Seasonal Air Monitoring Studies
In collaboration with the California Air Resources Board, we conduct seasonal ambient monitoring studies around high-use areas in close proximity to communities identified through the AB 617 process. Intensive seasonal ambient monitoring studies are normally conducted in multiple high-use communities during the high-use season for individual pesticides and can last anywhere from 4-16 weeks, depending on the study.
Seasonal ambient air monitoring studies produce data that is used to estimate concentrations associated with subchronic exposures. Data collected from these monitoring studies assists us in our assessment of the potential health risks associated with pesticide use, developing measures to mitigate risks, and measuring the effectiveness of regulatory requirements.
Find seasonal study reports on our Reports Directory.
Toxic Air Contaminant Program
California’s Toxic Air Contaminant Act created the statutory framework for the evaluation and control of chemicals as toxic air contaminants (TACs). In implementing the law, we must determine the levels of human exposure in the environment and estimate the potential human health risk from those exposures. Our evaluation report undergoes review by other government agencies, the public, and a multi-agency, scientific review panel.
Based on the evaluation, the Director of DPR determines whether the candidate is a TAC. If the Director determines the pesticide meets the criteria, we designate the pesticide a TAC in regulation and add it to the TAC list. The law also requires us to administratively designate pesticides as toxic air contaminants if they are substances listed as Hazardous Air Pollutants (HAPs) under section 7412 of Title 42 of the United States Code.
Once a pesticide is a designated TAC, it enters the control, or mitigation, phase. In the mitigation phase, we investigate the need for, and appropriate degree of, control for the TAC. If exposure should be reduced, we must develop control measures to reduce emissions to levels that adequately protect public health.
We may use other legal authority to implement control measures, particularly for pesticides that pose an immediate health threat.
1,3-Dichloropropene Field Fumigation Requirements
These resources contain the regulatory requirements and documents for TAC, 1,3-D.
1,3-Dichloropropene Quarterly Use Summary
The 1,3- Dichloropropene (1,3-D) pesticide use report data shows the summary of 1,3-D
use records by date, month, crop, county, and township.
Data from January 1, 2024 to September 30, 2025. Updated on October 22, 2025.
Accessible PDF versions of tabs (1,3-Dichloropropene Quarterly Use Summary) below:
Setback Calculator and Broadcast Equivalent
The setback table determines setback distances and application block sizes based on county, field fumigation method, application month and rate.
The broadcast equivalent calculates 1,3-D and chloropicrin broadcast equivalent application rates based on planted area, application block, center-to-center and bottom width distance, and product application rate.
Accessible PDF versions of tabs (Setback Calculator and Broadcast Equivalent) below:
Chloropicrin Regulatory Requirements
These resources contain the regulatory requirements and documents for TAC, Chloropicrin.
Volatile Organic Compound (VOC) Emissions
Volatile organic compounds (VOCs) contribute to the formation of ground-level ozone, which is harmful to human health and vegetation when present at high enough concentrations. The federal Clean Air Act requires each state to submit a State Implementation Plan (SIP) for achieving and maintaining federal ambient air quality standards, including the standard for ozone. Nonattainment areas (NAAs) are regions in California that do not meet either federal or state ambient air quality standards.
We are responsible for agricultural and commercial structural pesticide products, and the Air Resources Board (ARB) is responsible for pesticides in consumer products.
VOC nonattainment areas (NAAs) include:
- Sacramento Metro
- San Joaquin Valley
- South Coast
- Southeast Desert
- Ventura
How to Calculate Non-Fumigant VOC Emissions
Use our VOC emissions calculator, which we sourced from agricultural applications of non-fumigant pesticides. You can calculate VOC emissions from single or multiple pesticide products and applications.
The VOC emissions calculated here rely on the product’s emission potential (EP). EP is the percentage of the product assumed to potentially contribute to atmospheric VOCs. The benchmark method for estimating EPs is a laboratory test called thermogravimetric analysis (TGA). DPR has alternative methods for estimating EPs in the absence of TGA data. These are standard reproducible methods for determining product EPs, and so they provide the ability to accurately assess relative changes in VOC emissions from year to year. EPs may overestimate the absolute value of VOC emissions under certain circumstances because they do not account for other factors that can influence emissions, such as application methods or soil absorption.
Regulations for Reducing VOC Emissions from Nonfumigant Pesticides
Regulations (CCR Title 3, 6880) to reduce emissions of volatile organic compounds (VOCs) from nonfumigant pesticides apply to high-VOC products containing abamectin, chlorpyrifos, gibberellins, or oxyfluorfen when used in the San Joaquin Valley ozone nonattainment area during the ozone season May 1 through October 31. The regulations do not apply to low-VOC products for any active ingredients.
The prohibitions on the high-VOC products will be in effect between the May 1 through October 31 period during 2025.
Sales and use requirements for high-VOC products – The regulations (CCR Title 3, 6884) include requirements for pest control dealers selling a high-VOC product for use in the San Joaquin Valley and also include requirements for agricultural pest control advisers and growers prior to using a high-VOC product.
VOC Annual Reports
To view the current draft or final VOC report, please visit our Reports Directory.
We post a draft VOC report to provide an opportunity for public comment. To view current public comment opportunities, please visit our public comment portal, SmartComment.
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Still have a Question or Need More Information?
Please contact us with questions or visit the Contact Us page on our website to connect with other programs at DPR.
Email: Air.Program@cdpr.ca.gov
Department of Pesticide Regulation
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
