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INTRODUCTION

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) for 

the registration review of chloropicrin. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in the chloropicrin registration 

review docket (EPA-HQ-OPP-2013-0153). Chloropicrin is a non-selective fumigant with 

fungicidal, herbicidal, insecticidal, and nematicidal properties registered for use as a pre-plant 

soil fumigant for a variety of agricultural field crops and greenhouses, and for tree replant. 

Chloropicrin is also an active ingredient in antimicrobial wood preservative products.

The Agency is implementing the registration review 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 the FIFRA standard for 

registration. Changes in science, public policy, and pesticide use practices occur over time. The 

registration review program is intended to make sure that, as the ability to assess risk evolves and 

as policies and practices change, all registered pesticides continue to meet the statutory standard. 

The public phase of registration review begins when the initial docket is opened for each case. 

Information on this program is provided on the Agency’s website.

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The FWP begins with any updates since the PWP was issued. Next is a summary of substantive 

comments received during the public comment period 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 comments. This section is followed by registration 

review planned data needs, risk assessments expected to be conducted, and the projected

registration review timeline for chloropicrin. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

EPA approved a label amendment for a product with antimicrobial wood preservative uses: 

Timberfume II, EPA registration number 75340-1. This label amendment adopted the risk 

mitigation measures identified in the 2009 Amended RED.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the Chloropicrin Preliminary Work Plan, which 

opened on September 25, 2013 and closed on November 25, 2013, the Agency received 12

unique public comments in the chloropicrin docket. In addition, 2 comments related to 

chloropicrin were submitted to dockets for other fumigant active ingredients. Comments 

submitted by the registrant, agricultural associations, non-profit organizations, and one state 

agriculture department address the registration review process and/or utility of soil fumigants in 

agriculture. Two comments were submitted by the Pesticide Action Network of North America 

(PANNA): one mass comment campaign which received 5,645 signatures, and one with 

signatures from representatives from 34 organizations. These comments along with an additional 

 1 http://www.epa.gov/oppsrrd1/registration_review/
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comment from an individual, in part, request the Agency re-evaluate risk assessment levels of 

concern, buffer zone distances imposed by the 2008 reregistration eligibility decision, and the 

carcinogenicity of chloropicrin. In the PWP, EPA also solicited comments on the specific topics 

of environmental justice, water quality concerns, and trade irritants, but no comments or 

information were received on those issues. Public comments in their entirety are located in 

chloropicrin docket, EPA-HQ-OPP-2013-0153. In addition, the following response-to-comment 

documents are located in the chloropicrin docket:

• Comments and Agency responses related to the anticipated ecological risk assessment or 

data needs are in the Environmental Fate and Effects Division’s Response to Comments 

on the Chloropicrin Problem Formulation for Registration Review.

• Comments and Agency responses regarding the anticipated human health risk assessment 

or data needs are in The Health Effects Division’s Response to Pesticide Action Network 

North America on the Chloropicrin Registration Review Scoping Document for Human 

Risk Assessment.

• EPA’s responses to comments not addressed in the previously mentioned documents are 

in the Responses to Public Comments on the Chloropicrin Preliminary Work Plan. 

The Agency considered the issues and concerns raised by each of the comments submitted, but 

the registration review timeline, data-requirements, and anticipated risk assessment needs did not 

change as a result of these comments.

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for chloropicrin based on the Problem 

Formulation for the Environmental Fate, Ecological Risk, Endangered Species,

and Drinking Water Exposure Assessments in Support of the Registration Review of

Chloropicrin; Chloropicrin Registration Review Human-Health Assessment Scoping Document;

and response to PWP comments documents. The planned data needs have not changed from 

what was included in the PWP. The agency does not anticipate the need to require additional 

data for the wood preservative uses.

Table 1: Planned Data Needs for the Chloropicrin Registration Review for Soil Pre-plant 

Uses Only

Guideline 

Number2 Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

835.4300 Aerobic aquatic metabolism TGAI 24

850.4500 Aquatic non-vascular plant studies TGAI 12

 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 Availability” 77 FR 38282, June 27, 2012. 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0028
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Table 1: Planned Data Needs for the Chloropicrin Registration Review for Soil Pre-plant 

Uses Only

Guideline 

Number2 Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

850.6100

Environmental chemistry methods and 

associated independent laboratory validation 

studies in air and water

TGAI 12

Nonguideline Acute vapor exposure honey bee study TGAI 24

Outstanding Data Requirements from GDCI-081501-289053

850.4100 Seedling emergence (Tier II) TGAI TBD*

850.4150 Vegetative vigor (Tier II) TGAI TBD*

Nonguideline 

(listed in DCI 

as SS-2)

Avian acute inhalation TGAI TBD*

Outstanding Data Requirements from GDCI-081501-11554

Nonguideline Ambient Air Monitoring TEP Due May 15, 

2015

TGAI = technical grade active ingredient; TEP = typical end-use product;

* The registrant submitted data to the Agency that were determined to be insufficient to satisfy the data requirement;

the Agency is following up with the registrants to address these remaining data gaps.

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 chloropicrin. For human health, EPA 

anticipates the need to conduct revised residential bystander risk assessment during registration 

review for soil fumigant uses. EPA does not anticipate the need to conduct revised dietary and 

occupational risk assessments during registration review. However, if new field volatility studies 

become available or points of departure or uncertainty factors change, they will be considered in 

the new assessments, as well as any changes to the standard operating procedures or default 

exposure assumptions. 

 3 These studies listed in this section were previously required through a generic data call-in issued in March 2010

and are still outstanding. These studies will not be included in the anticipated Registration Review DCI because 

they are already required through the earlier DCI. 4 The study listed in this section was previously required through a generic data call-in issued in May 2012 and is 

still outstanding. This study will not be included in the anticipated Registration Review DCI because it is already 

required through the earlier DCI.
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Table 2 summarizes the planned registration review risk assessments based on the EFED 

Problem Formulation and HED Scoping Document and the planned assessments have not 

changed from what was included in the PWP.

Table 2: Planned Risk Assessments for the Chloropicrin 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 The primary stressor of ecological concern is

chloropicrin. Chloropicrin’s photodegration products

(phosgene and nitrosyl chloride) are expected to

quickly degrade, and for this reason, only

chloropicrin will be considered as a stressor of

concern.

Incidents Will check for 

updates

For a discussion of reported ecological incidents for 

chloropicrin, see page 19 of the Problem Formulation.

Human Health

Dietary

Food N The agricultural uses of chloropicrin are considered

non-food uses, since there is no reasonable

expectation of finite residues in/on food crops when

it is used as a pre-plant fumigant. A dietary

assessment is not anticipated in registration review.

Drinking water N Based on environmental fate data, the residual

contents in soils, and monitoring data, the Agency

does not expect chloropicrin to adversely impact

drinking water sources such as surface water and

ground water, so a drinking water assessment is not

anticipated in registration review.

Occupational

Handlers (mixers, loaders, 

applicators)

N New occupational handler exposure assessments are

not anticipated unless new studies become available

or points of departure or uncertainty factors change.

Post-application N New occupational post-application exposure

assessments are not anticipated unless new studies

become available or points of departure or

uncertainty factors change.

Residential

Handlers N Chloropicrin is restricted use. There are no

registered uses for applications by residential

handlers.

Post-application N Chloropicrin is restricted use. There are no

registered uses for applications facilitating typical

post-application exposure.
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Bystanders Y For soil uses, there is the potential for residential

bystander inhalation exposure to chloropicrin after a

soil fumigation application of chloropicrin. A

revised residential risk assessment is anticipated in

registration review to update risk to bystanders

during and following soil fumigant uses of

chloropicrin products.

Additionally, the Agency anticipates updating the

fumigant factors document, which provides a

discussion of values and parameters used as the

basis for buffer zone reduction credits (i.e., tarps) as

well as for establishing Good Agricultural Practices

(GAPs) for the fumigants. This document impacts

all of the soil fumigants including chloropicrin.

Buffer zones and GAPs were specified by the 2009

amended RED as measures to mitigate occupational

and bystander risk.

Other

Aggregate N Evaluates the combined risk from dietary and 

residential exposures. No dietary risk is anticipated

from chloropicrin. Therefore, an aggregate

assessment is not anticipated.

Cumulative N Chloropicrin is not a member of a cumulative group.

Tolerances N Chloropicrin is a preplant soil fumigant so there are

no tolerances established for this chemical.

Incidents Will check for 

updates

For a discussion of reported human incidents for 

chloropicrin, see page 9 of the Scoping Document and 

the Chloropicrin: Review of Human Incidents.
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TIMELINE

EPA has created the following estimated timeline for the completion of the chloropicrin

registration review in Table 3 below. The projected timeline has been updated to reflect the 

lengthening of the timeframe between posting of the draft risk assessment and the proposed 

decision by one quarter. The PWP inaccurately provided the wrong date for the 60-day public 

comment period for the draft risk assessments. It has been corrected in Table 3. 

Table 3: Registration Review for Chloropicrin – 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 2016: April – June 

60-day Public Comment Period for Draft Risk Assessments5 2017: Oct. – Dec.

Registration Review Decision

60-day Public Comment Period for Proposed Registration Review 

Decision

2018: July – Sept.

Registration Review Decision and Begin Post-Decision Followup2019

Total (years) 6

NEXT STEPS

As noted previously, the Agency plans to require several environmental fate, ecological effects, 

and human health studies for chloropicrin through a Data Call-In Notice, expected to be issued 

by June 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.