[Gamma-rays and ethylene oxide sterilization (author's transl)].
For many years there was doubt if gamma-irradiated PVC materials could be sterilized with ethylene oxide. It was feared that toxic concentrations of ethylene chlorohydrin (2-chlorethanol) might originate with this procedure. We investigated the various possibilities of ethylene chlorohydrin formation. Gamma-irradiated PVC tubes were resterilized with ethylene oxide and the 2-chlorethanol concentrations determined by gas chromatography. The 2-chlorethanol concentrations at the end of sterilization ranged from 240 to 436 ppm depending upon the composition of the tubes. After 4 d they ranged from < 5 to 280 ppm and after 21 d from < 5 to 218 ppm. For comparison were examined PVC tubes which were not gamma-irradiated but ethylene oxide sterilized only. We extracted < 5 to 23 ppm ethylene chlorohydrin from them. PVC tubes gas sterilized only and retaining 44 to 9300 ppm ethylene oxide were submerged in physiological NaCl solution for 2 h. The ethylene chlorohydrin concentrations formed by this procedure ranged from 43 to 75 ppm. After 4 d aeration before begin of extraction they decreased to < 5, 10 and 16 ppm. PVC tubes aerated for 5 or 7 d, containing at least 236 ppm ethylene chlorohydrin did not demonstrate any effect upon cultures of human fibroblasts. The toxic concentrations of 2-chlorethanol in our own animal- and cell culture experiments were 12 000 ppm or higher. Other investigators found no damaging effect on mouse fibroblasts by adding 20 000 ppm ethylene chlorohydrin. It appears to be sufficiently proven that gamma-irradiated PVC items may be resterilized with ethylene oxide and used in patients provided they they have been adequately aerated.
D002478:Cells, Cultured; D002849:Chromatography, Gas; D004865:Equipment and Supplies, Hospital; D005023:Ethylene Chlorohydrin / Q000032:analysis / Q000494:pharmacology; D005027:Ethylene Oxide; D005347:Fibroblasts / Q000187:drug effects; D005720:Gamma Rays; D006801:Humans; D011143:Polyvinyl Chloride; D011839:Radiation, Ionizing; D013242:Sterilization / Q000379:methods*
D005023:Ethylene Chlorohydrin; D011143:Polyvinyl Chloride; D005027:Ethylene Oxide
Gamma-Strahlen und Athylenoxid-Sterilisation.