In a three-part blog series over the last few months, we’ve been exploring the many fire hazards commonly present in warehouses beyond the obvious presence of high combustible loading from rack and palletized storage arrays. In case you missed it, in Part 1 of our Warehouse Fire Hazards blog series, we took a look at High Intensity Discharge Lighting. In Part 2, we reviewed idle pallets and the significant hazard they pose in warehouses. Now, in Part 3, we’ll take a look at the unique hazards and challenges found in refrigerated warehouses.

To begin, let’s review the four classes of cold storage found in refrigerated warehouses:

  1. Coolers (32° to 65°F) for the storage of foods such as apples, eggs, or nuts;
  2. Chill rooms (16° to 35°F) for curing meat;
  3. Freezers or holding rooms (-10° to 5°F) for storage of frozen foods (such as meats, poultry, fish or vegetables); and
  4. Sharp freezers (-35° to 0°F) for initial freezing (also used for normal storage of frozen foods).

Cold Storage Warehouses have all the typical hazards found in any warehouse, along with some unique hazards and fire protection challenges that must be overcome.

Unique Hazards in Cold Storage Warehouses

Insulated Metal Panels (IMP’s)

The need to efficiently maintain proper temperatures in cold storage facilities proves to be a challenge that is often overcome by adding insulation to the walls and ceiling of the building, but keep in mind, exposed sprayed-on plastic foam insulation should be avoided to reduce the potential for rapid spread of fire across the walls or ceiling.

One option to consider is to utilize Insulated Metal Panels (IMP’s). Note – IMPs may have core insulation material that is combustible, increasing the fire loading in the building. When choosing IMP’s, opt for those with a noncombustible core (ex: mineral wool), or ones that are FM approved (Class 1) under FM Approval Standard 4880.

FM Global provides guidance on protecting plastic foam insulation (typically expanded polyurethane (PU), Polyisocyanurate (PIR), or polystyrene (EPS) insulations) in Data Sheet 1-57, Plastic Building Materials in Construction. When EPS material is found in the walls or ceiling, it should be replaced or covered with a thermal barrier per FM Data Sheet 1-57.


Ammonia is often the refrigerant of choice for cold storage warehouses. Guidance on mechanical refrigeration systems is provided in FM Global Data Sheet 7-13, Mechanical Refrigeration and the ANSI Standard 15, Safety Code for Mechanical Refrigeration.

Anhydrous Ammonia is a flammable gas, and therefore presents the potential for explosions and fire.

Ammonia is also listed as a hazardous chemical and therefore falls under OSHA Process Safety Management Guidelines for Ammonia Refrigeration for systems containing more than 10,000 pounds of refrigerant. Information on the OSHA PSM requirements can be found at the following links:

In regards to ammonia, also note that ammonia leakage can result in significant contamination of raw materials and finished goods. To reduce extent of contamination, cold storage warehouses should be compartmentalized and equipped with ammonia detection anywhere there is the potential for an ammonia leak.

Those are just two unique fire hazards found in cold storage warehouses, but we’re not done yet. Next week, Part 2 of this blog will review a few more unique challenges, as well as a couple loss examples that illustrate just how serious fire hazards in cold storage warehouses can be.