Vertical stacking provides more surface area for combustion.
“Storage of Idle Pallets,” (December 2007). Retrieved from: federated.ca/files/pdfs/en_ca-LP-140StorageofIdlePallets.pdf.
“Storage of Combustible Pallets” (January 2016). Retrieved from: hanover.com/linec.
Joe Mlynek is president and safety and loss control consultant for Progressive Safety Services LLC, Gates Mills, OH; 216-403-9669; and content creation expert for Safety Made Simple, Olathe, KS.
A fire involving wooden pallets can spread quickly and cause structural failure in adjacent buildings or structures.
Most facilities store idle wooden pallets either inside or adjacent to buildings and structures.
Wooden pallets stored in protected areas, such as a storage building or under an overhang, quickly lose moisture.
As a wooden pallet dries, its edges tend to become frayed or splintered. This condition allows pallets to be ignited easily.
Proper Storage
When pallets are stored on edge or end, they create a vertical space that allows for rapid burning.
Vertical positioning provides the greatest amount of surface area for combustion. A fire occurring at the base of a pallet will spread upward as the rising gases pre-heat the thin slats above. This causes the fire to spread rapidly through the pallet pile.
Vertical positioning provides the greatest amount of surface area for combustion. A fire occurring at the base of a pallet will spread upward as the rising gases pre-heat the thin slats above. This causes the fire to spread rapidly through the pallet pile.
Flat stacking of pallets provides less surface area for combustion. When pallets are placed on top of another, the thin slats typically cover each other, reducing available surface area.
Due to the severe fire potential of wooden pallet storage, consider the following:
• Minimize the number of idle pallets located at a facility. Only store the amount needed.
• Store idle wooden pallets on the exterior of a building. The NFPA Uniform Fire Code provides general requirements for the storage of pallets outside. Among these requirements:
Pallet piles should be separated from other storage by at least 20 feet for piles of less than 50 pallets, 30 feet for piles of 50-200 pallets, and 50 feet for piles greater than 200 pallets.
Avoid stacking pallets on edge. Flat stacking is preferred.