29 CFR 1910.176
This short OSHA standard sets forth general requirements for material handling and storage. If mechanical handling equipment is used such as forklifts, the aisles and passageways must be kept clear enough to allow the equipment to maneuver. This standard, similar to the housekeeping standard, also requires that aisles and passageways be kept clear and in good repair to prevent accumulation of anything that might cause a hazard. It also requires permanent aisles to be marked.
If material is being stored, it should be stored in such a way that it is not a hazard. This means that anything stored in tiers such as bags, containers, and bundles should be stacked, blocked, interlocked and limited in height to be certain they are stable and secure against sliding and collapse.
All areas should be kept free from accumulation of materials which might cause trip or fire hazards. Packing material (dunnage), packing straps, pallets and other loose waste should be promptly cleaned up.
If there are areas with low ceilings, then clearance limits must be posted to notify of the restricted access; otherwise, forklifts with raised loads might impact the low ceilings causing damage and possible injury.
If railroad cars are loaded or unloaded, then derail and/or bumper blocks should be used to protect against a rolling car entering a building, work or traffic area and against a rolling car contacting a car being worked in.