What You Need to Know About the Chlorpyrifos Ban in California

What is chlorpyrifos?

Chlorpyrifos is an active ingredient in insecticides used primarily to treat agricultural food and feed crops. Chlorpyrifos is a “broad-spectrum, chlorinated organophosphate insecticide, acaricide and nematicide.”[1]  It was first registered for use in the United States in 1965. Chlorpyrifos was designated as a restricted material by the DPR in 2015 and has now been banned from use in California.[2]

Why has California banned chlorpyrifos?

Studies have shown connections between chlorpyrifos and developmental harm to infants which future studies show persisted into childhood. Other studies have shown contradictory results; however, the methodologies and conclusions were called into question. Three studies published in 2017 & 2018 have since shown that chlorpyrifos does in fact cause “decreased learning, hyperactivity and anxiety in rat pups.”[3] Upon careful consideration of the new studies, the California Department of Pesticide Regulation decided that the risks could not be mitigated, and moved to ban the product entirely.

Are there alternatives to chlorpyrifos?

CA DPR has established a workgroup to “develop short and long term action plans to identify and develop safer, more sustainable alternatives to chlorpyrifos. The work group will leverage the work of experts from across the globe to identify and develop pest management tools.”[4] Work is underway, and results can be expected in the spring of 2020.

When does the ban go into effect?

Registrations for products with chlorpyrifos as the active ingredient were made inactive on January 1, 2020. Distribution by California dealers ceased on February 6, 2020. However, possession and use does not have to cease until December 31, 2020.[5]

What are the conditions for use of chlorpyrifos through December 31, 2020?

Application limitations of chlorpyrifos include “a ban on aerial spraying, quarter-mile buffer zones and limiting use to crop-pest combinations that lack alternatives.”[6] The full description of interim permit conditions can be found here: https://www.cdpr.ca.gov/docs/chlorpyrifos/pdf/general_notice_append_o.pdf

What products are affected by this rule change?

The full list of affected products can be found in this CA DPR notice: https://www.cdpr.ca.gov/docs/chlorpyrifos/pdf/general_notice_append_o.pdf

If I still have affected products by December 31, 2020, what should I do with them?

“Do not throw unused pesticides in the trash. Check with your local solid waste management authority, environmental health department or county agricultural commissioner to find out whether your community has a household hazardous waste collection program.”[7]

Sources and Further Reading:

[1] http://npic.orst.edu/factsheets/archive/chlorptech.html
[2] https://calepa.ca.gov/2019/10/09/press-release-agreement-reached-to-end-sale-of-chlorpyrifos-in-ca-by-feb-2020/
[3] https://theconversation.com/why-california-is-banning-chlorpyrifos-a-widely-used-pesticide-5-questions-answered-130115
[4] https://www.cdpr.ca.gov/docs/chlorpyrifos/faq.htm
[5] https://www.cdpr.ca.gov/docs/chlorpyrifos/pdf/general_notice_append_o.pdf
[6] https://calepa.ca.gov/2019/10/09/press-release-agreement-reached-to-end-sale-of-chlorpyrifos-in-ca-by-feb-2020/
[7] https://www.cdpr.ca.gov/docs/dept/factshts/storage.pdf



California’s recent wildfires not only impact human lives but wildlife as well. Larger animals such as bear and deer will likely find their way out of the forests seeking safety in other areas outside of the fire zone. Other critters such as rabbits, rats, mice, raccoons, squirrels, and gophers use their natural instincts and burrow underground to escape the flames.

Once the fires have been extinguished, these creatures will re-emerge, seeking safety from predators, as well as food and shelter in the nearest structures to have survived the flames. This means that areas such as attics, walls basements, roofs, and crawl spaces will become a safe haven. Not only are they a nuisance but these intruders could potentially carry disease which causes health risks for both household pets and humans.

Of course, the owners of these infested structures will be seeking knowledgeable and experienced professionals to rid their homes of unwanted visitors. Pesticide Professionals are able to expand their knowledge base and earn valuable California DPR and SPCB approved continuing education credits by taking the two courses highlighted below.

Cage Trapping Techniques - 3-hour online video course $49
This California DPR and SPCB approved course focuses on the use of cage and box traps in the management of vertebrate pests in both urban and suburban environments in California. Best practices surrounding appropriate traps for target animals, effective baits, and safe and humane use of traps will be outlined.

Vertebrate Structural Pest Control And ID4-hour online video course $59
This California DPR and SPCB approved course focuses on the fundamentals of wildlife damage inspection including identification based on habitat, routes of entry, scat, and tracks. It will help you understand the unique biological and legal risks that are involved with the inspection process in California as well as the proper equipment and PPE that should be used.

Online Pesticide Professional Continuing Education

State-approved video continuing education courses are available 24/7.