Cholinesterase Monitoring

Attention: Baseline testing for 2010 will begin January 18.

• Medical provider information.
• Employer Information.

Rule adoption - Chapter 296-307-148 WAC, Cholinesterase Monitoring

The Department of Labor & Industries (L&I) has amended the cholinesterase monitoring rule to reflect current program practices and address stakeholder recommendations. The new rule language was adopted on December 20, 2005, and becomes effective February 1, 2006.

What are employers required to do?

The rule requires employers of agricultural pesticide handlers who use toxicity class I or II organophosphate or N-methyl-carbamate pesticides to take the following steps:

• Record the number of hours employees spend handling these pesticides.
• Implement a medical monitoring program for workers who could meet or exceed the handling threshold of 30 or more hours in any consecutive 30-day period.
• Identify a medical provider to provide medical monitoring services.
• Make baseline and periodic cholinesterase testing available to employees who could meet or exceed the handling threshold.
• Investigate work practices when a handler’s red blood cell (RBC) or serum cholinesterase level drops more than 20 percent below the employee’s personal baseline.
• Remove employees from handling and other exposures to organophosphate and N-methyl-carbamate pesticides when recommended by your health care provider.
• Provide training on cholinesterase monitoring to covered employees.
• Report employee handling hours to the medical provider with each periodic test.
• Maintain medical monitoring and other records for seven years.

Employer Cost Reimbursement

Employers may request reimbursement for the reasonable costs of training, recordkeeping, and medical expenses for cholinesterase monitoring by submitting the Cholinesterase Monitoring Reimbursement Request form along with required documentation.

• Cholinesterase Monitoring Reimbursement Form (96 KB PDF).

Resources

• Read the rule.
• Medical Monitoring Providers list (137 KB PDF).
• Handler Hours Tracking - Instructions (59 KB PDF).
  Handling hours Spreadsheet (695 KB Excel).
• Worker Protection Standard Checklist of Requirements - This form can be used to help evaluate your
  worker protection program and pesticide handling practices.
• List of covered pesticides.
• WRD 33.27: Cholinesterase Depression (DOSH Policy) (137 KB PDF).

What is cholinesterase?

Cholinesterase (acetyl cholinesterase) is an enzyme that removes the chemical neurotransmitter acetylcholine, from the junctions between nerves cells. Cholinesterase serves as the nervous system’s “off switch” and is essential to the normal function of the nervous system.

Why monitor cholinesterase levels?

Exposure to organophosphate or N-methyl-carbamate pesticides may lower the level of available cholinesterase. Without the normal protective levels of cholinesterase, nerves in the body may be over stimulated to the point of exhaustion, leading to symptoms ranging from blurred vision, diarrhea and tremors to seizures, loss of consciousness and even death.

Monitoring cholinesterase levels in the blood through simple laboratory tests can detect cholinesterase depression prior to the onset of illness. When significant cholinesterase depression is identified employers are required to evaluate their pesticide worker protection program and make corrections to prevent further over-exposure.

What are the benefits of cholinesterase monitoring?

The cholinesterase monitoring Cost Benefit Determination and Small Business Impact Statement identified the following benefits of cholinesterase monitoring:

• Prevention of illness after over-exposure.
• Increase hazard awareness and improve overall workplace safety related to pesticide use.
• Improve pesticide illness diagnosis and reporting.
• Provide greater certianty about frequency of pesticide over-exposure.
• Decrease the risk of unintended exposures to workers families.

Additional Resources

• 2009 Final Report: Cholinesterase Monitoring of Pesticide Handlers in Agriculture (143KB PDF).
• 2008 Final Report: Cholinesterase Monitoring of Pesticide Handlers in Agriculture (848KB PDF).
• 2007 Final Report: Cholinesterase Monitoring of Pesticide Handlers in Agriculture (191KB PDF).
• 2007 Cholinesterase Anaysis - Report from University of Washington (1389KB PDF).
• 2006 Cholinesterase Monitoring Report to the Legislature (88KB PDF).
• Final Report - Cholinesterase Monitoring of Pesticide Handlers in Agriculture: 2004 – 2006 (3687KB PDF).
• Worker Protection Standard Checklist (157KB PDF) can be used to evaluate your pesticide worker protection program and employee pesticide handling practices.
• Cholinesterase monitoring fact sheets for employees:
  • English version (53KB PDF).
  • Spanish Version (51KB PDF).
• Concise Explanatory Statement (1787KB PDF).
• Cost Benefit Determination (398KB PDF).
• Jorge's New Job - Washington - PDF Booklet.
  • 417-213-909-English (426KB PDF).
  • 417-213-909-Spanish (426KB PDF).
• Pesticide Worker Protection Standard (WPS).
• Questions and answers document (129KB PDF).
• Sample Training Program - (Spanish version) (82KB PDF) .
• 2004 L&I Report to the Legislature (156KB PDF).
• 2005 L&I Report to the Legislature (173KB PDF).
• 2005 L&I Final Report: Cholinesterase Monitoring of Pesticide Handlers in Agriculture (2201KB PDF).
• The Scientific Advisory Committee for Cholinesterase Monitoring: 2004 Report to the Department of Labor & Industries (856KB PDF) .

Contact L&I

The L&I office in your area has industrial hygienists who can assist with specific questions. Please call your local area L&I office and ask for a consultation supervisor.

Region 1: 425-290-1300

Island, San Juan, Skagit, Snohomish, and Whatcom counties.

Region 5: 509-454-3700 or 1-800-354-5423

Adams--west side, Asotin, Benton, Chelan, Columbia, Douglas, Franklin, Grant, Kittitas, Okanogan, Walla Walla and Yakima counties.

Ask an Expert

E-mail a Specialist - If you have questions about Cholinesterase.