One safety data sheet for similar chemical mixtures

July 9, 1985

Mr. D. R. Roeing
Government Affairs Manager
Croda Inks Corporation
[Recipient address omitted]
Dear Mr. Roeing:

Thank you for your letter of April 26 regarding the Hazard Communication Standard (HCS). I apologize for our delay in responding.

As you noted, the HCS allows manufacturers of complex mixtures with similar hazards and contents to prepare only one material safety data sheet for these mixtures. In your letter, you state that these mixtures have varying flash points and vapor pressures, and ask whether it is necessary to list these for the mixture. If the variation is slight, that is, the flash points and vapor pressures are within a small range and the hazard potential is the same, reporting of the range would suffice. However, if the hazard potential changes (e.g., a different flashpoint results in a chemical being flammable rather than combustible), then the specific information must be reported. The key to determining the appropriateness is to ensure similarity in contents and hazard--without both, a single data sheet will not suffice.

We hope this information will be helpful to you. If we can be of further assistance, please do not hesitate to contact us.

Sincerely,
Director
Directorate of Field Operations