• OSHA does not regulate specific heights for stacking materials, although 1910.176(b) notes that storage of material shall not create a hazard.
• OSHA does specify a clearance of 18 inches between materials and any fire sprinklers. Local fire codes may have additional requirements.

The Occupational Safety and Health Administration (OSHA) does not have a specific regulation on height of materials to be stacked. In terms of general hazards from material storage, OSHA simply says that:

• 1910.176(b) — Secure storage. 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.

OSHA does have a requirement in 1910.159(c)(10) regarding sprinkler clearance when stacking items: “The minimum vertical clearance between sprinklers and material below shall be 18 inches (45.7 cm).” Under the above, OSHA leaves it to the employer to determine a correct height based on a hazard assessment of the storage materials/arrangement.

Local fire codes may also have requirements based on type of sprinklers and materials being stored. For example, large stacks of empty pallets create the potential for fast-developing fire and intense heat released from the pallet stack; therefore, some fire codes address that issue.