Methylene Chloride Standard Up For Review
OSHA is conducting a review of its Methylene Chloride Standard under Section 610 of the Regulatory Flexibility Act and Section 5 of Executive Order 12866 on Regulatory Planning and Review. In 1997, OSHA promulgated the standard to protect workers from occupational exposure to methylene chloride. The purpose of this review is to determine whether there are ways to modify this standard to reduce the regulatory burden on small businesses and to improve its effectiveness.
Written comments to OSHA are welcomed by the agency and must be sent or postmarked by October 9, 2007.
Methylene chloride is a powerful solvent with a number of uses, chiefly for metal degreasing and aircraft paint removal. It is also 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. OSHA concluded that MC exposure created a significant risk of cancer and that 25 ppm was the lowest feasible level.
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 TWA, or short-term exposure limit (STEL) 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 standard also requires the establishment of a regulated area and procedures for determining employee exposure to MC. The employer is required to notify employees of monitoring results and to allow employees or their designated representative to observe monitoring. Employers also must establish a medical surveillance program for employees exposed to MC. The standard provides specific requirements depending on the nature of the exposure and health status of the employee. If a medical professional determines that exposure to MC may aggravate or contribute to an employee's existing skin, heart, liver, or neurological disease, the standard provides for temporary medical removal and protection of benefits during removal.
Employers must control exposures to MC to the PEL or below using engineering controls and work practices as the primary methods, unless the employer can demonstrate that these controls are infeasible. In these cases, respirators are permitted in combination with engineering controls and work practices. While the standard provides minimum requirements for respiratory protection, it notes that air filtration respirators are not very effective for MC. Finally, the standard includes requirements for protective clothing and equipment, maintaining records of exposure measurements and medical surveillance, providing information and training to employees, and providing facilities for washing MC off of persons or clothing.
For additional information, visit http://a257.g.akamaitech.net/7/257/2422/01jan20071800/edocket.access.gpo.gov/2007/E7-13208.htm.