United States Chemi cal Safety June 2011 Environmental Protection and Pollution Prevention Agency (7510P)



# Dimethoxane Registration Review: Final Work Plan June 2011Docket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

3 of 9 Dimethoxane Registration Review Team

Human Health & Environmental Effects Timothy Dole Srinivas Gowda

Risk Management Monisha Harris Lance Wormell

Office of General Counsel Philip Ross

________________________________________ Supporting documents for the dimethoxane case ma y be found in the registration review docket EPA-HQ-OPP-2010-0686 located on the internet at www.regulations.gov

.Docket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

4 of 9 Introduction

This is the Final Work Plan (FWP) of the Environmental Protection Agency (EPA or “the Agency”) for the registration review of dimet hoxane (case 3064). The work plan includes the expected registration review timeline. The work plan also addresses public comments received concerning the Preliminary Work Plan (PWP) in the Summary Document which was posted in the dimethoxane registration review docket, and any other comments concerning the initial docket postings. The Summary Document provided information on what EPA knows about the pesticide and what additional risk analyses and data or information the Agency believes are needed to make a registration review decision.

The Agency is implementing the registration revi ew program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and will review each registered pesticide every 15 years to determine whether it continues to meet th e FIFRA standard for registration. Changes in science, public policy an d pesticide use practices will occur over time. The registration review program is intended to ma ke sure that, as the ability to assess risk evolves and as policies and practi ces change, all registered pestic ides continue to meet that statutory standard. The public pha se of registration review begins when the initial docket is opened for each case. Information on this program is provided at: http://www.epa.gov/oppsrrd1/ registration_review/.

The first product containing dimethoxane (P C Code 001001) as an active ingredient was registered in the United States in 1962. Currently, there is only one product registered with EPA. Dimethoxane is a bacteriostat/fungistat used for the preservation of materi als such as industrial adhesives (tape joint co mpounds, silicone based adhesives, st arch based adhesives, and other adhesives), paints, emulsions (l atex, polyvinyl alcohol, silicone, oil, acrylic, polyethylene, polyvinyl chloride), coatings, sp ecialty industrial products (pigme nt slurries, dyestuffs, inks, thickeners, gums, lingosulfonates), textile chem icals and finishes ( dye levelers, textile auxiliaries, softeners, lubricants, antistats, sizi ngs, print pastes), leathe r processing liquors (dyes, wet processing leather finishes), and distillation fuels agains t microbial degradation during manufacture, storage, and service life. There are no tolerances or exemptions from tolerances for dimethoxane.

The Dimethoxane Preliminary Work Plan (P WP) (PC Code 001001) was published on December 22, 2010 and the 60-day comment period ended on February 22, 2010. The Preliminary Work Plan document is available on www.regul ations.gov docket numb er EPA-HQ-OPP-2010-0686.

Comments Received on the Preliminary Work Plan

The Agency received no comments during the pu blic comment period on the initial docket. In the PWP, the Agency solicited comments on speci fic topics: environmental justice, water body impairment, trade irritants, and structure activity relationships. No comments or information were received during the public comme nt period concerning these issues.

Therefore, the data needs, work plan, and time line described in the PWP remain as they were presented initially. Further, this document makes final the work plan for the dimethoxane registration review process.Docket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

5 of 9 Risk Assessments and Data Needs

The Agency will not conduct an ecological risk assessment. The Agency will conduct a human health risk assessment. The Agency will require additional data to conduct the registration review for dimethoxane.

Ecological Risk Assessment Status and Data Needs

• No ecological risk assessment has been perf ormed for dimethoxane. An ecological risk assessment was not performed at the time of the RED because the use patterns were expected to result in minimal exposure to the environmen t and because dimethoxane is not more than slightly toxic to fish and aquatic invertebrates, and slightly toxic to practically nontoxic to birds.

• The Agency does not anticipate the need to require additional ecological data for the registration review at this time.

• The Agency anticipates the need to require th e following additional environmental fate data to conduct the registration review of dimethoxane.

835.1110 -- Activated Sludge Sorption Isotherm 835.3110 -- Ready Biodegradability

• For more information, please refer to Summary of Product Chemistry, Environmental Fate, and Ecotoxicity Data for the Dimethoxane Registration Review Decision Document , located in the docket.

Human Health Risk Assessment Status and Data Needs

• The most recent human health risk assessments for dimethoxane were completed in 2009, in support of a new use in household, industrial, and institutional water based products. The application for the new use was withdrawn in 2010.

Dietary Assessment

• Dimethoxane is not registered for any direct or indirect f ood uses, nor does it have any FDA approvals for such uses. Product labeling does not permit use in the manufacture of coatings that may come in contact with food. Howe ver, there is a potential for drinking water exposure from the material preservative uses. The Agency expects th at the environmental fate data that are being required through registra tion review will be useful to evaluate this potential. Therefore, the need for a drinking water assessment will be determined after the environmental fate data are received and reviewed.

Tolerances and Intern ational Harmonization

• There are no tolerances or exempti ons from tolerances for dimethoxane.Docket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

6 of 9 Occupational and Residen tial Assessment and Risk

• Dimethoxane has a high vapor pressure rapidl y hydrolyzes to acetaldehyde. Based upon the use patterns, physical/chemical properties and hazard data, the following occupational exposures will need to be assessed: dermal and inhalation exposure to dimethoxane from the open pour application during paint preservation; inhalation exposure to acetaldehyde released from dimethoxane during paint preservation; derm al and inhalation exposure from the use of dimethoxane treated paints; and inhalation exposure to acetaldehyde from the use of dimethoxane treated paints.

• EPA intends to assess residential dermal and in cidental oral exposures to treated textiles and leather products, and residential dermal a nd inhalation exposure to treated paints.

Aggregate and Cumulative Exposure and Risk

• In examining aggregate exposure, EPA take s into account the available and reliable information concerning exposures to pesticide re sidues in food and drinking water, as well as non-occupational pesticide exposures. An aggr egate risk assessment may be needed for dimethoxane if it is determined that a dr inking water exposure could occur based on the environmental fate. The Agency will ma ke this determination once the required environmental fate data are received and reviewed.

• EPA does not have, at this time, available data to determine whether dimethoxane has a common mechanism of toxicity w ith other substances or how to include this pesticide in a cumulative risk assessment.

• For the purposes of this Registration Review , EPA has assumed that dimethoxane does not have a common mechanism of toxicity with othe r substances when used as an antimicrobial as registered.

Human Health Data Needs

• The Agency anticipates the need to require the following additional human health data to conduct the registration re view of dimethoxane.

870.2600 -- Skin (dermal) sensitization 870.3465 -- 90-day inhalati on toxicity (rat) 875.1200 -- Dermal indoor exposure 875.1400 -- Inhalation indoor exposure 875.1600 -- Application exposure data reporting and calculations 875.1700 -- Product use information Special Study -- Leaching study on textiles Special Study -- Leaching study on leather

• For more information, please refer to Summary of Human Health Effects Data for Dimethoxane Registration Review , located in the docket.Docket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

7 of 9 Product Chemistry Data Needs

• The Agency does not anticipate the need to re quire additional product chemistry data for the registration review at this time.

• For more information, please refer to Summary of Product Chemistry, Environmental Fate, and Ecotoxicity Data for the Dimethoxane Registration Review Decision Document , located in the docket.

Incidents:

Ecological:

• No dimethoxane ecological incidents have b een reported in the OPP incident database.

Human Health:

• No dimethoxane human poisoning incidents ha ve been reported in the OPP incident database.

Endangered Species

Based on the low hazard and exposure, the Agency concludes that the registered uses of dimethoxane will have 'no effect' (NE) on endangered or threatened terrestrial or aquatic species, or their designated critical habitats, as listed by the U.S. Fish and Wildlife Service (USFWS) and the National Oceanic and Atmospheric Administ ration's (NOAA) National Marine Fisheries Service (NMFS). EPA anticipat es conducting no further analys is of potential risks to endangered or threatened species unless public comment provides data or information that would otherwise inform the Agency's determination.

Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews num erous studies to asse ss potential adverse outcomes from exposure to chemicals. Collectiv ely, these studies includ e acute, subchronic and chronic toxicity, including asse ssments of carcinogenicity, ne urotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include e ndpoints which may be susceptible to endocrine influe nce, including effects on endocri ne target organ histopathology, organ weights, estrus cyclicity, sexual maturatio n, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess gr owth, developmental and reprod uctive effects in different taxonomic groups. As part of its reregistration decision, EPA reviewed th ese data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA sec tion 408(p), dimethoxane is subject to the endocrine screening part of the Endocrine Disruptor Screenin g Program (EDSP).

EPA has developed the EDSP to determine whet her 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 ot her such endocrine effect s as the AdministratorDocket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

8 of 9 may designate.” The EDSP employs a two-tiered approach to making th e 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 estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine-related eff ects 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 scre en all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/dat a call-ins for the firs t group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. Dimethoxane is not among the group of 58 pesticide active ingredients on th e initial list to be sc reened under the EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data call-ins, requiring the submission of EDSP screening assa ys for dimethoxane. For further information on the status of the EDSP, the policie s and procedures, the lis t of 67 chemicals, future lists, the test guidelines and the Tier 1 scr eening battery, please visit our website: http://www.epa.gov/endo/.

Timeline

EPA has created the following estimated time line for the completion of the dimethoxane registration review:

Anticipated Schedule Activities Estimated Month/Year Phase 1: Opening the docket Open Public Comment Period for Docket Completed December 2010 Close Public Comment Peri od for Docket Completed February 2010 Phase 2: Case Development Develop Final Work Plan (FWP) June 2011 Issue DCI June 2012 Data Submission June 2014 Open Public Comment Period for Prelim inary Risk Assessments December 2015
Close Public Comment Period for Pre liminary Risk Assessments March 2016 Phase 3: Registration Review Decision Open Public Comment Period for Pro posed Reg. Review Decision June 2016 Close Public Comment Period for Propos ed Reg. Review Decision September 2016 Final Decision and Begin Post-Decision Follow-up December 2016 Total (years) 6

Next StepsDocket Number: EPA-HQ-OPP-2010-0686 www.regulations.gov

9 of 9 A DCI will be developed regarding the data ne eds listed under the “Risk Assessments and Data Needs” section of this document. The Agency expects to issue the DC I in June 2012. A human health assessment will be conducted for all uses.