A Review of the Evidence in Support of a Short Term Exposure Limit for Occupational Exposure to Ethylene Oxide.
Issues raised by the Office of Management and Budget (OMB) regarding the appropriateness of a short term exposure limit (STEL) for ethylene-oxide (75218) (EtO) were reviewed. Specific concerns addressed by the OMB were that OSHA had not quantified the reduction in risk that would be afforded by a STEL, that certain studies OSHA used in making the recommendation were not appropriate, that the American Conference of Governmental Industrial Hygienists had reviewed these particular studies and found that they did not support a STEL, and that compliance with the STEL proposed by OSHA was not technically or economically feasible. Docket submissions, direct testimony and transcripts of the OSHA public hearing on the EtO proposed ruling were analyzed. The principal group of workers affected were hospital workers and others who operate sterilizing equipment. Estimates suggested as many as 100,000 workers were potentially exposed to EtO as a sterilant. Available scientific evidence was cited which indicated that EtO reacted with the genetic materials of at least 13 different species including humans as well. In some cases this has resulted in revertant mutations in microorganisms, dominant lethal mutations in mice, and indications in humans that damage from a single exposure was persistent. EtO has demonstrated mutagenic activity and fetotoxicity and has demonstrated adverse effects on the reproductive system of male cynomologus-monkeys. EtO appeared to exert its effects by alkylation of DNA. The request by OMB that workers use respirators for protection was discussed, in relation to the type of work performed by exposed workers, the high warning level for EtO, and difficulties presented by respirator programs.
NIOSH-Author; Carcinogenesis; Mutagenesis; Fetus; Reproductive-system-disorders; DNA-damage; Genotoxic-effects; Hospital-equipment; Toxic-gases;
NTIS Accession No.
Division of Standards Development and Technology Transfer, NIOSH, Cincinnati, Ohio, 27 pages, 11 references