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.

October 2, 1978

                   Regional Administrator Kansas City, Missouri

THRU:               DONALD E. MACKENZIE Field Coordinator

FROM:               BRUCE HILLENBRAND Acting Director, Federal Compliance
                   and State Programs

SUBJECT:            29 CFR 1910.106 - the use of fiberglass tanks for
                   storage of crude oil.

Any requirement or condition that is in compliance with the latest NFPA Code, which has no lessening effect on the safety and health of the employees, substantially, meets the intent of the Act and OSHA's program directive #200-67. Fiberglass tanks used for the storage of crude oil at isolated wellheads are acceptable to OSHA because they are located in areas completely isolated from other structures and there is little employee exposure to the tank. It is unnecessary to require compliance with more rigid standards for such isolated storage tanks. Any violation of the present OSHA standards for fiberglass storage tanks located at isolated wellheads will be considered de minimis.

The memorandum dated February 11, 1977, incorrectly stated that Class III B liquid in other than isolated rural areas would have to meet other requirements and is best handled through the variance route. At the present time OSHA standards do not provide regulations for Class III B liquids. However, fiberglass storage tanks used for storing Class III A to Class I liquids is permitted at isolation wellheads.