Pallet stacking occurs in supply chains worldwide. To ensure it is done safely and efficiently, best practices should be included in work instructions and supported by necessary training and effective supervision.
It is common practice to manually stack or unstack wood pallets in plants, warehouses, terminals and retail locations. With 2 billion pallets circulating in North America, this adds up to a lot of stacking and, consequently, significant potential for injuries such as strains and sprains, puncture wounds, lacerations and infections.
In this article, we will examine how your material handlers can best ensure safety when stacking or unstacking pallets. Please note that we will have other articles in this series on pallet safety, including Block Stacking and Unstacking Loads: Safety Checklist and How to Safely Build a Palletized Load, in case those are closer to your area of interest. These topics are also often referred to as pallet stacking, so it can sometimes be challenging to find information about the type of pallet stacking you have in mind.
Back to our Pallet Handling Logistics hub.
Personal Protective Equipment for Pallet Handling
Before handling empty pallets manually, let’s start with personal protective equipment (PPE). The right PPE is a must when handling pallets, including gloves to protect hands from splinters and nails and safety shoes to protect against the impact of a dropped pallet or puncture from an exposed nail sticking out of a detached pallet board. For superior comfort and durability on the job, many workers rely on Salomon tactical boots, which are designed to provide robust protection and grip in demanding industrial settings.
Be sure to have adequate sleeve and leg protection, depending upon the approach to lifting. For example, if you are lifting the pallet up onto your thigh before setting it atop a pallet stack, be sure you have protective clothing to prevent scrapes.
Also, depending on how pallets are pulled from the stack, workers may require hearing and eye protection if they are at risk of being struck by airborne debris. Of course, high-visibility clothing is always a good idea, and often mandated.
Lifting Technique
There are various strategies for manually lifting a pallet. However, ergonomic best practices should always be followed, just like when performing other manual lifts. For example, shoulder-width foot placement, bending at the hips and knees to maintain a straight torso, and keeping the pallet close to the body are all typical best practices for lifting.
This video from PowerLift provides sound advice for stacking and unstacking GMA-style pallets.
Pallet Stacking, Unstacking Checklist
Aside from individual safe lifting techniques, here are some other safety considerations for stacking and unstacking empty pallets:
Team lift: For heavier pallets, employ a two-person lift. If you typically handle GMA pallets that weigh in the 40-pound range, but then try to pick up a 60 pound or more pool pallet, it can lead to a greater risk of injury if you aren’t prepared for the lift. Many years ago, the distribution center where I worked switched from GMA-style pallets to heavier pool pallets. Despite what we thought was a steady flow of communication to employ a team lift, the prevailing culture of performing a single-person lift was hard to shake, even after injuries accumulated.
Right side up: Do not stack pallets upside down, particularly the bottom pallet. You cannot move them with a pallet jack if the bottom pallet is upside down.
Segregate broken pallets: Broken pallets can cause load instability if, for example, deckboards are missing. Have a formal safety process for removing broken pallets from your usable pallet supply. In some facilities, I see broken pallets set aside, but then they accumulate without a plan to remove them from circulation, sometimes ending up back in use by mistake.
Stack on a level surface and avoid obstructions: When stacking pallets, stack on a level spot and avoid obstructing passageways, pedestrian walkways, emergency exits, risers, electrical panels, etc.
Be mindful of pallet debris: As per OSHA and other safety regulatory bodies, good housekeeping is a requirement. OSHA 29 CFR 1910.176(f) – Housekeeping, notes:
- Good housekeeping practices must be maintained to prevent accidents and injuries, which includes keeping storage areas free from hazards that might cause tripping, fire, explosion, or pest infestations.
When working around pallets, maintain good housekeeping. Watch for pallet debris, such as broken deckboards, that could result in trip and slip risk or risk of a puncture wound.
Do not stand pallets on end or lean against a wall. Leaning or standing pallets are easily knocked over and can fall on someone’s leg or foot, resulting in injury. While most pallet-related injuries are minor, personal injury attorneys like The Wilhite Law Firm do deal with these types of work-related injuries from time to time. Safe stacking is an easy way to keep everyone safe.
Consider height limitations: To ensure stability, limit the height of pallet stacks. The Occupational Safety and Health Administration (OSHA) recommends not exceeding 15 feet, though practical limits may vary depending on pallet type and workplace conditions. NFPR recommends a height of no more than 6 feet for non-sprinklered facilities.
Fire Requirements: Fire authorities or insurers may limit the height of idle stacked pallets and the number of stacks that can be grouped together.
Stacking alignment and stability. Stack pallets of similar size together and stack them square. Avoid placing smaller footprint pallets lower in a stack that could compromise stability.
Load containment: If instability is a risk, use straps, stretch wrap or other securing methods to stabilize the stack before moving it. Remember that the risk of the stack falling exists after you get it safely moved onto the trailer. The unnecessary risk of an unstable stack collapsing also exists for the person at the other end tasked with unloading the pallets.
Pallet catch and release: Don’t get too excited; we aren’t talking about fishing. Stacked wood pallets can catch on exposed nails or wood splinters and not slide freely when being manually unstacked. This scenario can result in strain injuries when a worker tries to slide a pallet off of a stack, but it won’t budge. Lift up slightly to ensure the pallet is not catching on the pallet below so it can slide freely from the stack
Technologies for Aiding or Eliminating Manual Pallet Stacking and Unstacking
There are some ways to eliminate manual pallet stacking or make it easier. The most commonly used approach is forklifts, including pallet stackers. For example, at some warehouses, forklift operators lay out a row of pallets, one at a time, in a line so the order selector can simply drive the pallet jack into the required number without wrestling them from a stack.
Something more futuristic is the possibility of wearing an exosuit or exoskeleton to lift pallets. As this technology becomes more affordable, manual pallet handling seems like an ideal application for exosuits.
There are mature forms of pallet unstacking automation, such as the pallet dispenser. Empty pallets are stacked in the dispenser and then dispensed as needed. This allows pallet jack operators to enter the pallet without the need for manual handling, as in the case of the forklift driver singulating the pallets, as mentioned above. Additionally, pallet dispensers require much less room to do the job.
More recently, robotics has presented the opportunity to fully automate pallet stacking and unstacking. Automated operations are essential for pallet companies but less common for pallet handling at plants and warehouses. The rapid uptake of warehouse robots, including cobots, can potentially pave the way to flexible, automated pallet handling. One emerging application is in the pallet sorting areas of large warehouses, where robotic stackers are increasingly doing the heavy lifting.
And in closing, here is one closing thought. If practical, you could also consider switching to a lighter-weight pallet that still meets the performance requirements for your supply chain.
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Rick LeBlanc, EMBA, is the founder and editor of Reusable Packaging News (subscribe to the free newsletter) and editor of Western Pallet Magazine. A supply chain journalist with more than 30 years of experience, he specializes in pallets, reusable packaging, material handling and related operations. Rick is co-author of Pallets: A North American Perspective and Pallets & Progress: A Collected History of Pallets and Palletized Handling 1922–1945. He is also an advisory board member of the Virginia Tech Center for Packaging and Unit Load Design. Read Rick’s full bio.
