OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

June 5, 1997

Roger D. Davis, Vice President
Bondafoam Inc.
P.O. Box 705, Highway 32 East
Water Valley, Mississippi 38965

Dear Mr. Davis:

Thank you for your letter of December 16, 1996, addressed to President Bill Clinton, regarding the Occupational Safety and Health Administration's (OSHA) Methylene Chloride (MC) Standard. We wish to assure you that OSHA is aware of the concerns you raise regarding the impacts of the MC rule and has addressed these concerns in the preamble to the final rule and the Final Economic Analysis. We would like to take this opportunity to clarify some of the misimpressions being raised about the risks of MC exposure and the methods available to reduce those risks to the U.S. workforce. Please accept our apology for the delay in this response.

The OSHA MC rulemaking was initiated in 1986 when the Agency published an Advance Notice of Proposed Rulemaking in response to a petition from the United Auto Workers (joined by several other unions) to regulate MC because it was shown to be carcinogenic in laboratory animals. In 1991, OSHA published a Notice of Proposed Rulemaking which included a proposed 8-hour time-weighted average (TWA) permissible exposure limit (PEL) of 25 ppm, a short-term exposure limit of 125 ppm and ancillary provisions covering exposure monitoring, medical surveillance, regulated areas, etc. In 1992, the Agency convened informal public hearings on the proposed standard in Washington, DC and San Francisco, CA. In addition, the rulemaking record was opened several times to receive public comment on feasibility and risk assessment issues.

The final MC rule (published in the Federal Register on January 10, 1997 (62 FR 1493)) is based on careful evaluation of all available information, including information submitted to the record by representatives of small businesses. OSHA's rulemaking record (now in excess of 48,000 pages of information) contains extensive data regarding the feasibility of compliance with the final rule, including information on substitutes for MC, modifications to control or process equipment and alterations in work practices. Many of these feasible methods of compliance are as simple and common-sensical as providing adequate ventilation, or covering tanks and containers when not in use. Data in the record indicates that the final MC regulation is feasible in all affected industries. As you may be aware, OSHA must base its findings on its rulemaking record and must promulgate a regulation that is technologically and economically feasible for all affected industries.

The adhesives industry participated in OSHA's MC rulemaking, submitting comments to the rulemaking record and meeting with OSHA staff in April 1994 to explain their concerns. OSHA has determined that the final MC rule is feasible in nearly all affected industries without the need for substituting to alternative chemicals. It is not OSHA's intention to force industries to abandon MC, nor to promote the use of more flammable substitutes for MC. Information in the rulemaking record indicates that safe, non-flammable water-based adhesive formulations are currently being used successfully by many furniture manufacturers and foam fabricators. The Agency recognizes that some employers may choose to substitute another chemical for MC for a particular application rather than implement engineering or work practice controls to reduce worker exposure to MC vapors. OSHA recognizes that the employer would need to evaluate many factors in making a decision to substitute away from MC, including potential impact on product quality, hazards of the substitute and costs of implementing substitute technology. The hazards of any chemical substance under consideration must be evaluated by the employer, as required under the Hazard Communication Standard (29 CFR 1910.1200).

OSHA has been particularly concerned with the ability of small businesses to comply with the MC standard. Therefore the Agency has streamlined requirements to reduce potential economic and paperwork burdens on such employers, including extending compliance deadlines for employers with fewer than 20 employees. Many of the actions taken by OSHA to reduce the potential compliance burdens in the final MC rule were the direct result of input to the MC rulemaking by small employers.

OSHA has thoroughly evaluated all information submitted to the record concerning the health effects of MC, including cancer, and has used this information to conduct a quantitative risk assessment. The Agency has determined that the risks to workers exposed to 50 ppm as an 8-hour TWA are significant. Therefore, OSHA may not set an occupational health standard at that level when a lower level is feasible. The evidence that 50 ppm would be inadequate to protect workers includes a wealth of animal bioassay data, numerous studies detailing the human metabolism of MC to carcinogenic products, risk assessment based on this data, and several epidemiologic studies that suggest an elevated risk of biliary cancer and astrocytic brain cancer in MC-exposed workers.

OSHA's revised final MC risk assessment estimates that at lifetime occupational exposure to 25 ppm, the additional risk of dying of cancer is 3.6 deaths per 1000 workers. At 50 ppm, OSHA estimates 7.2 deaths per 1000 workers. OSHA's goal, where technologically and economically feasible, is to reduce cancer risks to below 1 death per 1000, consistent with Supreme Court guidance. Other agencies with statutory obligations to protect the general population aim for levels of protection which are more than 100 times more protective than the levels used by OSHA. Although the risks at both 25 ppm and 50 ppm are significant, the Agency is currently constrained from reducing the permissible exposure limit to below 25 ppm due to a lack of definitive evidence documenting the feasibility of lower limits. OSHA intends to promulgate the standard at 25 ppm, in order to reduce risks and because the Agency has determined that 25 ppm is technologically and economically feasible across industry sectors.

Enclosed is a copy of the January 10, 1997, Federal Register notice in which the Methylene Chloride standard is published along with a copy of a booklet that summarizes the standard. I hope these can be of some help.

Thank you for bringing your concerns to my attention. Your interest in occupational safety and health is greatly appreciated.


Adam M. Finkel, Sc. D.
Health Standards Programs

December 16, 1996


Dear President Clinton,

We are a small business located in the town of Watervalley, Mississippi. We employ about 50 persons, and are a manufacturer of carpet pads. We use methylene chloride in the manufacture of the carpet padding. It is in the adhesive that we use methylene chloride in processing the carpet pads.

The new regulation which is being proposed by OSHA would lower the PPM exposure level from 50 PPM to 25 PPM. This huge jump would cause us great difficulty, and expense. We believe that lowering the TLV to 50 PPM is more than adequate. There is no evidence that this material causes cancer in humans, even though it does cause cancer in rats.

It costs OSHA nothing to impose regulations on the industry that are much more strict than is necessary. It will cost industries millions of dollars to comply with the difference between 50 PPM, and 25 PPM. We could meet the 50 PPM limit without a great deal of difficulty or expense, but in order to meet the 25 PPM limit we would have to spend many thousands of dollars for additional plant ventilation. Why restrict industries, when it is not necessary?

Sincerely yours,

Roger D. Davis
Vice President