Safety Knights

Flammable aerosols are not automatically considered flammable liquids unless they have a component that meets the criteria in 1910.1200 Appendix B. It all depends on the individual components of the mixture. Some may be flammable, others may not. Look at 1910.1200 App. B.3.2 Classification Criteria.

I think retail stores have their own requirements, but I'm not certain without looking it up.

Nonetheless, I've wondered the same myself. Great question.

Check out 29cfr1910.106(d)(5)(iv) and (d)(5)(v)

Retail stores are considered mercantile occupancies in the building codes. Depending on which code your AHJ enforces, the requirement will be something like 100 gallons of flammable liquids with flashpoints under 90F allowed. If the building is protected by a sprinkler system like the one in the photo, that is doubled to 200 gallons. If those aerosol cans are the only flammable in the place, then that means you could have about 2000 cans without any special requirements.

Now, if that's a hardware store they likely have a ton more flammable liquids, plus oxidizers and other stuff. Chances are it is not considered a mercantile occupancy, but a high hazard one. If this is the case then there are other considerations such as building materials (steel and masonry vs wood), additional egress, and fire barriers between connected buildings.

I am surprised these are not locked up. Most stores in California lock all spray paint cans to deter shoplifting.

Here is a link to the International Fire Code as it relates to the storage of aerosols.
https://codes.iccsafe.org/content/IFC2021P2/chapter-51-aerosols