The ethylene oxide monitor is an easy method to sample for either 15 minute STEL or full shift 8 hour exposures. Ethylene oxide is collected on a flexible, inert charcoal wafer treated with hydrogen bromide. The hydrogen bromide converts ethylene oxide to 2-bromoethanol. At the lab, the excess hydrogen bromide is neutralized with sodium carbonate. Then, the 2-bromoethanol is extracted with 90/10 toluene/acetonitrile and analyzed by GC/ECD. No further derivatization is required.