[Mutagenic and cytotoxic effect of ethylene oxide on human cell cultures (author's transl)].

Certain ethylene-oxide residues in sterilized equipment can cause toxic effects in patients. Mutagenic effects of ethylene-oxide have also been described in experimental animals, plants, and bacteria. In our studies an increase of sister chromatid exchange (SCE's) served as indicator for a mutagenic effect of this substance. We cultivated fibroblasts of healthy volunteers and added liquid ethylene oxide in concentrations of 3.6 to 3600 ppm to them. In additional cell cultures we placed endotracheal tubes containing 12 to 3900 ppm ethylene oxide residues on top of the cell layers. After 24 h reaction time the cell cultures were read microscopically and the SCE ratios determined also. Liquid ethylene oxide in concentrations of 360 and 3600 ppm caused a total destruction of the cells. At 36 ppm the cells remained alive. This concentration produced a significant rise of the SCE rate from 12.53 to 16. Tubes with residues of 200 to 600 ppm ethylene oxide brought about a consistent rise of the SCE ratio in the sense of a dose-response relationship. Ethylene oxide has besides its toxic reaction a mutagenic effect upon human fibroblasts. Many other chemical substances have mutagenic potencies also. For safety reasons ethylene oxide sterilized equipment should be aerated before its use as completely as possible.