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.

October 24, 1988

Mr. Jeremy Millstone
Policy Analyst
Jellinek, Schwartz, Connolly
& Freshman, Inc.
1350 New York Avenue, N.W., Suite 400
Washington, D.C. 20005

Dear Mr. Millstone

This is in response to your letter of October 3, addressed to Assistant Secretary, John A. Pendergrass, regarding hazard determination and material safety data sheet requirements under the Hazard Communication Standard (HCS) 29 CFR 1910.1200.

The HCS under 1910.1200(d)(5)(ii) allows a chemical manufacturer to assume an untested mixture to present the same health hazards as do the components which comprise one percent or greater of the mixture; or to be a carcinogenic hazard, if the mixture contains a component in concentrations of 0.1 percent or greater where the component is considered to be a carcinogen. Your client's material safety data sheet would be prepared correctly if the health hazards of the component parts greater than one percent, or 0.1 percent for any carcinogenic components, are reported.

Generally applicable control measures including engineering controls, work practices or personal protective equipment and any generally applicable precautions for safe handling and use which are known to the chemical manufacturer should also be reported on the material safety data sheet. The statement "that respiratory protection is not needed with normal use," strongly implies that there are conditions of use, emergency or otherwise, for which respiratory protection or some other control measure would be necessary; i.e., use in confined spaces, in high temperatures or with inadequate ventilation. The conditions and appropriate protective measures must be included on the material safety data sheet. Similarly, the statement that "the product is not hazardous in normal use" implies that there are no hazards associated with the product. The standard is explicit in describing the criteria to be used to determine whether or not a chemical is to be considered hazardous for purposes of the HCS. The criteria can be found in Appendix B. It is the responsibility of the chemical manufacturer, importer or employer preparing the material safety data sheet to ensure that the information recorded accurately reflects the scientific evidence used in making the hazard determination.

Where the employer chooses not to undergo a hazard determination, and is assuming a mixture has the same properties as its hazardous component parts, the data sheets for the components will satisfy the material safety data sheet requirements for the mixture.

We hope this adequately responds to your concerns. If we can be of further assistance to you, please do not hesitate to contact us.


Thomas J. Shepich, Director
Directorate of Compliance Programs