AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

 WASHINGTON, D.C. 20460 

 

 Office of Chemical Safety and Pollution Prevention 

 

MEMORANDUM May 15, 2013

SUBJECT: Science Review in Support of the Registration of the TGAI/MP IR9804 and the 

EP, IRF 135, Respectively Containing 99.8% and 96.3% Allyl Isothiocyanate 

(AITC) As Their Active Ingredient. The TGAI/MP is an unregistered source of 

the active ingredient. 

Decision No : 469288 & 469289 

 DP Nos.: 406246 & 406248

 EPA Reg. Nos: 89285-R & -E 

 Chemical Class: Biochemical 

 CAS. No.: 57-06-7 

 PC Code: 004901

 Tolerance Exemptions : 40 CFR 180.1167 (for AITC) in Oil of Mustard 

MRID Nos. : 488241-01 to -08 & 489194-01 to -03

FROM: Russell S. Jones, Ph.D, Senior Biologist /S/ 05/15/2013 

Biochemical Pesticides Branch 

Biopesticides & Pollution Prevention Division (7511P) 

TO: Gina Burnett, Regulatory Action Leader /S/ 05/15/2013 

Biochemical Pesticides Branch 

Biopesticides & Pollution Prevention Division (7511P) 

ACTION REQUESTED 

On behalf of Isagro, A. Roberts (TSG) submitted a request for the registration of the TGAI/MP 

IR9804 and the EP, IRF 135, respectively containing 99.8% and 96.3% Allyl Isothiocyanate 

(AITC) as their active ingredient. The TGAI/MP is an unregistered source of the active 

ingredient. In support of the submission, the registrant has submitted Product Chemistry and 

Tier I Toxicity information and waivers for all Tier I Non-Target Organism data requirements. 

Under 40 CFR 180.1167 Allyl isothiocyanate is exempt from the requirement of a tolerance for 

residues when used as a component of food grade oil of mustard, in or on all raw agricultural 

commodities, when applied according to approved labeling. The inert ingredient is cleared for 

food use under 40 CFR 180.910. 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

The currently proposed label application methods are for pre-plant applications, which would be 

considered a non-food use. No residual activity is expected and the active ingredient will 

dissipate prior to crop seeding. 

RECOMMENDATIONS AND CONCLUSIONS

1a. The Product Chemistry data submitted in support of the TGAI/MP, IR9804 (EPA File 

 Symbol No. are 89285-R), are ACCEPTABLE. 

1b. The Product Chemistry data submitted in support of the EP, IRF135 (EPA File 

 Symbol No. are 89285-E), are ACCEPTABLE. 

2a. The Tier I Toxicity studies, data, and waiver rationales submitted in support of the 

 TGAI/MP data requirements are ACCEPTABLE. No additional data are required. 

2b. Tier I Toxicity information submitted in support of the TGAI/MP is bridged to support of 

 the EP data requirements. ACCEPTABLE.

3. Waiver rationales submitted in support of the TGAI/MP Non-Target Organism data 

 requirements are ACCEPTABLE. 

STUDY SUMMARIES 

I. Active Ingredient Characterization 

Allyl isothiocyanate (AITC) is the major component of natural mustard oil. It is present also in 

cooked cabbage, horseradish, and black mustard seed. It is synthetically produced from allyl 

iodide and potassium thiocyanate 

Product Names: TGAI/MP: IR9804 (99.8% a.i.) (EPA File Symbol No. 89285-R) 

 EP: IRF135 (96.3% a.i.) (EPA File Symbol No. 89285-E) 

Chemical Name: Allyl isothiocyanate 

Common Names: AITC, 3-Isothiocyanato-1-propene 

PC Code: 070704 

CAS No.: 56-06-7 

Molecular Wgt.: 99.15 

Chemical Formula: C4H5NS 

See MRID 48824101, pp. 5 & 6, and Attachment 1 for additional details on IR9804. 

See MRID 48919401, pp. 5, and Attachment 1 for additional details on IRF135. 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

A. Product Chemistry (MRIDs 488241-01 & -02; 489194-01 & -02) 

Data submitted to support the product chemistry data requirements for the TGAI/MP (IR9804; 

EPA File Symbol No. 89285-R) are summarized in Table 1 below. Physical and chemical 

properties data are summarized in Table 2 below. Refer to MRIDs 488241-01 and -02 for more 

information. 

TABLE 1. Product Chemistry Data Requirements for TGAI/MP IR9804 (99.8% AITC) (40 CFR § 158.2030) 

OPPTS Guideline No. Study Results MRID 

830.1550 

to 

830.1670 

Product identity; 

Manufacturing process; 

Discussion of formation of 

unintentional ingredients 

Submitted data satisfy the requirements 

for product identity, manufacturing 

process, and discussion of formation of 

impurities. 

ACCEPTABLE 

48824101 

830.1700 Analysis of samples Submitted data satisfy the requirements 

for analysis of samples. 

ACCEPTABLE

48824102 

830.1750 Certification of limits Limits listed in the CSF are 

ACCEPTABLE

- 

830.1800 Analytical method ACCEPTABLE 48824102 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

TABLE 2. Physical and Chemical Properties of TGAI/MP IR9804 (99.8% AITC) (40 CFR § 158.2030)

OPPTS Guideline 

No. 

Property Description of Result MRID 

Method/Reference 

830.6302 Color Colorless or pale yellow liquid 48824101

JECFA (2005) – see 

Attachment 1 1

830.6303 Physical State Liquid 48824101

JECFA (2005) – see 

Attachment 1 1

830.6304 Odor Very pungent, irritating aroma 48824101

JECFA (2005) – see 

Attachment 1 1

830.6313 Stability to Normal and Elevated 

Temperatures, Metals and Metal Ions 

Reported stable. 48824101

EPA-HQ-OPP-2009-

0904 – Vegetable and 

Flower Oils Summary 

Document for 

Registration Review – 

March 2012

830.6315 Flammability Flashpoint = 46°C 48824101

International 

Chemical Safety 

Card, CDC/NIOSH 

(1997) – see 

Attachment 1

830.6317 Storage Stability Study in progress – 

anticipated completion date is 

the last quarter of 2013. 

48824101

Per method of 

analysis used in 

OCSPP 830.1800.

830.6319 Miscibility Not Applicable; TGAI/MP is 

not an emulsifiable liquid and 

is not diluted with petroleum 

solvents. 

- 

830.6320 Corrosion Characteristics Study in progress – 

anticipated completion date is 

the last quarter of 2013. 

48824101

Visual inspection of 

packaging materials 

during a one-year 

storage stability study.

830.7000 pH 4-5 pH meter

830.7050 UV/Visible Light Absorption Refractive index 1.524-1.531; see 

http://www.fao.org/ag/agn/jefcaflav/img/img/1560.gif for the 

absorbance spectrum

48824101

JECFA (2005) – see 

Attachment 1 1

830.7100 Viscosity Not Applicable for TGAI/MP - 

830.7200 Melting Point/Range -102.5°C 48824101

International 

Chemical Safety 

Card, CDC/NIOSH 

(1997) – see 

Attachment 1

830.7220 Boiling Point/Range 

150-151°C 

148-154°C

48824101

JECFA (2005) – see 

Attachment 1 1

International 

Chemical Safety 

Card, CDC/NIOSH 

(1997) – see 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

TABLE 2. Physical and Chemical Properties of TGAI/MP IR9804 (99.8% AITC) (40 CFR § 158.2030)

OPPTS Guideline 

No. 

Property Description of Result MRID 

Method/Reference 

Attachment 1

830.7300 Density 

1.013-1.020 

1.0

48824101

JECFA (2005) – see 

Attachment 1 1

International 

Chemical Safety 

Card, CDC/NIOSH 

(1997) – see 

Attachment 1

830.7520 Particle Size, Fiber Length and 

Diameter Distribution 

Not Applicable; TGAI/MP is 

not fibrous 

- 

830.7550 

830.7560 

830.7570 

Partition Coefficient 

 (n-Octanol/Water) Log P = 2.11

48824101

IARC Monograph 

Volume 73 – see 

Attachment 1

830.7840 Water Solubility Slightly soluble in water 48824101

JECFA (2005) – see 

Attachment 1 1

830.7950 Vapor Pressure 

1.33 kPa @ 38.3°C 

0.493 kPa@ 20°C

48824101

IARC Monograph 

Volume 73 – see 

Attachment 1 

International 

Chemical Safety 

Card, CDC/NIOSH 

(1997) – see 

Attachment 1

Classification: ACCEPTABLE
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

Data submitted to support the product chemistry data requirements for the EP (; EPA File 

Symbol No. 89285-E) are summarized in Table 3 below. Physical and chemical properties data 

are summarized in Table 4 below. Refer to MRIDs 489194-01 and -02 for more information. 

TABLE 3. Product Chemistry Data Requirements for EP IRF135 (96.3% AITC) (40 CFR § 158.2030) 

OPPTS Guideline No. Study Results (below are example results) MRID 

Method/Reference 

830.1550 

to 

830.1670 

Product identity; 

Manufacturing process; 

Discussion of formation of 

unintentional ingredients 

Submitted data satisfy the requirements 

for product identity, manufacturing 

process, and discussion of formation of 

impurities. 

ACCEPTABLE

489194-01 

830.1700 Analysis of samples Not required for EP 489194-02 

830.1750 Certification of limits Limits listed in the CSF are 

ACCEPTABLE

489194-01 

830.1800 Analytical method Not required for EP 489194-02 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

TABLE 4. Physical and Chemical Properties of EP IRF135 (96.3% AITC) (40 CFR § 158.2030)

OPPTS Guideline 

No. 

Property Description of Result MRID 

830.6302 Color Not applicable per 40 CFR 

158.2030(e) – Product is an EP.

- 

830.6303 Physical State Liquid 489194-01 

Visual inspection at 

room temperature 

830.6304 Odor Not applicable per 40 CFR 

158.2030(e) – Product is an EP. - 

830.6313 Stability to Normal and Elevated 

Temperatures, Metals and Metal Ions 

Not applicable per 40 CFR 

158.2030(e) – Product is an EP. - 

830.6315 Flammability (flashpoint) 47oC 489194-02 

Pensky-Martens 

Closed Cup 

830.6317 Storage Stability Study in progress–

anticipated completion 

date is the last quarter of 

2013.

489194-01 Per 

method of analysis 

used in OCSPP 

830.1800. 

830.6319 Miscibility Not applicable per 40 CFR 

158.2030(e)(10) – EP is not 

an emulsifiable liquid and is 

not to be diluted with 

petroleum solvents.

- 

830.6320 Corrosion Characteristics Study in progress– 

anticipated completion 

date is the last quarter 

of 2013. 

489194-01 

Visual inspection 

of packaging 

materials during a 

one-year storage 

stability study. 

830.7000 pH 4.87 (1% soln) 489194-02 

pH meter 

830.7050 UV/Visible Light Absorption Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP.

- 

830.7100 Viscosity 0.6 centistokes @ 40°C 

0.8 centistokes @ 20°C 

489194-02 

ASTM D445/D446 

Test Methods and 

OPPTS 830.7100 

830.7200 Melting Point/Range Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP.

- 

830.7220 Boiling Point/Range Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP.

- 

830.7300 Density 1.019 g/mL @ 20°C 489194-02 

CIPAC MT-3, 

ASTM D891-95, 

OPPTS 830.7300 

and OECD TG 109

830.7520 Particle Size, Fiber Length and 

Diameter Distribution 

Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP.

- 

830.7550 

830.7560 

830.7570 

Partition Coefficient (nOctanol/Water) 

Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP. 

- 

830.7840 Water Solubility Not applicable per 40 CFR 

158.2030(e) – Product is an - 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

TABLE 4. Physical and Chemical Properties of EP IRF135 (96.3% AITC) (40 CFR § 158.2030)

OPPTS Guideline 

No. 

Property Description of Result MRID 

EP.

830.7950 Vapor Pressure Not applicable per 40 CFR 

158.2030(e) – Product is an 

EP.

- 

Classification: ACCEPTABLE

II. Human Health Assessment

A. Toxicology for TGAI/MP (MRID 48824108) 

The data presented in Table 5 below are a summary of the toxicity data and information 

submitted to support the TGAI/MP . Refer to the DERs for more information. 

Table 5. Mammalian Toxicology Data Requirements for TGAI/MP AITC (40 CFR § 158.2050)

Study/OPPTS Guideline No. Results Toxicity 

Category/Description 

MRID 

Acute oral toxicity (rat) 

(870.1100) 

LD50 = 425.4 mg/kg 

ACCEPTABLE 

II 488241-03 

Acute dermal toxicity (rat) 

(870.1200) 

LD50 > 200 mg/kg 

ACCEPTABLE 

II 488241-04 

Acute inhalation toxicity (rat) 

(870.1300) 

LC50 > 0.21 mg/L 

ACCEPTABLE 

II 488241-05 

Primary eye irritation (rabbit) 

(870.2400) 

Waiver due to observed corrosiveness on skin 

ACCEPTABLE 

I 1 

Primary dermal irritation (rabbit) 

(870.2500) 

Corrosive 

ACCEPTABLE 

I 488241-06 

Dermal sensitization (guinea pig) 

(870.2600) 

Sensitizer 

ACCEPTABLE 

- 488241-07 

Hypersensitivity incidents 

(885.3400) 

- - - 

90-Day oral toxicity 

(870.3100) 

Rationale submitted 

ACCEPTABLE

 488241-08 

90-Day dermal toxicity 

(870.3250) 

Rationale submitted 

ACCEPTABLE

 488241-08 

90-Day inhalation toxicity 

(870.3465) 

Rationale submitted 

ACCEPTABLE

 488241-08 

Mutagenicity 

(870.5100, 5300 and 5375) 

Rationale submitted 

ACCEPTABLE

 488241-08 

Developmental toxicity 

 (870.3700) 

Rationale submitted 

ACCEPTABLE

 488241-08 

 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

1. Acute Toxicity for the TGAI/MP IR9804 (99.8%; EPA File Symbol No. 89285-R)

The AITC technical (EPA Reg. No. 89285-R; 99.8% a.i.) is in Toxicity Category II for acute oral 

toxicity, acute dermal toxicity, and acute inhalation toxicity. It is in Toxicity Category I for 

primary eye irritation and primary dermal irritation due to its corrosivity. No hypersensitivity 

incidents have been reported. 

NOTE: All references cited in the following discussions of the rationales submitted in 

support of the Tier I data requirements may be found in the respective sections of MRID 

48824108. Similarly, more detailed discussions of Methods and Materials used in the cited 

studies may be found in MRID 48824108 or in the cited studies themselves. 

2. Subchronic Toxicity 

90-Day Oral Toxicity in Rodents (OCSPP 870.3100): A Guideline 90-day oral toxicity study 

was not submitted. In lieu of a study, the applicant submitted a rationale to support the data 

requirement. The rationale is based on the following: 

a. A 90-day oral toxicity study conducted by the National Toxicology Program (NTP, 1982) on 

 F344/N rats dosed with 1.5 to 25 mg AITC/kg-body wgt/day, five days per week for 13 

 weeks had a No Observed Adverse Effect Level (NOAEL) of 25 mg AITC/kg-body wgt/day, 

 the highest level tested. No mortalities occurred during the course of the study and no 

 treatment-related effects were observed on tissues obtained from the test animals when 

 compared to non-treated controls. There were no differences in body weights between 

 treated animals and non-treated controls. 

b. Humans are regularly exposed to AITC in the diet, and to sinigrin, a precursor to AITC, 

 which is converted to AITC by the enzyme, myrosinase, upon disruption of cells. AITC and 

 sinigrin are present at relatively high levels in cauliflower, kale, horseradish, wasabi, and 

 mustard. For example, Wasabi contains up to 34 umol of sinigrin/AITC per gram and brown 

 mustard has been shown to contain approximately 0.453 mg AITC per gram. The official 

 serving size of Grey Poupon Dijon mustard (according to the product label) is one teaspoon, 

 which is equal to 5 grams, equivalent to 2.27 mg AITC/serving (Bhattacharya et al., 2010; 

 Jiao et al., 1994; & Zhang, 2010). 

c Oral exposure to AITC when used as a soil-applied pesticide is not expected to increase 

 above normal dietary exposure in foods due to the rapid degradation of AITC in soil and 

 water. AITC degradation in soil has been reported to be rapid with a half-life ranging from 

 20 to 60 hours, with a mean half-life of 47 hours (+ 27) in six different soil types. 

 Degradation is greatest in soils with high organic matter (OM) and total nitrogen (N) content, 

 and increases with increasing temperature. Up to 97.1% AITC degrades within 10 days at 20 o

C in high OM and N soils (Borek et al., 1995; & Pechacek et al., 1997). 

d. The primary degradation products of AITC in moist soils are likely to be allyl thiocyanate 

 (ATC), allylamine (AA), and carbon disulfide, (CDS) based on experiments using AITC in 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

 aqueous solution at varying temperatures (20-80 o

C for 80 minutes) and pH levels pH 6-8). 

 ATC, an isomer of AITC, was identified at each pH level tested and is expected to degrade as 

 rapidly as AITC. Likewise, the chemically similar AA, if it is formed, is expected to degrade 

 quickly. CDS is already present in the environment and is released to terrestrial soils via 

 exudates from tree roots, and is present in tidal marshes. Increased oral exposure to AITC 

 degradates via application of AITC to soils is unlikely based on natural occurrence and the 

 environmental fate of these compounds (HSDB, 2012; & Pechacek et al., 1997). 

e. In addition, the Agency notes that the proposed end-use product is intended for use as a preplant soil treatment . The product label specifies that the soil applied product be permitted to 

completely dissipate from the treated soil prior to the planting of any crop (as determined by 

lettuce seed and/or tomato/pepper transplant bioassays. The presence of residues on edible 

commodities, as well as oral dietary exposure to AITC are highly unlikely. 

CLASSIFICATION: ACCEPTABLE

90-Day Dermal Toxicity (OCSPP 870.3250): A Guideline 90-day dermal toxicity study was 

not submitted. In lieu of a study, the applicant submitted a rationale to support the data 

requirement. The rationale is based on the following: 

a. The proposed end-use product is intended for use as a pre-plant soil treatment. 

b. The product is not intended for application to human skin. 

c. Prolonged or repeated dermal contact is not expected when the EP is applied in accordance 

 with label use directions. The application methods are: (i) tractor mounted shank injection 

 at a depth of 8 to 15 inches, followed by tarp overlay, (ii) by drip injection, also covered by 

 tarp overlay, and (iii) by deep injection to depths greater than 17 inches, with no tarp 

 covering. These application methods minimize the potential for dermal exposure. 

d. In addition, the Agency notes that the product label specifies a 48-hour re-entry interval 

unless wearing appropriate PPE (coveralls, protective eyewear, chemical resistant gloves, 

and footwear plus socks). Repeated dermal exposure to the pre-plant soil applied end-use 

product is highly unlikely. 

CLASSIFICATION: ACCEPTABLE

90-Day Inhalation Toxicity (OCSPP 870.3465): A Guideline 90-day dermal toxicity study 

was not submitted. In lieu of a study, the applicant submitted a rationale to support the data 

requirement. The rationale is based on the following: 

a. Repeated inhalation exposure to AITC aerosol, vapor or gas is highly unlikely and not 

 expected, when the EP is applied in accordance with label use directions. The application 

 methods are: (i) by tractor mounted shank injection at a depth of 8 to 15 inches, followed by 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

 tarp overlay, (ii) by drip injection, also covered by tarp overlay, and 3) by deep injection to 

 depths greater than 17 inches, with no tarp covering. These application methods minimize the 

 potential for inhalation exposure. 

b. AITC degrades readily in soil and water and, therefore, inhalation exposure is highly unlikely 

 to occur after the tarps are removed following treatment (Borek et al., 1995; Pecháček et al., 

 1997). AITC degrades rapidly in the soil with a short half-life (T1⁄2) ranging from 20 to 60 

 hours (Borek et al., 1995). The average T1⁄2 of AITC in six different soil types was reported 

 to be 47 ± 27 hours, with the greatest degradation rate of in soils that have high organic 

 carbon and total nitrogen (N) content. In addition, the AITC T1⁄2 in soil increases with 

 increasing moisture content and decreases in soil with increasing temperature between 10o

C 

 and 25oC. During the first 24 hours, an average of 29.8% of AITC was transformed, or 

 degraded, and over the first 10 days at 20o

C, an average of 97.1% was degraded (Borek et al., 

 1995). The data also demonstrate that AITC transforms in sterilized soil at the same rate as 

 intact soil, indicating that microbial populations are not responsible for the degradation 

 (Borek et al., 1995). The more rapid degradation that occurs in soil with higher levels of 

 organic carbon suggests that AITC reacts with the organic material and is inactivated. The 

 rapid degradation of AITC in treated soil suggests that inhalation exposure will be highly 

 unlikely following pre-plant soil treatments in accordance with label use directions. 

c. The metabolism of AITC has been described in evaluations of food and food additives, and is 

 not expected to be any different following inhalation exposure than following oral exposure. 

 AITC is metabolized in humans by conjugation with glutathione and this conjugate is further 

 metabolized to mercapturic acids that are eliminated via the urine (Shapiro et al., 1998). The 

 available data suggest that AITC is metabolized via the same pathways regardless of the 

 route of exposure. 

d. Based on the information discussed above in paragraph “c,” acute and subchronic oral 

 toxicity data may be used to characterize the potential risk from inhalation exposure to 

 AITC. A 90-Day Oral Toxicity study with AITC that provided a no-observed-adverse-

 effect-level (NOAEL) of 25 mg/kg/day has been conducted (NTP, 1982). AITC was 

 administered to rats by gavage at doses of 0, 1.5, 3, 6, 12, and 25 mg/kg/day for 13-weeks. 

 Any AITC inhalation exposure identified may be compared to an acceptable exposure level 

 identified based on the NOAEL from this study. 

CLASSIFICATION: ACCEPTABLE

3. Developmental Toxicity (OCSPP 870.3700): A Guideline Prenatal Developmental Toxicity 

study was not submitted. In lieu of a study, the applicant submitted a rationale to support the 

data requirement. The rationale is based on the following: 

a. Allyl Isothiocyanate (AITC) was one of 16 chemically-related compounds evaluated in a 

study designed to correlate potential developmental toxicity with molecular structure 

(Ruddick et al., 1976). In this study, a single dose of AITC was administered to pregnant 

dams at 60 mg/kg or 120 mg/kg by gavage on day 12 or 13 of gestation and the dams were 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

sacrificed on day 22 and examined for individual litter weight, litter size, and number of 

deciduomas and corpora lutea. Control animals were administered equivalent doses of either 

water or corn oil. The results were compared against pregnant dams dosed with the 

suspected teratogen, ethylenethiourea (ETU). The higher dose was close to the LD50 for 

AITC, so only results at the lower dose were used. No difference in the percentage of 

abnormal fetuses in AITC-treated offspring were detected compared to control, and no 

difference between treated and control in the % dead fetuses was detected. The authors 

concluded that AITC did not display any teratogenic potential at the NOAEL of 60 mg/kg. 

The 60 mg/kg dose would be equivalent to 4.2 g AITC for a standard 70 kg human. 

b. Human dietary exposure to AITC is common due to natural occurrence of AITC in many 

foods. Many vegetables contain AITC or produce the precursor to AITC, sinigrin, which is 

converted by the enzyme myrosinase to AITC upon disruption of the cells (Bhattacharya et 

al., 2010; Zhang, 2010) and upon exposure to moisture. Sinigrin and/or AITC levels are 

typically high in cauliflower, kale, horseradish, wasabi and mustard. Wasabi may contain up 

to 34 μmol sinigrin / AITC per gram (Zhang 2010), whereas brown mustard has been shown 

to contain approximately 0.453 mg of AITC per gram, such that a 10 gram serving contains 

4.53 mg of AITC (Jiao et al., 1994). The official serving size for Grey Poupon Dijon mustard 

identified on the label is one teaspoon, which is equal to 5 grams (2.27 g AITC equivalent or 

0.54x of the NOAEL) 

c. See discussion under part “b.” of the 90-day Inhalation rationale above. In addition, possible 

degradation products of AITC in soil can be proposed based on the decomposition products 

of AITC present in an aqueous solution in the pH range between 6 and 8, where AITC is 

proposed to degrade completely (Pecháček et al., 1997). Within this pH range, Pecháček et 

al. (1997) observed that the primary decomposition products identified at 80 o

C and in lower 

quantities at 20 o

C and 40 oC after an 80 min incubation, were: allyl thiocyanate (ATC); 

allylamine (AA); and carbon disulfide (CDS). ATC, an isomer of AITC, was identified at 

each pH and sampling interval; AA is expected to biodegrade quickly in the environment, 

and so if it is formed following AITC treatment of soil, human and animal exposure is 

unlikely (HSDB). CDS is naturally occurring in the environment, and is released from tree 

roots, tidal marshes and soil (HSDB). CDS is considered ubiquitous in the environment, and 

so formation of carbon disulfide from treating soil with AITC would not increase exposure 

over levels currently in the environment (HSDB, accessed 8/2012). 

d. Application methods together with appropriate PPE will mitigate human exposure. The 

application methods are: (i) by tractor mounted shank injection at a depth of 8 to 15 inches, 

followed by tarp overlay, (ii) by drip injection, also covered by tarp overlay, and 3) by deep 

injection to depths greater than 17 inches, with no tarp covering. These application methods 

minimize the potential for inhalation exposure. 

 Human exposure to the primary degradates of AITC identified in aqueous solutions 

following soil treatment in the environment appears unlikely based on the natural occurrence 

and environmental fate of these compounds, as well as the methods of application 

CLASSIFICATION: ACCEPTABLE
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

4. Mutagenicity (OCSPP 870.5100; 870.5300; & 870.5375): Guideline Mutagenicity studies 

were not submitted. In lieu of a study, the applicant submitted a rationale to support the data 

requirements. The rationale is based on the following: 

a. The National Toxicology Program (NTP) has conducted a battery of mutagenicity studies 

(NTP, 1981, 1988, & 1991) on AITC, including a Bacterial Reverse Mutation Assay using S. 

typhimurium strains TA100, TA1535, and TA99 with and without S9 activation; and In 

Vitro Mammalian Gene Mutation Test using mouse lymphoma L5178Y TK+/- cells; and an 

In Vivo Mammalian Chromosome Aberration Test. 

b. Two reverse mutation studies (NTP, 1981) confirmed that mutagenicity responses were 

negative in all strains tested with and without S9 activation. 

c. Three in vitro mammalian gene mutation studies were conducted using mouse lymphoma 

cells without S9 activation (NTP, 1988). A negative response was observed in the first trial 

using mouse lymphoma cells without S9 activation at concentrations ranging from 0.05 to 

0.8 mg/mL AITC. A second trial without S9 exhibited a significant increase in average 

mutant frequency and significant reduction in relative total growth at AITC concentrations of 

0.4, 0.6, and 0.8 mg/mL; 1.0 mg/mL was cytotoxic. A third trial without S9 also exhibited a 

significant increase in average mutant frequency at concentrations of 0.6 to 1.4 mg/mL and a 

significant reduction in growth; a concentration of 1.6 mg/mL was cytotoxic. It is noted that 

the positive results were observed without S9 activation and in the presence of substantial 

cytotoxicity. 

d. An in vivo mammalian chromosome aberration study (NTP, 1991) was conducted with mice 

dosed intraperitoneally with 0, 25, or 50 mg/kg AITC and compared against mice dosed with 

a positive control, dimethylbenzanthracine (DMBA). Increases in chromosome aberrations 

were not observed in AITC treated mice when compared to non-treated (negative) controls, 

while a positive response was observed in DMBA-treated mice. 

e. The weight of evidence demonstrates that AITC is not likely to be a mutagen. In addition, 

the method of application and rapid degradation rate, together with appropriate PPE, 

mitigates exposure to humans. 

 CLASSIFICATION: ACCEPTABLE

B. Toxicology for EP (MRID 488919103) 

Guideline studies for acute toxicity testing were not submitted. In lieu of Guideline studies, the 

registrant submitted a request to bridge the acute toxicity data submitted in support of the 

TGAI/MP (containing 99.8% AITC) to support the acute toxicity data requirements for the EP 

(containing 96.5% AITC) which also contains 3.5% (w/w) of a well known surfactant approved 

for formulation with food use pesticides under 40 CFR 180.910. 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

Conclusions: The concentration of AITC is slightly lower in the EP (96.5%) than in the 

TGAI/MP (99.8%). Furthermore, the inclusion of a relatively small amount of a well known 

surfactant (3.5% of product, w/w) that is already approved for food use (under 40 CFR 180.910), 

is not expected to change the toxicity profile. The bridging of acute toxicity data submitted in 

support of the TGAI/MP registration to support the registration of the EP, is acceptable. 

CLASSIFICATION: ACCEPTABLE 

III. Nontarget Organism Assessment (MRID 48824108) 

The data presented in Table 6 below are a summary of the nontarget organism toxicity data and 

information submitted to support of the TGAI/MP. Refer to the appropriate pages in MRID 

48844108 for more detailed information and specific reference citations from the scientific 

literature. . 

Table 6. Non-Target Organism Data Requirements for TGAI/MP AITC (40 CFR § 158.2060)

Study/OPPTS Guideline No. Results Toxicity Category/Description MRID 

Avian Acute Oral/OPPTS 

850.2100 

Rationale submitted 

ACCEPTABLE 

No acute oral exposure based 

on application method and 

rapid environmental 

degradation 

48824108, p. 18 

Avian Dietary/OPPTS 850.2200 

Rationale submitted 

ACCEPTABLE 

No dietary exposure based on 

application method and rapid 

environmental degradation 

48824108, p. 20 

Freshwater Fish LC50/OPPTS 

850.1075 

Rationale submitted 

96-hr LC50 = 0.077 ppm 

ACCEPTABLE 

Very Highly Toxic, but no 

aquatic exposure based on 

application method and rapid 

environmental degradation 

48824108, pp. 22, 

37-47 

Freshwater Invertebrate/OPPTS 

850.1010 

Rationale submitted 

48-hr EC50 = 0.73 ppm 

ACCEPTABLE 

Very Highly Toxic, but no 

aquatic exposure based on 

application method and rapid 

environmental degradation 

48824108, pp. 23, 

216-221 

Non-target Plants/OPPTS 

850.4100 & 4150 

Rationale submitted 

ACCEPTABLE 

No non-target exposure based 

on application method and 

rapid environmental 

degradation 

48824108, pp. 24-

27 

Non-target Insects Rationale submitted

ACCEPTABLE 

No non-target exposure based 

on application method and 

rapid environmental 

degradation 

48824108, pp. 28, 

29 

 

SUMMARY: 

Guideline studies were not submitted in support of the non-target organism data requirements. 

In lieu of Guideline studies, the applicant submitted rationales, on a Guideline-by-Guideline 

basis, for each non-target organism data requirement, which were supported both by scientific 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

literature citations as well as an argument for a lack of exposure to non-target organisms to AITC 

based on its rapid degradation in soil, its widespread presence in commonly eaten foods, as well 

as by the methods and timing of application of the EP. 

AITC degrades readily in soil and water and, therefore, inhalation exposure is highly unlikely to 

occur after the tarps are removed following treatment (Borek et al., 1995; Pecháček et al., 1997). 

AITC degrades rapidly in the soil with a short half-life (T1⁄2) ranging from 20 to 60 hours (Borek 

et al., 1995). The average T1⁄2 of AITC in six different soil types was reported to be 47 ± 27 

hours, with the greatest degradation rate of in soils that have high organic carbon and total 

nitrogen (N) content. In addition, the AITC T1⁄2 in soil increases with increasing moisture 

content and decreases in soil with increasing temperature between 10o

C and 25oC. During the 

first 24 hours, an average of 29.8% of AITC was transformed, or degraded, and over the first 10 

days at 20o

C, an average of 97.1% was degraded (Borek et al., 1995). The data also demonstrate 

that AITC transforms in sterilized soil at the same rate as intact soil, indicating that microbial 

populations are not responsible for the degradation (Borek et al., 1995). The more rapid 

degradation that occurs in soil with higher levels of organic carbon suggests that AITC reacts 

with the organic material and is inactivated. The rapid degradation of AITC in treated soil 

suggests that inhalation exposure will be highly unlikely following pre-plant soil treatments in 

accordance with label use directions. 

In addition, possible degradation products of AITC in soil can be proposed based on the 

decomposition products of AITC present in an aqueous solution in the pH range between 6 and 

8, where AITC is proposed to degrade completely (Pecháček et al., 1997). Within this pH range, 

Pecháček et al. (1997) observed that the primary decomposition products identified at 80 o

C and 

in lower quantities at 20 oC and 40 oC after an 80 min incubation, were: allyl thiocyanate (ATC); 

allylamine (AA); and carbon disulfide (CDS). ATC, an isomer of AITC, was identified at each 

pH and sampling interval; AA is expected to biodegrade quickly in the environment, and so if it 

is formed following AITC treatment of soil, human and animal exposure is unlikely (HSDB). 

CDS is naturally occurring in the environment, and is released from tree roots, tidal marshes and 

soil (HSDB). CDS is considered ubiquitous in the environment, and so formation of carbon 

disulfide from treating soil with AITC would not increase exposure to non-target organisms over 

levels currently in the environment (HSDB, accessed 8/2012). 

IRF135 is an end-use product (EP) formulated from IR9804, which is a technical grade active 

ingredient (TGAI/MP) containing 99.8% allyl isothiocyanate (AITC). IRF135 is approximately 

96.5% AITC and 3.5% of a well known surfactant approved for food use under 40 CFR 

180.910. IRF135 is intended for use in an as a pre-plant soil treatment to control and repel 

fungi, insects, nematodes and weeds. AITC is a component of many common cruciferous 

vegetables including broccoli and Brussels sprouts, and is particularly concentrated in mustard 

seed, horseradish, and wasabi. 

Application methods together with appropriate PPE will mitigate human exposure. The 

application methods are: (i) by tractor mounted shank injection at a depth of 8 to 15 inches, 

followed by tarp overlay, (ii) by drip injection, also covered by tarp overlay, and 3) by deep 

injection to depths greater than 17 inches, with no tarp covering. These application methods 

minimize the potential for exposure to non-target organisms. 
AITC (in Oil of Mustard) DP Numbers: 406246 & 406248

PC Code: 051102 EPA File Symbol Nos.: 89285-R & -E 

Product chemistry, Tier I Tox, Non-Target Organisms Hazard Assessment 

CLASSIFICATION: ACCEPTABLE