Emission characteristics of plastic syringes sterilized with ethylene oxide—A controlled study

Objectives: This study examined the emission characteristics of ethylene oxide (EO)-sterilized syringes under various environmental conditions, aiming to develop control strategies to minimize worker exposure. Methods: Experiments were performed in a facility in which temperature, relative humidity (RH), and air change rate (ACR) were controlled. Results: Analytical results indicate that the main effects of the four test variables on kinetic parameters were statistically significant (p < 0.05), except for the effect of the product on the decay rate constant, the effect of ACR on maximum EO concentration, and effect of RH on the area under the curve-days 1 and 2. The interactive effects among test variables were also evident, indicating complex emission behaviors. The mean EO emission factors during the days 1 and 2 and at the 48th hour for the 1- and 30-ml products were 2302, 1301, and 1031 mg/m3/h, and 871, 490, and 381 mg/m3/h, respectively. The times required for air EO concentrations from tested products to return to ∼0 and 1 ppm (permissible limit) were 417 and 218 h, respectively. Conclusions: Plastic content, temperature, RH, and ACR affected EO emissions. ACR is an achievable means of control; however, the aeration area/system should be isolated to ensure adequate ventilation is achieved. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009