Docket Number EPA-HQ-OPP-2014-0544 

www.regulations.gov 

4-Chlorophenoxyacetic Acid ( 4-CP A) 

Interim Registration Review Decision 

Case Number 2115 

December 2014 

Approved by: cu..,tL...P 4-> 

Richard P. Keigwin, Jr. 

Director 

Pesticide Re-evaluation Division 
4-CP A -Table of Contents 

Introduction 3 

Statutory and Regulatory Authority 4 

4-CP A Chemical Facts 4 

Use and Usage Information 5 

Recent Actions 5 

Scientific Assessments 5 

Interim Registration Review Decision 8 

Next Steps 8 

References: 

This document summarizes the Environmental Protection Agency's current position based on the 

following documents: 

1. EFED Preliminary Risk Assessment to Classify Registered 4-CP A Uses as De Minimus 

Risk to Listed/Non Listed Species and "No Effects " Determination. Edward Odenkirchen, 

Ph.D., Senior Science Advisor. June 5, 2014. 

2. 4-Chlorophenoxyacetic Acid. Human Health Risk Assessment in Support of Registration 

Review. ldeliz Negr6n-Encarnaci6n, Ana Rivera-Lupianez, Seyed Tadayon, Ronnie J Bever 

Jr., Ph.D. July 17,2014. · 

3. BEAD Chemical Profile for Registration Review: 4-CPA and Salts (01040 1). Sunil 

Ratnayake, Sepehr Haddad, and Derek Berwald. May 3, 2012. 

4. 4-Chlorophenoxyacetic Acid, and Salts: Tier I Review of Human Incidents. Shanna Recore, 

Elizabeth Evans. June 26, 2014. 

These and other supporting documents for the 4-CP A registration review case may be found in 

the docket EPA-HQ-OPP-2014-0544 at http://w.¥W.regulations.gov. 

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I. INTRODUCTION 

This document is the Environmental Protection Agency's (EPA or the Agency) Interim 

Registration Review Decision for 4-chlorophenoxyacetic acid (4-CPA), pursuant to 40 CFR 

§ 155.56 and § 155.58. A registration review decision ~s the Agency's determination that a 

pesticide meets, or does not meet, the standard for registration in the Federal Insecticide, 

Fungicide, and Rodenticide Act (FIFRA). The Agency may issue, when it deems appropriate, an 

interim registration review decision before completing a registration review. Among other 

things, the interim registration review decision may ( 1) require new risk mitigation measures; (2) 

impose interim risk mitigation measures; (3) identify data or information required to complete 

the review; and (4) include schedules for submitting the required data, conducting the new risk 

assessment, and completing the registration review. 

FIFRA, as amended by the Food Quality Protection Act (FQPA) of 1996, mandated the 

continuous review of existing pesticides. All pesticides distributed or sold in the United States 

generally must be registered by EPA, 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 

and reduce risk evolves and as policies and practices change, all registered pesticides continue to 

meet the statutory standard of no unreasonable adverse effect to human health or the 

environment. Through the registration review program, the Agency periodically reevaluates 

pesticides to make sure that as these changes occur, pr<:>ducts in the marketplace can be safely 

used. Information on this program is provided at: 

http://www.epa.gov/oppsrrd 1 /registration review/. In 2006, the Agency implemented the 

Registration Review program pursuant to FIFRA Section 3(g) and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. 

The pesticide 4-CP A is a plant growth regulator registered for use exclusively as a 

soaking agent for mung bean sprouts in greenhouse operations to prevent root formation which 

improves the sorting and handling of the mung bean sprouts for packaging. All of the use occurs 

indoors. 4-CP A is applied in a dilute solution of 2 to 3 mg/L of active ingredient to a water bath 

to soak batches of about 3500 pounds of beans. Once the beans have soaked for several hours, 

they are washed to remove the surface residues, and are then germinated indoors for several 

days. After sprouting, the hulls and roots are discarded, and the remaining portion is packaged 

and sold for human consumption. 

EPA completed the Reregistration Eligibility Decision (RED) for 4-CPA in March 1997 

and reassessed 4-CP A tolerances in the 2003 Tolerance Reassessment Progress and Risk 

Management Decision. EPA formally initiated registration review for 4-CPA in 2014, with the 

posting of the 4-CPA Combined Work Plan, Summary Document, and Proposed Interim 

Registration Review Decision on September 24, 2014 for a 60-day comment period. EPA 

received comments from the Center for Biological Diversity, which agreed with the Agency's 

finding regarding endangered and threatened (listed) species. 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. 

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For further information on the registration review of 4-CPA, see EPA's public docket (EPA-HQOPP-2014-0544) at www.regulations.gov. 

STATUTORY AND REGULATORY AUTHORITY 

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

program. All pesticides distributed or sold in the U.S. generally must be registered by EPA, 

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 at 

www.epa.gov/oppsrrd 1 /registration review/. 

The Agency is implementing the registration review program pursuant to Section 3(g) of 

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. 

4-CPA CHEMICAL FACTS 

PC code 019401 

Case Number 2115 

CAS Number 122-83-3 

Year first registered 1969 

Pesticide Type Conventional Chemical 

Chemical class Phenoxy 

Reregistration Eligibility March 1 , 1997 

Decision (RED) 

Tolerance Reassessment April 4, 2003 

Eligibility Decision (TRED) 

Cumulative Group EPA has not made a common mechanism of toxicity finding as to 

4-CP A and any other substances, .and 4-CP A does not appear to 

produce a toxic metabolite produced by other substances. 

40 CFR Citation Tolerances are established in the 40 CFR § 180.202 for residues of 

4-CPA in or on mung bean sprouts at 0.2 ppm. 

Non-pesticidal uses No non-pesticidal uses of 4-CP A 

Pesticide Re-evaluation Miguel Zavala, zavala.miguel@epa.gov, 703-347-0504 

Division, Chemical Review 

Manager 

4 
Registration Division, 

Product Mana er 

Tony Kish, kish.tony@epa.gov, 703-308-9443 

USE AND USAGE INFORMATION 

4-CP A is registered for use in the food industry as a plant growth regulator to restrict root 

growth during seed germination of mung beans. Below is a summary of the use/usage of 4-CP A. 

For more details please see BEAD Chemical Profile for Registration Review: 4-CPA and Salts 

(010401), May 3, 2012. 

Summary of Use 4-CP A is applied to a water bath to soak mung beans. The beans 

soak for several hours, are washed, and then germinated indoors 

for several days. After sprouting, the hulls and roots are 

discarded, and the remaining portion is packaged and sold for 

human consumption. 

Use Sites Indoor uses. 

Summary of Usage 10-20 lbs active ingredient are used annually nationwide 

Formulation Type(s) Amorphous powder 

Technical Registrant(s) ConAgra Foods 

No. of Registrations 1 

Restricted Use No I 

RECENT ACTIONS 

I 

There are no recent actions for 4-CP A. 

SCIENTIFIC ASSESSMENTS 

A summary of the Agency's human health and environmental fate and ecological risk 

assessments, 4-Chlorophenoxyacetic Acid. Human Health Risk Assessment in Support of 

Registration Review (July 17, 20 14) and EFED Preliminary Risk Assessment to Classify 

Registered 4-CP A Uses as De Minimus Risk to Listed/Non Listed Species and "No Effects " 

Determination. (.June 5, 2014) is presented below. For the detailed risk assessments, see the 4-

CPA public docket (EPA-HQ-OPP-2014-0544) at www.regulations.gov. 

Human Health Assessment 

Hazard Characterization and Risk 

The toxicological database is considered adequate for characterizing hazard and assessing 

risk from 4-CP A. No additional studies are anticipated to be needed for registration review. 

Dietary Exposure Assessment 

A chronic dietary (food only) exposure and risk assessment was conducted using 

tolerance-level residue values for mung bean and assuming 100% of crop treated. Drinking water 

is not an anticipated exposure pathway, as application of 4-CP A occurs indoors and the use is 

limited. The chronic dietary risk for 4-CPA was below the Agency's level of concern for the 

general population and all population subgroups. 

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Food Tolerances 

A tolerance of 0.2 ppm is established in the 40 CFR § 180.202 for residues of 4-CPA 

in/on bean, mung, sprouts. The tolerance expression currently includes measurement of residues 

of parent 4-CP A and its metabolite 4-chlorophenol. The Agency has completed an evaluation of 

the established tolerance and determined that the tolerance expression needs to be modified in 

accordance with current Agency policy for writing tolerance expressions and to exclude 

measurement of the metabolite 4-chlorophenol because it is no longer considered a metabolite of 

risk concern. 

Canada has established a maximum residue limit (MRL) of2 ppm for residues of 4-CPA 

in or on mung beans. EPA's 0.2 ppm tolerance is based on updated residue data that has not been 

submitted to Canada. We did not receive any comments on this disparity in MRLs and there are 

no trade barriers to U.S. growers. For more information please refer to 4-Ch/orophenoxyacetic 

Acid. Human Health Risk Assessment in Support of Registration Review (July 17, 2014). 

Residential and Occupational Exposure 

A residential handler and post-application exposure assessment is not needed for 

registration review because there are no registered residential uses of 4-CP A. For occupational 

use, the Agency believes that the potential for exposure to 4-CPA during pesticide handling 

operations exists, but is very low. Based on a conservative quantitative assessment of 

occupational handler exposure and risk, no risks of concern were identified. Occupational postapplication exposure was not quantitatively assessed. However, based on 4-CPA's use pattern 

and low exposure potential, the occupational handler assessment is expected to be protective of 

potential worker post-application exposure. 

Environmental Assessment 

EPA conducted a qualitative environmental fate and effects assessment for 4-CPA and 

has determined that effects to non-target species are unlikely. EPA considered potential 4-CPA 

exposure to non-target organisms, available information on the toxicity of 4-CP A from 

ecological structure activity relationships, and annual usage information. Spent mung bean 

soaking solution can be disposed of down municipal wastewater drains and represents a 

complete exposure pathway to downstream receiving waters. However, there is a low likelihood 

for significant toxicity to aquatic organisms, the taxa most likely to be exposed via a wastewater 

discharge scenario, based on predictions from ecological structure activity relationships. In 

addition, the 20 pounds of 4-CPA used annually is expected to be geographically disperse and 

greatly diluted before reaching receiving waters. 

Threatened and Endangered Species 

Based on the type and extent of use, the low expected toxicity predicted by quantitative 

structure activity relationships, and the highly diffuse nature of the use site coupled with extremely 

low annual usage, the Agency concludes that effects on the environment are not reasonably expected 

to occur from the registered use of 4-CP A. Therefore, the EPA is making a "no effects" 

determination under the Endangered Species Act (ESA) for all listed species and no adverse 

modification of designated critical habitat for such species from the registered use of 4-CP A. 

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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 4-CPA, 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), 

4-CP A is subject to the endocrine screening part of the Endocrine Disrupter Screening Program 

(EDSP). 

EPA has developed the EDSP to determine whether certain substances (including active 

pesticides 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 I 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 I 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 20 I 0, 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 

chemicals identified for EDSP screening was published on June 14, 2013 1 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 l screening battery, please visit our website.2 

In this Interim Registration Review Decision, EPA is making no human health or 

environmental safety findings associated with the EDSP screening of 4-CP A. Before completing 

this Registration Review, the Agency will make an EDSP FFDCA section 408(p) determination. 

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

chemicals. 2 http://www.epa.gov/endo/ 

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INTERIM REGISTRATION REVIEW DECISION 

In accordance with 40 CFR Sections 155.50, 155.56, and 155.58, the Agency is issuing 

this Interim Registration Review Decision. Except for the EDSP component of the 4-CP A 

registration review case, the Agency has made the following interim decision: (I) no additional 

data are required at this time; and (2) no changes to the affected registrations or their labeling are 

needed at this time. EPA has not identified any risks of concern to human health. Currently 

registered uses of 4-CPA are not expected to result in adverse effects to listed or non-listed 

species, or critical habitat. As such, EPA concludes "no effect" for all listed species and no 

adverse modification of designated critical habitat for such species for all currently registered 

uses of 4-CP A. 

NEXT STEPS 

EPA will make a final registration review decision for 4-CP A after an EDSP FFDCA 

section 408(p) determination has been made. 

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