Refrigerators and Freezers: Storing Flammable Liquids

It is unsafe to store flammable liquids in domestic refrigerators or freezers. Explosions, injuries, and costly laboratory fires have resulted from this dangerous practice. There are two types of refrigerators used in campus laboratories to prevent the ignition of flammable vapors:

  • "laboratory-safe" or "flammable material"
  • "explosion-proof"

Flammable material refrigerators and freezers are designed to prevent ignition of flammable vapors inside the storage compartment and should be purchased whenever a refrigerator is needed to store flammable liquid. A flammable liquid is defined by the fire code as having a flash point of less than 100 F (38C). Some examples of common flammable liquids are listed at the end of this Tips Sheet.

All the electrical components in this type of refrigerator are outside the refrigerator, and the compressor is sealed or located at the top of the unit. Flammable material refrigerators also may incorporate design features such as thresholds, self-closing doors, magnetic door gaskets, and special inner shell materials that control or limit the damage should a reaction occur within the storage compartment. A label stating "Flammable Materials Refrigerator: Keep fire away" can identify such refrigerators. The refrigerators must be U.L. Listed as Flammable Material Storage Refrigerators. Ultra low freezers (less than -40F) generally cannot be approved for storage of flammable materials.

Explosion-proof refrigerators are designed to prevent ignition of flammable vapors or gases that may be present outside the refrigerator. This type of refrigerator must be used in locations such as solvent dispensing rooms, where a flammable atmosphere may develop at some time in the room. Explosion-proof refrigerators have very limited use on campus and require special hazardous-location wiring rather than simple cord-and-plug connections. Please contact the fire safety specialist at EH&S (206.616.5530) if you believe you have a need for an "explosion-proof" refrigerator.

If you are unsure what type of refrigerator you have in your laboratory or what type you should purchase, contact EH&S (206.616.5530).

Regardless of type, every laboratory refrigerator and freezer must be clearly labeled to indicate whether it is appropriate for the storage of flammable materials. If your laboratory refrigerator is unlabeled, it is probably a domestic refrigerator that needs the label below. Contact EH&S (email avanv@uw.edu) to request the following sticker:

Laboratory refrigerators should also be labeled "No Food" or "Food Only," depending on their use. Food should never be stored or consumed near chemicals. These stickers are also available from EH&S.

Work with your department to dispose of broken or unwanted refrigerators. All biological, radiological, and chemical hazards must be removed from the refrigerator. If the refrigerator was used to store radioactive isotopes, it should be cleaned and surveyed. Radiation Safety should be contacted to confirm that it is clean. Surplus Property and Salvage (206.685.1573, ext. 7) will pick up refrigerators if there are no visible hazards or hazardous labels. There is a recharge for recycling the refrigerator and the freon refrigerant. The freon refrigerant must be collected and removed because it is an EPA regulated environmental pollutant. There may be a recharge for collecting the Freon.

Flammable liquids may never be stored with strong oxidizers or acids, and compressed gases should not be stored in enclosed spaces like refrigerators.

For more information on using refrigerators and freezers for storing hazardous materials, contact EH&S (206.616.5530).


Common Laboratory Solvents

Do not store these flammable or any other liquids in domestic refrigerators. Flammable liquid has a flash point <100F/ 38C.

Chemical
Flash point (F)
Chemical
Flash point (F)
Acetone
4
Isopropanol
53
Acetonitrile
42
Methanol
54
Benzene
12.2
Petroleum Ether
20
Butanol
84
Propyl Alcohol
74
Cyclohexene
10
Pyridine
68
Dioxane
54
Tetrahydrofuran
6
Ethyl Acetate
24
Tetramethyl- ethylenediamine
50
Ethyl Alcohol
55
Toluene
40
Ethyl Ether
-49
Triethylamine
20
Hexane
-7
Xylene
84