EPA Proposes New Safety Measures for Chlorpyrifos

This original announcement was published by the EPA on December 4, 2020. Click here for more information.


EPA is taking the next step in its regulatory review of chlorpyrifos, an insecticide used for a large variety of agricultural uses and non-agricultural uses. Today, EPA is proposing measures to reduce the risks identified in the agency’s September 2020 draft risk assessments to better protect human health and the environment. As outlined in the proposed interim decision (PID), EPA is proposing:

  • Label amendments limiting application to address potential drinking water risks of concern.
  • Additional personal protection equipment and application restrictions to address potential occupational handler risks of concern.
  • Spray drift mitigation, in combination with the use limitations and application restrictions identified to address drinking water and occupational risks, to reduce exposure to non-target organisms.

The PID presents proposed mitigation with the 10-fold (10X) Food Quality Protection Act (FQPA) Safety Factor, reflecting the uncertainties around doses that may cause pre- and post-natal neurodevelopmental effects. Under FQPA, EPA evaluates new and existing pesticides to ensure they can be used with a reasonable certainty of no harm to infants, children, and adults. EPA is required to consider the special susceptibility of children to pesticides by using an additional 10X safety factor unless adequate data are available to support a different factor. EPA additionally included a FQPA factor of 1X to reflect the range of potential risk estimates of chlorpyrifos, as illustrated in the September 2020 draft risk assessments.

Upon publication of the PID in the Federal Register, public comments will be accepted for 60 days on both the September 2020 draft risk assessments as well as the PID. By holding the comment period for both of the actions at the same time, the public has access to more information and can provide more informed, robust comments.

EPA will also consider the input and recommendations from the September 2020 FIFRA Scientific Advisory Panel (SAP) meeting once it releases its report in December 2020. Depending on the SAP’s conclusions, EPA may further revise the human health risk assessment. After a thorough review of the best available science and carefully considering scientific peer review and public comments, EPA will then determine next steps in the registration review process for chlorpyrifos.

Read the PID here. Upon publication of the Federal Register notice, public comments will be accepted for 60 days in the chlorpyrifos registration review docket # EPA-HQ-OPP-2008-0850 at

EPA Takes Next Step in Review Process for Insecticide Chlorpyrifos, Making Draft Risk Assessments Available

This original announcement was published by the EPA on September 23, 2020. Click here for more!

Today, the U.S. Environmental Protection Agency (EPA) is taking an important step in the Agency’s review of chlorpyrifos. Meeting an important commitment made in the Agency’s July 2019 response to the related petition denial, EPA has released its draft risk assessments for chlorpyrifos for public review. These draft risk assessments are the next stage in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) registration review process and are not a denial or approval of the insecticide.

The draft risk assessments are the product of an extensive evaluation of available data on chlorpyrifos’s health and environmental impacts. Specific findings include:

  • The revised human health risk assessment identifies dietary (including children) and occupational handler risks of concern and incorporates the updated drinking water assessment.
  • With the limited remaining residential uses of chlorpyrifos EPA found no risks of concern, including to children’s health, when products are used according to the label instructions.
  • The Agency’s draft ecological risk assessment identifies potential adverse effects to mammals, birds, fish, and terrestrial and aquatic invertebrates.

Full details on these potential risks and EPA’s methods for estimating them can be found within the revised human health and draft ecological risk assessments located on the Agency’s website.

EPA will take public comment on the draft risk assessments (DRAs) during the same 60-day public comment period that the Agency plans to open when it issues its Proposed Interim Decision (PID) in October 2020. The PID, which is the next step in the FIFRA process, will outline potential risk management options for this insecticide to address any potential risks of concern identified in the DRAs.

By holding the comment period at the same time as the Proposed Interim Decision, the public will have access to more information on chlorpyrifos and can provide the Agency with more informed, robust comments. EPA will review and respond to comments for both documents prior to issuing an Interim Decision.

EPA will also consider the input and recommendations from the September 2020 FIFRA Scientific Advisory Panel (SAP) meeting once the SAP report is released in December 2020. Depending on the SAP’s conclusions, EPA may further revise the human health risk assessment. After a thorough review of the best available science and carefully considering scientific peer review and public comments, EPA will then determine the next steps in the registration review process for chlorpyrifos.

Nootkatone Now Registered by EPA

This original announcement was published by the EPA on August 11, 2020. Click here for more! 


A new active ingredient, discovered and developed by the Centers for Disease Control and Prevention (CDC), has been registered by the Environmental Protection Agency (EPA) for use in insecticides and insect repellents.

Studies show that when products are formulated from the new ingredient, nootkatone, they may repel and kill ticks, mosquitoes, and a wide variety of other biting pests. Nootkatone is responsible for the characteristic smell and taste of grapefruit and is widely used in the fragrance industry to make perfumes and colognes. It is found in minute quantities in Alaska yellow cedar trees and grapefruit skin.

Nootkatone can now be used to develop new insect repellents and insecticides for protecting people and pets. CDC’s licensed partner, Evolva, is in advanced discussions with leading pest control companies for possible commercial partnerships. Companies interested in developing brand name consumer products will be required to submit a registration package to EPA for review, and products could be commercially available as early as 2022.

“CDC is proud to have led the research and development of nootkatone,” said Jay C. Butler, MD, Deputy Director for Infectious Diseases. “Providing new alternatives to existing bite-prevention methods paves the way to solving one of biggest challenges in preventing vector-borne diseases—preventing bites.”

Studies show that when nootkatone is formulated into insect repellents, they may protect from bites at similar rates as products with other active ingredients already available and can provide up to several hours of protection.

Having a new effective ingredient for insecticide available will assist in addressing the growing levels of insecticide-resistance to other products currently in use, according to EPA.

“EPA is pleased to be continuing our partnership with CDC on registering nootkatone, which provides another tool to help protect the American public from biting insects and ticks,” said Alexandra Dapolito Dunn, EPA Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. “This new active ingredient has the potential to be used in future insect repellents and pesticides that will protect people from disease. In many areas of the United States, mosquitoes have become resistant to currently available pesticides. A new active ingredient in our toolbox will help vector-control programs.”

Mosquito- and tickborne diseases are a growing threat in every U.S. state and territory. The number of reported cases of mosquito- and tickborne diseases doubled from 2004 to 2018. Tickborne diseases represent almost 8 in 10 of all reported vector-borne disease cases in the U.S. Increasing risk from these diseases means increasing demands on federal, state, and local health departments and vector control agencies.

CDC has partnered with Evolva since 2014. In 2017, Evolva was awarded a Biomedical Advanced Research and Development Authority (BARDA) contract with the key objective of advancing the development of nootkatone and nootkatone-based products for protection against mosquito-borne diseases, including dengue and Zika. This work has been supported with federal funds from CDC and managed by the Office of the Assistant Secretary for Preparedness and Response (ASPR), BARDA, under Contract No. HHSO100201700015C.