Overview
Rated cabinets are:
- Metal or wood
- Meet design requirements
- Commercially labeled
Rated cabinets are not:
- Usually under fume hoods
- ‘Lined’ cabinets
- Standard metal storage cabinets
Flammable liquids outside of rated cabinets:
- Numerical and Performance standards
- Focus on chemicals in storage versus those that appear to be in use
A flammable liquid is defined by the NFPA (National Fire Protection Association) as having a flash point of less than 100°F (38ºC). OSHA’s GHS standard uses a Flash Point of 93°F. For the purposes of this checklist item, apply the GHS definition, since that is the information that will be readily available to you on labels. Below is a list of common, flammable laboratory solvents and their flash points. Note, this is not an all encompassing list. If you need further information regarding a chemical’s flashpoint, please refer to the chemical’s Safety Data Sheet.
- Acetone (4°F)
- Isopropanol (53°F)
- Temed (<21°F)
- Acetonitrile (42°F)
- Ethyl Alcohol (55°F)
- Sigmacote (25°F)
- Tetramethylethylenediamine (50°F)
- Propyl Alcohol (74°F)
- Methanol (54°F)
- Ether (diethyl) (−49°F)
NFPA regulations have both numerical and performance standards related to storage of flammable liquids i.e., the quantity of flammable liquids stored in the space outside of rated cabinets is in excess of 25 gallons (95 liters) or the quantity of flammable liquids being stored in a single flammable storage rated cabinet exceeds 60 gallons. Note that we are specifically talking about STORAGE.
When evaluating this checklist item, we are really looking at two things. First are flammable liquids that are obviously not in use being stored outside of a flammable liquids cabinet? Don’t go so far as to cite something like the 500 ml squeeze bottles of ethanol that you often see in a laboratory. The second part of this checklist item is whether the flammable liquid storage cabinets are appropriately designed and in good condition. Homemade cabinets and cabinets that are not designed and manufactured to the appropriate standards are not acceptable. We’ll contrast rated and unrated cabinets in the next few slides.
The Exhibit A shows a rated cabinet constructed of wood. Most are constructed of metal, but wood is acceptable. Notice the label on the end of the cabinet. It clearly states that the cabinet meets NFPA design requirements. Exhibit B shows improper storage of a flammable liquid in an ordinary cabinet. It also shows disorganized storage that could easily lead to leakage of the containers.