By this notice, the Occupational Safety and Health Administration (OSHA) is proposing to amend its existing occupational standard that regulates employee exposure to ethylene oxide (EtO). The basis for this action is a determination by the Assistant Secretary, based on animal and human data, that exposure to EtO at OSHA's current permissible exposure limit (PEL) of 50 parts EtO per million parts of air (50 ppm) as an eight (8)-hour time-weighted average (TWA) is inadequate for employee health protection. OSHA proposes to reduce the PEL for EtO to a TWA of 1 ppm. An action level of 0.5 ppm as a TWA is ?ed in the proposal as a mechanism ?empting an employer from the ?gation to comply with certain requirements, such as employee exposure monitoring and medical surveillance, in instances where the employer can demonstrate that the employees exposures are at very low levels. The proposal would provide for among other requirements certain methods of exposure control, personal protective equipment, measurement of employee exposures, training, medical surveillance, signs and labels, regulated areas, emergency procedures and recordkeeping.