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 21, 1990

Mr. John A. Knoll,
Sales Manager
Natural Gas Odorizing, Inc.
3601 Decker Drive
Post Office Box 1429
Baytown, Texas 77522-1429

Dear Mr. Knoll:

This is in response to your letter of June 18, in which you raised the question of jurisdiction over tanks of malodorant gas. I apologize for the delay in responding to your inquiry.

Section 4(b)(1) of the Occupational Safety and Health Act (OSH Act) provides that "nothing in this chapter shall apply to working conditions of employees with respect to which other Federal agencies exercise statutory authority to prescribe or enforce standards or regulations affecting occupational safety or health." The purpose of this exemption is to avoid duplication in Federal regulation of safety and health conditions in the workplace. Once another Federal agency exercises its authority to regulate specific working conditions, the Occupational Safety and Health Administration (OSHA) cannot enforce regulations covering the same hazard against an employer who is regulated by the other Federal agency.

We wish to emphasize that Section (4)(b)(1) does not authorize industrywide exemptions from OSHA regulations. OSHA is prohibited by Section (4)(b)(1) only from regulating hazards regulated by other agencies. If the Department of Transportation has adopted regulations regarding the safety of refitted propane tanks that are used to store malodorant agents at pipeline facilities, OSHA would generally be precluded from regulating the safety conditions addressed by these requirements.

We hope that this response is satisfactory. If you have any further questions please feel free to contact us at (202) 523-8031.


Patricia K. Clark, Director
Directorate of Compliance Programs