Whether you own a local grocery store or are shipping goods across the country between large warehouses, you will usually come across shipping pallets of some form. Pallets are made of either wood or plastic, and they are used to easily transport stored goods using forklifts. Due to the convenience of pallets, they are also used in large quantities. After all, they are needed to efficiently utilize space and quickly transport goods. However, the physical properties of these pallets also present a major fire hazard. Firstly, they are made of highly combustible materials, and the spaces between pallets allow for high airflow. Given that pallets are stacked into piles, this creates the ideal conditions for a fire to grow out of control. Thus, your business should take the number of pallets you will use into account before choosing your fire suppression measures. In this article, we will go into more detail about the risks of pallet storage, and how to manage your fire risk.
Idle pallets are defined in NFPA 1 and NFPA 13 as pallets that are not in use, and are stored in stacked piles. These codes apply to storage configurations including palletized storage, solid-piled storage, and storage in bin boxes, on shelves, or on racks. Pallets are usually made out of wood or plastic. In the US, we commonly find two different types of hardwood pallets—oak and pine. In contrast, plastic pallets are made from high density polyethylene (HDPE) or polypropylene (PP). However, these are not all-inclusive, since different countries and industries will have their own materials, sizes, and design standards for pallets.
According to an assessment by FM Global on property loss, 91% of losses involved wood pallet storage, while the remaining 9% involved plastic pallets. Also, 57% of the indoor fires reported sprinkler protection was effective, with the remaining reported as ineffective in reducing the extent of the loss. For this reason, it is preferred to store pallets outdoors and away from other structures and storage, in accordance with NFPA guidelines.
Pallets are extremely dangerous from a fire prevention standpoint, since they increase your combustible load, release large amounts of heat, and can easily spread flames to other locations. When wooden pallets are dry or damaged, this risk is increased even further. Pallets that are dry and frayed can ignite and spread flames more easily. Additionally, upper pallets can shield the lower ones, which makes suppression even more difficult when coupled with the large amount of energy the pile can release. Accordingly, many fire suppression systems are drastically undersized because they do not take pallet storage into account.
Important factors in your storage arrangement are the height of pallet piles, the number of pallets in each pile, pallet geometry, and the height of your ceiling. Although the chance of a fire starting in rack-stored pallets is lower than in floor storage, the speed at which the flames spread will be much quicker. Especially since the rack assembly may fail when exposed to the high thermal energy of a pallet fire. This can cause the fire to spread further. The same danger extends to pallets that are stored indoors. Due to the high thermal energy, indoor steel structures can rapidly fail, leading to the collapse of a building, and spreading the fire further. For this reason, it is always recommended to have fireproofing on your steel structures, to reduce risk as much as possible in warehouse locations. Lastly, pallet piles can generate a large amount of smoke, which can make a fire even more deadly to occupants.
Read More: What Is Passive Fire Protection?
According to the NFPA, there are several things we can do to limit our fire risk and increase the effectiveness of fire suppression. For instance, we should never use solid-self racks to store idle pallets, since that would make fire suppression too difficult. In addition, you should always store idle pallets in stable piles, and make sure to remove any damaged pallets. This decreases the surface area for fire to spread, since the thin slats will cover each other. Moreover, pallets should not be stored vertically, as this creates a vertical flue space for oxygen to reach the fire. The optimal configuration for pallets is in flat stacks, and away from other combustible materials. As always, you should also never obstruct paths of egress with pallets either.
The NFPA gives more guidelines on the specifics of pallet storage configurations. If you have less than 50 pallets, piles should be separated from other storage by at least 20 feet. For 50-200 pallets, the minimum distance is increased to 30 feet. Finally, when the number of pallets exceeds 200, the minimum distance is 50 feet. To add, all idle pallet stacks must not exceed 15 feet in height and 400 square feet in area. Lastly, all idle pallet stacks should have 8 feet of space between stacks, and they must be positioned at least 8 feet away from any property line. By locating your stacks outside and separating them from other buildings or storage, you decrease the likelihood of a pallet fire spreading to other areas. As a downside, outdoor pallets can be susceptible to theft or environmental damage.
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The Occupational Safety and Health Administration (OSHA) also gives limitations and guidelines to the storage of idle pallets. OSHA 1910.176(b) states that and cargo, pallets and other material stored in tiers should be stacked in such as manner as to provide stability against sliding and collapse. We can infer that pallet piles must be stacked and limited in height so they are stable and do not create an additional hazard. As such, you should remember not to stack mixed sizes of pallets, keep them at a safe height, and not reuse damaged pallets. While there is not specific OSHA standard that sets limits on the height of your stack, it is recommended that your stack is at least 3 feet away from ceiling level sprinklers and 6 inches away from in-rack sprinklers.
High Expansion Foam Systems, Early Suppression Fast Response, Control Mode Density Area, and Control Mode Specific Application sprinklers are recommended for idle pallet storage. (Make sure the specifications on the related sprinklers match the requirements of the NFPA as well K-factor, etc.).
While pallets are essential for efficient storage and transport, they also post significant fire risks if not stored properly. The highly combustible materials, like wood and plastic, along with the way pallets are stacked, can create an environment where a fire can quickly spread and become difficult to control. Both NFPA and OSHA have clear guidelines for pallet storage to help mitigate these risks, including recommendations on proper stacking height, spacing between pallets, and fire suppression systems. By adhering to these standards and maintaining good fire prevention practices, you can significantly reduce the risk of fire in your storage areas. Likewise, choose a sprinkler system that will adequately protect the number of pallets you wish to have.
Ultimately, a proactive approach to fire safety—incorporating proper system design, regular maintenance, and staff training—is essential to minimize the risk of fire and ensure that your facility is prepared for emergencies. By adhering to fire safety codes and regulations, you create a safer, more resilient environment for staff. At FireAlarm.com, our expert team is ready to assist you with system design, installation, inspection, and maintenance services tailored to your needs. Reach out to us today to discuss how we can get your business compliant with the codes.
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