Microwave desorption: a combined sterilizer/aerator for the accelerated elimination of ethylene oxide residues from sterilized supplies.

Ethylene oxide gas is widely used in medical and related facilities for low-temperature sterilization of surgical devices. Evidence of its toxicity and, in particular, its mutagenicity and carcinogenicity provide sufficient reasons for caution in its use and for minimizing exposure. Little advancement has been made in the removal of ethylene oxide residuals from plastics into which the gas is heavily absorbed during sterilization, despite the fact that the gas has been used for 20 years or more. This article describes a novel process (PCT Application/GB85/00509) in which microwave irradiation of ethylene oxide-sterilized materials is utilized to enhance the rate at which the gas is desorbed. The experimental apparatus is described, and an explanation of the effect of microwaves on the energy of activation for diffusion is given. Data are presented in support of the authors' claim of a 400% improvement in the efficiency of the new process over conventional aeration procedures. The advantages and economy of an integrated sterilizer/microwave-enhanced desorber are discussed in the context of the implications that arise from the current regulatory debate.