The Importance of Commodity Classification for High-Piled Storage Occupancies –

Class III Commodities

By John Swanson

Many communities are seeing an increase in the number of warehouses built in their jurisdiction. Often, these warehouses are used for high-piled storage. Many of us have experienced and come to appreciate the ability to order something online and receive it the next day or maybe even the same day. The need for businesses to store products and materials near urban and suburban areas, so they can be accessed quickly for shipping, is a necessity for businesses to survive and thrive in today’s economy. Therefore, the need for warehouse space to store their materials will likely increase.

Commodity classifications are used in Chapter 32 of the International Fire Code (IFC) and Chapter 20 of NFPA 13, Standard for the Installation of Sprinkler Systems, to identify materials in storage occupancies to determine the appropriate fire protection requirements. The square footage of the high-piled storage area, along with the commodity classification, are used to determine when sprinklers are required and the overall design of the sprinkler system.

This blog will address some of the misconceptions about high-piled storage and how to determine when additional fire protection requirements apply. Over the next few weeks, this blog series will review the different commodity classifications; Class I – IV, high-hazard and Group A plastics, from the IFC and NFPA 13.

What is High-Piled Combustible Storage?

The IFC defines high-piled storage as, “storage of combustible materials in closely packed piles or combustible materials on pallets, in racks, or on shelves where the top of storage is greater than 12 feet in height. Where required by the fire code official, high-piled combustible storage also includes certain high-hazard commodities…where the top of storage is greater than 6 feet in height”. The term “combustible” in high-piled combustible storage can be misleading, as high-piled storage does include non-combustible materials. It’s important to note that simply because a product is noncombustible does not exempt the building or storage arrangement from additional fire protection requirements.

NFPA 13 contains the same requirements for Class I-IV commodities. However, it’s important to point out that NFPA 13 applies the same storage criteria to Group A plastics high hazard commodities, when stored over 5 feet in height.  Some wonder if this is a conflict between the codes and standard. However, it’s important to understand the overall goals and objectives of each document. The codes define when certain fire protection features are required, while the standards define how a fire protection system is installed. In other words, the IFC, based on the definition above, determines when Chapter 32 applies. NFPA 13 determines how the sprinkler system, when required by the IFC, must be designed to properly protect the materials being stored.

Class III Commodities

Section 3203.4 in the 2021 IFC says, Class III commodities are products of wood, paper, natural fiber cloth, or Group C plastics or products thereof, with or without wood pallets. NFPA 13 goes on to say that Class III commodities are fashioned from wood, paper, natural fibers, or Group C plastics with or without cartons, boxes, or crates and with or without pallets. Class III commodities are permitted to contain a limited amount (5% or less by volume) of expanded plastic of Group A or Group B plastics.

Example of Class III Commodities

It’s important to remember that when determining the commodity classification, the model codes and NFPA 13 take the product, the packaging, and the type of pallets used to determine the overall commodity classification. All three must be taken into consideration to accurately determine the commodity classification based on the IFC and NFPA 13.

Accurately determining the commodity classification is critical in determining the applicable fire protection requirements and sprinkler design. Assigning a commodity classification that does not adequately consider the product, the packaging and the type of pallet used, can have devastating consequences from a fire protection perspective.

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More about the author

John Swanson currently serves as NFSA’s Codes and Standards Specialist. In this role he provides training and education and represents NFSA on codes and standards technical committees. He currently serves as a Principal member of the NFPA 72 – National Fire Alarm and Signaling Code Technical Committee and is a member of the International Building Code (IBC) Fire Safety Committee and past member of the International Fire Code (IFC) Interpretation Committee. From 2013-2017, John served as a fire service representative to the Minnesota Board of Architecture and Engineering.