Active Ingredient: Methyl Isothiocyanate (MITC), Metam-Sodium, Potassium N-Methyldithiocarbamate (Metam Potassium), and Dazomet
Human Health Risk Assessment and Mitigation
Documents and Activities

• Name: Methyl isothiocyanate (MITC)
• DPR Chemical Code: 392
• Chemical Class: Organosulfur
• Pesticide Types Registered: Bactericide, Fungicide
• Fumigant: Yes
• California Restricted Material: Yes, with exceptions
• Toxic Air Contaminant (TAC): Yes
• Volatile Organic Compound (VOC) Regulations: Yes
• Potential Groundwater Contaminant: No
• Reevaluation: Not applicable

• Name: Metam-sodium
• DPR Chemical Code: 616
• Chemical Class: Organosulfur
• Pesticide Types Registered: Antimicrobial, Fungicide, Herbicide, Insecticide, Nematicide
• Fumigant: Yes
• California Restricted Material: Yes, with exceptions
• Toxic Air Contaminant (TAC): Yes
• Volatile Organic Compound (VOC) Regulations: Yes
• Potential Groundwater Contaminant: No
• Reevaluation: Concluded

• Name: Potassium N-methyldithiocarbamate (metam potassium)
• DPR Chemical Code: 970
• Chemical Class: Organosulfur
• Pesticide Types Registered: Fungicide, Herbicide, Insecticide, Nematicide
• Fumigant: Yes
• California Restricted Material: Yes, with exceptions
• Toxic Air Contaminant (TAC): Yes
• Volatile Organic Compound (VOC) Regulations: Yes
• Potential Groundwater Contaminant: No
• Reevaluation: Concluded

• Name: Dazomet
• DPR Chemical Code: 233
• Chemical Class: Organosulfur
• Pesticide Types Registered: Algaecide, Antimicrobial, Bactericide, Disinfectant, Fungicide, Herbicide, Nematicide, Slimicide
• Fumigant: Yes
• California Restricted Material: Yes
• Toxic Air Contaminant (TAC): Yes
• Volatile Organic Compound (VOC) Regulations: Yes
• Potential Groundwater Contaminant: Yes
• Reevaluation: Concluded

Risk Characterization Documents (RCDs) estimate the nature and likelihood of adverse health effects in humans who may be exposed to pesticides.

• August 2016 – Update to the Critical Subchronic and Chronic Points of Departure and Associated Reference Exposure Levels Evaluated in 2003 RCD (PDF)
• July 2004 – Risk Characterization Document (Metam-Sodium) (PDF)
  • July 2002 – Comments on Metam-Sodium Risk Characterization Document (PDF)
  • January 2002 – Response to Comments of the Metam-Sodium Task Force on the California Department of Pesticide Regulation Exposure Assessment Document for Metam-Sodium (PDF)
• July 2003 – Risk Characterization Document (PDF)
• Toxic Air Contaminant (TAC) Assessment
  • August 2002 – Director's Proposed Decision (PDF)
  • August 2002 – Scientific Review Panel's Findings (PDF)
  • August 2002 – Executive Summary (PDF)
  • August 2002 – Part A: Environmental Fate (PDF)
  • August 2002 – Part B: Exposure Assessment (PDF)
  • August 2002 – Part C: Human Health Assessment (PDF)
  • February 2002 – Office of Environmental Health Hazard Assessment's Findings (PDF)

Other Documents

• June 2017 – Methyl Isothiocyanate (MITC) — Calculation of Intermediate (1-month) and Annual Residential Exposures and Risk Using Measured Air Concentrations from the Ambient Air Monitoring Network (PDF)
• July 2010 – WHS Branch Involvement Related to the Investigation of Priority Illness Episode 26-Ker-05 (Project 0508) (PDF)
• April 2010 – A Worker Health and Safety Investigation of Fieldworker Exposure To Methylisothiocyanate After a Metam Sodium Application; Priority Illness 60-Mon-08 (Project 0802) (PDF)
• August 2008 – Calculation of Eight-Hour Maximum Methyl Isothiocyanate Flux from Dazomet Applications (PDF)
• August 2008 – Environmental Monitoring Results of Multi-Fumigant Applications in Manteca, California 2005
• July 2008 – Environmental Monitoring Results of Basamid®G (Dazomet) Application in Watsonville, California 2006
• September 2007 – An Evaluation Of Illnesses Associated With Exposure To Agricultural Uses Of Metam Sodium, Metam Potassium, And Dazomet (PDF)
• April 2006 – Dazomet Flux Analysis and Recommendations for Future Study (PDF)
• November 2005 – Estimation of Methyl Isothiocyanate Air Concentrations Associated with Priority Case Number 026-KER-05 (PDF)
• October 2005 – Flux Estimation Calculated from a Sprinkler Application of Methyl Isothiocyanate
• July 2005 – Illnesses Related to Shank Application of Metam-Sodium, Arvin, California, July 2002 (PDF)
• June 2005 – Monitoring a 1,3-Dichloropropene/Metam Sodium Application in Del Norte County
  • Appendices
  • Laboratory Method
• March 2005 – Monitoring an Untarped Bedded Drip Application of Metam Sodium in Merced County-Spring 2004
  • Attachments
• February 2005 – Variability in Daytime Stability Class Designation under Partly Foggy Conditions in a Monitoring Study (PDF)
• December 2004 – Determination of MITC Soil Flux Density and Emission Ratio from a Field Following a Tarped Bed Drip Application of Metam-Sodium
• June 2004 – Estimation of Exposure of Persons in California to Metam-Sodium during Soil Applications of Products Containing Metam-Sodium (PDF)
• June 2004 – Final Report for the 2002 Application Air Monitoring for Metam Sodium Breakdown Products in Ventura County
  • Appendices
• January 2004 – Final Report for the 2001 Ambient Air Monitoring for Chloropicrin and Metam Sodium Breakdown Products in Monterey and Santa Cruz Counties
  • Appendices
• November 2003 – Final Report for the 2001 Ambient Air Monitoring for Chloropicrin and Metam Sodium Breakdown Products in Kern County
  • Appendices
• August 2002 – Statistical Confidence that the Maximum 24-Hour MITC Concentration Was Captured in the 2000 Lompoc Fumigant Monitoring (PDF)
• January 2002 – Response to Comments on Metam-Sodium Exposure Assessment Document (HS-1703) (PDF)
• August 2001 – Illness Related to Exposure to Metam-Sodium Byproducts in Earlimart, California in November 1999 (PDF)
• November 2000 – Metam Sodium: In Vitro Absorption Through Rat and Human Skin (PDF)
• November 1999 – Revised Evaluation of Potential Chronic and Subchronic Exposure to Methyl Isothiocyanate Using Pesticide Use Report Data (PDF)
• June 1998 – Dermal Absorption of Tralomethrin, Metam-Sodium, Tribufos, Azinphos-Methyl, and Amitraz in Rats (PDF)
• June 1997 – Ambient Air Monitoring for MIC and MITC After Soil Injection Application of Metam Sodium in Kern County during August 1995
  • Appendices
• June 1994 – Air Monitoring for Methyl Isothiocyanate during a Sprinkler Application of Metam-Sodium
  • Executive Summary
• May 1994 – Metam Sodium - Methods of Application and Annual Number of Occupational Exposure Days (PDF)
• April 1994 – Ambient Air Monitoring for MITC in Kern County During Summer 1993 After a Ground Injection Application of Metam Sodium to a Field
  • Appendices
• April 1994 – Ambient Air Monitoring for MITC in Kern County During Summer 1993
  • Appendices
• November 1993 – Comments on the Use of Vaporooter and "Generic" Use of Metam Sodium for Treating Sewer Systems (PDF)
• July 1993 – Ambient Air Monitoring in Contra Costa County During March 1993 After an Application of Metam Sodium to a Field
  • Appendices
• July 1993 – Metam Sodium: In vivo Dermal Absorption in the Rat and Stability Determination of Aqueous Solutions (PDF)
• October 1991 – Monitoring of the Cantara Metam-Sodium Spill (PDF)

RMDs identify pesticide exposures that require mitigation in order to further protect human health.

• December 2002 – Risk Management Directive (PDF)

• August 2017 - Completion of Mitigation (Occupational Exposures) (PDF)
• June 2015 – Completion of Mitigation (Resident and Bystander Exposures) (PDF)
• July 2009 – Request for Comments on Proposed Mitigation Measures of Metam Sodium, Metam Potassium and Dazomet (PDF)
• December 2007 – Draft Metam Sodium/Metam Potassium Mitigation to Control Off-Site and Bystander Short-Term Exposure (PDF)
• April 2007 – Control Measures (En Español)
• February 2007 – Development of Additional Methyl Isothiocyanate Buffer Zones for the Metam Sodium Mitigation Proposal (PDF)
• January 2007 – Mitigation Proposal

Enforcement Letters

• May 2015 – ENF 2015-08 - Revised Recommended Permit Conditions
• May 2013 – ENF 2013-09 - Soil Fumigant 2012 Labeling and Permit Conditions - Questions and Answers
• March 2013 – ENF 2012 -21 - Soil Fumigant Phase 2 Label Implementation - Enforcement Status, and Revisions to Restricted Materials and Permitting Compendium Volume 3
• August 2012 – ENF 2012 -16 - Soil Fumigant Label Changes - Phase 2
• October 2011 – ENF 2011-25 - Soil Fumigant 2010 Labeling and Permit Conditions - Questions and Answers
• April 2011 – ENF 2011-14 - Updates to Volume 3, Restricted Materials and Permitting, Pesticide Use Enforcement Program Standards Compendium
• March 2011 – ENF 2011-09 - U.S. EPA Soil Fumigant Label Changes
• November 2010 – ENF 2010-22 - Recommended Permit Conditions for Metam Sodium, Metam Potassium, and Dazomet
• September 2008 – ENF 2008-25 - Updates to Volume 3, Restricted Materials and Permitting, Pesticide Use Enforcement Program Standards Compendium
• August 2008 – ENF 2008-23 – Director's Decision to Approve Metam-Potassium And Metam-Sodium Sprinkler 4:00 A.M. Start Method
• July 2008 – ENF 2008-21 - Volatile Organic Compounds (VOC) Field Fumigation Emission Reduction Regulations
• June 2008 – ENF 2008-17 - Updates to Volume 3, Restricted Materials and Permitting, Pesticide Use Enforcement Program Standards Compendium
• May 2008 – ENF 2008-013 – Director's Decision to Approve Drench Application Method of Metam-Potassium or Metam-Sodium and Clarification to Nighttime Application Methods of Metam-Sodium
• April 2008 – ENF 2008-012 - Updates to Volume 3, Restricted Materials And Permitting, Pesticide Use Enforcement Program Standards Compendium - Director's Decision To Approve Two Additional Nighttime Application Methods Of Metam-Sodium
• March 2008 – ENF 2008-005 - Director's Decision to Approve Two Additional Nighttime Application Methods of Metam-Sodium
• July 2003 – ENF 2003-026 - Metam-Sodium Applications, Summer 2003
• July 2002 – ENF 2002-032 - Metam-Sodium Applications, Summer 2002
• August 2001 – ENF 2001-041 - Dazomet and Potassium N-methyldithiocarbamate on Restricted Materials List
• December 2000 – ENF 2000-046 - Emergency Regulation Designating Dazomet and Potassium N-methyldithiocarbamate Restricted Materials
• November 2000 – ENF 2000-044 - Permit Conditions for Applications of Metam-Sodium and Potassium N-methyldithiocarbamate (Metam-Potassium) Products
• March 2000 – ENF 2000-010 - Draft Suggested Permit Conditions for Metam-Sodium Applications

• January 2022 – Pesticide Registration and Evaluation Committee Meeting Agenda (PDF)
  • Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
  • Presentation on Air Monitoring of Workers During Loading and Application of Fumigants
• May 2010 – Pesticide Registration and Evaluation Committee Meeting Agenda (PDF)
  • Pesticide Registration and Evaluation Committee Meeting Minutes (PDF)
  • Presentation on Proposed Mitigation Measures for MITC Generating Pesticides (PDF)
• November 2009 – Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
  • Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
• November 2008 – Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
• Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
• April 2007 – Agricultural Pest Control Advisory Committee Meeting Agenda (PDF)
  • Agricultural Pest Control Advisory Committee Meeting Minutes (PDF)
• 2004 – Modeling of Methyl Isothiocyanate Air Concentrations Associated with Community Illnesses Following a Metam-Sodium Sprinkler Application
• 2003 – Illnesses Associated with a November 1999 Sprinkler Application of Metam Sodium in Earlimart, CA (PDF)
• 2003 – Methyl Isothiocyanate (MITC): Risk to Humans Following Agricultural Applications of Metam Sodium (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
  • Environmental Fate Reviews
• 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