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.

August 6, 1991

Mr. C. R. Hamilton
Manager, Technical Operations
Golden Technologies Company, Inc.
BioChem Systems Division
15000 West 6th Avenue, Suite 202
Golden, Colorado 80401

Dear Mr. Hamilton:

This is in response to your letters of May 10 and May 23, and your conversation with Sanji Kanth of my staff subsequent to your May 10th letter, concerning the flash point of Bio T products that your company manufactures. We apologize for the delay in our response.

You indicated in your first letter that your Bio T products have a flash point of 130 degrees F. During your telephone conversation with the above staff member, you apparently expressed your concerns regarding the accuracy of this flash point. As a result of the telephone conversation with my staff member, you provided in your second letter:

1) Your understanding of the definition of the flash point, which is a point where there is visible and sustainable flame.

2) The new flash point of the Bio T products, which you determined to be 195 degrees F based on the above definition.

3) The Pensky-Marsen Closed Cup (PMCC) flash point data for a Bio T 300B product.

You requested our office to review the data and discussion, and confirm in writing, if the flash point, which you determined for the material, is correct.

The definition of the flash point contained in the Occupational Safety and Health Administration (OSHA) general industry standards at 29 CFR 1910.106, is as follows:

"... the minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid, and ..."

As you may know, OSHA developed its standards at 1910.106 from the National Fire Protection Association (NFPA), NFPA 30-1969, entitled "Flammable and Combustible Liquids Code." Similar to NFPA's definition on flash point as contained in Fire Protection Guide On Hazardous Materials, 9th edition (see enclosure), OSHA interprets the "ignitable mixture" contained in our definition of flash point, to be a mixture within the flammable range (between lower and upper limits) that is capable of propagation of flame. The term propagation of flame is meant to be the spread of flame away from the ignition source of the test apparatus. This flame need not be sustained. The temperature at which the flame becomes self-sustained so as to continue burning the liquid, is called fire point. The definition of "fire point" is contained in the Society of Fire Protection Engineers Handbook of Protection Engineering, a copy of which is enclosed.

Therefore, "flash point" is a minimum temperature at which an ignitable mixture capable of propagating a flame away from the test flame, is formed during the appropriate test conditions prescribed by the American Society of Testing Materials (ASTM).

The test data you submitted, such as the temperatures at which the change in color occur and the blowing out of the test flame, do not determine the flash point of a certain flammable or combustible material. On the other hand, the minimum temperature at which the flame propagation actually begins, determines the flash point.

Many factors, including the precise steps to be taken while conducting the actual flash point tests, contribute to the correctness of the flash point of a given material. Since we have no knowledge of the tests in question and the way they were conducted, and have no test data consisting of the minimum temperature at which an "ignitable mixture" capable of propagating a flame, is formed, we cannot make a determination on flash point of your Bio T products, at this time.

If you believe through the PMCC test(s) that the flame propagation for your Bio T products begins to occur at 195 degrees F, you can reclassify the flash point of your product.

In order to determine the proper flash point of your products, we suggest that you contact an independent consultant who is not knowledgeable of your products and of their previous test results, and who is thoroughly familiar with ASTM test methods for determining the flash points.

Thank you for your interest in safety and health. If we may be of further assistance, please contact us.


Patricia K. Clark, Director
Directorate of Compliance Programs