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.

December 31, 2002

Patricia H. Falls
Firstline Safety Management, Inc.
P.O Box 3069
Winchester, VA 22604

Re: Whether use of double-walled tanks meets the requirement in §1926.152(e) that tanks be protected from collision damage

Dear Ms. Falls,

This is in response to your April 29, 2002, letter to the Occupational Safety and Health Administration (OSHA). You ask that we further clarify our April 26, 2002, response to you concerning the use of double-walled tanks; we apologize for the delay in responding. In our April 26 letter, we stated the question and answer as follows:

Question: Section 1926.152(e)(4) provides that, with respect to dispensing flammable and combustible liquids, "The dispensing units shall be protected against collision damage." If a fuel tank has double walls, are barriers or other devices required to meet the requirements of this provision?

Answer While double walls reduce the chance of a tank rupture from a collision, it does not necessarily eliminate the combustion/explosion hazard from collisions addressed by 29 CFR 1926.152(e)(4). For example, the location and design of equipment attached to the tank may render the system equally vulnerable irrespective of whether the tank is single or double-walled. The extent of the measures required to meet this requirement depends upon the nature of the collision risk where the unit is located. For example, more extensive measures would be required for a refueling tank located next to a roadway or other high traffic area than for a system located in an area used only by vehicles approaching for filling operations.

Follow-up question
In your April 29 follow-up letter, you ask us to more definitively state whether the use of a double-walled tank supplants a need for any additional measures, such as barricades, for preventing collision damage.

In general, the fact that a tank is double-walled would not, by itself, be sufficient to meet the requirements of §1926.152(e)(4), for the reasons stated in our previous letter. The extent of other measures required depends on factors such as the proximity of the tank to high volume or high-speed traffic, as previously discussed. Other factors such as whether vehicles back up to the tank (posing a higher collision risk) are also relevant.

Typically, where collision risk is very low (such as a separate refueling area in which: traffic is limited to refueling vehicles, there is plenty of maneuvering room, there is low traffic volume and speed, and backing-up to the tank is not necessary), some form of visual warning that marks an approach boundary would be required, irrespective of whether the tank was double-walled. Where collision risk is higher, more substantial measures would be required.

In sum, the fact that a tank is double-walled typically would be insufficient by itself to meet the requirement in §1926.152(e)(4) for protection against collision damage.

Please let us know if you need any further clarification on this subject and feel free to contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, [Office of Construction Standards and Guidance], fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson



1This interpretation applies only to states covered by Federal OSHA. States with an approved State OSHA program may have additional standards or standards that are more stringent then the Federal standards. If you are interested in how a comparable requirement is interpreted in the State of Virginia or other State program, please contact that State. [back to text]