EPA is reopening the comment period on the proposed rule regarding chlorpyrifos because it has revised its human health assessment and drinking water exposure assessment. Comments will be accepted through Jan. 17, 2016.

What is chlorpyrifos?

Chlorpyrifos is an organophosphate insecticide used to control many types of pests. It was first registered as an insecticide in 1965 and was reregistered by the U.S. Environmental Protection Agency in 2006.

Why did EPA do the assessment?

Chlorpyrifos is an organophosphate insecticide is used primarily on corn, but also on soybeans, fence posts and golf courses. (Photo: chas53/Thinkstock)

On Aug. 10, 2015, the U.S. Court of Appeals for the Ninth Circuit directed the EPA to respond by Oct. 31, 2015, to the Pesticide Action Network North America and the Natural Resource Defense Council's petition to revoke all chlorphyrifos tolerances and cancel all chlorpyrifos registrations. As a result of that timing, EPA had not yet completed portions of its scientific assessment when it issued the proposed rule.

What did the assessment show?

The assessment shows dietary and drinking water risks from the use of chlorpyrifos.

Do the revised analyses result in changes to EPA's proposal to revoke all tolerances?

No, but it does modify the methods and risk assessment used to support that finding. The revised analysis indicates that expected residues of chlorpyrifos on most individual food crops exceed the "reasonable certainty of no harm" safety standard under the Federal Food, Drug and Cosmetic Act. In addition, the majority of estimated drinking water exposures from non-food uses continues to exceed safe levels even taking into account more refined drinking water exposures.

Where is more information available?

The information can be found in the following dockets: EPA-HQ-OPP-2015-0653, the docket for the proposed tolerance revocations, and EPA-HQ-OPP-2016-0062, the FIFRA SAP docket, which contains the Chlorpyrifos Issue Paper and supporting materials. Both dockets can be accessed through http://www.regulations.gov.

How can comments be submitted?

Submit your comments, identified by docket identification (ID) number EPA-HQ-OPP-2015-0653, by one of the following methods:

Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting comments. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute.

Mail: OPP Docket, Environmental Protection Agency Docket Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC 20460-0001.

Hand Delivery: To make special arrangements for hand delivery or delivery of boxed information, please follow the instructions at http://www.epa.gov/dockets/contacts.html.

What will EPA do next?

EPA will consider all comments received during the 60-day comment period before issuing a final tolerance decision by March 31, 2017.

Additional instructions on commenting or visiting the docket, along with more information about dockets generally, is available at http://www.epa.gov/dockets.

Source: EPA