Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents
• Standard Number: 1910.106; 1910.106(d)(7)(iv)

April 25, 2003

Mr. Donald L. Schmidt
Senior Vice President
Marsh USA, Inc.
200 Clarendon Street
Boston, MA 02116-5093

Dear Mr. Schmidt:

Thank you for your December 16, 2002 letter to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs (DEP). You have questions regarding OSHA'sFlammable and Combustible Liquids Standard, §1910.106. Please be aware that this response may not be applicable to any question or situation not delineated within your original correspondence. Your specific question is related to the storage of water reactive materials with other materials.

Scenario: Our client stores multiple products including flammable liquids, water-reactive chemicals, and non-hazardous products at their distribution center. The water-reactive chemicals in question are solid materials. These solids are also classified as flammable. These chemicals include:


Water Reactive/Flammable Chemicals
Chemical CAS #
Calcium Carbide 75-20-7
Potassium Metal 7440-09-7
Zinc Metal Powder 7440-66-6
Sodium Metal 7440-23-5
Magnesium Metal 7439-95-4


Our client stores these water-reactive/flammable materials inside "Flammable Cabinets" (storage cabinets). These storage cabinets are stored in 2-hour fire rated inside storage rooms ("vaults") protected with foam-water fire protection systems.

Fire codes require flammable products be stored in the inside storage rooms. According to OSHA's standard related to water-reactive materials, 29 CFR 1910.106(d)(7)(iv), "Materials which will react with water shall not be stored in the same room with flammable or combustible liquids". No (OSHA) regulation addresses the storage of products that are both water-reactive and flammable.

Question: Does OSHA permit the storage of water-reactive products that are also classified as "flammable" within a fire rated, foam-water protected flammable liquids storage room so long as the water-reactive chemicals are stored within approved cabinets?

Reply: First, the materials in question you wish to store in the same inside storage room with flammable liquids are solid materials which are both water-reactive and flammable. OSHA's standard, 29 CFR 1910.106(d)(7)(iv), makes no distinction about the physical state, i.e., liquid or solid, of the"materials which will react with water." In other words, regardless of the physical state of the water-reactive materials, they cannot be stored in the same room with flammable or combustible liquids.

OSHA and the National Fire Protection Association (NFPA)
(1),(2) have long held that storage of water-reactive materials with flammable or combustible liquids in the same room or area constitutes an "unreasonable hazard and risk."(3) Therefore, even though your proposal includes segregating the water-reactive/flammable solid materials inside approved cabinets, the cabinets are stored inside the same inside storage room with flammable liquids. Consequently, this would be a violation of 29 CFR 1910.106(d)(7)(iv).

Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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 http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.

Sincerely,

Richard E. Fairfax, Director
Directorate of Enforcement Programs


1 NFPA 30 Flammable and Combustible Liquids Code Handbook, 5th Ed. - 1994, pg. 220, Rule 4.8.8 [Back to Text]


2 NFPA 30 - 2000, Flammable and Combustible Liquids Code, Rule 4.10.1 [Back to Text]


3 NFPA 30 Flammable and Combustible Liquids Code Handbook, 1st Ed. - 1981, pg. 132, Rule 4-7.4 [Back to Text]


Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents