Aerosol products combine a flammable liquid base, a flammable propellant, and a sealed pressure vessel in a package designed to be stacked by the thousand. Heated in a fire, the container pressurizes until it fails, and when it fails it does not simply burst. It vents directionally and propels itself, frequently across substantial distance, carrying burning product with it. This is why NFPA 30B exists as a separate code and why aerosol storage carries some of the highest sprinkler density requirements in NFPA 13.
Rocketing is what makes the hazard categorically different from ordinary commodity storage. A conventional warehouse fire spreads by radiation and convection along predictable paths, which is what sprinkler design accounts for. Rocketing containers spread fire ballistically: past aisle separations, over fire walls, through openings, and into areas the protection scheme treated as separate. A fire that would have stayed in one rack section establishes simultaneous ignition points across the building.
NFPA 30B manages this through classification. Aerosols are assigned Level 1, 2, or 3 based on the chemical heat of combustion of their contents, and the level drives permitted quantity, storage arrangement, separation, and required protection. Level 3 aerosols in palletized or rack storage generally require in-rack sprinklers in addition to a high-density ceiling system, because ceiling-only protection cannot deliver water into the pile fast enough to prevent the container failures that start the ballistic spread.