September 26 2008

Mr. Curt Riggs
Risk Control Consultant
IMA of Kansas, Inc.
P.O. Box 2992
Wichita, KS 67201-2992

Dear Mr. Riggs:

Thank you for your July 9, 2008 letter to the Occupational Safety and Health Administration (OSHA) Department of Enforcement Programs. You had a specific question regarding the applicability of the Process Safety Management (PSM) regulation, 29 CFR 1910.119 (the standard), to biodiesel manufacturing plants. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence. For clarification, your specific question is paraphrased below, followed by OSHA's response.

Question: Are Biodiesel plants subject to the Process Safety Management standard?

Reply: A biodiesel manufacturing process is subject to the requirements of 29 CFR 1910.119 if it meets certain conditions specified in §1910.119 (a)(l), namely, if it is:

• A process which involves a chemical at or above the specified threshold quantities listed in Appendix A to this section;
• A process which involves flammable liquid or gas (as defined in 1910.1200(c) of this part)¹ on site in one location, in a quantity of 10,000 pounds (4535.9 kg)..."

Biodiesel production processes vary, but generally involve the catalyzed esterification of vegetable oils or greases (of either animal or vegetable origin) with a flammable alcohol(s), such as methanol (methyl alcohol), in a batch reactor. Biodiesel facilities are classified under NAICS code 325199, "all other basic organic chemical manufacturing."

A biodiesel process is covered in accordance with §1910.119 (a)(l)(ii) if it contains 10,000 pounds or more of flammable materials, including mixtures that meet the flashpoint thresholds defined by the standard. As a result, if it has not already done so, your client must make itself aware of the flashpoint of mixtures present in the biodiesel manufacturing process. This potentially could include raw biodiesel product if it contains enough residual methanol to create a flammable liquid as defined by the standard.

As referenced in your letter, OSHA is not currently enforcing the PSM standard on atmospheric storage tanks containing flammable liquids "which are kept below their normal boiling point without benefit of chilling or refrigeration" (§1910.119 (a)(l)(ii)(B)) as a result of the attached 1997 memorandum. This enforcement policy applies only to tanks used solely for storage. Tanks used for mixing, blending, heating, cooling, filtration, clarification, or similar purposes are considered to be process tanks, are subject to enforcement under the PSM standard, and their contents are included when determining if more than 10,000 pounds of flammable materials are contained in the process.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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 interpretation 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.

If you have any further questions, please call the Office of General Industry Enforcement at 202-693-1850.

Sincerely,

Richard E. Fairfax, Director
Directorate of Enforcement Programs

¹ As defined in 1910.1200(c), flammable liquids have flashpoints below 100°F, except any mixture having components with flashpoints of 100°F or higher, the total of which make up 99 percent or more of the total volume of the mixture.