Page 2 of 5 d-Limonene Final Work Plan

Introduction:

This is the Environmental Protection Agency’s (EPA’s) Final Work Plan (FWP) for the registration review of d-Limonene (“limonene” unless otherwise specified). The FWP includes the expected registration review timeline. Th e FWP also addresses public comments received concerning the Preliminary Work Plan in the Summary Document , which was posted in the limonene registration review docket (EPA -HQ-OPP-2010-0673), 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 ma ke a registration review decision.

The Agency is implementing the new registra tion review program and will review each registered pesticide every 15 years to determin e whether it continues to meet the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA) standard for registration. Changes in science, public policy, and pesticide use practices will occur over time. The registration review program is intended to make sure that, as the ab ility to assess risk evolves and as policies and practices change, all registered pesticides contin ue to meet the statutory standard. The public phase of registration review begins when the ini tial docket is opened for e ach case. Information on this program is provided at: http://www.epa.gov/oppsrrd1/registration_review/

.

Limonene has a lemon-like flavor and smell, and occurs naturally in citrus and certain fruits, vegetables, meats, and spices. Limonene is us ed as both an active and inert ingredient in pesticide products, and as an ingredient in food products, soaps, and perfumes. Pesticide products containing limonene as an active ingredie nt are registered for use as insecticides, herbicides, insect repellents, and animal (dog and cat) repellents. As a pe sticide inert ingredient, it is used as a solvent or fragrance in an timicrobial products. The U.S. Food and Drug Administration (FDA) considers d-limonene to be Generally Recognized as Safe (GRAS) as a food additive when used as a synthetic flavor ing substance and adjuva nt (21 CFR §182.60).

Limonene is registered for use in/on terrestria l food, feed crops, non-food crops, for residential uses, and as an inert ingredient. Non-pesticid al uses of limonene include use in solvents (substitute for chlorinated hydrocarbons, chlorofl uorocarbons, and other solvents); use as a metal degreaser; use as a cleaning agen t in the printing industry and household cleaning products; and, as a solvent for paint. Limonene was first re gistered as an insecticide in 1958 and as an antimicrobial in 1971. Currently, the only antimi crobial uses of limonene are as an inert ingredient and are not subject for registration review. The re registration eligibility decision (RED) was issued in 1994 and th e tolerance reassessment eligibility decision (TRED) was issued

in 2005.

Comments Received on Preliminary Work Plan

No comments were received on the limonene Preliminary Work Plan (PWP) during the public comment period. The 60-day public comment pe riod on the limonene PWP began on September 22, 2010 and closed on November 22, 2010.Page 3 of 5 Risk Assessment and Data Needs:

• The most recent ecological risk assessment for limonene was completed in 1994 to support the RED.

• The Agency has not conducted a risk asse ssment that supports a complete endangered species determination for limonene. The ecological risk assessment planned during registration review will allow the Agency to determine whether limonene’s use has “no effect” or “may affect” federally listed threat ened or endangered sp ecies (listed species) or their designated critical ha bitats. When an assessment c oncludes that a pesticide’s use “may affect” a listed species or its designate d critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services), as appropriate.

• Based upon the use pattern and limonene’s cu rrent ecotoxicity and environmental fate database, the Agency will require the following data in order to conduct a complete ecological risk assessment, including an e ndangered species assessment, for all uses:

o GLN 850.4100 - Seedling emergence, Tier II (using TEP)

o GLN 850.4150 - Vegetative vi gor, Tier II (using TEP)

o GLN 850.4400 - Aquatic plant toxicity test using Lemna spp. , Tier II (using TEP)

o GLN 850.5400 - Algal toxicit y, Tier II (using TEP)

• Please refer to the document, Registration Review – Problem Formulation for dLimonene dated June 30, 2010

, located in the docket for a detailed discussion of the anticipated risk assessment and data needs.

Human Health Risk:

• The most recent human health risk assessm ent for limonene was completed in 2004 to support the TRED.

• The RED Data Call-in (DCI) required a de velopmental toxicity study and a 2-week dermal toxicity study. These studies have been received by the Agency and will be reviewed during registration review. The t oxicity endpoints establ ished in the 2004 risk assessment may be updated following Agency review of these studies.

• The human health toxicity database (inclu ding the developmental and dermal study) for limonene is adequate to support its curre nt use patterns and the Agency does not anticipate requiring new data to support a human health risk assessment for registration

review.

• The Agency will conduct a new dietary risk assessment that incorporates potential drinking water residues a nd revised endpoints to s upport registration review.

• Limonene is listed in 40 CFR §180.539 without numeric toleran ces and is identified as being safe for use, as an insecticide, in ta blecloths and repellant strips and in food orPage 4 of 5 feed-handling establishments. The Agency doe s not anticipate the need to re-evaluate this tolerance expression during registration review.

• The residential exposure assessment that wa s conducted to support the 2004 TRED only examined dermal exposure to pesticide products containing lim onene as an active ingredient. The Agency will update the 2004 residential assessment using the revised Agency Standard Operating Procedures (SOP s) for residential exposure to incorporate potential changes in dermal and inhalation endpoints, and to include exposure from outdoor uses and pet product uses.

• To support registration review, the Agency will conduct a new and updated aggregate risk assessment incorporating new toxicity endpoints as a ppropriate, the dietary risk assessment incorporating drinking water residues and the updated residential assessment.

• The most recent occupational exposure and risk assessments for limonene were conducted in 2008 to support proposed new uses (use on nut, vine, and berry crops, and non-crop areas). The Agency will update the occupational exposure and risk assessment to include the inhalation route of exposure a nd potential changes in the hazard endpoints. This 2008 occupational exposure and risk asse ssment may be found in the docket under

the document titled d-Limonene Occupational Exposur e/Risk Assessment for Proposed New Uses of d-Limonene on Tree, Nut, Vine, Berry Crops and Non-Crop Areas

.

• Please refer to the document, d-Limonene: Human Health Assessment Scoping Document in Support of Registration Review dated August 13, 2010

, located in the

docket for a detailed discussion of the antic ipated risk assessment and data needs for

human health.

Other Data Needs:

• GLN 830.7050 UV/Visible Light Ab sorption – this study is a new data requirement under 40 CFR part 158 (Product Chemistry Data Requi rements) for registration of a pesticide (food and non-food uses). The Agency will requi re this study to obtain basic information about the compound’s identity/composition and the wavelengths at which the compound may be susceptible to photochemical degradation.Page 5 of 5 Timeline:

EPA has created the following estimated timeline for the completion of the limonene registration

review. This timeline has been shortened since the PWP to account for a shorter period between issuance of the DCI and data submission, since th e Agency will not be requiring any studies that take more than one year to conduct.

Registration Review for Limonene – Pr ojected Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and Public Comm ent Period 2010 – September

Close Public Comment 2010 – November Case Development Final Work Plan 2011 – January

Issue DCI 2011 – Oct – Dec

Data Submission 2012 – Oct – Dec Open Public Comment Period for Preliminar y Risk Assessments 2014 – April – June Close Public Comment Period 2014 – July – Sept Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2014 – Oct – Dec.

Close Public Comment Period 2015 – Jan. – March Final Registration Review Decision a nd Begin Post-Decision Follow-up 2015 Total (years) 5

Data Requirements Table

The Agency will issue a DCI for the following studies listed in both the PWP and FWP.

Data Requirement Guideline Number Listed In PWP Listed In FWP Seedling emergence, Tier II (using TEP) 850.4100 The Agency’s anticipated data needs did not change and the Agency will issue a DCI for these

studies. Vegetative vigor, Tier II (using TEP) 850.4150

Aquatic plant toxicity test using Lemna spp.

, Tier II (using TEP) 850.4400

Algal toxicity, Tier II (using TEP) 850.5400

UV/Visible Light Absorption 830.7050