California Medical Supervision Program

The California Medical Supervision program is designed to protect workers who regularly mix, load, or apply the highly toxic Category I and Category II organophosphate (OP) and N-methyl carbamate pesticides (CB). The goal of the program is to identify and prevent excessive OP and CB exposure and resulting pesticide-related illness. Exposure to OPs or CBs may lower the level of available cholinesterase (ChE) -- an enzyme essential to the proper functioning of the nervous system. Depression of cholinesterase levels can lead to symptoms ranging from blurred vision, diarrhea and tremors to seizures, loss of consciousness and even death. Monitoring plasma and red blood cell ChE levels allows detection of cholinesterase depression prior to the onset of illness.

Physician Registration Guidelines for Physicians Physician Training ChE Calculator List of registered supervisors

NEW! OEHHA and DPR released the 2021 Update Report on the Effectiveness of the California Medical Supervision Program and the Utility of Laboratory-based Reporting of Cholinesterase Testing for Illness Surveillance and Prevention (April 29, 2022)

Learn more about the program (for physicians):

Since January 1, 2017, physicians that have contract(s) with one or more employers to provide medical supervision services are required to register with OEHHA.

All new requirements and responsibilities can be found here.