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EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR 

PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: [P.V. Shah, 703-308-1846]

INSTRUCTIONS: Please utilize this outline in preparing the pesticide petition. In 

cases where the outline element does not apply, please insert “NA-Remove” and 

maintain the outline. Please do not change the margins, font, or format in your 

pesticide petition. Simply replace the instructions that appear in green, i.e., “[insert 

company name],” with the information specific to your action.

TEMPLATE:

[Ecolab, Inc.]

1E7936

EPA has received a pesticide petition (1E7936) from Exponent on behalf of 

Ecolab, Inc. (Ecolab, EPA Company Number 1677)], [370 N. Wabasha Street, St. Paul, 

Minnesota, 55102] requesting, pursuant to section 408(d) of the Federal Food, Drug, and 

Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 to establish an 

exemption from the requirement of a tolerance for Sodium Xylene Sulfonate (SXS, CAS 

# 1300-72-7) under 40 CFR 180.940(a) for use as an inert ingredient in antimicrobial 

pesticide formulations applied to food-contact surfaces in public eating places, dairyprocessing equipment, and food-processing equipment and utensils at 500 parts per 

million (ppm). EPA has determined that the petition contains data or information 

regarding the elements set forth in section 408 (d)(2) of FDDCA; however, EPA has not 

fully evaluated the sufficiency of the submitted data at this time or whether the data 

supports granting of the petition. Additional data may be needed before EPA rules on the 

petition.

A. Residue Chemistry

1. Plant metabolism. [Not applicable/Not required for the establishment of a 

tolerance exemption for inert ingredients.]

2. Analytical method. [Not applicable/Not required for the establishment of a 

tolerance exemption for inert ingredients.]

3. Magnitude of residues. [Not applicable/Not required for the establishment of a 

tolerance exemption for inert ingredients.]

B. Toxicological Profile
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1. Acute toxicity. [The acute toxicity data indicate that the hydrotropes category

described in the OECD SIDS Assessment, which includes SXS, has a low hazard 

potential. Acute oral LD50 values for rats range from 1,044 mg a.i./kg bw, (calcium 

xylene sulfonate) to 6,480 mg a.i./kg bw (sodium xylene sulfonate). The acute dermal 

LD50 value was >2000 mg/kg bw (624 mg a.i./kg bw following 24 hr exposure). The 

inhalation LC50 in rats was > 557 mg/L. Overall, hydrotropes, and therefore SXS, 

demonstrate a relatively low order of acute oral and dermal toxicity. The hydrotropes 

category is considered to have a low skin and eye irritation potential. Sodium xylene 

sulfonate was not found to be a skin irritant.]

2. Genotoxicty. [The hydrotropes category, including SXS, has been assessed for 

mutagenic/genotoxic potential in a variety of in vivo and in vitro assays, specifically:

mouse micronucleus assays with calcium xylene sulfonate and sodium cumene sulfonate, 

an Ames assay, mouse lymphoma, sister chromatid exchange, and chromosome 

aberration assay with SXS, an Ames assay with calcium xylene sulfonate and an Ames 

assay with sodium cumene sulfonate. EPA has previously concluded that there were no 

positive results in the in vitro or in vivo genotoxicity studies, and that there was no 

evidence of carcinogenic potential for both mice and rats dermally exposed for two 

years.]

3. Reproductive and developmental toxicity. [There are no reproductive toxicity 

studies reported for hydrotropes. However, EPA concluded that the 91-day oral rat 

feeding study with sodium cumene sulfonate, the 90-day feeding study with SXS, and the 

2-year dermal study with SXS included examination of the reproductive organs of both 

sexes and there is no evidence to suggest that SXS would have an adverse effect on 

reproductive organs.

No developmental effects or maternal toxicity were observed in a developmental toxicity 

study in rats conducted with calcium xylene sulfonate. The NOAEL for maternal and 

fetal toxicity was set at the highest dose tested, 3000 mg/kg bw/day or 936 mg a.i./kg 

bw/day. Based on this OECD guideline study, hydrotropes, including SXS, are not 

considered to be developmental toxicants.]

4. Subchronic toxicity. There are several oral and dermal repeat dose subchronic 

studies. EPA has previously concluded that no significant systemic toxicity was noted in 

the dermal studies. The most appropriate NOAEL for local effects was determined to be 

440 mg a.i./kg bw based on epidermal hyperplasia at the site of application (dermal 

exposure) in male mice. 

EPA determined that the most appropriate NOAEL for systemic toxicity from the oral 

subchronic studies was 763 mg/kg bw/day from a 90-day rat oral toxicity study. Effects 

observed in this study were a decrease in spleen weight in females along with some 

clinical chemistry and hematology changes. No adverse effects were reported in males.]

5. Chronic toxicity. [Chronic toxicity/carcinogenicity data for rats and mice 

dermally exposed to SXS for two years showed no treatment related effects with the 

exception of epidermal hyperplasia at the application site in female rats at 120 and 240 
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mg. Based on these data, EPA concluded that there was no evidence of carcinogenic 

potential for SXS.]

6. Animal metabolism. [There are no adsorption, distribution, metabolism and 

elimination studies for the hydrotropes category identified in the OECD SIDS 

Assessment. However, based on available physicochemical properties of the hydrotropes 

(molecular weight of 194-226, water solubility of 553 g/L and octanol/water partition 

coefficient (Log P) value of –2.7) and available toxicological information, the OECD 

SIDS Assessment made qualitative comments regarding absorption, concluding that the 

available data suggest that absorption will be significantly greater following oral 

exposure as compared to dermal exposure.]

7. Metabolite toxicology. [No metabolites of toxicological concern are expected.]

8. Endocrine disruption. [SXS does not belong to a class of chemicals known or 

suspected of having adverse effects on the estrogen receptor or endocrine system. SXS in 

association with the structurally similar compounds included in the OECD Hydrotropes 

Category have been evaluated in acute, repeated dose, developmental, and chronic 

toxicity studies capable of detecting effects on endocrine mediated events.]

C. Aggregate Exposure

1. Dietary exposure. [Dietary (food and drinking water) and residential (dermal 

and inhalation) exposures are possible from the use of SXS as an inert ingredient in 

antimicrobial formulations. SXS is predicted to be readily biodegradable, which will 

reduce the likelihood of residues on food. For the same reason EPA did not anticipate 

significant contributions to drinking water from the use of hydrotropes as inert 

ingredients in pesticide products. Hydrotropes have low toxicity and exposure to residues 

above toxicity levels of concern are not anticipated. 

The proposed chronic Population Adjusted Dose (cPAD) for SXS is 7.63 mg/kg/d based 

on the NOAEL of 763 mg/kg/d for reduction in relative spleen weight in female rats from 

a 90-day oral toxicity study. The standard 10X uncertainty factors for inter- and intraspecies extrapolation are applied to calculate the cPAD. 

A dietary risk assessment was conducted using the proposed use pattern for SXS as an 

inert ingredient in antimicrobial formulations. Conservatively estimated potential SXS 

dietary exposures resulting from the use of sanitizing solutions containing SXS are very 

low even when all potential sources are considered. Total exposure estimates reported 

are 0.061% of the cPAD for adult males, 0.071% of the cPAD for adult females and

0.28% of the cPAD for children.]

i. Food. [Exposures are well below 100% of the cPAD, and are therefore below 

EPA’s established level of concern for all U.S. subpopulations.]

ii. Drinking water. [Dietary and residential exposures are possible from the use of 

SXS as an inert ingredient in pesticide products. Hydrotropes are predicted to be readily 
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biodegradable according to OECD criteria, which will reduce the likelihood of residues 

on food. For the same reason, EPA did not anticipate significant contributions to drinking 

water from these chemicals as inert ingredients in pesticide formulations applied to 

growing crops and animals. Exposures to residues above toxicity levels of concern are

not anticipated.]

2. Non-dietary exposure. [The greatest non-dietary exposure to the consumer was 

considered dermal exposure following use of personal care products, typically diluted 

during use and then rinsed off. Dermal contact may also occur with laundry and/or

cleaning products. There is some potential for incidental / accidental ingestion of, and/or 

eye contact with, product during handling and use. Low volatility minimizes the potential 

for inhalation. Given the low estimate of dietary exposure from uses of SXS in 

antimicrobial formulations, there is ample room in the overall aggregate MOE to 

conservatively account for non-dietary uses of SXS.]

D. Cumulative Effects

[EPA previously assumed that hydrotropes do not have a common mechanism of 

toxicity with other substances. For the purpose of the tolerance exemption action cited 

herein, Ecolab has assumed that SXS will not have a common mechanism of toxicity 

with other substances.]

E. Safety Determination

1. U.S. population. [Based on the conservative exposure estimates, there is a 

reasonable certainty that no harm will result to the U.S. population from the aggregate 

exposure to SXS]

2. Infants and children. [The FFDCA Section 408 requires an additional tenfold 

margin of safety for the protection of infants and children in case of threshold effects to 

account for prenatal and postnatal toxicity, and an inadequate toxicity database. Where 

an adequate and reliable database is available and there is a lack of evidence for increased 

susceptibility, the FQPA safety factor may be reduced or removed. 

An evaluation of susceptibility and uncertainty issues associated with SXS has been 

performed, and EPA has previously reduced the FQPA safety factor from the default 10X 

to 1X for the following reasons: 

•

•

The availability of a substantial and scientifically sound mammalian toxicology 

database that includes acute, repeat dose, reproduction, developmental, chronic 

and carcinogenicity toxicity data for Hydrotropes, including CAS # 1300-72-7;

•

OECD testing indicating that there was no evidence of developmental toxicity or 

malformations in the developing offspring;

•

There is no evidence to suggest that SXS would have an adverse effect on the 

reproductive organs;

SXS does not belong to a class of chemicals known or suspected of having 
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adverse effects on the estrogen receptor or endocrine system. SXS in association 

with the structurally similar compounds included in the OECD Hydrotropes 

Category have been evaluated in acute, repeated dose, developmental, and chronic 

toxicity studies capable of detecting effects on endocrine mediated events.]

F. International Tolerances

[There are no known international tolerances for SXS specified in this petition.]