Everyday Hazmat User’s Training Guide, Page 20

Everyday Hazmat User's Training Guide

Section III Hazardous Materials Management (continued)

Combustible Liquids

Combustible liquids are less dangerous than flammable liquids because they have higher flashpoints. Class II combustible liquids have flashpoints between 100 and 140 °F. Class IIIA combustible liquids have flashpoints between 140 and 200 °F. Class IIIB combustible liquids have flashpoints higher than 200 °F. Follow the specific storage, use, and transportation requirements for the appropriate type of combustible liquid.

Definitions

Click on image for larger descriptive view

Storage Cabinets

Proper storage cabinets can protect workers and the environment, and can allow you to store larger quantities of combustible liquids safely.

Indoor Storage

Incidental Storage

Storage of combustible liquids is strictly regulated for the safety of personnel and facilities. Incidental storage of combustibles is permissible as long as the quantity does not exceed the maximum allowed, and proper storage containers are used. Permissible quantities differ depending on the occupancy of the building where the incidentals are located. Empty containers previously used for combustible liquids must be stored as if they still contained a combustible liquid.

Image of a floor plan for the incidental indoor storage of combustible liquids.
Floor Plan

Important Requirements

No more than 10 gallons of flammable and combustible liquids incidental to the operation and maintenance of equipment, and for demonstration, treatment, and laboratory work, outside of an approved cabinet.
Incidental liquids must be stored in approved containers and in a garage or other approved location.
An approved cabinet must be used to store more than 10 gallons of flammable and combustible liquids incidental to the operation and maintenance of equipment, and for demonstration, treatment, and laboratory work.

Control Areas

Control areas increase the quantity of liquids you can store. However, there are limits. These amounts can be increased if you use approved cabinets and if the area has sprinklers. Several control areas can be used if they are properly separated. Empty containers previously used for combustible liquids must be stored as if they still contained a combustible liquid.

Floor Plan
Click on image for larger descriptive view

Important Requirements

Avoid storing combustible liquids in basements.
Containers with less than 30 gallons capacity may not be stacked more than two containers or 3 feet high unless they are on shelving or are otherwise secured.
Containers that hold more than 30 gallons may not be stacked.
Containers must be stored in an upright position.
Combustible commodities must not be stored above flammable and combustible liquids.
Combustible liquids must be at least 3 feet from beams, girders, or other obstructions.
Combustible liquids must be at least 3 feet below sprinkler deflectors, discharge orifices, or other overhead fire protection systems.
Combustible liquids must not be stored in the same rack or group as flammable materials.
The maximum amount of combustible liquids that can be stored in a control area is: 120 gallons of class II liquids, 330 gallons of class IIIA liquids, and 13,200 gallons of class IIIB liquids.
Amounts can be increased by 100 percent if proper cabinets are used, and by another 100 percent if the area has sprinklers—not to exceed 300 percent of the original volume with both cabinets and sprinklers. An unlimited amount of class IIIB liquids can be stored in buildings with sprinklers.
Spill control and secondary containment are required if any individual container has more than a 55-gallon capacity or if the total capacity of all containers exceeds 1,000 gallons.

Interior Rooms

For larger quantities of flammable and combustible liquids, you can use cutoff and inside rooms. A room with one outside wall is a cutoff room, and a room with no outside walls is an inside room. Empty containers previously used for combustible liquids must be stored as if they still contained a combustible liquid.

Image of a floor plan for the indoor storage of combustible liquids in interior rooms. The floor plan indicates the locations of a cutoff room and an inside room.
Floor Plan

Important Requirements

Cutoff and inside rooms can be used if the storage volumes of class I, II, and III liquids exceed the amount that can be stored as incidentals or within control areas inside a building.
The quantities of class I, II, and III liquids that can be stored in cutoff and inside rooms depend on the size of the building and its structural features.
Check with your hazmat coordinator for specific structural requirements and safety features before designating an existing room for liquid storage or constructing a new room.
Spill control and secondary containment are required if any individual container has more than a 55-gallon capacity, or if the total capacity of all containers exceeds 1,000 gallons.