Pesticide Contamination Prevention Act Review Process Triggered by Detections of Chlorthal Dimethyl in Groundwater

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Legal Agricultural Use Determination

Detections in groundwater of monomethyl tetrachloroterephthalate (MTP) and 2,3,5,6-tetrachloroterephthalic acid (TPA), degradation products of chlorthal dimethyl (DCPA), were determined to be from legal agricultural use and DPR responded by placing chlorthal dimethyl (DCPA) in the formal detection response process.

  • Memorandum, PDF - Request to proceed with detection response process for chlorthal dimethyl, 2018
    • Attachment 2, PDF - Legal agricultural use determination for DCPA degradate detections in California, 2018

Formal Review Process and Regulatory Changes

A formal review process began in March 2018 following detection of chlorthal dimethyl (DCPA) degradates in groundwater.

Notice of detection cover letter, PDF listing the product containing DCPA, the registrant, procedures for registrant to request a public hearing before a subcommittee of the Pesticide Registration and Evaluation Committee (PREC), and related information.

  • Attachment 1, PDF - Notice of chlorthal-dimethyl degradation product residue detections in California ground water and registrant opportunity to request a hearing, 2018
  • Attachment 2, PDF - Legal agricultural use determination for DCPA degradate detections in California, 2018

Registrant letter to request a public hearing before a subcommittee of the PREC:

  • AMVAC Chemical Corporation, March 29, 2018, PDF

Public Hearing: August 29, 2018

  • Notice of public hearing, PDF A hearing has been requested by the registrant of chlorthal-dimethyl to review continued use of their product that contains this active ingredient. The hearing will be at 9:00 a.m. Wednesday, August 29, 2018 in the Sierra Hearing Room at the California Environmental Protection Agency, 1001 I Street, Sacramento. Public testimony will be taken and the meeting will be available through a live Webcast.
  • AMVAC Chemical Corporation, Information and Report Concerning Chlorthal-Dimethyl and its Metabolites, PDF

Subcommittee Findings and Director's Decision