June 19, 1992

Mr. Neil Jay King
Wilmer, Cutler & Pickering
2445 M Street, N.W.
Washington, D.C. 20037-1420

Dear Mr. King:

This is in response to your letter of April 9, concerning the American Iron and Steel Institute's (AISI) meeting with representatives from the Occupational Safety and Health Administration (OSHA) and the Office of the Solicitor regarding the OSHA standard, Process Safety Management of Highly Hazardous Chemicals. AISI wished to resolve any misunderstanding relative to the standard and its application. We have reviewed your discussion and offer the following comments with regard to your answers. It should be noted that while we are answering questions 5 and 6, they were not discussed at the meeting and there may be additional significant facts that should be considered.

Question 1: Under subparagraph (a)(1)(ii)(A) of the Process Safety Management Standard, 29 C.F.R. 1910.119 (the "Standard"), hydrocarbon fuels used solely for workplace consumption as a fuel are excluded from coverage, if they are not part of a process containing another highly hazardous chemical covered by the Standard. Propane and gasoline are referred to in the rule as examples of such fuels. What are some other examples of fuels that may qualify for the exclusion set forth in 29 C.F.R. 1910.119(a)(1)(ii)(A)?

AISI Answer: Examples of materials used as fuels that also qualify for the exclusion set forth in 29 C.F.R. 1910.119(a)(1)(ii)(A) are bunker oil, blast furnace gas, coke oven gas, fuel oils, heating oils, MAPP gas, natural gas, and tars.

OSHA Response to #1: The intent was to exclude fuels used solely for workplace consumption such as described in the AISI answer, if the fuels are not used in a process containing another highly hazardous chemical covered by the standard.

Question 2: Coke oven gas and blast furnace gas are generated in steel industry processes and used as fuel at steel mills. Do these gases qualify for the exclusion set forth in 29 C.F.R. 1910.119(a)(1)(ii)(A)?

AISI Answer: Coke oven gas and blast furnace gas generated in steel industry processes and used as fuel at steel mills qualify for the exclusion set forth in 29 C.F.R. 1910.119(a)(1)(ii)(A), so long as they are not part of a process involving another highly hazardous chemical covered by the Standard. However, if material removed from coke oven gas in a by-product recovery plant is itself a highly hazardous chemical, the by-product recovery plant process in which the chemical is recovered or otherwise handled may be subject to the Standard if the recovered chemical is present in an amount exceeding the applicable threshold quantity.

OSHA Response to 2: The fuels described would be part of the exclusion as long as they were not used in a process involving another highly hazardous chemical covered by the standard. However, the second part of your answer should be that if a material is removed from coke oven gas in a by-product recovery plant, the by-product recovery plant process in which the chemical is recovered or otherwise handled is subject to the standard.

Question 3: Are railroad tank cars containing highly hazardous chemicals subject to the requirements of the Process Safety Management Standard?

AISI Answer: A railroad tank car is subject to the requirements of the Standard if it contains a highly hazardous chemical, as defined in 29 C.F.R. 1910.119(b), in an amount that equals or exceeds the applicable threshold quantity. However, the exception in 29 C.F.R. 1910.119(a)(1)(ii)(B) for flammable liquids stored in atmospheric tanks or transferred below their normal boiling point without benefit of chilling or refrigeration may apply to railroad tank cars, just as it does to other tanks.

OSHA Response to #3: The exception for flammable liquids in atmospheric tanks would include rail cars that are not pressurized.

Question 4: Are flammable liquid storage tanks that are gas blanketed for vapor control covered by the Process Safety Management Standard?

AISI Answer: Flammable liquids stored in atmospheric tanks are exempt from the Standard under subparagraph (a)(1)(ii)(B). For purposes of the Standard, an atmospheric tank means a storage tank which has been designed to operate at pressures from atmosphere through 0.5 p.s.i.g. Therefore, a tank in which gas blanketing is maintained at or below 0.5 p.s.i.g. is exempt from the Standard under 29 C.F.R. 1910.119(a)(1)(ii)(B). Tanks containing 10,000 pounds or more of a flammable liquid are covered by the Standard if they are gas blanketed at a pressure greater than 0.5 p.s.i.g.

OSHA Response to #4: Flammable liquids stored in atmospheric tanks (0.5 p.s.i.g. or less) are exempt from the standard unless they are connected to a process that is covered by the standard.

Question 5: If two or more fuels, each of which would qualify individually for the exclusion set forth in 29 C.F.R. 1910.119(a)(1)(ii)(A), are blended for workplace consumption as a fuel, does the resulting fuel mixture quality for the exclusion as well?

AISI Answer: Yes, so long as the fuel mixture is not being used as a part of a process containing another highly hazardous chemical covered by the standard.

OSHA Response to #5: We concur with the AISI answer.

Question 6: Are the contents of reserve gas cylinders that have not yet been connected to the process in which the gas will eventually be used considered to be part of that process?

AISI Answer: Before it is connected to the process in which the gas will be used, a reserve gas cylinder is a separate vessel. Accordingly, it could be considered part of the process for purposes of determining whether the threshold quantity for the gas is exceeded under 29 C.F.R. 1910.119 only if it is so located that the gas contained in the cylinder could be involved in a potential release of the same gas from the process, or vice-versa.

OSHA Response to #6: We concur with the AISI answer except that the flammable gas thresholds are not chemical specific so that any combination of flammable gases meeting the threshold would be covered.

I hope this information answers your concerns.

Sincerely,



Roger A. Clark Director,
Directorate of Safety Standards Program