Improper stacking and storage can result in injuries to workers and damage to costly materials. Make sure your material handlers stack up when it comes to safety.
Although OSHA does not provide much specific direction concerning safe stacking and storage, 29 CFR 1910.176(b) of the material handling standard does generally require secure workplace storage of materials. The regulation states: “Storage of material shall not create a hazard. Bags, containers, bundles, etc., stored in tiers shall be stacked, blocked, interlocked and limited in height so that they are stable and secure against sliding or collapse.”
General safe stacking and storage rules with which employees who handle materials should be familiar include:
- Ensure that stacks are stable and self-supporting.
- Observe height limitations when stacking materials.
- Allow sufficient clearance around stacks for safe handling and easy access.
- Make sure there is sufficient clearance between stacks and lights, heating pipes, and sprinkler heads.
- Make sure stacks don’t block emergency exits, emergency equipment, or fire alarms.
When stacking boxes, employees should:
- Place boxes on a pallet for stability and to make them easy to move.
- Interlock boxes to make a more stable stack.
- Band boxed materials or secure them with cross-ties or shrink wrap.
A good rule of thumb for ensuring a stable stack is to observe a height to base ratio that does not exceed 3:1 (or 4:1 at most if the stack is effectively interlocked and there is a good grip between the contacting surfaces).
When stacking bags, sacks, and baled and bundled materials, workers should:
- Stack bags and bundles in interlocking rows to keep them secure.
- Stack bagged material by stepping back the layers and cross-keying the bags at least every 10 layers.
- Store baled paper and rags inside a building no closer than 18 inches to the walls, partitions, or sprinkler heads.
When stacking pipes, poles, and bars, employees should:
- Not store pipes, poles, and bars in racks that face main aisles to avoid creating a hazard to passersby when removing supplies.
- Stack and block pipes and poles as well as structural steel, bar stock, and other cylindrical materials to prevent spreading or tilting unless they are in racks.
When stacking barrels and drums, workers should:
- Stack drums, barrels, and kegs symmetrically.
- Chock the bottom tiers of drums, barrels, and kegs to keep them from rolling if stored on their sides.
- Place planks, sheets of plywood dunnage, or pallets between each tier of drums, barrels, and kegs to make a firm, flat stacking surface when stacking on end.
When stacking lumber, employees should:
- Stack lumber no more than 16 feet high if it is handled manually, and no more than 20 feet if using a forklift.
- Remove all nails from used lumber before stacking.
- Stack and level lumber on solidly supported bracing.