Active Ingredient: Chlorpyrifos
Human Health Risk Assessment and Mitigation
Documents and Activities
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Overview
- Name: Chlorpyrifos
- DPR Chemical Code: 253
- Chemical Class: Organophosphate
- Pesticide Types Registered: Insecticide
- Fumigant: No
- California Restricted Material: Yes
- Toxic Air Contaminant (TAC): Yes
- Volatile Organic Compound (VOC) Regulations: Yes
- Potential Groundwater Contaminant: No
- Reevaluation: Concluded
Risk Characterization Documents (RCDs) estimate the nature and likelihood of adverse health effects in humans who may be exposed to pesticides.
- Toxic Air Contaminant (TAC) Assessment
- August 2018 - Director’s Proposed Determination Concerning Chlorpyrifos as a Toxic Air Contaminant (PDF)
- August 2018 - Scientific Review Panel's Findings (PDF)
- July 2018 - Executive Summary (PDF)
- July 2018 - Final Toxic Air Contaminant Evaluation of Chlorpyrifos (Complete Document) (PDF)
- July 2018 - Final Toxic Air Contaminant Evaluation of Chlorpyrifos (Evaluation Only) (PDF)
- Appendix 1 – Summary of Toxicology for Chlorpyrifos (PDF)
- Appendix 2 – Exposure Estimates and Margins of Exposure for Developmental Neurotoxicity (PDF)
- Appendix 3 – Revised Margins of Exposure for Acetylcholinesterase Inhibition (PDF)
- Appendix 4 – Andrews and Patterson, 2000 (PDF)
- Appendix 5 – Mechanistic Studies of Chlorpyrifos Related Neurodevelopmental Effects (PDF)
- Appendix 6 – December 2017 Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (PDF)
- June 2018 - Scientific Review Panel Meeting Presentation: Consideration of Addendum to Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (PDF)
- June 2018 - Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (Addendum to December 2017 Draft Evaluation) (PDF)
- June 2018 - Cover Letter to Scientific Review Panel (PDF)
- December 2017 – Scientific Review Panel Meeting Presentation: Overview of Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (PDF)
- December 2017 – Office of Environmental Health Hazard Assessment Findings on the Health Effects of Chlorpyrifos as a Candidate Toxic Air Contaminant (PDF)
- January 2018 – Responses to OEHHA Findings (PDF)
- December 2017 – Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant for the Scientific Review Panel (PDF)
- December 2017 – Cover Letter to Scientific Review Panel (PDF)
- December 2017 – Charge Questions for the Scientific Review Panel (PDF)
- August 2017 – Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (PDF)
- December 2017 – Responses to Technical Comments by the Public (PDF)
- December 2017 – Responses to Comments by Dow AgroSciences LLC (PDF)
- December 2015 – Draft Risk Characterization Document (PDF)
- August 2017 – Responses to Comments by the California Air Resources Board (PDF)
- August 2017 – Responses to Comments by the Office of Environmental Health Hazard Assessment (PDF)
- August 2017 – Responses to Comments on Toxicology by Dow AgroSciences LLC (PDF)
- August 2017 – Responses to Comments on Exposure by Dow AgroSciences LLC (PDF)
- June 1993 – Exposure Assessment Document (PDF)
- May 1992 – Dietary Exposure Assessment Document (PDF)
Other Documents
- August 2017 – Revised: Estimation of Chlorpyrifos Horizontal Deposition and Air Concentrations for California Use Scenarios (PDF)
- August 2017 – Report for Pesticide Application Air Monitoring for Chlorpyrifos and Chlorpyrifos-Oxon in San Joaquin County in July 2015
- August 2017 - Cases Reported to the Pesticide Illness Surveillance Program and Evaluated as Associated with Exposure to Chlorpyrifos, Alone or in Combination with Other Products, 2004-2014 (PDF)
- December 2016 – Report for Pesticide Application Site Monitoring for Chlorpyrifos and Chlorpyrifos-Oxon in Imperial County in October 2014
- December 2015 – Estimation of Chlorpyrifos Horizontal Deposition and Air Concentrations for California Use Scenarios (PDF)
- March 2013 – Lompoc Monitoring Report
- August 2011 – Comments On U.S. EPA's Preliminary Risk Assessment For Chlorpyrifos: With A Focus On Exposure Assessment (PDF)
- May 2010 – Comparison of Initial Deposition and Residue Dissipation of Chlorpyrifos Using Conventional Flat Fan Nozzles vs. Hypro® TwinCap™ Nozzles Fitted with Ultra-Lo Drift Spray Tips (PDF)
- September 2007 – Results from Sample Collection in Tulare County for A Suspected Organophosphate Exposure Event (PDF)
- September 2007 – Project 0706 - Worker Health and Safety's Involvement In: Chlorpyrifos Drift Investigation In Fresno County (PDF)
- September 2007 – Project 0704 - WHS Involvement In Priority Investigation 41-Tul-07: Chlorpyrifos Drift Investigation, Tulare County (PDF)
- September 2007 – Project 0703 - Tulare County Chlorpyrifos Restricted Entry Interval Violation in Oranges (PDF)
- February 2005 – Chlorpyrifos Field Spike Degradation Study, Project #0403 (PDF)
- April 2004 – Forensic Review and Sampling of PPE/Respiratory Protective Equipment Associated with Priority Investigation 3-RIV-04 (PDF)
- March 2004 – Forensic Review and Sampling of PPE/Respiratory Protective Equipment Associated with Priority Investigation 3-RIV-04 (PDF)
- October 2002 – Response to Comments from Dow AgroSciences LLC on the Draft Chlorpyrifos Risk Characterization Document by the California Department of Pesticide Regulation (Exposure Assessment Section) (PDF)
- October 2001 – WH&S Branch Activities and Results of Analyses Related to the Investigation of Priority Illness Episode 45-TUL-00 (Project 0002) (PDF)
- October 2001 – WH&S Branch Activities and Results of Analyses Related to the Investigation of 22-TUL-00 (Project 0001) (PDF)
- WH&S Branch Activities and Results of Analyses Related to the Investigation of 43-FRE-99 (Project 9903) (PDF)
- July 1999 – Chlorpyrifos Odor Provoking the Onset of Clinical Symptoms (PDF)
- January 1999 – Oral and Dermal Absorption of Chlorpyrifos: A Human Volunteer Study (PDF)
- April 1998 – Report for the Application and Ambient Air monitoring of Chlorpyrifos in Tulare County During Spring/Summer, 1996
- Appendices
- February 1998 – Contact Dermatitis in California Nursery Workers: Part II. Pilot Field Study (PDF)
- February 1993 – Aerial Movement and Deposition of Diazinon, Chlorpyrifos, and Ethyl Parathion (PDF)
- Executive Summary
- December 1991 – 1989 Probe Study to Determine the Exposure of Aerial Application Flaggers to Organophosphate Pesticides Via Urinary Metabolite Monitoring (PDF)
- August 1991 – Determination of Dermal Absorption of Chlorpyrifos in Humans (PDF)
- April 1991 – Structural Chemical Exposure Studies Provide Human Metabolism and Urine Clearance Data for Chlorpyrifos, Dimethoate and Malathion (PDF)
- March 1991 – Situational Chemical Exposure Studies Provide Human Metabolism and Urine Clearance Data for Chlorpyrifos, Dimethoate, and Malathion (PDF)
- March 1991 – Measuring Potential Dermal Transfer of Surface Pesticide Residue Generated from Indoor Fogger Use: Using the CDFA Roller Method, Interim Report II (PDF)
- May 1990 – Measuring Potential Dermal Transfer of Surface Pesticide Residue Generated from Indoor Fogger Use: An Interim Report (Chemosphere 20, (3/4), 349-360, 1990) (PDF)
- January 1990 – Human Illnesses/Injuries Reported by Physicians in California Involving Indoor Exposure to Pesticides Containing Chlorpyrifos, DDVP and/or Propoxur 1983-1986 (PDF)
- July 1986 – Dissipation of Dislodgeable Foliar Residue for Chlorpyrifos and Dichlorvos Treated Lawn: Implication for Safe Reentry (Bull Environ Contam & Toxicol 37, 33-40, 1986) (PDF)
- December 1985 – Monterey County Residential Air Monitoring
- November 1984 – Dissipation of Dislodgeable Residue of Chlorpyrifos and DDVP on Turf (PDF)
- July 1984 – Degradation of Dislodgeable Residues of Chlorpyrifos and Diazinon on Turf - A Preliminary Survey (PDF)
- Cancellation of Chlorpyrifos Products
- Consultation on Proposed Cancellation of Chlorpyrifos Products
- August 2019 – Response to Comments Received from the California Agricultural Commissioners and Sealers Association for Proposed Cancellation
- August 2019 – Response to Comments Received from the California Department of Food and Agriculture for Proposed Cancellation
- July 2019 – California Agricultural Commissioners and Sealers Association Comments on Proposed Cancellation
- July 2019 – California Department of Food and Agriculture Comments on Proposed Cancellation
- May 2019 -- Risk Management Directive for Chlorpyrifos, PDF
- June 2019 – Response to Comments Received for Proposed Risk Management Directive
- April 2019 – Office of Environmental Health Hazard Assessment Comments on Proposed Risk Management Directive
- April 2019 – California Air Resources Board Comments on Proposed Risk Management Directive
- May 2019 – California Air Pollution Control Officers Association Comments on Proposed Risk Management Directive
- April 2019 – California Department of Food & Agriculture Comments on Proposed Risk Management Directive
- November 2018 - Revised Interim Permit Conditions (PDF)
- October 2017 - Revised Interim Permit Conditions (PDF)
- October 2017 - Evaluation and Options for Interim Mitigation Measures to Reduce Acute Chlorpyrifos Exposure to Bystanders (PDF)
- August 2017 – Directive for Interim Mitigation Measures to Address Health Risk from Chlorpyrifos (PDF)
- July 2015 – Interim Permit Conditions (PDF)
- July 2015 – Designating Chlorpyrifos as a Restricted Material
Enforcement Letters
- November 2018 - ENF 2018-22 – Updates to Volume 3, Restricted Materials and Permitting, Pesticide Use Enforcement Program Standards Compendium, Appendix O-Chlorpyrifos Interim Recommended Permit Conditions
- October 2017 - ENF 2017-23 - Updates to Volume 3, Restricted Materials and Permitting, Pesticide Use Enforcement Program Standards Compendium, Appendix O: Chlorpyrifos Interim Recommended Permit Conditions
- July 2015 – ENF 2015-09 - Interim Recommended Permit Conditions for Chlorpyrifos used to Produce and Agricultural Commodity: Addition to Compendium Volume 3, Restricted Material and Permitting
- February 2005 – ENF 2005-008 - Chlorpyrifos Phase Out Questions and Answers
- September 2020 – Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
- Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
- Presentation on Chlorpyrifos Workgroup Updates (Available upon request via email to LicenseMail@cdpr.ca.gov)
- January 2019 – Pesticide Registration and Evaluation Committee Meeting Agenda (PDF)
- Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
- Presentation on Interim Recommended Permit Conditions for Chlorpyrifos (Available upon request via email to publicrecords@cdpr.ca.gov)
- September 2018 – Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
- Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
- Presentation on Chlorpyrifos Update (Available upon request via email to LicenseMail@cdpr.ca.gov)
- September 2018 – Pesticide Registration and Evaluation Committee Meeting Agenda (PDF)
- Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
- Presentation on Chlorpyrifos Updates (Available upon request via email to publicrecords@cdpr.ca.gov)
- September 2017 – Pesticide Registration and Evaluation Committee Meeting Agenda (PDF)
- Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
- Presentation on the Chlorpyrifos Draft Risk Assessment (Available upon request via email to publicrecords@cdpr.ca.gov)
- September 2017 - Pesticide Registration and Evaluation Committee Agenda (PDF)
- California's Toxic Air Contaminant Program for Pesticides (PDF)
- Draft Evaluation of Chlorpyrifos as a Toxic Air Contaminant (PDF)
- Directive for Interim Mitigation Measures to Address Health Risks from Chlorpyrifos (PDF)
- March 2015 - Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
- Chlorpyrifos Update
- Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
- November 2014 - Pest Management Advisory Committee Meeting Agenda (PDF)
- Proposed Regulation to Designate Chlorpyrifos a Restricted Material (PDF)
- October 2014 - Critical Uses of Chlorpyrifos
- September 2014 - Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
- Chlorpyrifos Update (PDF)
- August 2014 - Pesticide Registration and Evaluation Committee Agenda (PDF)
- Chlorpyrifos Update (PDF)
- Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
- January 2009 - Pesticide Registration and Evaluation Committee Agenda (PDF)
- Status of Chlorpyrifos and Diazinon Reevaluations (PDF)
- Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
- May 2007 - Pest Management Advisory Committee Meeting Agenda (PDF)
- Pesticide Product Database
- Human Health Assessment Branch Memos
- Human Health Assessment Branch Publications, Posters/Abstracts and Presentations
- Worker Health and Safety Reports and Memos
- Environmental Monitoring Branch Publications
- Air Monitoring Network
- Pesticide Use Reporting (PUR)
- California Pesticide Illness Query (CalPIQ)
- Environmental Justice (EJ)
- OEHHA Proposition 65 Information
- U.S. EPA Pesticide Chemical Search
- PubChem-Chemical Information
For content questions, contact:
Christine Herrera
Worker Health and Safety Branch
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
Phone: (916) 445-4261
E-mail: Christine.Herrera@cdpr.ca.gov
Kara James
Pesticide Registration Branch
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
Phone: (916) 324-3523
E-mail:
Kara.James@cdpr.ca.gov