2

Chloropicrin Preliminary Work Plan – Table of Contents

Overview 4

Anticipated Data Needs 5

Statutory and Regulatory Authority 6

Chemical Facts 6

Use and Usage Information 7

Recent Actions 10

Anticipated Risk Assessments for Registration Review 10

Timeline 13

Next Steps 13

Appendix – Additional Areas Considered in the Chloropicrin Registration Review 14

References:

This Preliminary Work Plan summarizes the Environmental Protection Agency's current position 

based on the following documents:

1. Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, 

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

Chloropicrin. Gelmann, Elyssa; Mostaghimi, Siroos; et. al. DP Barcode D410110. 

August 28, 2013. 

2. Chloropicrin Registration Review Human-Health Assessment Scoping Document. Smith, 

Charles; Schlosser, Christopher; et. al. DP Barcode D410119. September 3, 2013.

3. Chloropicrin: Review of Human Incidents. DP Barcode D414490. Recore, Shannon; 

Evans, Elizabeth. August 29, 2013.

4. BEAD Chemical Profile (BCP) for Registration Review: Chloropicrin (081501). 

Chandgoyal, Tara; Doucoure, Cynthia; Lee, Andrew. April 29, 2013.

5. Usage Data. Chloropicrin (081501) Screening Level Usage Analysis (SLUA). April 20, 

2012.
3

6. PRD Label Data Report: Food/Feed & Non-Food/Non-Feed Uses Considered in 

Registration Review Work Planning; Chloropicrin (081501). May 1, 2013.

7. Amended Reregistration Eligibility Decision (RED) for Chloropicrin. May 2009. EPA-HQOPP-2007-0350-0396.

8. Revised Screening Ecological Risk Assessment for the Reregistration of Chloropicrin. DP 

Barcode 348669. April 16, 2008. EPA-HQ-OPP-2007-0350-0175.

9. Chloropicrin: Third Revision of the HED Human Health Risk Assessment. DP Barcode 

348637. April 30, 2009. EPA-HQ-OPP-2007-0350-0398.

Unless noted above, these and other supporting documents for the chloropicrin registration 

review case may be found in the docket EPA-HQ-OPP-2013-0153 at 

http://www.regulations.gov.
4

OVERVIEW

The docket for chloropicrin is now open, initiating the first public comment period for this 

registration review (docket number 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. 

This Preliminary Work Plan (PWP) document explains what EPA's Office of Pesticide Programs

knows about chloropicrin, highlighting anticipated data and assessment needs, identifying the 

types of information that would be especially useful to the Agency in conducting the review, and

providing an anticipated timeline for completing the registration review for chloropicrin. 

The registration review process was designed to include a public participation component to 

solicit input from interested stakeholders. The Agency intends, by sharing this information in the 

docket, to inform the public of what it knows about chloropicrin and what types of new data or 

other information would be helpful for the Agency to receive as it moves toward a decision on 

chloropicrin. The Agency encourages all interested stakeholders to review the PWP and 

Appendix and to provide comments and additional information that will help the Agency’s 

decision-making process for this chemical. In addition to general areas on which persons may 

wish to comment, there are some areas identified in the PWP and Appendix about which the 

Agency specifically seeks comments and information. Interested stakeholders could include: 

environmental non-profit or interest groups; pesticide manufacturers; agricultural labor or 

commodity groups; commercial, institutional, residential, and other users of pesticides; or the 

public at large.

The Preliminary Work Plan begins by listing the anticipated data needs for chloropicrin. Next, it 

discusses the statutory and regulatory authority for registration review. Then the document 

provides chemical facts, use and usage information, recent actions, the anticipated risk 

assessments, and a projected registration review timeline for chloropicrin. Finally, the Appendix 

to this document includes identification and discussion of some areas that are considered 

generally in registration review along with some additional chemical case-specific information.
5

ANTICIPATED DATA NEEDS

Table 1 below summarizes anticipated data needs for chloropicrin. For additional discussion of 

the anticipated data needs, see the Problem Formulation for the Environmental Fate, Ecological Risk, 

Endangered Species, and Drinking Water Exposure Assessments in Support of the Registration Review of 

Chloropicrin and Chloropicrin Registration Review Human-Health Assessment Scoping Document.

Table 1: Anticipated Data Needs for the Chloropicrin Registration Review

Guideline 

Number1 Study Title1

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

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-081501-289052

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-081501-11553

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.

 1 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 2 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. 3 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.
6

STATUTORY AND REGULATORY AUTHORITY

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program. All 

pesticides distributed or sold in the United States (U.S.) generally must be registered by the 

Environmental Protection Agency (EPA or the Agency), based on scientific data showing that 

they will not cause unreasonable risks to human health or the environment when used as directed 

on product labeling. 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 of no unreasonable adverse effects to human health or the 

environment. Changes in science, public policy, and pesticide use practices will occur over time. 

Through the registration review program, the Agency periodically reevaluates pesticides to make 

sure that as change occurs, products in the marketplace can be used safely. Information on this 

program is provided on EPA’s website.

4

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. The regulations governing registration review begin at 40 CFR 155.40. The 

Agency will consider benefits information and data as required by FIFRA. The public phase of 

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

Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses 

and data or information it believes are needed to make a registration review decision. After 

reviewing and responding to comments and data received in the docket during this initial 

comment period, the Agency will develop a Final Work Plan (FWP) and anticipated schedule for 

the registration review of chloropicrin.

CHEMICAL FACTS

Table 2 provides a summary of the chemical facts for chloropicrin.

Table 2: Chemical Facts for Chloropicrin

PC code 081501

Case Number 0040

CAS Number 76-06-2

Year first registered 1975

Pesticide Type Nonselective soil fumigant with fungicidal, herbicidal, insecticidal, 

and nematicidal properties, and an antimicrobial for remedial wood 

treatment.

Chemical class Fumigant

Reregistration Eligibility 

Decision (RED)

RED, July 2008; Amended RED, May 2009

 4 http://www.epa.gov/oppsrrd1/registration_review/
7

Table 2: Chemical Facts for Chloropicrin

Tolerance Reassessment 

Eligibility Decision 

(TRED)

Not applicable

Cumulative group Not applicable. Chloropicrin has not been identified as a member of 

a cumulative group that shares a common mechanism of toxicity.

40 CFR Citation There are no tolerances established for chloropicrin. All registered 

food uses are pre-plant.5

Dual-use Yes. Registered for conventional and antimicrobial uses

Non-pesticidal uses Used as a warning agent for some structure fumigations 

Pesticide Re-evaluation 

Division, Chemical 

Review Manager

Carolyn Schroeder

schroeder.carolyn@epa.gov

703-308-2961

Antimicrobial Division, 

Chemical Review 

Manager

Sandra O’Neill

oneill.sandra@epa.gov

(703)-347-0141 

Registration Division, 

Product Manager

Hope Johnson

johnson.hope@epa.gov

703-305-5410

USE AND USAGE INFORMATION

Table 3 summarizes the use and usage information for chloropicrin. Please see the BEAD 

Chemical Profile (BCP) for Registration Review: Chloropicrin (081501) in the registration 

review docket for more details.

Table 3: Chloropicrin Use and Usage Information

Summary of Use Chloropicrin is a broad spectrum fumigant with fungicidal, 

herbicidal, insecticidal, and nematicidal properties registered for 

use in pre-plant fumigation. Chloropicrin is also an active 

ingredient in antimicrobial wood treatment products. 

Use Sites Conventional Uses: Pre-plant soil use on agricultural crops 

including beans, beets, bell peppers, caneberries, carrots, citrus, 

cole crops, cucumber, cucurbit vegetables such as melons, 

deciduous fruit trees, eggplant, field crops such as corn, soybeans, 

and sugar beets, fruits unspecified, ginger, grapes, hops, legume 

vegetables, lettuce, mint, onions, orchards, peanuts, pepper, 

pineapple, potatoes, radish, stone fruit, strawberry, sweet potatoes,

 5 Chloropicrin’s volatility in the environment and results of metabolism studies in plants assure that there is no 

reasonable expectation of finite residues to be incurred in/on any raw agricultural commodity when these products 

are applied according to label directions. Therefore, this fumigant does not require food tolerances and is not 

subject to the amendments to the FFDCA promulgated under the Food Quality Protection Act of 1996. (See the 

Chloropicrin: Third Revision of the HED Human Health Risk Assessment. April 30, 2009.)
8

Table 3: Chloropicrin Use and Usage Information

tomatoes, tree nuts, yams, and other vegetables. 

Nonagricultural/non-food sites include Christmas tree plantations, 

conifers, forest nursery plantings (for transplant purposes), forest 

plantings (reforestation programs), golf course turf, nonagricultural 

uncultivated areas/soils, nursery stock, ornamental and/or shade 

trees, ornamental grasses, ornamental herbaceous plants, 

ornamental lawns and turf, ornamental nonflowering plants, 

ornamentals unspecified, ornamental woody shrubs and vines, 

potting soil/top soil, recreation area lawns, preplant soil, tobacco, 

and wood protection treatment to buildings/products outdoor, forest 

products (seasoned), and aquatic structures/items.

Antimicrobial Uses: Preservative to prevent internal decay in 

wooden poles/timbers, pilings and glue-laminated beams; in-place 

treatment of wood piles, poles, and timbers; poles piles, and timbers

in terrestrial sites; and treatment of in-service wood in aquatic sites. 

Summary of Usage Conventional Uses: Based on usage data from 2007-2011, 

chloropicrin's annual agricultural usage averaged 12 million pounds 

of active ingredient, treating an average of approximately 200,000

acres, for an average application rate of 136 pounds active 

ingredient per acre. For the same time period, strawberries (33%), 

tobacco (20%), tomatoes (17%), and peppers (11%) accounted for 

the largest percentages of usage in terms of total pounds of active 

ingredient applied. 

Based on available usage data from 2009, nursery and floriculture 

applied approximately 434,000 pounds of active ingredient for an 

average application rate of 105 pounds of active ingredient per acre.

Antimicrobial Uses: Usage data are not available for the 

antimicrobial use of chloropicrin.

Formulation Type(s) Conventional Uses: Chloropicrin is commonly formulated alone or 

with methyl bromide or 1,3-dichloropropene as an emulsifiable 

concentrate, soluble concentrate/liquid, liquid ready to use, or as 

pressurized gas.

Antimicrobial Uses: Chloropicrin is formulated alone as a ready-touse liquid solution.

Application Method(s) Conventional Uses: Chloropicrin is applied to soil using tractormounted fumigation injection equipment including shanks, chisels,

and plowsoles, as well as through drip irrigation and hand operated 

soil injection equipment.

Antimicrobial Uses: Chloropicrin is applied as a wood preservative 

by injecting or pouring directly into pre-drilled holes or through 
9

Table 3: Chloropicrin Use and Usage Information

encapsulated vials. Chloropicrin is predominantly packaged into 

prefilled vials which are later injected into the center of the timber. 

The certified applicator drills a hole in the wood timber, inserts a 

vial containing the liquid chloropicrin deep into the drilled hole of 

the timber and then permanently caps or seals the hole in the 

timber. The vials slowly degrade over time and the chloropicrin 

vapor then releases into the wood timber.

Technical Registrant(s) Conventional Uses: Great Lakes Chemical Corporation; Niklor

Chemical Co., Inc.; Trinity Manufacturing, Inc.; Ashta Chemicals, 

Inc.

Antimicrobial Uses: Osmose Railroad Services, Inc. 

No. of Registrations Conventional Uses: 60 Section 36, 4 Section 24 c 

Antimicrobial Uses: 1 Section 3

Restricted Use Yes

Guidance for Commenters: Additional areas of use and usage-related information

requested for this registration review, and of particular interest to EPA, are described below.

• Confirmation of the following label information: sites of application; formulations;

application methods and equipment; maximum application rates; frequency of 

application, application intervals, and maximum number of applications per season; and 

geographic limitations on use.

• Use distribution (e.g., acreage and geographical distribution of relevant use sites).

• Median and 90th percentile reported use rates (pounds of active ingredient per acre) from 

usage data – national, state, and county.

• Typical application timing (date of first application) – national, state, and county.

• Usage/use information for non-agricultural uses.

• State or local use restrictions.

• Foreign technical registrants not listed above who supply technical chloropicrin to the US 

market.

In addition, the Agency will continue the dialogue with stakeholders about label issues that have 

evolved during the RED label implementation process.

 6 Section 3 product labels can be obtained from the Pesticide Product Label System (PPLS) website 

(http://oaspub.epa.gov/pestlabl/ppls.home).
10

RECENT ACTIONS

A Reregistration Eligibility Decision (RED) was completed for chloropicrin in July 2008 and 

amended in May 2009. The Agency determined that chloropicrin products were eligible for 

reregistration provided a number of risk mitigation measures adopted and label amendments are 

made to reflect these measures. For details on the mitigation measures, see the Amended 

Reregistration Eligibility Decision (RED) for Chloropicrin, dated May 2009. Additionally, the 

Agency’s Soil Fumigant Toolbox website contains information on these and other soil fumigants: 

http://www.epa.gov/pesticides/reregistration/soil_fumigants/. 

The product reregistration process, which starts after completion of a RED, is still ongoing for 

chloropicrin products. 

Additionally, the Agency plans to work with stakeholders to determine if chloropicrin fumigant 

product labels should be reorganized or revised in order to clarify the Good Agricultural 

Practices and buffer zones that correspond to each of the various application methods.

Since publication of the 2008 RED, the following products with antimicrobial wood preservative 

uses were cancelled: TM-442, EPA registration number 66330-47, cancelled on 2-20-13 (77 FR 

72343 (12-5-12)); and Timberfume, EPA registration number 75341-3, cancelled on 7-27-12 (77 

FR 44229 (7-27-12)). The Agency is anticipating the submission of a label amendment for 

Timberfume II, EPA registration number 75340-1. This label amendment will adopt risk 

mitigation measures identified in the RED.

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for chloropicrin was completed in 

April 2009 in preparation for the amended Reregistration Eligibility Decision. An addendum to 

the assessment was completed in January 2011. The most recent antimicrobial occupational and 

residential exposure assessment was completed in April 2007. The most recent ecological and 

environmental fate risk assessment was completed in April 2008 for the Reregistration Eligibility 

Decision completed in July 2008. Findings and conclusions from these risk assessments are 

summarized in the Problem Formulation for the Environmental Fate, Ecological Risk, 

Endangered Species, and Drinking Water Exposure Assessments in Support of the Registration 

Review of Chloropicrin and the Chloropicrin Registration Review Human-Health Assessment 

Scoping Document.

During registration review, the Agency anticipates the need to conduct a comprehensive

ecological risk assessment, including an endangered species assessment, for all uses of

chloropicrin. For human health, 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.
11

Table 4 below summarizes the anticipated registration review risk assessments based on the 

EFED Problem Formulation and HED Scoping Document.

Table 4: Anticipated 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.
12

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 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.

Guidance for Commenters: Additional ecological information requested for this 

registration review, and of particular interest to EPA, is described below.

• Ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and 

mammalian mortalities) not already reported to the Agency.

• Water quality monitoring data (see Appendix for further details).
13

TIMELINE

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

registration review in Table 5 below.

Table 5: Projected Chloropicrin Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period 2013 – September

Close Public Comment 2013 – November

Case Development

Final Work Plan 2014 – February

Issue DCI 2014 April - June

Data Submission 2016 April – June

60-day Public Comment Period for Draft Risk 

Assessments7

2018 October– December

Registration Review Decision

60-day Public Comment Period for Proposed 

Registration Review Decision

2019 April - June

Registration Review Decision and Begin Post-Decision 

Follow-up

2019

Total (years) 6

NEXT STEPS

After the 60-day public comment period closes, the Agency will review and respond to any 

comments received in a timely manner and then issue a Final Work Plan for the registration 

review of chloropicrin.

 7 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.
14

Appendix – Additional Areas Considered in the Chloropicrin Registration 

Review

PUBLIC COMMENTS AND FEEDBACK:

Guidance for Commenters: The areas below highlight topics of special interest to the Agency 

where your comments, data submissions, or reference to sources of additional information could 

be of particular use.

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade 

irritants and, to the extent feasible, take steps toward facilitating irritant resolution. The Agency 

will work to harmonize tolerances and international maximum residue limits (MRLs) and may 

modify tolerance levels to do so, when possible. Growers and other stakeholders are asked to 

comment on any trade irritant issues resulting from lack of MRLs or disparities between U.S. 

tolerances and MRLs in key export markets, providing as much specificity as possible regarding 

the nature of the concern. Because chloropicrin is not registered for food/feed uses in the U.S., 

it has no U.S. tolerances; therefore, the Agency does not anticipate any trade irritant issues for it.

Water Quality:

Chloropicrin is not identified as a cause of impairment for any water bodies listed as impaired 

under section 303(d) of the Clean Water Act.

8

 In addition, no Total Maximum Daily Loads 

(TMDL) have been developed for chloropicrin.

9

 More information on impaired water bodies 

and TMDLs can be found at the Agency’s website.

10 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 Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and 

Management Process11 in order to ensure they can be used quantitatively or qualitatively in 

pesticide risk assessments.

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all 

people, regardless of race, color, national origin, or income, in the development, implementation, 

and enforcement of environmental laws, regulations, and policies. To help address potential 

environmental justice issues, the Agency seeks information on any groups or segments of the 

population who, as a result of their location, cultural practices, or other factors, may have 

atypical, unusually high exposure to chloropicrin compared to the general population. Please

 8 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

9

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_

group_name=PESTICIDES

10 http://www.epa.gov/owow/tmdl/ 11 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm
15

comment if you are aware of any sub-populations that may have atypical, unusually high 

exposure compared to the general population.

ENDANGERED SPECIES:

A risk assessment that supports a complete endangered species determination has not been 

conducted for chloropicrin. The ecological risk assessment planned during registration review 

will allow the Agency to determine whether use of chloropicrin has “no effect” or “may affect” 

federally listed threatened or endangered species (listed species) or their designated critical 

habitats. When an assessment concludes that a pesticide’s use “may affect” 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 Services), as appropriate.

ENDOCRINE DISRUPTOR SCREENING PROGRAM:

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its most recent registration decision for chloropicrin, EPA 

reviewed these data and selected the most sensitive endpoints for relevant risk assessment 

scenarios from the existing hazard database. However, as required by FFDCA section 408(p), 

chloropicrin is subject to the endocrine screening part of the Endocrine Disruptor Screening 

Program (EDSP). 

EPA has developed the EDSP to determine whether 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 other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the 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 estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects 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 screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list of 
16

chemicals identified for EDSP screening was published on June 14, 201312 and includes some 

pesticides scheduled for Registration Review and chemicals found in water. For further 

information on the status of the EDSP, the policies and procedures, the lists of chemicals, future 

lists, the test guidelines and the Tier 1 screening battery, please visit our website.13

In the interim, EPA is making no human health or environmental safety findings associated with 

the EDSP screening of chloropicrin. Before completing this Registration Review, the Agency 

will make an EDSP FFDCA section 408(p) determination.

HUMAN STUDIES:

Chloropicrin-specific Human Studies

Past chloropicrin risk assessments have relied in part on a human study which involved 

intentional exposure to chloropicrin. In the course of registration review EPA will reconsider 

this study, as well as any other research involving intentional exposure of human subjects to 

chloropicrin brought to its attention. If EPA decides to rely on any of these studies, EPA will 

ensure that all applicable regulatory requirements are met, including, but not limited to, the 

requirements for EPA ethics review and Human Studies Review Board review of certain 

research involving intentional exposure of human subjects.

 12 See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of 

chemicals. 

13 http://www.epa.gov/endo/