Two types of large charcoal tubes (PCB and JXC charcoal based), two diffusion type passive monitors (DuPont Pro-Tek® C-70 and 3 M #3550), and MIRAN® Infrared Model 103 analyzer were tested simultaneously over six concentrations (0.25 to 10.7 ppm) at 65% relative humidity. Exposure times were from 4–6 hours, and all established sampling analytical precautions were taken with charcoal tubes to ensure reliable results. At least six replicates were tested at each concentration. Passive badges were analyzed by the respective manufacturers. Only the DuPont ethylene oxide badge met the accuracy criteria in the OSHA ethylene oxide standard over the entire concentration range tested.