UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

July 29, 2014 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: PC Code: 878001; Sulfuric Acid; Human Health Risk Assessment and 

Ecological Effects Assessment to Support Proposed Exemption from the 

Requirement of a Tolerance When Used as Inert Ingredients in Pesticide 

Formulations. 

All PC Code: 878001 DP Barcode: N/A 

Decision No.: N/ A 

Petition No: IN-10654 

Inert Tracking No: N/A 

Regulatory Action: Inert 

Tolerance Exemption; 40 

CFR 180.940(a). 

All CAS Reg. No: 7664-

93-9 

FROM: 

Inert 

Lisa Austin, 

Ingredient 

Ph.D., 

Assessment 

Toxicologist 

Branch (IIAB) 

~ ~ Registration Division (7505P) 

THROUGH: Kerry Leifer, Team Leader 

Inert Ingredient Assessment Branch (IIA 

Registration Division (7505P) 

TO: PV Shah, Ph.D., Branch Chief 

Inert Ingredient Assessment Branch (IIAB) 

Registration Division (7505P) 

Page 1 of 13 
I. EXECUTIVE SUMMARY 

EPA received a petition (IN-10654) from Exponent, Inc. (1150 Connecticut Avenue, NW 

Washington, DC 20036), on behalfofEcolab (370 N. Wabasha St., St. Paul, MN 55102) 

requesting an exemption from the requirement of a tolerance for sulfuric acid (CAS Reg. No. 

7664-93-9) for use as an inert ingredient on food contact surfaces in public eating places, dairy 

processing equipment and food processing equipment and utensils up to 600 ppm in microbial 

formulations under 40 CFR part 180.940(a). EPA published the notice of filing (NO F) for this 

petition in the Federal Register on July 19, 2013 (78 FR 43117). No comments were received in 

response to this notice. 

Currently, sulfuric acid is exempt from the requirements of a tolerance under 40 CFR § 180. 940(b) 

and (c) (dairy processing equipment and food processing equipment and utensils; limited to 288 

and 228 ppm, respectively), 40 CFR § 180.910 (pre- and post-harvest crop uses as pH control 

agent, limited to 10% in pesticide formulations) and 40 CFR § 180.1019 (limited to 10% in 

pesticide formulations). It is approved by the Food and Drug Administration under 21 CFR § 

184.1095 for Direct Food Substances Affirmed as Generally Recognized as Safe (GRAS). 

In September, 2006, the EPA published the "Tolerance Reassessment Decisions for 40 CFR 

§180.940 Tolerance Exemptions" which included sulfuric acid. In 2008, the Agency published the 

"Mineral Acids Summary document: Registration Review", "Sulfuric acid on potato vines: 

Registration Review Scoping Document for Human Health Assessments", "Summary of Human 

Health Effects Data for the Mineral Acids Registration Review Decision Document" and the 

"Summary of Product Chemistry Fate, and Ecotoxicology Data for the Sulfuric Acid Registration 

Review Decision Document". The toxicological database for sulfuric acid is considered adequate. 

The conclusions and recommendations presented herein rely principally on the Agency's previous 

analyses. No new data have been received by the Agency which might alter the conclusions 

presented in the 2008 Mineral Acids Registration Review Decision Document. 

Sulfuric acid is a strong acid. In water it dissociates into sulfate ions and hydrogen protons, it also 

decreases the pH. The extent and duration of the drop will depend on the neutralizing ions, the 

buffering capacity, and the dilution. Many of the end-use products are significantly diluted and 

this has a large effect on the overall toxicity of the chemical as the acid is neutralized in water and 

would dissociate to ions. (EPA, November 25, 2008). 

As no new data were submitted for review, the following summary was reproduced from the 

Registrant's submission which included the following documents: the EPA's "Tolerance 

Reassessment Decision for 40 CFR § 180.940 Tolerance Exemptions", "Summary of Product 

Chemistry Fate, and Ecotoxicology Data for the Sulfuric Acid Registration Review Decision 

Document", "Sulfuric acid on potato vines: Registration Review Scoping Document for Human 

Health Assessments", and "Summary of Human Health Effects Data for the Mineral Acids 

Registration Review Decision Document". Also, included in the submission was the "Sulfuric 

Acid SIDS Initial Assessment Report for 11th SIAM UNEP Publication", this was also 

reproduced. 

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The acute oral toxicity of sulfuric acid in rats is moderate, the LDSO =350 mg/kg (toxicity category 

II). The acute dermal toxicity in rabbits is moderate, the LD 50> 2000 mg/kg (toxicity category 

III). The acute inhalation in guinea pigs is in toxicity category III, the LCSO is 18 mg/m3. 

Sulfuric acid is corrosive to the eyes and skin in rabbits. 

Data from repeated dosing toxicity studies with animals are not available for sulfuric acid. Based 

on the toxicity data reviewed for the 2002 TRED, there are no adverse effects that would be 

expected from dietary exposure to the general population or infants and children for sulfuric acid. 

In fact, sulfuric acid would not be present in consumed foods. The small amounts of acids that 

might be added to a food during processing react rapidly with a food substance. Thus, the exposure 

is actually to sulfate residues. In an aqueous environment, sulfuric acid rapidly ionizes to sulfate 

ions and enters the body electrolyte pool (OECD SIDS, Sulfuric Acid, 2001). Following ingestion, 

sulfate anions are predominantly not absorbed from the gastrointestinal tract and are excreted 

unchanged in urine. However, the sulfate anion is a normal constituent in the body, predominantly 

resulting from the body's metabolism of sulfur-containing food sources such as foods containing 

the essential amino acids cysteine and methionine. Sulfate anions are vital components in a 

number of human biosynthetic pathways such as cartilage production and the formation of 

pancreatic digestive enzymes. Additionally, the sulfate anion is also an important conjugate in the 

Phase II conjugation/ elimination of oxidized (OH) aromatic ring metabolites and for hydroxyl 

steroid hormones, such as estrogen, where it acts as a transport agent to target organ tissue 

receptors. Therefore, the sulfate anion will not play a specific toxicological role. 

Sulfuric acid was not mutagenic in the Ames test. It caused chromosomal aberrations in a nonbacterial test in vitro. However, it is well known that the aberrations were a consequence of 

reduced pH. 

Neither a neurotoxicity nor an immunotoxicity study was avail(:lble for review. However, any 

sulfuric acid absorbed into the body would be in the form of inorganic sulfate, which is 

indistinguishable from endogenous sulfate. As a normal body constituent, sulfate is unlikely to be 

neurotoxic or immunotoxic. 

Dietary exposure (food and drinking water) to sulfuric acid can occur following ingestion of foods 

with residues from food-contact surface sanitizing solutions for public eating places, treated dairyand food-processing equipment and utensils; pre- and post-harvest crop uses and as a direct food 

additives. However, a quantitative dietary exposure assessment was not conducted since an 

endpoint for risk assessment was not identified. 

Residential (dermal and inhalation) exposure are not expected from the current requested use 

pattern. However, residential (dermal and inhalation) exposure can occur from the use of 

consumer products containing sulfuric acid (ie. stain remover, drain solutions). Since an endpoint 

for risk assessment was not identified, a quantitative residential exposure assessment for sulfuric 

acid was not conducted. 

In considering aggregate exposure, information concerning exposures from the pesticide residue in 

food due to the use of sulfuric acid on pre- or post-harvest commodities; dairy processing 

equipment, food processing equipment and utensils, a direct food substance; and all other nonoccupational exposures, including drinking water from ground water or surface water and exposure 

Page 3 of13 
through pesticide use in gardens, lawns, or buildings (residential and other indoor uses). Since a 

quantitative assessment was not performed an aggregate assessment was not necessary. 

The Agency believes that amending the existing tolerance exemption to include 40 CFR § 

180.940(a) will not significantly increase occupational. exposure. The change in use pattern would 

be expanded to include food contact surfaces such as tableware, utensils, dairies and beverage and 

food processing plants. Based on the regulatory history of sulfuric acid and no new toxicological 

information to indicate otherwise, it is not necessary to quantitatively assess occupational 

exposure. 

Potential areas of environmental justice concerns, to the extent possible, were considered in this 

human health risk assessment, in accordance with U.W. Executive Order 12898 "Federal Actions 

to Address Environmental Justice in Minority Populations and Low-Income Populations" 

http://www.eh.doe.gov/oepalguidance/justice/eo 12898.pdf. 

Environmental fate data for sulfuric acid were not submitted for review. All environmental fate 

and ecological effects data for sulfuric acid were waived. The Agency concluded that the 

registered uses of sulfuric acid did not pose unreasonable adverse effects and risks to the 

environment (Gowda, S. 11124/2008, D359048). 

Taking into consideration all available information on sulfuric acid (CAS Reg. No. 7664-93-9), 

EPA concludes that there is a reasonable certainty that no harm will result to the general 

population or to infants and children from exposure to sulfuric acid. Therefore, the establishment 

of an exemption from tolerance under 40 CFR 180.940(a) for residues of sulfuric acid for use as an 

inert ingredient on food contact surfaces in public eating places, dairy processing equipment and 

food processing equipment and utensils up to 600 ppm in microbial formulations in the endproduct formulation can be considered safe under section 408 of the FFDCA. 

II. BACKGROUND 

On September 30, 2013 Exponent, Inc. (1150 Connecticut Avenue, NW Washington, DC 

20036 submitted a petition (IN-1 0654) requesting an amendment to 40 CFR 180 by establishing an 

exemption from the requirement of a tolerance for residues of sulfuric acid (CAS Reg. No. 7664-

93-9), when used as an inert ingredient, at a concentration not to exceed 600 ppm in microbial 

formulations used on food contact surfaces in public eating places, dairy processing equipment and 

food processing equipment and utensils. EPA published the NOF for this petition in the Federal 

Register on February 25, 2014 (79 FR 10460). No comments were received in response to this 

notice. 

Sulfuric acid is a clear, colorless, odorless, viscous liquid that is very corrosive and infinitely 

soluble in water in all proportions. It is used in many industries, as agricultural fertilizer, 

production of dyes, alcohols, plastics, rubber, ether, glue, film, explosives, drugs, paints, food 

containers, wood preservatives, soaps and detergents, pharmaceutical products, petroleum 

products, pulp and paper. Principal uses include ore processing, fertilizer manufacturing, oil 

refining, wastewater processing, and chemical synthesis. 

Page 4 of 13 
Currently, sulfuric acid is exempt from the requirements of a tolerance under 40 CFR § 180.940(b) 

and 40 CFR § 180. 940( c) when used in antimicrobial pesticide formulations for uses on dairy 

processing equipment and food processing equipment and utensil, when end-use concentrations do 

not exceed 288 and 228 ppm, respectively, when ready for use. It is also approved under 40 CFR 

§ 180.910 for pre- and post-harvest crop uses or raw agricultural commodities after harvest at up to 

1 0% in a pesticide formulation. It is approved as an active ingredient and has an exemption from 

the requirement of a tolerance as listed in 40 CFR § 180.1019 with a limitation of 10% of the 

pesticide formulation (non-aerosol formulations only). 

In addition, it is approved by the Food and Drug Administration under 21 CFR § 184.1095 (pH 

control agent, processing aid) for Direct Food Substances Affirmed as Generally Recognized as 

Safe (GRAS). 

Previously, sulfuric acid was included in the Mineral Acids Registration Eligibility Document 

published in December, 1993. Its inert and active ingredient uses were reassessed in 2006. In 

2008, the Registration Review docket for Mineral Acids (including sulfuric acid) was opened and 

the following documents were included: Summary of Human Health Effects Data for the Mineral 

Acids Registration Review Decision Document", the "Summary of Product Chemistry Fate, and 

Ecotoxicology Data for the Sulfuric Acid Registration Review Decision Document", Mineral 

Acids Summary Document: Registration Review", and "Sulfuric acid on potato vines: Registration 

Review Scoping Document for Human Health Assessments". The toxicological database for 

sulfuric acid is adequate. 

Much of the discussion of sulfuric acid is taken from the Registrant's petition which includes the 

aforementioned documents. 

III. PHYSICAL/CHEMICAL PROPERTIES 

Sulfuric acid is a clear, colorless, odorless, viscous liquid that is very corrosive and infinitely 

soluble in water in all proportions. In water sulfuric acid completely dissociates to hydronium 

cations (H30+) and sulfate anions (Soi·). 

Table 1. Physical and Chemical Properties of Sulfuric Acid 

Parameter Value Source 

0 

II so-s-oa 

Structure II Summary of Product Chemistry, 0 Environmental Fate and 

Ecotoxicity Data for the Sulfuric 

Acid Registration Review 

Chemical Name Oil of vitriol, Dihydrogen sulfate Decision Document 

CAS# 7664-93-9 

Molecular Weight (g/mol) 98.078 

Common Names Sulfuric acid 

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