantly increased in females. 

Dermal Administration Route

NTP 2-Week Study in Rats: Groups of five male and female rats received dermally 

administered DBDCB in acetone at concentrations of 0, 37.5, 75, 150, 300, or 600 mg/mL, 5 

days per week, for 16 days. The dose formulations were applied at constant volume of 0.5 

mL/kg to yield doses of 0, 37.5, 75, 150, 300, or 600 mg/kg/day. No mortality or effects on body 

weights were reported. The thyroid gland weights of males in the 600 mg/kg/day group were 

significantly less than those of the controls, while the liver and kidney weights of 300 and 600 

mg/kg/day females were significantly increased. Dermal reactions were observed including 

irritation, thickened skin, and ulcers at the site of application in most dosed animals. 

NTP 2-Week Study in Mice: Groups of five male and female mice were dermally administered 

DBDCB in acetone at concentrations of 0, 37.5, 75, 150, 300, or 600 mg/mL, 5 days per week, 

for 16 days. The dose formulations were applied at 2.0 mL/kg to yield doses of 0, 75, 150, 300, 

600, or 1,200 mg/kg/day. No mortality was reported. The final mean body weight of 300 

mg/kg/day males was significantly lower than those of the controls. Hyperactivity was observed 

in all dosed groups. The organ weights (liver, heart, and kidneys) were significantly increased in 

the groups of 600 and 1,200 mg/kg/day animals (kidneys weight increased in males at 150 

mg/kg/day). The thymus weights were significantly decreased in males dosed 300 mg/kg/day 

and beyond and in all dosed female groups. All dermal reactions seen in the 2-week rat study 

were also observed in this 2-week mouse study. 

NTP 3-Month Study in Rats: Groups of 10 male and 10 female rats were dermally 

administered DBDCB in acetone at concentrations of 0, 0.4, 1.2, 4, 12, or 36 mg/mL, 5 days per 

week, for 14 weeks. The dose formulations were applied at 0.5 mL/kg to yield doses of 0, 0.2, 

0.6, 2, 6, or 18 mg/kg/day. One 2 mg/kg/day female died on day 91, while all males survived the 

study. No effects on the body weights were reported for either males or females. Clinical 

findings included thin hair coat in both male and female animals and skin irritation at the site of 

application in males. All dermal reactions observed in the 2-week studies were also reported for 

this 3-month study at the doses of 0.6 mg/kg/day (1.2 mg/mL) or beyond in dosed animals. 

NTP 3-Month Study in Mice: Groups of 10 male and 10 female mice received dermal 

administration of DBDCB in acetone at concentrations of 0, 0.1, 0.3, 1, 3 or 9 mg/mL. The dose 

formulations were applied at 2.0 mL/kg to yield doses of 0, 0.2, 0.6, 2, 6, or 18 mg/kg/day. All 

animals survived the study and no effects were reported on the body weights of dosed animals. 

The liver and lung weights of dosed females were significantly lower than those of the controls. 
Page 8 of 23 

Dermal findings were similar as those of in the 3-month rats study, and generally seen at the 

doses of 2 mg/kg/day (1 mg/mL) and beyond. 

Inhalation Administration Route 

No inhalation studies are available for DBDCB. 

3.2b. Chronic Toxicity/Carcinogenicity 

Oral Administration Route 

No chronic or carcinogenicity oral studies are available for DBDCB. 

Dermal Administration Route

NTP Two Year Study in Rats: Groups of 50 male and 50 female rats were dermally 

administered DBDCB in 95% ethanol at concentrations of 0, 4, 12, or 36 mg/mL, 5 days a week, 

for 104 to 105 weeks. The dose formulations were applied at constant volume of 0.5 mL/kg to 

yield doses of 0, 2, 6, or 18 mg/kg/day. Survival of 18 mg/kg/day males was significantly higher 

than that of the controls; however, body weights of this dose group of both sexes were 7% lower 

than those of the controls after 1 year. No increases in the incidences of neoplasms were 

observed in dosed animals. The combined incidence of mammary gland fibroadenoma, 

adenoma, or adenocarcinoma showed a negative trend, and significantly decreased incidence was 

observed in 6 mg/kg/day females. Dermal adverse reactions such as epidermal hyperplasia were 

observed in males and females dosed at 6 or 18 mg/kg/day and the incidences of hyperkeratosis 

of the epidermis were significantly increased in all dosed groups. The incidences of 

inflammation of the nose were reported to be significantly higher in all dosed male rats. 

NTP Two Year Study in Mice: Groups of 50 male and 50 female mice were dermally 

administered DBDCB in 95% ethanol at concentrations of 0, 0.3, 1, or 3 mg/mL, 5 days a week, 

for 105 weeks. The dose formulations were applied at constant volume of 2.0 mL/kg to yield 

doses of 0, 0.6, 2, or 6 mg/kg/day. No effects were reported on the survival rate or body weight. 

No clinical findings were attributed to the test material, and no increases in the incidences of 

neoplasms were observed in the doses animals. At the site of application, significantly increased 

incidences of minimal to mild hyperplasia of the epidermis were reported in 2 and 6 mg/kg/day 

males and all dosed females. Female mice also showed significantly increased incidences of 

minimal to mild chronic active inflammation in the dermis at all doses. 

3.2c. Developmental Toxicity 

Developmental Study in Rats (MRID 92199012) - DBDCB was administered by gavage to rats 

at doses of 0, 25, 100, or 175 mg/kg/day on gestation days (GD) 6 through 15. Surviving dams 

were sacrificed on GD 20; necropsied and reproductive status recorded. The maternal NOAEL 

is 25 mg/kg/day and the LOAEL is 100 mg/kg/day based on significant decrease in body weight 
Page 9 of 23 

change. There were no mortalities among dams. Clinical signs were observed in high-dose 

dams including dyspnea, hypoactivity, and staining of mouth. No change in mean fetal weight 

with respect to dose was reported. There were no compound-related external, visceral or skeletal 

variations or malformations in the treated fetuses in comparison to controls on either a litter or 

fetal basis. The developmental toxicity NOAEL is 175 mg/kg/day (HDT). The resorptions 

observed in the treated groups were considered to be the result of significant maternal toxicity at 

the mid- and high-dose levels because of (1) a lack of statistically significant decrease in litter 

size accompanying the increased resorptions; (2) marginally significant pairwise difference in 

the number of litters with one or more resorption in each group; and (3) no statistically 

significant dose-related trend 

Developmental Study in Rabbits (MRID 43540502) - DBDCB was administered by gavage to 

presumed pregnant New Zealand white rabbits (20/dose) at 0, 10, 30, or 60 mg/kg/day from GD 

6 through GD 18. One animal in the mid-dose group was found dead on GD 25, and one animal 

in the high-dose group was sacrificed moribund due to intubation error. Two animals from the 

control group aborted on GD’s 24 and 28. None of these findings were considered to treatmentrelated. No clinical and necropsy findings were considered to be treatment-related in these 

animals or in those surviving the treatment and sacrificed at termination. Although decreased 

maternal body weight gain occurred during GD 6-9 and decreases in feed consumption were 

observed during GDs 6-9 and 9-12 (both were at the high dose group), there were no statistically 

significant decreases when the entire dosing interval (GD 6-18) for each was compared to those 

of the controls. Therefore, these effects were not considered to be treatment-related. The 

maternal and developmental toxicity NOAEL is 60 mg/kg bw/day (HDT). 

3.2d. Reproductive Toxicity 

There were no reproductive toxicity studies in the RED. The 90-day feeding study in rats 

exposed in utero (MRID 00055028) summarized below was included in the RED as an 

acceptable subchronic study. This study was reviewed and found to be unacceptable as a onegeneration reproduction study for the following reasons as noted in D213921: 

1. The number of animals used (10/sex/group was too low to properly measure reproductive 

indices. 

2. The lack of day zero data, i.e., accurate pup count prevents a determination of potentially 

dose related decreases in pups born. 

3. The report indicated that only healthy F1 pups were randomly selected for the 90 day 

portion of the study. The report stated that “obviously diseased” pups were removed but 

the report did not clearly state nature of disease and when and how many “diseased” pups 

were removed. 

4. No data were provided on maternal weight during pregnancy and weight and count of the 

number of pups born to determine resorption. 
Page 10 of 23 

90 Day Feeding Study in Rats Exposed in Utero (MRID 00055028) - DBDCB was 

administered to rats (10 animals/sex/dose group) in the diet at 6.3, 37, or 275 mg/kg/day for 

males and 7.5, 43, or 360 mg/kg/day for females seven days before mating and throughout the 

14-day mating, gestation, and lactation periods. Forty (20/sex) of the weanling offspring (F1

rats) receiving each dosage level were randomly selected for use in the 90-day phase of the 

study. After 13 weeks, the F1 animals were necropsied and tissues preserved. Effects seen at the 

high-dose group in both sexes of the F1 animals included significant decrease in body weight, 

decrease in brain weight, increase in pituitary weight, increase in pituitary to body weight ratio 

and pituitary to brain weight ratio, increase in spleen to body weight ratio, and splenic 

hematopoiesis. Additionally, males showed a significant increase in liver to body weight ratio 

and significant decrease in testes with epididymides weight and testes with epididymides to brain 

weight ratio, and females showed an increase in thyroid weight and thyroid to body weight ratio. 

The weight gain in both sexes were much lower (32-36%) than controls in the high-dose group, 

although they were higher than controls in both sexes in the low- and mid-dose groups (20-25% 

and 10%, respectively) on days 1-21. The NOAEL is 6.3 mg/kg/day for males and 7.5 

mg/kg/day for females, and the LOAEL is 37 mg/kg/day for males and 43 mg/kg/day for 

females based on increased severity in splenic extramedullary hematopoiesis in F1 males and 

increased pituitary weight and pituitary to body weight ratio in F1 females. 

3.2e Mutagenicity 

The DBDCB RED included six submitted mutagenicity studies. DBDCB was negative for 

mutagenic effects except in an in vitro Chinese hamster ovary (CHO) assay. However, the in 

vivo cytogenetics assay in rats was negative. The study results are summarized in Table 5. 

Table 5 – Mutagenicity Studies Included in the DBDCB RED 

MRID Test Results 

25091 Bacterial Mutagenicity 

(Ames Assay) 

Not mutagenic up to viability limits with and without S9 

activation. 

128134 Chinese Hamster Ovary 

(CHO) Assay 

Produced significant frequencies of chromosomal aberrations 

(i.e. it was mutagenic) in CHO at 11 μg/ml without S9 

activation and 190 μg/ml with S9 activation. 

125850 In Vivo Mammalian 

Erythrocyte Micronucleus 

Assay (Rat) 

Not mutagenic in rat erythrocytes when tested up to 50 

mg/kg/day. 

144412 In Vitro Mammalian Cell 

Gene Mutation Assay 

Not mutagenic in Chinese hamster lung fibroblasts up to 

cytotoxicity limits with and without S9 activation. 

137288 Unscheduled DNA 

Synthesis (UDS) Assay

Did not induce UDS in human embryonic lung fibroblasts 

with and without S9 activation. 

55029 Dominant Lethal Mutation 

Assay (Mouse) 

Did not produce dominant lethal mutations in male mice 

(10/dose) administered dietary doses of 0, 12.5, 75.0, and 450 

mg/kg/day for 8 weeks prior to mating. 

In addition, DBDCB was negative in the Ames Assay and the In Vivo Mammalian Erythrocyte 

Micronucleus Assay (Mouse) conducted by NTP. 
Page 11 of 23 

3.2f Absorption, Distribution, Metabolism and Excretion (ADME) 

One metabolism study has been submitted to the Agency and one study was found in the 

literature. 

In the submitted metabolism study (MRID 55031), male CD rats were administered a single oral 

dose of 50 mg/kg radiolabeled 14C-DBDCB. Total recovery of radioactivity during the 7 day 

collection period in the urine, feces, and respired air was 84-91%, 6-10%, and 0.5% of the 

administered dose, respectively, and most of the radioactivity in the urine was found during the 

first 24 hours post-administration. Tissue assay 7 days post-administration indicated that the 

lung, liver, kidneys and spleen contained 2.7, 2.5, 2.3 and 2.3 ppm, respectively. Maximum 

blood concentration (71μg/ml) of DBDCB equivalent was attained at 5 hours postadministration. On the basis of percent dose per whole organ, each of these retentions is 

calculated to be less than 0.1%, except for liver at 0.3%. This study provides supplemental 

information on metabolism of DBDCB despite deficiencies identified. 

A study on the metabolism of DBDCB was located in the open literature (MRID 48767302). 

Radiolabeled 14C-DBDCB was administered to male Fischer 344 rats at doses of 8 mg/kg, 80 

mg/kg, and 25 mg/kg by the IV, oral, and dermal routes, respectively. Radiolabeled 14CDBDCB was absorbed greater than 60%, approximately 85%, and less than 12% of dosed parent 

compound following IV, oral, and dermal administration. No parent compound was detected in 

the blood regardless of route of administration (including the 1-min time point for IV route); 

however, 2-methylene-glutaronitrile (CAS No. 1572-52-7), a debrominated metabolite of 

DBDCB, was identified following IV and oral administration but not dermal administration. 

Despite its relatively high levels, 2-methylene-glutaronitrile declined rapidly and was not 

detectable within one hour of IV administration. A small amount of the dose for IV, oral and 

dermal route was retained in tissues 72 hours post-administration and distributed evenly among 

tissues including liver and the GI tract (for oral route). However, 12.5% of the dose was bound 

to the erythrocyte fraction of the blood following IV route of administration. 14C-DBDCB was 

primarily excreted in urine followed by feces and exhaled air. Urinary metabolite profiles were 

almost identical for each route of administration; the primary metabolite was N-acetyl-S-(2,4-

dicyanobutane)-L-cysteine which is a mercapturate conjugate of 2-methyleneglutaronitrile. The 

authors concluded that DBDCB is totally debrominated prior to systemic distribution; therefore, 

tissues exposure to intact DBDCB was expected to be exceedingly low regardless of the routes 

of administration. This conclusion will be further evaluated during registration review. 

3.2g Neurotoxicity 

No neurotoxicity studies are available for DBDCB. 
Page 12 of 23 

3.3 Toxicology Endpoints 

Dietary exposures were not assessed in the RED because indirect food additive tolerances had 

been established for the DBDCB indirect food uses in adhesives and paper/paperboard and 

dietary exposures from these uses were expected to be minimal. Occupational and residential 

exposures to DBDCB were not assessed in the RED because no endpoints of concern were 

identified for short and intermediate term exposures and no chronic exposures were anticipated 

(US EPA, 1996). No additional toxicology data were required in the RED; however, two 

additional studies (two generation reproduction and 90 day inhalation) will be needed for 

registration review and endpoints may need to be selected based on the outcome of these studies. 

4.0 DIETARY ASSESSMENT 

Information regarding dietary exposures is taken from DP397607, Summary of Dietary and 

Drinking Water Exposures for the 1,2-Dibromo-2,4-dicyanobutane (DBDCB) Registration 

Review Scoping Document. 

4.1 Dietary Exposure 

DBDCB is regulated by the FDA as an indirect food additive. Tolerances have been established 

for DBDCB as a preservative in food grade adhesives (see 21 CFR § 175.105) and as a slimicide 

in the manufacture in food grade paper and paperboard at a maximum level of 0.005% of dry 

weight fiber (see 21 CFR § 176.300). Dietary (food) exposure to DBDCB is likely because it is 

used as a slimicide in food contact paper and paperboard production and to preserve papermaking chemicals. Migration of DBDCB from paper packaging to the food contents may occur. 

A migration study is anticipated to be needed as will a dietary (food source) risk assessment to 

support the antimicrobial uses of DBDCB as a part of this registration review case. 

4.2 Drinking Water Exposure 

The fate of DBDCB in water is discussed in the Product Chemistry, Environmental Fate, and 

Ecological Effects Scoping Document in Support of Registration Review of DBDCB (D397530). 

The submitted environmental fate studies demonstrate the relative lack of persistence of parent 

DBDCB and more persistent degradates. They also show that all residues of DBDCB have 

limited sorption to soil and sediment, indicating that the primary residues that can reach surface 

and ground water are the metabolites. The registrant has submitted environmental fate studies 

that were considered to be “supplemental, upgradeable” and “not completely acceptable”. 

However, the information is of sufficient quality to use in the ecological risk assessment. The 

hydrolysis half-life of DBDCB is pH dependent and ranges from 13 days in alkaline conditions 

to 190 days in acidic conditions at 25 o

C. Two major degradates are formed, including trans 1-

bromo-2,4-dicyanobutene (BDCB) and 2-methyleneglutaronitrile (MGN). The aerobic aquatic 

half-life of MGN is on the order of 4.6 days. The overall degradation of DBDCB appears to lead 

to stable degradates that have not been identified, but the remaining portion of the compound is a 

straight-chain aliphatic hydrocarbon which can become part of the organic matter of soil. 

Limited sorption to soil and sediment for all residues was demonstrated by the near quantitative 
Page 13 of 23 

partitioning to water in the aquatic metabolism study and the limited Freundlich Kads values of 

0.26-0.70 ml/g. 

To address the fate of the degradate BDCB in the waste water treatment plant process, studies on 

biodegradability in sewage sludge and activated sludge respiration inhibition are anticipated to 

be needed. Based on the above environmental fate information, drinking water consumption 

from ground or surface water is likely to be limited for parent DBDCB at environmental pH 

values (+ pH 7) but is more likely for the metabolites. The available fate data and the requested 

studies will be used during the risk assessment stage of registration review to determine the 

potential for discharged residues to result in human dietary exposure via drinking water and, if 

needed, to trigger a drinking water assessment. 

5.0 OCCUPATIONAL AND RESIDENTIAL EXPOSURES 

If endpoints of concern are identified from the toxicology studies that are required for 

registration review, then exposures to DBDCB will need to be assessed during registration 

review. The exposure routes could include dermal and inhalation for occupational exposures 

and dermal, inhalation and incidental oral for residential exposures. A listing of the exposure 

scenarios for DBDCB is included in Table 6. 

Table 6 – Occupational and Residential Exposure Scenarios for DBDCB 

Scenario Exposure Route(s) Duration 

Occupational Exposures 

Open pour liquids Dermal and Inhalation Short and Intermediate 

Term 

Open pour wettable powder Dermal and Inhalation Short and Intermediate 

Term 

Using treated metal working fluids Dermal and Inhalation Short, Intermediate and 

Long Term

Painting with treated paints 

(Airless spray and brush/roller) 

Dermal and Inhalation Short and Intermediate 

Term 

Residential Exposures 

Using treated cleaning solutions Dermal and Inhalation Short and Intermediate 

Term

Painting with treated paints 

(Airless spray and brush/roller) 

Dermal and Inhalation Short Term 

Toddlers playing on floors cleaned with treated 

cleaning solutions 

Dermal and Incidental Oral Short and Intermediate 

Term

6.0 AGGREGATE AND CUMULATIVE EXPOSURE 

The DBDCB RED does not include a human health assessment, as no endpoints of concern had 

been identified. The RED also assumed that residential handler exposures from treated products 

were not expected to pose a significant risk because of the low concentrations used. For 

registration review, upon an evaluation of toxicological studies requested for DBDCB and if 

endpoints of concern are identified from these studies, then aggregate exposures to DBDCB will 

need to be assessed. The exposure routes could include dermal, inhalation and incidental oral for 
Page 14 of 23 

residential exposures; all of which may be appropriate to aggregate with dietary and drinking 

water exposures. 

 

7.0 INCIDENTS 

There are no human incidents reported in the OPP incident database that are associated with 

DBDCB exposure. 

8.0 TOLERANCES 

Indirect food additive tolerances have been established for DBDCB as a preservative in food 

grade adhesives (see 21 CFR § 175.105) and as a slimicide in the manufacture in food grade 

paper and paperboard at a maximum level of 0.005% of dry weight fiber (see 21 CFR § 

176.300). 

9.0 ENDOCRINE DISRUPTION EFFECTS 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. As part of the re-registration eligibility decision in 1996, EPA 

reviewed the available toxicology data and determined that there were no endpoints of concern 

for the existing use patterns. However, as required by FFDCA section 408(p), DBDCB is 

subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. Under FFDCA 

section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and 

February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which 

contains 58 pesticide active ingredients and 9 inert ingredients. DBDCB is not among the group 

of 58 pesticide active ingredients on the initial list to be screened under the EDSP. For further 
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information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, 

future lists, the test guidelines and the Tier 1 screening battery, please visit our website: 

http://www.epa.gov/endo/. 

10.0 ANTICIPATED DATA NEEDS 

10.1 Toxicology Studies 

Additional studies are needed to assess the hazards of DBDCB. These studies are listed in Table 

7 and detailed justifications are provided in Appendix A. 

Table 7 –Toxicology Studies Needed for DBDCB 

Study Needed Guideline Applicable Uses 

90 day Inhalation Toxicity 870.3465 

 

1. All uses involving open pour applications 

2. Metal working fluids 

3. Paints 

4. Cleaning solutions 

2- Generation Reproduction 870.3800 All uses that can result in dietary and drinking water exposures. 

10.2 Exposure Studies 

Several dietary and occupational and residential exposure studies are needed to assess the 

antimicrobial uses of DBDCB. These studies are listed in Table 8 and detailed justifications are 

provided in Appendix A. 

Table 8 –Dietary and Occupational Residential Exposures Studies Needed for DBDCB 

Study Needed Guideline Applicable Exposure Scenarios 

Indoor Exposure, Dermal 

Indoor Exposure, Inhalation 

Data Reporting/Calculations 

875.1100 

875.1300 

875.1600 

1. Open pour liquidsA,C

2. Open pour wettable powderB,C

3. Application of preserved paints - brush/roller or airless sprayC

4. Use of treated metal working fluidsC

5. Trigger sprayer and mop application of preserved cleaning solutionsC

Surface Residue Dissipation 875.2300 1. Residential post application dermal and incidental oral exposure to floors 

cleaned with preserved household cleaning solutions. 

Nature of Residue on Surfaces 

Migration 

N/A 

N/A 

1. Dietary exposures from countertops cleaned with preserved household 

cleaning solution. 

2. Dietary exposures from DBDCB treated paper products used in food 

packaging. 

Product Use Information 875.1700 All above scenarios 

A. If the labels are amended to require closed mixing/loading, the exposure study can be waived. 

B. If the labels are amended to require water soluble packaging, the exposure study can be waived. 

C. It may be possible to use proprietary surrogate exposure data if data compensation issues can be addressed. 
Page 16 of 23 

11.0 REFERENCES 

Kline, 2006. Specialty Biocides North America 2004/2005, Kline and Company, Inc. 

MRID 48767301. Toxicology and Carcinogenesis Studies of 1,2-Dibromo-2,4-Dicyanobutane 

(CAS No. 35691-65-7) in F344/N Rats and B6C3F1 Mice (Dermal Studies). NTP TR 555, NIH 

Publication No. 10-5896. National Toxicology Program, June 2010. 

http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/TR555.pdf) 

MRID 48767302. Sauer, JM, Smith, RL, and Bao, J, et al. (1998). Metabolic and Dispositional 

Fate of 1,2-Dibromo-2,4-Dicyanobutane in the Male Fischer 344 Rat. Drug Metabolism and 

Disposition. 26:429-36. http://dmd.aspetjournals.org/content/26/5/429.long

US EPA, 1996. Registration Eligibility Decision (RED) for 1,2-Dibromo-2,4-dicyanobutane, 

United States Environmental Protection Agency, August 1996 

D213921. Toxicology Review for the Registration Eligibility Decision Document on Tektamer 

(1,2-dibromo-2,4-dicyanobutane) , Paul Chin, EPA Office of Pesticide Programs, Health Effects 

Division, Toxicology Branch, February 5, 1996. 

D397530. Product Chemistry, Environmental Fate, and Ecological Effects Scoping Document in 

Support of Registration Review of Dibromodicyanobutane. Srini Gowda, David Bays, Ph.D.,

James Breithaupt, EPA Office of Pesticide Programs, Antimicrobials Division, Risk Assessment and Science Support Branch. 

D397607. Summary of Dietary and Drinking Water Exposures for the 1,2-Dibromo-2,4-

dicyanobutane (DBDCB) Registration Review Scoping Document, Talia Lindheimer, EPA 

Office of Pesticide Programs, Antimicrobials Division, Risk Assessment and Science Support 

Branch. 

 

D397608. Dibromodicyanobutane: Summary of Mammalian Toxicology Data for the 

Registration Review Scoping Document, Jenny Tao, EPA Office of Pesticide Programs, 

Antimicrobials Division, Risk Assessment and Science Support Branch. 

 
Page 17 of 23 

Appendix A – 

Justification for the 

Studies Needed for the 

Human Health Registration Review of 

Dibromodicyanobutane 
Page 18 of 23 

Study Title: 90-Day Inhalation Toxicity (Rat) 

Guideline Numbers: 870.3465

Rationale for Requiring the Data 

Occupational (i.e. worker) inhalation exposures to dibromodicyanobutane are expected during the 

open pour addition of liquids and wettable powders during materials preservation, paper production 

operations and oil field treatments. Occupational and residential (i.e. homeowner or consumer) 

inhalation exposures are also expected during the use of preserved products such as paints, metal 

working fluids and household cleaning solutions. Given that dibromodicyanobutane has a fairly low 

vapor pressure of 5.0 x 10-5 mm hg, the exposures will be primarily to aerosols rather than vapors. 

Practical Utility of the Data 

1) How did the Agency make its earlier regulatory decision without these data? 

Inhalation risk has never been assessed for dibromodicyanobutane even though inhalation exposures 

are expected. There is no route-specific study available to appropriately use in a quantitative 

assessment of inhalation exposures. 

2) How would the data be used? 

The data would be used to properly evaluate inhalation hazards and risks to occupational workers 

during open pour addition of dibromodicyanobutane liquids and wettable powder products during 

industrial treatment operations such as materials preservation and when working with treated paints 

and metal working fluids. This data would also be used to evaluate risks to residential adults during 

painting and when using household surface cleaners. 

3) How could the data impact the Agency’s future decision making? 

In the absence of inhalation toxicity data, the Agency would have to estimate inhalation risks using an 

oral toxicity study and rely on the assumption that absorption and toxicity of dibromodicyanobutane 

are the same via the oral and inhalation routes of exposure. Note that absorption of pesticides into the 

bloodstream via the lungs is often higher than that via the oral route and often many times higher than 

via the dermal route. Paired with the requested inhalation exposure data, the route-specific 90-day 

inhalation toxicity study on dibromodicyanobutane will permit EPA to conduct occupational and 

residential risk assessments that are refined and in which there is a high degree of confidence. 

 
Page 19 of 23 

Study Title: Two-Generation Reproduction Study 

Guideline Numbers: 870.3800

Rationale for Requiring the Data 

The two-generation reproduction study is conditionally required for non-direct food contact use 

pesticides, such as material preservatives like dibromodicyanobutane, under the data requirements of 

40 CFR 161.340. In this case, the trigger for this requirement is the chronic (>6 months) human 

exposure to dibromodicyanobutane via indirect-food and drinking water sources. There is no 

reproduction toxicity study or other alternative information (e.g., SAR), surrogate data, or weight-ofevidence available to be utilized to evaluate the potential for reproduction and fertility effects. 

The existing 90-day feeding study in rats exposed “in utero” is not adequate and acceptable to address 

reproductive toxicity due to a lack of reproductive parameters that are required by the guideline. 

These parameters include fertility, birth, viability, offspring sex ratio, parental (P) females cycle 

pattern and mean estrous cycle length, implantation data and postimplantation loss for P parental 

females, as well as total cauda epididymal sperm number, homogenization-resistant testis spermatid 

number, number and percent of progressively motile sperm, number and percent of morphologically 

normal sperm, and number and percent of sperm with each identified anomaly. 

This study will provide information of potential reproductive hazards of dibromodicyanobutane. In 

addition, the data generated may also provide a toxicity endpoint applicable to risk assessment for 

occupational and residential exposures. 

Practical Utility of the Data 

1) How did the Agency make its earlier regulatory decision without these data? 

The Agency has never characterized and quantified the potential reproduction and fertility hazard and 

risks associated with the registered uses of dibromodicyanobutane due to a lack of the study. 

2) How would the data be used? 

The data would be used to characterize and quantify the hazard and risks of dibromodicyanobutane 

via the oral route to the U.S. general population including infants and children as required by the 

FQPA. The data would allow the Agency to conclude more definitively whether or not there would 

be any concerns for reproduction and fertility. A toxicity endpoint may be selected from this study for 

use in quantitative risk assessments. 

3) How could the data impact the Agency’s future decision making? 

This study may result in a change in how risks are quantified and would greatly increase the Agency’s 

confidence in the hazard profile of dibromodicyanobutane which increases the confidence in future 

risk assessments and, hence, regulatory decisions. This study could be used as the source for selection 

of toxicity endpoints for use in the assessment of human risks. 
Page 20 of 23 

Study Titles: Indoor Exposure Dermal, Indoor Exposure Inhalation, Data Reporting and Calculations

Guideline Numbers: 875.1100, 875.1300, 875.1600

Rationale for Requiring the Data 

Dermal and inhalation exposures to dibromodicyanobutane are expected during the open pour 

additionA of liquids and wettable powdersB during materials preservation, paper production operations 

and oil field treatments. These exposures were not assessed in the RED because no endpoints of 

concern were identified. If additional toxicological studies for dibromodicyanobutane are required 

during registration review and endpoints of concern are identified from these studies, then the 

exposures to dibromodicyanobutane will need to be assessed during registration review. 

Dermal and inhalation exposures are also expected during the use of preserved products such as 

paints, metal working fluids and household cleaning solutions. These exposures also were not 

assessed in the RED. 

 

Dermal and inhalation exposures from these scenarios are evident in exposure studies in the Pesticide 

Handlers Exposure Database (PHED). The existing Chemical Manufacturer Association (CMA) data 

base and PHED for these scenarios are limited in scope for QA/QC and the number of replicates (i.e., 

number of times a worker is monitored for a specific activity). EPA presented the need for additional 

handler exposure data to the January 2007 Science Advisory Panel (SAP) as well as to the April 2007 

Human Studies Review Board (HSRB) and both groups agreed that additional data are warranted. 

Practical Utility of the Data 

1) How would the data be used? 

The data would be used to assess dermal and inhalation exposures that result from the open pour 

addition of liquidsA and wettable powdersB and during the use of treated materialsC including paints, 

metal working fluids and household surface cleaners. 

2) How could the data impact the Agency’s future decision making? 

The exposure data would be used to assess the risks of exposure and to determine if mitigation 

measures, such as closed system loading, water soluble packaging, decreased application rates or use 

of PPE are needed to reduce these risks. If exposure data are not available, these assessments will 

have to be made using models which might lead to the overestimation of risk and the requirement for 

excessive and onerous mitigation measures.

A. If the labels are amended to require closed mixing/loading, the study for the open pour scenario can be waived. 

B. If the labels are amended to require water soluble packaging, the exposure study can be waived. 

C. There are proprietary studies that can be used as surrogate data for these exposure scenarios if data compensation 

issues are addressed 
Page 21 of 23 

Study Title: Surface Residue Dissipation (Floors and Carpets) 

Guideline Numbers: 875.2300

Rationale for Requiring the Data 

Dermal and incidental oral exposures to dibromodicyanobutane are expected for toddlers who sit or 

play on household floors after they are cleaned with household cleaning solutions that are preserved 

with dibromodicyanobutane. These exposures were not assessed in the RED because no endpoints of 

concern were identified. If additional toxicological studies for dibromodicyanobutane are required 

during registration review and endpoints of concern are identified from these studies, then the 

exposures to dibromodicyanobutane will need to be assessed during registration review. 

 

Practical Utility of the Data 

1) How would the data be used? 

The surface residue data would be used to assess dibromodicyanobutane exposures that result from the 

use of household cleaning solutions preserved with dibromodicyanobutane. 

2) How could the data impact the Agency’s future decision making? 

The surface residue data will be used during registration review to decide if the exposures to 

dibromodicyanobutane from its use in household cleaning solutions generate a risk of concern that 

requires mitigation. This mitigation could include reduction of the application rate or elimination of 

the use. If surface residue data are not available, then the standard assumption of 100 percent 

transferable surface residue will be used which might overestimate the risk and require excessive 

mitigation. 

 
Page 22 of 23 

Study Titles: Nature of Residue on Surfaces, Migration Study

Guideline Numbers: No Guidelines

Rationale for Requiring the Data 

These residue chemistry studies will allow the Agency to conduct chemical-specific, quantitative 

dietary risk assessments that utilize the measured quantities of DBDCB and/or degradation 

products that will be available for dietary consumption when food contact surfaces that have been 

freshly cleaned with preserved products or preserved with DBDCB itself. In the past, the Agency 

did not assess exposures to residues on counter tops or from treated pulp and paper. Furthermore, 

no consideration was given to dissipation/loss of surface residues via volatilization, identity of 

degradates, or preferential migration of residues to certain types of food depending on porosity, 

water or fat content, etc. The Nature of the Residue on Surfaces study will determine whether 

residues persist on treated food-contact surfaces, the identity of those residues, and a measured 

upper limit on total surface residue level. The Migration Studies are automatically required but 

may be waived depending on the outcome of the Nature of the Residue on Surfaces study. 

Migration Studies determine the concentrations of specific residues of toxicological concern 

transferred from treated food-contact surfaces to various types of food coming in contact with 

these surfaces. Data from these studies will replace any default leaching and migration rates used 

in earlier risk assessments. 

Practical Utility of the Data 

1. How will the data be used? 

The Nature of the Residue on Surfaces study will be used to determine whether the active 

ingredient remains on the treated food-contact surface, whether it degrades, to what it degrades, 

and the upper limit on total food-contact surface residues. This study may negate the need for a 

dietary risk assessment, may be used as an upper (yet more refined) exposure limit, and may be 

used to either waive or provide direction for the Migration Studies. Migration Studies determine 

the concentrations of specific residues of toxicological concern transferred from treated foodcontact surfaces to various types of food coming in contact with these surfaces. 

2. How could the data impact the Agency’s future decision-making? 

If residues of DBDCB and/or degradation products transfer from treated surfaces to food, human 

exposure will occur. These studies will permit the conduct of chemical-specific, quantitative 

dietary risk assessments that are much more refined than earlier assessments and in which the 

Agency has higher confidence. This information will permit a determination of which use 

patterns are expected to result in exposures less than the Agency’s level of concern, which ones 

must be supported by additional data, and which ones are likely to have risks of concern and, 

therefore, must be mitigated. In addition, these data will permit a more realistic estimate of 

human aggregate risk.

 
Page 23 of 23 

Study Title: Product Use Information

Guideline Numbers: 875.1700

Rationale for Requiring the Data 

Product use information serves as the basis for determining what exposure scenarios should be 

assessed and what assumptions and exposure data are needed to perform these assessments in a 

manner that does not over or underestimate the actual risk. 

Practical Utility of the Data 

1) How would the data be used? 

The product use information will be used to define and characterize the exposure scenarios that will be 

assessed in the risk assessment. 

2) How could the data impact the Agency’s future decision making? 

A complete description of product use would ensure that the risk assessment is inclusive of the types 

of exposures occurring during use and that these exposures are accurately assessed. Without product 

use information the Agency will have to use default assumptions that might over estimate the actual 

risk.