Eliminating Worker Exposure to Ethylene Oxide from Hospital Sterilizers: An Evaluation of Cost and Effectiveness of an Isolation System

Abstract

This study illustrated that by using standard industrial hygiene methods, the goal of “zero worker exposure” without personal protective equipment (PPE) can be approached for most procedures involving ethylene oxide (EtO), and that the costs of these measures are not prohibitive. Air monitoring had been conducted in a large tertiary care hospital which showed that workers were exposed to high levels of EtO (up to 500 ppm for short periods). The purpose of this project was to develop a system for using EtO that would eliminate unnecessary uses, and reduce all worker exposure to levels as low as reasonably achievable without resorting to PPE and without requiring large incremental expenditures. All areas using EtO were inspected, work procedures were carefully reviewed, and the design of the equipment was assessed. A series of cost-effective control measures were then recommended and implemented. These included reducing the need for EtO by using alternate sterilization methods where possible, isolating the sterilizers from other work areas, implementing a combination of local and general ventilation to further ensure isolation of the sterilizers from surrounding workers, and developing a procedure manual to train workers to use the new system and related controls. Following implementation of these measures, the areas were retested. Instantaneous measurements, using an infrared analyzer, revealed that peak levels associated with the connecting and disconnecting cylinders, pressurizing the sterilizer, opening the door, and discharging to the sumps were reduced to between 0 and 2.8 ppm. This contrasts sharply with the short-term worker exposures of up to 500 ppm before the changes.