Residual ethylene oxide: Levels in medical grade tubing and effects on anin vitro biologic system

Abstract

The level of residual ethylene oxide after sterilization was evaluated as a function of aeration time for three medical grade tubings. Toxicity resulting from residual ethylene oxide was determined in an in vitro tissue culture system utilizing L‐cells. The absorption and desorption of ethylene oxide from poly(vinylchloride) and polyether–polyurethane tubing were similar. In contrast, silicone tubing absorbed 85% less ethylene oxide. The time required for desorption of residual ethylene oxide was 2 hr for silicone tubing and 7 to 8 hr for poly(vinylchloride) and polyether–polyurethane tubing. Tubing samples containing 1,500 ppm or more residual ethylene oxide elicited toxic tissue culture reactions whereas samples containing 900 ppm or less showed no toxic tissue culture response.