Everyday Hazmat User’s Training Guide, Page 27

Everyday Hazmat User's Training Guide

Section III Hazardous Materials Management (continued)

Hazardous Materials Storage Cabinets

Design and Construction

The cabinets you purchase for hazardous materials storage must have:
- Double-walled construction of metal with welded or riveted joints.
- A built-in secondary containment or sill in the bottom of the cabinet.
- Three-point door latches.
Wooden cabinets are allowed only for storing flammable and combustible liquids. They must be made of 1-inch-thick exterior plywood with rabbeted joints fastened in two directions.
Self-closing doors may be required in some jurisdictions. Check with your local fire marshal.
Flammable and combustible liquid cabinets must have red lettering on a contrasting background saying: FLAMMABLE�KEEP FIRE AWAY.
Cabinets containing other types of hazardous materials must have red lettering on a contrasting background saying: HAZARDOUS�KEEP FIRE AWAY.

Image of a commercial storage cabinet. The cabinet has two upright doors that wing open from the middle. A warning, FLAMMABLE: KEEP FIRE AWAY, is visible on the front of the cabinet.

Commercial storage cabinets can be purchased in a range of sizes for many different hazardous materials. However, all cabinets must meet certain design and construction criteria to be acceptable.

Cabinet Venting

Venting generally is not recommended because it may reduce the cabinet�s fire resistance. However, some jurisdictions may require venting.

If you vent the cabinet, you must vent to the outside, the vent must have a flashback protection device, and there must be an internal fan to ensure air circulation.

Cabinet Storage Limits

Every commercial cabinet that meets the OSHA codes is designed to store a certain volume of product. In addition, there are limits of how much of a particular product can be stored in a container. Here are some guidelines:

Store no more than a total of 60 gallons of class I flammable liquids and class II combustible liquids. Do not exceed the cabinet�s design size; all containers must be sound and tightly closed.
Store no more than 120 gallons of class III combustibles.
Do not store more flammable solids than the maximum specified for the cabinet.
Do not store more oxidizers than the maximum specified for the cabinet.
Do not store more corrosives than the maximum specified for the cabinet.

Other Considerations

Only compatible materials can be stored in the same cabinet.
Compressed gas cylinders (no matter how small) cannot be stored in storage cabinets.
A total of 120 gallons of a combination of class I, II, and IIIA materials may be stored in a single cabinet so long as the capacity of the cabinet is not exceeded; no more than 60 gallons of class I and II materials can be stored in a single cabinet.

Firewall Equivalent

Commercial cabinets that meet OSHA specifications also qualify for the 1-hour firewall or 20-foot separation of incompatible materials. If you store incompatible materials in separate cabinets that meet OSHA specifications, you can put the cabinets next to each other. HOWEVER, there are limits to how many cabinets you can use; refer to the section covering the specific type of hazardous product for more information.