Methylene Chloride.

摘要

When established under the authority of the Occupational Safety and Health Act of 1970, the Occupational Safety and Health Administration (OSHA) had 2 years to adopt existing federal standards or national consensus standards 1 so it would have Standards in place to enforce. OSHA chose to adopt existing federal standards issued under the Walsh-Healey Public Contracts Act, which were derived from threshold limit values of the American Conference of Governmental Industrial Hygienists and consensus standards from standards developing organizations such as the American National Standards Institute (ANS I). For methylene chloride, OSHA adopted an ANSI standard under Subpart Z of Title 29 Code of Federal Regulations (CFR ), Part 1910.1000 to ensure that employee exposure did not exceed 500 parts per million parts of air (500 ppm) as an 8- hour time-weighted average TWA--i.e., the average exposure during an 8-hour period. Since 1971, however, industrial experience, new developments in technology, and emerging scientific data clearly indicate that this limit did not adequately protect worker health. The agency realized the need to better control worker exposure to methylene chloride due to its harmful health effects.