California is recognized for having the most stringent and protective laws and regulations in the nation governing the use of pesticides, including fumigants.
This section provides an overview of those laws and regulations, including the role of County Agricultural Commissioners, the actions required before a farmer can use a restricted-use pesticide, proposed new regulations for the fumigant 1,3-D, notification requirements near schools and homes, air monitoring requirements, and answers to some commonly asked questions.
FAQ
What Federal Regulations Govern the Approval of Pesticides for Use on Conventional and Organic Crops?
The U.S. Environmental Protection Agency (U.S. EPA) follows a rigorous scientific evaluation process to register pesticides for use in agricultural production, ensuring they will not harm human health, non-target species, or the environment when used according to label instructions. These evaluations consider the protection of infants, children, and other vulnerable populations—as well as adults—from the potential harmful effects of pesticide exposure.
Organic farmers may use pesticides derived from natural sources, as well as certain synthetic substances, provided they comply with the regulations of the U.S. Department of Agriculture’s (USDA) National Organic Program (NOP).
What is the role of the California Department of Pesticide Regulation (CDPR) regarding agricultural pesticide applications?
The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) authorizes state regulation of the sale and use of federally registered pesticides as long as state regulations are at least as restrictive as federal standards. U.S. EPA has given primary enforcement responsibility to CDPR to regulate the use of pesticides in California. CDPR has a comprehensive secondary registration process that must be met before a pesticide can be used in the state. CDPR often adds regulations more protective of health and the environment to a product label and continues evaluating pesticides after registration has been granted.
California is now recognized for having the most stringent laws and regulations governing the approval and use of pesticides in the nation, which are protective of residents, consumers, farm workers and the environment.
Learn more about CDPR here.
What is the role of County Agricultural Commissioners regarding agricultural pesticide applications?
In California, County Agricultural Commissioners are responsible for enforcing state and federal laws related to pesticide use to protect the health and safety of residents, workers and the environment within their respective counties.
Can County Ag Commissioners require more stringent rules on pesticide applications than the state?
Yes. County Agricultural Commissioners have authority to impose tougher restrictions tailored to local conditions.
Restricted use permits are issued for pesticides deemed to have a higher potential to cause harm to public health, farm workers, domestic animals, honeybees, the environment or other crops. With certain exceptions, restricted materials may be purchased and used only by or under the supervision of a certified commercial or private applicator with a permit issued by the County Agricultural Commissioner.
Are restricted use permits required for fumigant applications?
Yes, these permits are required for applications of fumigants. Additional site specific permit conditions can be added, however, the additional rules cannot be so restrictive that they prohibit effective pest control.
What is the process for securing a restricted materials permit to apply a fumigant?
Under a 1976 determination by the state’s Attorney General, a restricted materials permit is the equivalent of an environmental impact report if certain conditions are met. The permit application process allows the County Agricultural Commissioner to evaluate the site proposed for fumigation and surrounding properties to protect people and the environment as well as provide for effective pest control and public review of permits. The process determines what site-specific practices should be followed beyond the requirements on the product label, and what conditions are needed to minimize potentially adverse effects. Restricted materials permits are only issued to the operator of the property or his or her authorized representative, a licensed pest control business.
The County Ag Commissioner’s office must follow a comprehensive checklist to ensure the application is complete. Detailed plans for each site scheduled for fumigation must include:
- Farm name, acres treated, commodity and pesticides to be applied.
- Aerial maps, which must identify neighboring properties.
- Measurements to neighboring properties.
- Identification of schools, parks, houses, public roads, occupied buildings, lakes, waterways, wildlife management areas, habitats of rare, threatened or endangered species and other sensitive areas within one-quarter mile.
- Buffer zones: Areas around the perimeter of each application site that extends outward from the edge equally in all directions. All non-handlers, including field workers, residents, pedestrians and other bystanders, must be excluded from the buffer zone for an established minimum time period from when the application starts to when it is complete. All normal activities can occur outside the buffer zone perimeter without restrictions.
- Emergency response measures if residents and/or businesses are within proximity to a buffer zone.
Applicants are asked if alternatives were considered, including non-pesticide treatments or non-restricted materials. The farmer is required to complete a field fumigation work plan and submit it to the County Ag Commissioner’s office for approval. The work plan must be approved by a licensed agricultural inspector biologist and be signed by the farmer prior to starting the fumigation.
Additionally, prior to the start of the application, the certified applicator supervising the application must complete the fumigation management plan (FMP) and make the FMP available to inspectors upon request during the application process.
Denial of a permit requires due process, including an appeal hearing.
You can learn more about pesticide application permit conditions by visiting the website of your County Ag Commissioner.
CDPR is considering new, more stringent regulations for the fumigant 1,3-D.. What are those?
The proposed regulations were developed to increase protections for occupational bystanders. (Note: fumigation is conducted several days or weeks prior to planting when no farm employees are working.)
If adopted, these regulations would establish buffer zone distances (distances from the edge of a treated area where certain activities are restricted), require CDPR to include an evaluation in the 1,3-D Annual Report of whether the 1,3-D air concentration in any township exceeds the acceptable level of 0.21 part per billion, and to develop appropriate measures to reduce exposures if target air concentration levels are exceeded.
Township caps for 1,3-D applications are annual limits on the amount of the fumigant that can be applied within a defined six-mile by six-mile area.
The proposed regulation also includes new field application requirements, including provisions regarding the use of total impermeable film (TIF) tarps following fumigation.
CDPR has held hearings and received public comments on these proposed regulations. If adopted, these regulations are scheduled to be implemented in January 2026.
Visit CDPR webpages here and here to learn more about the proposed regulation for occupational bystanders and application requirements.
How does CDPR protect schools located near agriculture fields when pesticides/ fumigants are applied?
In 2018, regulations were implemented by CDPR that require annual notification to schools and licensed day care centers about pesticides and fumigants that may be applied within a quarter mile of a school. The regulation also prohibits many pesticide applications within a quarter mile of public K-12 schools and licensed child day-care facilities during school hours, Monday through Friday between 6 a.m. and 6 p.m. This includes applications by aircraft, sprinklers, air-blast sprayers, and all fumigant applications.
Learn more about CDPR school protections here.
What if California residents want to learn more about pesticide or fumigant applications near their homes?
In March 2025, California became the only state in the nation to implement a statewide system to provide the public with access to information prior to intended agricultural applications of restricted material pesticides. Named SprayDays California, this program increases transparency on when and how restricted use pesticides, including fumigants, are used and how they are strictly regulated in the state to protect people and the environment.
California residents can sign up to receive information through email and text message notifications 48 hours before the intended use of soil fumigants and 24 hours before the intended use of other restricted material pesticides used on farms.
Click here to sign up for SprayDays notifications and to learn more about this one-of-a-kind program.
About Air Quality
How does CDPR protect the air we breathe?
In 2011, CDPR launched an air monitoring network as part of its continuous evaluation of pesticides. Over 40 pesticides, including fumigants, are monitored at CDPR stations in this long-term, multi-year program.
California is the only state that monitors air to ensure the protection of workers, residents and the environment. CDPR also conducts field studies to monitor exposure to workers and to measure how pesticides move and break down in air, soil and water.
What are the results from CDPR’s air monitoring program.
CDPR released the 2023 air monitoring results in October 2024. CDPR found no pesticide concentration exceeded current acute, sub-chronic or chronic screening regulatory levels in 2023, meaning that pesticide concentrations found in the air are unlikely to be harmful to human health.
How are air monitoring sites selected?
CDPR selects communities due to their proximity to agricultural use of pesticides, based on Pesticide Use Reports. (California was the first and remains among the only states that require comprehensive pesticide use reporting for all industries, including agriculture, that rely on pesticides. It should be noted that the CDPR report shows the top two pesticides used in agriculture are approved for both conventional and organic crops. Learn more about CDPR’s Pesticide Use Report here.)
Where are the air monitoring stations for pesticides located?
CDPR operates four monitoring stations in the following California communities:
- Oxnard (Ventura County)
- Santa Maria (Santa Barbara County)
- Shafter (Kern County)
- Watsonville (Santa Cruz County)
In 2023, a total of 8,085 analyses (samples multiplied by the number of chemicals analyzed in each sample) were conducted on the air samples collected from the four monitoring sites operating in 2023.
In addition to the four monitoring stations, CDPR also operate stations specifically to monitor Telone in the following communities:
- Delhi (Merced County)
- Parlier (Fresno County)
How does CDPR evaluate the air monitoring data?
DPR evaluates potential pesticide risks by comparing pesticide air concentrations with health thresholds called screening levels and regulatory targets established by CDPR scientists. If pesticide concentrations in ambient air ever exceeds these thresholds, DPR takes steps to investigate the cause and, if warranted, develop and implement mitigation measures to reduce exposures to protect human health.
Commonly Asked Questions
What is an Agricultural Pest Control Adviser (PCA)?
PCAs are consultants used by farmers and licensed by CDPR to provide pest management recommendations for both conventional and organic farms. They also advise farmers on land preparation, planting, fertilization, irrigation, cultivation and harvesting. Federal, state and local laws and regulations for crop production have become so complex that most farmers hire PCAs to help them navigate this complicated system in place to protect farmer workers, residents and the environment. All PCAs must register annually with the County Agricultural Commissioner, who can audit them to ensure their recommendations to farmers conform with the law. You can learn more about the licensing requirements for PCA’s here.
Is there a requirement to post signs when agricultural pesticides are applied?
Posting is required for pesticide applications on crops where there is a restricted entry interval of 24 hours or longer. CDPR does not require posting for non-crop, dormant crop, pre-plant, or pre-emergent applications or when applications are not made directly onto plant, tree or vine foliage. However, many farmers post notification whenever a pesticide is applied on their crops for the benefit of their workers.
If I smell an odor in the vicinity of agricultural fields, is it a pesticide?
Some pesticides emit odors, but others don’t. The County Agricultural Commissioner’s Office responds to all odor complaints. Many times the odor is determined not to be pesticide-related. Odors are also emitted by fertilizers, compost, bodies of water, harvest of certain crops, and disking under harvested crops, like broccoli and Brussel’s sprouts, as well as other sources.
What happens if pests and diseases are not properly controlled on farms?
Our modern food supply, public health and resource management all rely on the appropriate use of pesticides. The United Nations estimates that 20% to 40% of our global crops are lost to pests and diseases each year. Farmers utilize crop protection products (herbicides, insecticides, fungicides, fumigants, etc.) to help control the numerous weed species, harmful insects and plant diseases that can afflict and damage crops which lead to economic losses for both farmers and their farm employees. Whether organic or conventional, farmers face these same challenges each growing season. But, adequate and appropriate pest and disease control is also important to consumers for two reasons: It keeps food prices down because it reduces on-farm crop losses and maintains quality by reducing damage to the fruit and vegetables we buy.
Can organic farmers use pesticides on their crops?
Yes. Organic farmers use pesticides derived from natural sources and pesticides that include synthetic substances within the regulations of the U.S. Department of Agriculture’s National Organic Program. Organic is a production term – it does not address the quality, safety or nutritional value of a product. Both conventional and organic farming emphasizes preventative practices that include crop rotation, mixed plantings and beneficial insects to manage pests and maintain and improve soil quality. Both conventional and organic farming typically rely on the use of pesticides as a last resort to control pests and diseases on crops. Click here for more information on pesticides approved for organic production.
How do I know the produce I buy is safe following a pesticide application?
California, the U.S. Department of Agriculture (USDA) and the Food and Drug Administration (FDA) monitor the food supply to verify safety. The USDA Pesticide Data Program is the most comprehensive pesticide residue database in the United States. The program samples, tests and reports pesticide residues on agricultural commodities in the U.S. food supply with an emphasis on those commodities highly consumed by infants and children. USDA’s program consistently shows that over 99% of the foods sampled, including fruits and vegetables, have residues well below EPA safety standards. In its most recent report, 40% of the foods sampled had no detectable residues at all. California and FDA sampling programs report very similar findings to the USDA PDP. Click here for more information on the USDA PDP.
In addition, an analysis by toxicologists with the University of California’s Personal Chemical Exposure Program of the USDA PDP results found that a child could eat hundreds to thousands of servings of a fruit or vegetable in a day and still not have any effects from pesticide residues. This analysis further verifies how low residues really are, if present at all. Click here to learn more about the analysis.
Regarding fumigants, they are injected into the soil or drip system several days or weeks prior to planting crops, trees or vines and quickly dissipate therefore residues on food are not possible.