In this Final Standard, OSHA establishes a permissible exposure limit for occupational exposure to ethylene oxide (EtO) of 1 part EtO per million parts of air (1 ppm) determined as an 8-hour time-weighted average concentration. The basis for this action is a determination by the Assistant Secretary, based on animal and human data, that exposure to EtO presents a carcinogenic, mutagenic, genotoxic, reproductive, neurologic and sensitization hazard to workers. The standard provides for, among other requirements, methods of exposure control, personal protective equipment, measurement of employee exposures, training, medical surveillance, signs and labels, regulated areas, emergency procedures and recordkeeping. An "action level" of 0.5 ppm as an 8- hour time-weighted average is established as the level above which employers must initiate certain compliance activities such as periodic employee exposure monitoring and medical surveillance. In instances where the employer can demonstrate that employee exposures are below the action level, the employer is not obligated to comply with most of the requirements set forth in this final rule. The 1 ppm 8-hour limit reduces significant risk from exposure to EtO and is considered by OSHA to be the lowest levels feasible. This final standard shall become effective August 21, 1984, except the following paragraphs which contain information collection requirements which are under review at OMB: 1910.1047(a)(2), (d), (e), (f)(2), (g)(3), (h), (i), (j)(1), (j)(2) , and (j)(3).