From a post on ORC Worldwide’s web site, written by Dee Woodhull, CIH: “EPA found in 1985 that methylene chloride (MC) is a probable human carcinogen and poses a long-term danger to human health. OSHA published its final MC Standard (29 CFR 1910.1052) on January 10, 1997, reducing the permissible exposure limit from an 8-hour-time-eighted-average (TWA) of 500 parts per million (ppm) to 25 ppm. OSHA has now completed a review of the MC standard, pursuant to the Regulatory Flexibility Act and Executive Order 12866 on Regulatory Planning and Review. The review was conducted to determine whether the MC Standard has functioned as intended, whether it could be simplified or improved to reduce the regulatory burden on small businesses, or whether it is no longer needed and should be rescinded.”

ORC Worldwide is a Washington-based environmental health and safety consultancy.

OSHA’s review concludes that:
  • The standard remains justified and necessary in light of ongoing hazards and fatalities. It has produced the intended benefits (i.e., protecting workers’ health), and has not been unduly burdensome.
  • The standard does not impose an unnecessary or disproportionate burden on small businesses or on industry in general.
  • Although the standard does impose costs, these costs are essential to protecting worker health.
  • The look-back review did not identify any industries in which the standard diminished the industries’ viability.
  • There is no indication that employers are unable to comply due to the complexity of the standard.
  • In general, the Standard is compatible with and not does not overlap or duplicate other state or federal rules.
  • Economic and technological trends have not reduced the need for the standard.
  • No public commenter felt the MC standard should be rescinded. Several of the comments underscored the hazards associated with exposure to MC and that it is feasible to comply with the standard. Other comments contained specific suggestions for how compliance with the standard could be improved through compliance assistance, and how worker health could be improved through information on the toxicity of substitutes for MC use.


OSHA recommends the following:
  • The MC Standard should continue without change.
  • According to public comments, lack of information and training are the most common barriers in the construction industry for compliance with the MC Standard. Therefore, OSHA recommends reviewing its compliance assistance materials to determine the need for updates. OSHA also recommends reviewing the adequacy of how these materials are disseminated and additional means for reaching affected populations.
  • The use of substitutes for MC has increased in certain industries. These substitutes may pose their own health hazards. Therefore, based on public comments, OSHA will consider putting out guidance recommending that, before a substitute for MC is used, the toxicity of that substitute should be checked on the EPA and NIOSH Web sites