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.

March 12, 1986

Mr. Loren Anderson, CIH
International Business Machines, Corp.
740 New Circle Road
Lexington, Kentucky 40511

Dear Mr. Anderson:

This letter is in reference to our previous telephone conversation on March 12 regarding hazard evaluation.

Hazard evaluation is a process which relies heavily on the professional judgment of the evaluator. Employers evaluating chemicals shall describe in writing the procedures they used to determine the hazards of the chemical they evaluate. If a determination has been made that a hazard does not exist, then the labeling and material safety data sheet requirements will not apply.


John B. Miles, Jr., Director
Directorate of Field Operations

March 7, 1986

Loren Anderson, CIH
International Business Machines, Corp.
740 New Circle Road
Lexington, Kentucky 40511

Dear Mr. Anderson:

Thank you for your letter dated January 28 in regards to the Hazard Communication Standard. Please accept my apology for the delay in response. The overwhelming number of letters and telephone calls regarding the Hazard Communication Standard has caused unavoidable delays in responding to the public's concerns.

Methylene chloride has been shown through established scientific studies to be a suspect carcinogen. However, since the chemical is not listed as a carcinogen by IARC or the NTP, labeling is not listed as a carcinogen by IARC or the NTP, labeling requirements are not necessary.

Material safety data sheets are required to be prepared if the chemical has been determined to be a health hazard and comprises 1% or greater of the composition, except that chemicals identified as carcinogens shall be listed if the concentrations are 0.1 % or greater.

The material safety data sheet must provide a health hazard description of the chemical based on the positive studies of carcinogenicity for methylene chloride. The material safety data sheet must state the studies have indicated that it is a suspect carcinogen.

If we may be of further assistance on this matter please feel free to contact our office at (202)523-8036.


John B. Miles, Jr., Director
Directorate of Filed Operations

January 28, 1986

Mr. Dave Smith
Director, Office of Health
Compliance Assistance
200 Constitution Avenue
Washington D.C. 20210


We currently manufacture a typewriter/printer ribbon that uses methylene chloride in one of the manufacturing processes. Because of the nature of the process, a small amount of residual methylene chloride remains in the ribbon as it is shipped to customers. Currently, the level of methylene chloride in each ribbon is less than 0.1% by weight.

In order to make our manufacturing process more efficient, we are contemplating a change that would raise the residual methylene chloride to a maximum of 0.5% by weight. Extensive airborne monitoring has been performed on typewriters and printers using ribbons with 0.5% to 1% residual methylene chloride. Even under the most extraordinary operating conditions, the highest level of methylene chloride measured at or around the machine is only 0.12 PPM. This is over 4000 times below the current OSHA Permissible Exposure Limit of 500 PPM. Although there have been conflicting studies about the carcinogenicity of methylene chloride, neither IARC nor the latest NIP Annual Report list it as a carcinogen. Since the ribbon is enclosed in a cassette cartridge, this eliminates the need for dermal contact during normal use. Using any of the available exposure criteria for this solvent, we have concluded that there is no inhalation or dermal hazard associated with this ribbon.

In light of the requirements of 29CFR1910.1200, we would like to market this ribbon with a maximum of 0.5% residual methylene chloride without a warning label or Material Safety Data Sheet. We would appreciate your review of our conclusion to ensure that it meets the intent of the Hazard Communication Standard. I would appreciate a written response to this inquiry. If you have any additional questions, please call me at (606) 232-2839.

Thank you.

Staff Industrial Hygienist