Cholinesterase calculator for Medical Supervisors

This calculator is to assist Medical Supervisors in calculating cholinesterase activity levels in agricultural workers who regularly handle highly toxic (category I and II) organophosphate (OP) and carbamate (CB) pesticides. Please refer to the flow chart below.

Worker before handling pesticides

Step 1: Estimate Baseline

A plain black cartoon human stick figure.

When worker has not been exposed to OP or CB pesticides for at least 30 days, establish baseline estimates for RBC and Plasma ChE activity.


Day 1

Day 3-14


Baseline Estimate: 

Baseline Difference: 

Action recommended: 

Worker handling pesticides


Step 2: Order follow-up tests

A plain black cartoon human stick figure wearing a hat and holding a spade, representing a farmer.

If worker enters qualifying period, as defined in the Guidelines for Physicians, order follow-up tests for both plasma and RBC ChE activity levels.

Step 3: Interpret results

A plain black symbol of a clip board containing the words “follow-up results:” underlined and “% of baseline” underneath.

Compare follow-up and baseline results for both RBC and plasma ChE activity levels.

Step 4: Make recommendations

A cartoon human stick figure wearing a stethoscope (representing a physician) with a blue arrow on the right pointing downwards towards another human stick figure wearing a tie (representing an employer) and another blue arrow on the left pointing downwards towards a human stick figure wearing a hat and holding a spade (representing a farmer).

Make recommendations to the employer and employee according to the Guidelines for Physicians.





Percent of Baseline: 

Action recommended: 

Need more help? Please, e-mail or call 510-622-3166.