Fire barrier between oxygen and acetylene cylinders on a cart

May 23, 2001

John J. Stallbaumer

Harper Trucks, Inc.

[Recipient address omitted]

Re: §1926.350(a); storage of welding gas cylinders; fire-resistance barriers

Dear Mr. Stallbaumer,

This is in response to your April 25, 2001, letter in which you asked the Occupational Safety and Health Administration (OSHA) to determine if an engineered steel fire barrier installed on a cart between oxygen and acetylene gas tanks complies with the separation/firewall requirement for the storage of gas cylinders in §1926.350(a)(10).

Section 1926.350(a) requires gas cylinders to be stored in compliance with its prescribed criteria. We issued an interpretation letter to Mr. Dineen on December 31, 1998, which clarifies when a gas cylinder is considered to be in storage. The standard sets requirements for gas cylinders storage. To be properly stored, the employer must meet all the requirements of §1926.350(a). One of those requirements is §1926.350(a)(10):

Oxygen cylinders in storage shall be separated from fuel-gas cylinders or combustible materials (especially oil or grease), a minimum distance of 20 feet (6.1 m) or by a noncombustible barrier at least 5 feet (1.5 m) high having a fire resistance rating of at least one half hour.

You provided literature about and described a situation where some manufacturers are fabricating gas cylinder carts with engineered steel fire barriers in order to comply with §1926.350(a)(10). The purpose of the barrier is to allow employers to "store" the cylinders on the cart and still meet the firewall requirement. You ask us if this method of complying with the standard is adequate.

The literature you provided about these products indicates that the steel barrier has been engineered specifically to meet a ½-hour fire resistance rating and to prevent a fire in one cylinder from spreading to the other cylinder on the cart. The barrier is also depicted as meeting the standard's height requirement. While we do not have the background technical information regarding the design and testing of that product, and are not in a position to independently evaluate the product, as long as the barrier is at least 5 feet high, meets the ½-hour fire resistance rating and is designed to prevent the spread of the fire from one cylinder to another, employers using the product would meet the requirements of §1926.350(a)(10).

You also referred to a letter issued by OSHA to Mr. Anastasi on April 21, 1991. In that letter the Agency stated that a "heavy gauge metal partition" proposed by Mr. Anastasi would not meet this requirement. As discussed above, the steel barrier in the literature you submitted is not simply a sheet of metal but is comprised of a series of baffles and purports to have been designed and tested to meet the standard.

Please let us know if you need any further clarification on this standard and feel free to contact us again by writing to: Directorate of Construction-Office of Construction Standards and Compliance Assistance, Room 3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210.

Sincerely,

Russell B. Swanson, Director

Directorate of Construction