Q. What is a safety can?
A. NFPA 30 and OSHA 29 Code of Federal Regulations (CFR) 1910.106 (a)(29) define a safety can as, an approved container, of not more than 5 gallons (18.9 liters) capacity, having a spring-closing lid and spout cover so designed that it will safely relieve internal pressure when subjected to fire exposure.
Q. How are flammable liquid safety cabinets designed, constructed and tested to meet NFPA 30?
A. NFPA 30 Chapter 4.3.3 (b) and OSHA 29 CFR 1910.106 (d)(3)(ii)(a) state, Metal cabinets constructed in the following manner are acceptable.
The bottom, top, door, and sides of the cabinet shall be at least No. 18 gauge sheet steel and double-walled with a 1 1/2 in. (3.8 cm) air space. Joints shall be riveted, welded or made tight by some equally effective means.
The door shall be provided with a three-point latch arrangement and the door sill shall be raised at least 2 inches (5 cm) above the bottom of the cabinet to retain spilled liquid within the cabinet.
NFPA 30 Chapter 4.3.3 (a) also states, Storage Cabinets shall be designed and constructed to limit the internal temperature at the center, 1 inch (2.5 cm) from the top, to not more than 325 degrees F (162.8 degrees C) when subjected to a 10- minute fire test with burners simulating a room fire exposure using the standard time temperature curve as given in NFPA 251, Standard Methods of Fire Tests of Building Construction and Materials. All joints and seams shall remain tight and the door shall remain securely closed during the fire test.
Q. Are wooden cabinets acceptable for flammable storage?
A. NFPA 30 Chapter 4.3.3 (c) states, Wooden cabinets constructed in the following manner are acceptable. The bottom, sides, and top shall be constructed of exterior grade plywood at least 1 inch (2.5 cm) in thickness, which shall not break down or delaminate under fire conditions. All joints shall be rabbetted and shall be fastened in two directions with wood screws.
When more than one door is used, there shall be a rabbetted overlap of not less than 1 inch (2.5 cm). Doors shall be equipped with a means of latching, and hinges shall be constructed and mounted in such a manner as to not lose their holding capacity when subjected to fire exposure. A raised sill or pan capable of containing a 2 inch (5 cm) depth of liquid shall be provided at the bottom of the cabinet to retain spilled liquid within the cabinet.
Q. Do flammable liquid storage cabinets have to be vented?
A. NFPA Chapter 4.3.4 states, The storage cabinet shall not be required by this code to be vented for fire protection purposes, and vent openings shall be sealed with the bungs supplied with the cabinet or with bungs specified by the cabinet manufacturer. However, if the storage cabinet is vented for any reason, the cabinet shall be vented directly to outdoors in such a manner that will not compromise the specified performance of the cabinet and in a manner that is acceptable to the authority having jurisdiction.
Q. What is a flammable liquid? What is a combustible liquid?
A. Flammable and combustible liquids are defined and classified by their flash point and boiling point as the chart below illustrates.
Flammable and Combustible Liquid Classes
<73 degrees F
<100 degrees F
<73 degrees F
>100 degrees F
>73 degrees F and <100 degrees F
>100 degrees F and <140 degrees F
>140 degrees F and <200 degrees F
>200 degrees F
The class of a liquid can change due to contamination
Classifications do not apply to mixtures
Volatility of liquids increases when heated
Classifications are based on information from OSHA 29 CFR1910.106 (a) (18)
Q. What are some things to look for when inspecting a chemical storage area?
A. All chemicals should be properly labeled. Chemicals should have their caps secured at all times. No chemicals should be stored on bench tops, fume hoods, on the floor or extending into traffic aisles. Chemical shelves should not be over crowded. Chemicals should not be stored above eye level.
Q. What should we do if we have old, unlabeled chemicals in the house?
A. Hire an expert to come in and evaluate the situation and properly dispose of the materials.
Q. What are some things to consider when planning a chemical store room?
A. The chemical store room should have a cool, dry atmosphere, sufficient lighting in all areas, a ventilation system that exhausts to the outside, secure and sufficient shelving, and unobstructed aisles with no blind areas.
Q. What emergency equipment should be located near the chemical storage area?
A. First aid supplies, emergency phone numbers, eyewash and shower facilities, fire extinguishers, spill cleanup supplies and personal protective equipment should be readily available.