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.

June 5, 1992

Ms. Meg MacLeod
Health and Safety Supervisor
ABB Environment Services, Inc.
261 Commercial Street
P.O. Box 7050
Portland, Maine 04112

Dear Ms. MacLeod:

Thank you for your letter of February 5, to Acting Assistant Secretary Dorothy L. Strunk, requesting clarification regarding the applicability of the compressed gas cylinder standard at 29 CFR 1910.101(b) to workplaces subject to the Hazardous Waste Operations and Emergency Response Standard at 29 CFR 1910.120. The questions you asked and the corresponding replies follow.

Question 1: The regulation (1910.101(b)) states that in-plant handling, storage, and utilization of all compressed gases in cylinders shall be in accordance with the Compressed Gas Association Pamphlet P-1-1991. Does this apply to operations at hazardous waste sites?

Reply: Employers who employ workers at hazardous waste sites are subject to the Occupational Safety and Health Administration (OSHA) General Industry Standards at 29 CFR 1910. The standard at paragraph 1910.101(b) requires that in-plant handling, storage and utilization of compressed gases in cylinders which are subject to Subpart H - Hazardous Materials standards shall be in accordance with the Compressed Gas Association (CGA) Pamphlet P-1-1965. "In-plant" refers to specific workplaces, that is, fixed facilities. Under an OSHA policy for "de minimis" violations, employers are allowed to abide by the most current consensus standard, for example, CGA Pamphlet P-1-1991, applicable to their operations, rather than with the standard in effect at the time the OSHA standard was issued, when the employer's action provides equal or greater employee protection. "De minimis" violations are violations of existing OSHA standards which have no direct or immediate relationship to safety or health. Such violations of the OSHA standards result in no citation, no penalty and no required abatement.

Question 2: The Pamphlet states that all compressed gas cylinders in service or in storage shall be secured to prevent them from falling, and that only certain sized cylinders can be stored in a horizontal position. Does this mean that cylinders (no size restrictions), while in use, can rest in a horizontal position and do not have to be secured if there is not a chance of them rolling, falling, or an item falling on them?

Reply: By paragraph of CGA Pamphlet P-1-1991, gas cylinders with a water volume less than 305 cubic inches (5.0 liters) may be stored in a horizontal position when properly secured to prevent them from falling. Storage in the horizontal position may be prohibited by the type of gas, for example, acetylene, stored in the compressed gas cylinders.

Question 3: Does the Pamphlet also apply to breathing air compressed gas cylinders?

Would it be acceptable for a Level B work set-up where airline hoses are supplied by four breathing air compressed gas cylinders connected to one another, to be placed horizontally and not secured in a passenger truck or to be placed on the ground. Are these set-ups in compliance with the regulations? If not, what rules apply to breathing air compressed gas cylinders while in use?

Rely: The General Safe Handling Rules For Compressed Gas Cylinders in CGA Pamphlet P-1-91 are applicable to "breathing air compressed gas cylinders". Please note that the standards at 29 CFR 1910, Subpart H - Hazardous Materials, including paragraph 1910.101(b) referenced in your letter, are not applicable to compressed air cylinders. Employers could be cited for unsafe storage, transport or use of compressed cylinders in the workplace with respect to the general duty clause, Section 5(a)(1) of the Occupational Safety and Health Act of 1970 and reference to CGA Pamphlet P-1-91, a national consensus standard. Unsecured compressed gas cylinders lying horizontally on a truck bed, as described in your letter, where they can roll and strike against each other or other surfaces do not meet the safe handling standards in paragraph 3.5 of CGA Pamphlet P-1-91.

Question 4: Are there any OSHA regulations which apply to transportation of compressed gas cylinders when traveling over a long distance or on highways?

Reply: The Department of Transportation, not OSHA, regulates the transportation in commerce of compressed gases in cylinders in accordance with 29 CFR Parts 171 through 177 - Hazardous Materials Regulations.

We appreciate your interest in employee safety and health. If we can be of further assistance, please do not hesitate to contact us.


Patricia K. Clark, Director
Directorate of Compliance Programs