Docket Number: EPA-HQ-OPP-2008-0444

www.regulations.gov

Temephos

Registration Review Final Decision

September 2011
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Temephos

Registration Review Final Decision

September, 2011

Case Number 0006

Approved by: ______________________

Richard P. Keigwin, Jr.

Director, Pesticide Re-evaluation Division

Date: ______________________
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TABLE OF CONTENTS

I. INTRODUCTION........................................................................................4

II. BACKGROUND INFORMATION ...........................................................5

III. REGISTRATION REVIEW FINAL DECISION.....................................6
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I. INTRODUCTION

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

Registration Review Final Decision for temephos and is being issued pursuant to 40 CFR 

§ 155.57 and § 155.58. A registration review decision is the Agency’s determination 

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

Insecticide, Fungicide, and Rodenticide Act (FIFRA).

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 must generally 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. Through the 

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

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

this program is provided at: http://www.epa.gov/oppsrrd1/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. 

Pursuant to 40 CFR § 155.50, the Agency formally initiated registration review 

for temephos (case 0006). The following timeline highlights significant events that have 

occurred during the registration review of temephos:

 June 25, 2008 – Publication of the temephos Summary Document, Scoping 

Document, and Problem Formulation in the temephos docket (EPA-HQ-OPP2008-0444) for a 90-day public comment period. The Summary Document also 

included the Preliminary Work Plan for the registration review of temephos.

 November 7, 2008 – Signature of the temephos Final Work Plan and the 

Agency’s response to the public comments received during the 90-day comment 

period on the temephos Summary Document. The one comment received did not 

change the work plan set out in the Preliminary Work Plan.

 November 10, 2010 – Publication of a Notice of Receipt of requests to voluntarily

cancel all remaining pesticide registrations containing temephos in the Federal 

Register (75 FR 69073) (FRL-8851-5). The docket number for the receipt of the 

voluntary cancellation is EPA-HQ-OPP-2009-1017. During the 30-day comment 

period, comments were received regarding temephos from the American 

Mosquito Control Association and the IR-4 Project. Both organizations 

emphasized the benefits of temephos as it is used in public health for mosquito 

control and requested that EPA extend the comment period for these product 
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cancellations. The Agency recognizes the role of temephos in mosquito control 

and has agreed to a 4-year phase-out of the product registrations to accommodate 

the public health need and allow registrants time to develop replacement products. 

The current temephos products will not be cancelled until December 30, 2015. 

 February 25, 2011 – Publication of the Product Cancellation Order for all

remaining pesticide registrations containing temephos in the Federal Register (76

FR 10587) (FRL-8863-4).

 May 25, 2011 - Publication of the temephos Registration Review Proposed Final 

Decision Notice of Availability in the Federal Register (76 FR 25340-25342).

 July 5, 2011 – Closure of the 60-day public comment period on the proposed 

decision. Value Garden Supply and the IR-4 Project submitted comments to the 

docket regarding temephos. As before, the comments emphasized the benefits of 

temephos as it is used in public health for mosquito control. Also, Value Garden 

Supply requested to rescind their voluntary cancellation. In response to Value 

Garden Supply’s request to rescind their voluntary cancellation request, the 

Agency has been in discussions with the registrant about the specific scientific 

data required to support their temephos product registrations affected by the 

Cancellation Order. If the required temephos data are submitted by the registrant, 

reviewed, and found acceptable by the Agency prior to December 30, 2015, the 

Agency may amend the Cancellation Order for the affected product registrations. 

II. BACKGROUND INFORMATION

Temephos is a non-systemic organophosphate insecticide which is applied to 

standing water, shallow ponds, lakes, woodland pools, tidal waters, marshes, swamps, 

waters high in organic content, highly polluted water, catch basins (and similar areas 

where mosquitoes may breed), stream margins, and intertidal zones of sandy beaches. 

Target pests include aquatic larvae of mosquitoes, midges, gnats, punkies, and sandflies. 

Temephos is one of a few organophosphates registered to control mosquito larvae, and is 

the only organophosphate with any appreciable larvicidal use. There are no crop uses 

and no residential uses. Temephos is currently labeled for application only by public 

health officials, personnel of mosquito abatement districts, and other similar government 

agencies or personnel under contract to these entities. The most recent environmental 

fate, ecological, and human health risk assessments for temephos were completed in 1999 

in support of the temephos Reregistration Eligibility Decision (RED), which was 

completed in July 2001.

The temephos registration review Final Work Plan was signed in November 2008

and the registration review data call-in (DCI) was issued in April 2010. In the DCI, the 

Agency required environmental fate, ecological, and human health data that would have 

been used to conduct revised ecological and human health risk assessments for the 

registration review of temephos. In response to the DCI, the technical and end-use 

product registrants, Clarke Mosquito Control Company, Inc. and Value Garden Supply,
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informed the Agency that they were requesting to voluntarily cancel all of their temephos

product registrations. 

A Notice of Receipt of requests to voluntarily cancel all pesticide registration 

containing temephos published in the Federal Register on November 10, 2010. The 

Agency then issued the product cancellation order on February 25, 2011 for all remaining 

temephos product registrations. Copies of those documents are included in the docket 

for registration review. As specified in the Cancellation Order, registrants are prohibited 

from selling or distributing existing stocks of products containing temephos for all uses 

as of December 31, 2015. After December 31, 2016, persons other than registrants are 

prohibited from selling or distributing existing stocks of products containing temephos 

labeled for all uses. After December 31, 2016, existing stocks of products containing 

temephos labeled for all uses, already in the hands of users, can be used legally until they

are exhausted, provided that such use complies with the EPA-approved label and labeling 

of the affected product.

However, during the public comment period for the proposed registration review 

decision, Value Garden Supply requested that the Agency rescind their voluntary

cancellation. In response to Value Garden Supply’s request, the Agency has been in 

discussions with the registrant about the specific scientific data required to support their 

temephos product registrations affected by the Cancellation Order. In those discussions, 

the Agency indicated that the registrant has the option to actively collaborate with IR-4 to 

identify possible funding sources to support the data required in the temephos registration 

review DCI. 

If the required temephos data are submitted by the registrant, reviewed, and 

determined to the acceptable by the Agency prior to December 30, 2015, the Agency may 

amend the Cancellation Order for the affected product registrations. If this occurs, the 

Agency will revisit the registration review process and develop a new registration review 

schedule for products containing temephos. 

III. REGISTRATION REVIEW FINAL DECISION

As stated in the temephos Preliminary Work Plan, the Agency had intended to 

revise the existing risk assessments for temephos. However, due to the cancellation order 

issued affecting all temephos product registrations in the United States, the Agency found 

that it is not necessary to conduct new risk assessments for temephos and, therefore,

issued a proposed decision pursuant to 40 CFR Part 155.53(c)(2) and 40 CFR Part 

155.58. The voluntary cancellation of all remaining U.S. temephos registrations will 

become effective the same year as the final registration review decision would be

completed. The anticipated registration review timeline introduced in the temephos 

Preliminary Work Plan changed due to the issuance of the temephos DCI in April 2010. 

If the temephos registrations had not been voluntarily cancelled, the Agency would issue 

the preliminary risk assessments by January 2014 and issue the revised risk assessments 
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by July 2014, with a final registration review decision scheduled for completion by May

2015. 

The Agency does not expect the current risks associated with temephos use to 

differ from those identified during the temephos reregistration process. In order to 

mitigate the risks identified during reregistration, the Agency specified mitigation 

measures in the temephos RED, which are already in effect on temephos product labels. 

The existing stocks, sales, and distribution deadlines included in the February 25, 2011

cancellation order ensure that temephos sale, distribution, and use will decline and 

eventually cease entirely in the United States in the future. During this period, given the 

mitigation measures that are specified in the RED and are currently in place, the Agency

believes that existing stocks of temephos products may be used until depleted without 

causing unreasonable risk to human health and the environment. Pursuant to 40 CFR § 

155.57 and 155.58, the Agency is issuing the registration review final decision, thus 

concluding the temephos registration review for the reasons discussed above. The 

affected product registrations are subject to the terms and conditions of the February 25, 

2011 cancellation order.