2 INTRODUCTION

This is the Environmental Protection Agency’s (E PA or the Agency) Final Work Plan (FWP) for the registration review of propylene oxide (PPO ). This work plan addresses public comments received concerning the Preliminary Work Plan (PWP), which was posted in the PPO registration review docket (E PA-HQ-OPP-2013-0156). PPO is re gistered for use as an insecticidal fumigant on several foods such as processed spices , dried garlic and onion, cocoa (beans and powder), in-shell and processed nutmeat s (except peanuts), figs, raisins, and prunes. Nonfood uses include those on cosmetics, non- edible gums, ores, packaging, pigments, pharmaceutical materials, and discarded nut shells pr ior to disposal. In addition, there is a label claim that PPO aids in the control of microbiologi cal spoilage and it is us ed as a sterilant on food and nonfood products for this purpose.

The Agency is implementing the registration revi ew program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), a nd will review each registered pesticide every 15 years to determine whether it continues to meet th e FIFRA standard for registration. Changes in scienc e, public policy, and pesticide us e practices occur over time. The registration review program is intended to make su re that, as the ability to assess risk evolves and as policies and practices change, al l registered pesticides continue to meet the statutory standard. The public phase of registration review begins wh en the initial docket is opened for each case. Information on this program is provided on the Agency’s website. 1

The FWP begins with any updates since the PWP wa s issued. Next is a summary of substantive comments received during the public comment peri od for the PWP concerning anticipated data needs, expected risk assessments, or the estimated timeline identified in the PWP, and a summary of the Agency’s responses to those comme nts. This section is followed by registration review planned data needs, risk assessments expected to be conducted, and the projected registration review timeline for PPO. Lastl y, there is a discussi on of next steps.

UPDATES SINCE TH E PWP WAS ISSUED

There are no additional upda tes on PPO since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the PPO Preliminary Work Plan, which opened on September 25, 2013 and closed on November 25, 2013, the Agency received public comments
from seven submitters. Comments were subm itted by the registrant ABERCO, the American Spice Trade Association, the Minor Crop Farme r’s Alliance, the American Farm Bureau, the California Almond Board, the Physicians Committ ee for Responsible Medicine, and the Citrus
Research and Education Center at the Institute of Food and Agricultural Sciences, University of
Florida. The comments do not address the time line described in the PWP, but they do address the data requirements and generally address the planned ecological a nd human health risk assessments. In the PWP, EPA also solicited co mments on the specific topics of environmental justice, water quality concerns, and trade irritants. The comment from the registrant ABERCO

1 http://www.epa.gov/oppsrrd1/registration_review/3 indicated that they have no information on the former two topics, but with regard to trade irritants they indicated that they are worki ng with EPA towards CODEX acceptance of current
MRLs.

Public comments did not result in changes to the anticipated regist ration review data needs, risk assessments, or timeline. Public comments and the EPA response to comments document are located in the docket at EPA-HQ-OPP-2013-0156.

PLANNED DATA NEEDS

Table 1 below summarizes the planne d data needs for PPO based on the Registration Review: Preliminary Problem Formulati on for Environmental Fate an d Ecological Risk, Endangered Species, and Drinking Water Assessments for Propylene Oxide (PPO) and the Propylene Oxide: Human Health Assessment Scoping Docu ment in Support of Registration Review . The planned data needs have not changed from what was included in the PWP.

Table 1: Planned Data Needs for the PPO Registration Review

Guideline
Number 2 Study Title 2 Test Material Estimated
Timeframe
(Months from receipt of DCI)

Anticipated Data Needs for the Parent PPO

NonGuideline Avian acute inhalation toxicity TGAI 24

NonGuideline Honeybee acute vapor exposure toxicity TGAI 24

NonGuideline Terrestrial plant toxicity TEP 12

875.1400 Inhalation indoor exposure TEP 24

875.1700 Product use information TEP 12 875.2500 Inhalation exposure study 3 TEP 24

NonGuideline Acute inhalation toxicity study - rodent TGAI 12

NonGuideline Monitoring data on fumigated commodities TEP 24

NonGuideline Ambient air monitoring TEP 36

2 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 – Ecological Effects Tests

– including renumbering and other designations or changes for some guideline studies. See “Final Test Guidelines; OCSPP 850 Series; Notice of Av ailability” 77 FR 38282 , June 27, 2012. http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0154-0028

3 This study is needed to assess post-application expo sures for workers within and near structural fumigation facilities/operations or who work with treated commodities/materials.4 Table 1: Planned Data Needs for the PPO Registration Review

Guideline
Number 2 Study Title 2 Test Material Estimated
Timeframe
(Months from receipt of DCI)

Anticipated Data Needs for Propylene Ch lorohydrin (PCH), Reaction Product

870.6200 Acute neurotoxicity - rat Reaction
Product 12

870.3700 Prenatal developmental toxicity – rat and rabbit Reaction
Product 24

Outstanding Data Require ments from GDCI-042501-26627 4

860.1650 Submittal of analytical reference standards PAI, residue of

concern Due August
2008 TGAI = technical grade active ingredient; TEP = typi cal end-use product; PAI = pure active ingredient

4 The study listed in this section was previously required th rough a generic data call-in issued in August 2006 and is

still outstanding. The study will not be included in the anticipated Registra tion Review DCI because it is already required through the earlier DCI. The Agency is working with the registrant to follow up on the overdue study.5 RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, the Agency will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of PPO. For human health, EPA will conduct revised dietary, resident ial, aggregate and occupational risk assessments during registration review. If toxico logical endpoints or points of de parture are revised based on the data that are required for registration review, they will be considered in the new assessments, as well as any changes to the standard operating procedures or default exposure assumptions.

Table 2 below summarizes the planned registrati on review risk assessments based on the EFED Problem Formulation and HED Scoping Docume nt and the planned assessments have not changed from what was included in the PWP.

Table 2: Planned Risk Assessments for the PPO Registration Review

Type of Risk Assessment Conduct? Notes
Ecological and Environmental Fate Comprehensive ecological (species to be assessed include terrestrial and aquatic organisms), including endangered species Y Only the parent PPO will be assessed. There is no evidence that degradates will form substantially in air for terrestrial non-target e xposure. Aquatic non-target exposure will not be assessed because of PPO’s volatility and short retention time in water.
Incidents Will check for updates There are no reported incide nts. For a discussion of reported ecological incidents for PPO, see page 13 of
the Problem Formulation.
Human Health Dietary Food Y A new dietary exposure risk assessment may be required during Registration Review to incorporate potential changes to the PPO and PCH toxicological points of departure (PODs), updated consumption information, and utilization of the newest version of
DEEM-FCID. Drinking water N PPO is unlikely to have detectable residues for both parent and degradates in surface water and ground

water. Occupational Handlers (mixers, loaders, applicators) Y A new occupational handler risk reassessment may be completed during registrati on review to incorporate the most recent exposure data, Agency policies, or if toxicological reev aluation of PPO results in changes to endpoints.6 Post-application Y Tasks for workers near fumigation facilities/operations need to be defined in order to assess post-application activities. Potential exposures due to off-gassing will also be assessed for workers conducting post-application ac tivities near treatment operations.
Residential
Handlers N There are no re sidential uses of PPO. Post-application N There are no residential uses of PPO. Bystander Y Additional or revi sed residential bystander risk assessments may be necessary based on the most recent exposure data, Agency policies, or if the toxicological reev aluation results in changes to the endpoints. Additional use information requested
above under the Use and Usage Information – Guidance for Commenters section would refine this analysis.
Other Aggregate Y Evaluates the comb ined risk from dietary and residential exposures. Aggregate risk assessments may be required during registration review because residential bystander exposure may be assessed.
Cumulative N EPA has not made a common mechanism of toxicity finding as to PPO and any other substance, and has
also not assumed that PPO has a common mechanism of toxicity with other substances. Tolerances Y The tolerance expres sion for propylene oxide will be reviewed during registration review to ensure that it appropriately covers metabol ites and degradates and that it specifies the residues to be measured for each commodity; modifications will be made as needed.
Incidents Will check for updates No cases involving PPO were identified. For a discussion of reported human incidents for PPO see page 10 of the Scoping Document and Propylene Oxide: Review of Human Incidents

.

TIMELINE

EPA has created the following estimated timelin e for the completion of the PPO registration review in Table 3 below. The projected timelin e has been updated since the PWP to reflect the lengthening of the timeframe between posting of the draft risk assessm ent and the proposed decision by one quarter.7 Table 3: Registration Review for PPO – Projected Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and 60-day Public Comment Period Sept. 2013 – Completed
Close Public Comment Nov. 2013 – Completed Case Development
Final Work Plan March 2014 - Completed

Issue DCI 2014: April - June

Data Submission 2017: April - June 60-day Public Comment Period for Draft Risk Assessments 5 [1] 2018: Oct. – Dec. Registration Review Decision 60-day Public Comment Period fo r Proposed Registration Review
Decision 2019: July – Sept.

Registration Review Decision a nd Begin Post-Decision Follow-up 2020 Total (years) 7

NEXT STEPS

As noted previously, the Agency plans to requir e several environmental fa te, ecological effects, and human health studies for PPO through a Data Ca ll-In Notice, expected to be issued in 2014.

5 The regulations governing Registration Review generally require the Agency to provide a public comment period

of at least 30 calendar days for draft risk assessments; see 40 CFR Part 155.53(c). For conventional pesticides, the Agency plans to provide a 60 calendar day public comment period generally for draft risk assessments.