Page 2 of 9 HPMTS REGISTRATION REVIEW DECISION

PRODUCT CHEMISTRY, ENVIRONMENTAL FATE AND ECOLOGICAL EFFECTS SUMMARY

PC Code: 035604 ; Case No. 3033

Introduction:

HPMTS is an organosulfur compound known by the trade name Busan 74. Chemically, HPMTS (2- H ydroxy p ropyl m ethane t hio s ulfonate) is Methanesulfonothioic acid, S-(2- hydroxypropyl) ester. It is a tr ansparent, amber colored liquid with a sour, pungent, vegetablelike odor, is completely soluble in water and has a high vapor pressure of 1.78 mm Hg @ 25°C.

HPMTS (80% TGAI) was first registered wi th the EPA on February 2, 1971. Currently there is only one active product registered for form ulating use and there are no registered end-use products. See Table 1 below. A Reregistration Eligibility Decision (RED ) was issued by EPA in December 1995.

The chemical name for the active ingredient in this registration review case is 2- hydroxypropyl methanethiolsulfonate (HPMTS). Bu san 74 is a trade name that refers to a product, which is no longer registered, that co ntained HPMTS as an active ingredient. Although the name for this registration review case is Busa n 74, hence forward this cas e will be referred to by its chemical name, 2-hydroxypropyl- methanethiolsulfonate (HPMTS).

Table 1. Registered Active Products of HPMTS

Registration Number Registration Name Company Name Formulation Type % of Active Ingredient

1448-31 HPMTS Buckman Laboratories Inc. Formulating Use Only 80%

Use Patterns:

For Formulating Use Only.

No use sites or use patterns are listed on the label.

HPMTS EPA Reg. No.: 1448-31 Active Ingredient: 2-Hydroxypropyl methanethiosulfonate 80% For formulating use only.Page 3 of 9 Science Findings

The Agency has conducted a review of the available product chemistry, environmental fate and ecotoxicity data for HPMTS. The findings are summarized below.

Product Chemistry Summary

The data submitted pertaining to the physical and chemical characteristics of the active ingredient, HPMTS are adequate. All product ch emistry data requirements have been fulfilled for the active ingredient HPMTS. Therefore, th e Agency does not antici pate needing additional product chemistry data for HPMTS at this time. Tables 2 and 3 contain the chemical and physical properties of HPMTS.

Table 2. Chemical Identity of HPMTS

Chemical Name HPMTS

Common Names Methanesulfonothioi c acid, S-(2-hydroxypropyl) ester Synonyms 2-Hydroxypropyl methanethiosulfonate (HPMTS) Methanesulfonic acid, thio -, S-(2-hydroxypropyl) ester S-(2-Hydroxypropyl) thiomethanesulfonate Trade Name Busan 74 Molecular Weight 171.25 g/mole

PC Code 035604 CAS Registry Number 30388-01-3 Molecular Formula C 4 H 10 O 3 S 2 Registration Review Case No. Registration Review Case Name 3033 Busan 74 Classification Sulfonate ThiosulfonatesTable 2. Chemical Identity of HPMTS

Molecular Structure: CH 3 CH(OH)CH 2 SSO 2 CH 3

Table 3. Product Chemistry Data Summary of HPMTS (TGAI 80 %)

Page 4 of 9 Guideline No. Physical and Chemical Properties Value

830.1550 Product identity and composition Refer to Table 2

830.1600 Description of materials used to produce the product CBI

830.1620 Description of production

process CBI

830.1650 Description of formulation

process CBI

830.1670 Discussion of formation of impurities CBI

830.1700 Preliminary analysis CBI 830.1750 Certified limits CBI 830.1800 Enforcement analytical method Gas chromatography

830.1900 Submittal of samples NA 830.6302 Color Light yellow/brilliant yellow 830.6303 Physical State Tran sparent, amber liquid with no trace of solid or sediment. 830.6304 Odor Strong sour, pungent vegetable-like odor 830.6313 Stability to sunlight, normal and elevated temperature, metals/metal ions % Change from nominal after 4 days exposure to: Iron: -4.01% Copper: -0.14% Aluminum: -1.63% After 24 cumulative hours exposure to sunlight: -1.11 % Some evidence of separation af ter 18 hours in 1:20 water solution. 830.6314 Oxidation/Reduction: Chemical Incompatibility Not required; product does not contain any oxidizing or reducing agent. 830.6315 Flammability/Flame Not required; product does not contain any combustible liquids.Page 5 of 9 Guideline No. Physical and Chemical Properties Value

extention 830.6316 Explodability Not required; product is not potentially explosive. 830.6317 Storage Stability Stable under all storage conditions The concentration of HPMTS decreased 2.8% when stored at room temperature over a 12-month test period. 830.6319 Miscibility Not required, product will not be diluted with petroleum solvents.

830.6320 Corrosion Characteristics No signs of corrosion were noted in the packaging material over the one-year storage period at room temperature. 830.6321 Dielectric breakdown voltage N/A

830.7000 pH 3.7 at 22°C

830.7050 UV/Visible Light Absorption Not Required for TGAI

830.7100 Viscosity Not determinable by standard method; test material crystallized at 20 °C 830.7200 Melting point N/A; product is a liquid

830.7220 Boiling point 164°C 830.7300 Density 1.2893 at 22°C 1289.3 (1.2893 relative density) kg/m3 @ 22 °C 830.7370 Dissociation Constant Not applicable for this active ingredient 830.7550 Partition coefficient ( n

octanol/water) Not applicable for organic, polar active ingredients

830.7840 Solubility in water At concentrations > 40%, soluble at any concentration; at concentrations < 40%, not completely soluble

Completely soluble in water 830.xxxx Solubility in organic solvents Ethanol Miscible in all proportions Hexane <16 mg in 100 ml C8-18 Fatty Acids Mean fat solubility at 37°C is 5.42+0.04 g/100 g 830.7950 Vapor pressure 1.40 mm Hg at 20°C and 1.70 mm Hg at 25°C TGAI: Total vapor pressure (20°C) =1.4 mm Hg TGAI: Total vapor pressure (25°C) =1.78 mm Hg Total vapor pressure = vapor pressure of HPMTS + impurities N/A = Not applicable; TGAI=Technical Grade Active I ngredient; CBI= Confidential Business InformationEnvironmental Fate Summary

2- H ydroxy p ropyl m ethane t hiosul f onate (HPMTS) is an antimicrobial for formulating use. The Agency has reviewed one environm ental fate study (hydrolysis) for HPMTS and the results are summarized in Table 4. The Agency ’s conclusion for the hydrolysis study is as follows.

Hydrolysis (Abiotic)

2-Hydroxypropyl methanethiosulfonate hydrolyzed with half-lives of >30 days at pH 5, 8.5-9.9 hours at pH 7 and 5.4-6.1 minutes at pH 9 in sterile aqueous buffered solutions that were incubated at 25°C in darkness for up to 30 days . The major degradates di-(2-hydroxyisopropyl) disulfide and di-(2-hydr oxypropyl) disulfide were isolated from all three solutions. The hydrolysis study is acceptable and satisfies the hydrolysis data requirements (OPP 161-1) for HPMTS.

Table 4. Environmental Fate Data Summary for HPMTS

OPP Guideline Fate Studies Half-Life Degradates Study Status

161-1 Hydrolysis pH 5 pH 7 pH 9 (101 mg/L) >30 Days 8.5-9.9 Hours 5.4-6.1 Minutes Major Degradates : di-(2-hydroxyisopropyl) disulfide

di-(2-hydroxypropyl) disulfide Acceptable

Table 5. Degradates of HPMTS

Di-(2-hydroxypropyl) disulfide

Page 6 of 9Page 7 of 9 Water Quality

HPMTS is not identified as a cause of impair ment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation_cy.cause_detail_303d?p_cause_group_id=88 5 . In addition, no Total Maximum Daily Load s (TMDL) have been developed for HPMTS, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation.tmdl_pollutant_de tail?p_pollutant_group_id =885&p_pollutant_group_name=PESTICIDES . More information on impaired water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedur e: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Regi stration Review Risk Assessment and Management Process (see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1- sop.pdf ), in order to ensure they can be used qua ntitatively or qualitatively in pesticide risk

assessments.

Ecological Effects Summary

The Agency has reviewed seven ecotoxicol ogy studies for HPMTS. The seven studies submitted on the HPTMS active ingredient were a ll found to be acceptable for use in a hazard assessment. Ecotoxicity guideline studies and the results are summarized in Table 6. The Agency's conclusions for the avian and aquatic effects studies are as follows.

(1) Terrestrial Data

(a) Avian Subacute Dietary Toxicity HPMTS is slightly toxic to birds on a subacu te dietary basis. The guideline requirement is fulfilled.

(2) Aquatic Data

(a) Freshwater Fish Toxicity The results of the aquatic toxicity studies indi cate that HPMTS is slightly toxic to both cold and warm freshwater fish. The guideline requirement for acute t oxicity testing of the technical on freshwater fish is fulfilled.

(b) Freshwater Invertebrate Toxicity The results of the aquatic invertebrate toxicity studies indicate that HPMTS is moderately to slightly toxic to Daphni a. The guideline requirement for acute toxicity testing on freshwater invertebrates is fulfilled.

HPMTS is slightly toxic to avian species on a subacute dietary basis, slightly toxic to fish, and slightly to moderately toxic to aquatic invertebrates. Ecotoxicity data are adequate to provide the Agency with sufficient informati on to determine appropriate label precautions.Page 8 of 9 Table 6. Ecotoxicity Data Summary for HPMTS

GUIDE LINE COMMON NAME TAXONOMIC NAME TYPE % AI STUDY TIME DOSE TYPE TOXI CITY TOX LEVEL NOEL STUDY STATUS TOX CATEGORY Avian Subacute Dietary Toxicity

850.2200

71-2a Bobwhite quail Colinus virginianus D 79.8 8 D LC 50 >5000 (3991 ppm ai) PPM >5000 (3991 ppm ai) Core Slightly toxic

850.2200

71-2b Mallard duck Anas platyrhynchos D 79.8 8 D LC 50 >5000 (3991 ppm ai) PPM >5000 (3991 ppm ai) Core Slightly toxic

Freshwater Fish Acute Toxicity

850.1075

72-1c Rainbow

trout Oncorhynchus mykiss F 81.4 96 hr LC 50 28 PPM 15.8 Core Slightly toxic

850.1075

72-1b Bluegill sunfish Lepomis macrochirus F 81.4 96 hr LC 50 38.2 PPM 17 Core Slightly toxic

850.1075

72-1b Bluegill sunfish Lepomis macrochirus S 80 96 hr LC 50 78 PPM 32 Suppl Slightly toxic

Freshwater Invertebrate Acute Toxicity

850.1010

72-2a Water flea Daphnia

magna F 81.4 96 hr EC 50 3.13 PPM 1.39 Core Moderately toxic

850.1010

72-2a Water flea Daphnia

magna S 80 48 hr EC 50 12 PPM 8 Suppl Slightly toxic

Ecological Effects Risk Assessment

There are no registered end- use products and the regist ered manufacturing use product will not result in human or environmental expos ure because it is for formulating use only. Therefore, an ecological risk assessment is no t needed in support of registration review.

Risk to Threatened and Endangered Species

Labels may be categorized into two types: labels for manufacturing uses and label for end-use products. Manufacturi ng use products are not used dire ctly in the environment, but instead, are used to make formulated or end-use products. End-use products are used to control a pest and carry label instructi ons that indicate how the product may legally be used. There are currently no registered end-us e products for HPMTS; the only registration is for the manufacturing use product. There is no enviro nmental exposure anticipated and the Agency has determined the registration of the manufactur ing use product will have "no effect" (NE) on endangered or threatened terrestr ial or aquatic species, or their designated critical habitats, as listed by the U.S. Fish and Wildlife Serv ice (USFWS) and the National Oceanic and Atmospheric Administration (NOA A). Therefore, no additional environmental risk assessment is anticipated to be undertaken. However, the EPA will review any comments made by the public on this document and will conduct an environmental risk assessment, if new information warrants such action. If such a decision is made, the environmental risk assessment will conclude that the registered pesticide's use ha s “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designa ted critical habitats. When anPage 9 of 9 assessment concludes that a pesticide’s use “may aff ect” a listed species or its designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Se rvices), as appropriate.

Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

No data gaps.