Comment Period for Methylene Chloride Standard Review Extended to March 10
OSHA is reopening the comment period for its review of the Methylene Chloride Standard. The 90-day comment period ended on Oct. 9, 2007. In response to a request for additional time to comment, OSHA is reopening the comment period for an additional 60 days. Accordingly, written comments must now be submitted (sent or postmarked) by March 10, 2008.
The current standard covers occupational exposures to MC in all workplaces in general industry, shipyard employment, and construction. Employers are required to ensure that no employee is exposed to an airborne concentration of MC in excess of 25 ppm as an 8-hour time-weighted average, or short-term exposure limit in excess of 125 ppm during a sampling period of 15 minutes. The action level for a concentration of airborne MC is 12.5 ppm calculated as an 8-hour TWA. Reaching or exceeding the action level signals that the employer must begin compliance activities, such as exposure monitoring and medical surveillance.
The review is being conducted under Section 610 of the Regulatory Flexibility Act and Section 5 of Executive Order 12866 on Regulatory Planning and Review. On July 10, 2007, OSHA provided background information about the review, raised questions of special concern to the Agency, and requested public comments, which may be submitted electronically at http://www.regulations.gov.
Methylene chloride is a powerful solvent with a number of uses. Major uses include metal degreasing and aircraft paint removal. It is used to strip finishes from furniture prior to refinishing, a use carried out by very small businesses. MC is used in the manufacturing of some plastics, adhesives, inks, and ink solvents. It also is used as the expansion agent in the manufacture of flexible polyurethane foam, and to manufacture polycarbonates. Another major, but diminishing, use is in the manufacture of film base. Other uses of MC are as an aerosol in spray cans, as a cleaning agent for semiconductors, and in the manufacture of some pesticides and pharmaceuticals.