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.

May 3, 1990

Ms. Valerie L. Sheaffer Betz Laboratories, Inc. Somerton Road Trevose, Pennsylvania 19047

Dear Ms. Sheaffer:

This is in response to your letter of February 26, requesting an Occupational Safety and Health Administration (OSHA) interpretation of the 29 CFR 1910.106 standard covering flammable and combustible liquids. Your request concerns the use of combustible materials with high-density cross-linked polyethylene tanks and portable tanks, and linear polyethylene drums. You indicated in your letter the flashpoints of the materials to be in the range of 100-200 degrees F.

The OSHA standards at 29 CFR 1910.106 do not specify the use of any type of plastic containers, tanks, or drums, for storage or processing of the liquids. OSHA, however, under its "de minimis violations" policy, permits the use of polyethylene containers as described in OSHA Instruction STD 1-5.14A. The U.S. Department of Transportation's (DOT) requirements were taken into consideration in the issuance of this instruction. Copies of the de minimis violations policy and the instruction are enclosed.

Under the de minimis policy, compliance with the requirements of current applicable industry consensus standards, such as the standards published by National Fire Protection Association (NFPA), is accepted as compliance with the Occupational Safety and Health Act (OSH Act), if the consensus standards provide for equal or greater personnel protection than corresponding OSHA standards.

For example, NFPA 30, Flammable and Combustible Liquids Code, 1987 edition, allows storage of combustible liquids in containers of up to 60 gallon capacity, which are DOT specification 34 containers and polyethylene drums authorized under DOT exemption procedures. OSHA would accept these under the de minimis policy. A copy of a portion of NFPA 30 pertinent to the storage of flammable and combustible liquids is enclosed. You may contact DOT to determine their requirements at the following address:

U.S. Department of Transportation 400 7th Street, S.W Washington, D.C 20590

In the situation you described, the use of polyethylene tanks for processing of flammable and combustible liquids would be in violation of the OSHA standards and the OSH Act. To be in compliance with the OSH Act, the maximum capacity of the polyethylene containers that could be used for storage of flammable and combustible liquids is five and 60 gallons, respectively. Unless it is demonstrated that DOT allows higher capacities, the capacities stated above, for storage purposes, shall not be exceeded.

If we may be of further assistance, please contact us. Thank you for your interest in safety and health.


Patricia K. Clark Director Designate Directorate of Compliance Programs