I don’t believe that propane cylinders would fall under the requirements of Subsection 4.2.4 for Assembly or Residential Occupancies as propane is a liquefied gas under pressure. Therefore propane does not fall under the definition of Flammable Liquid (within the defined terms of Sentence 188.8.131.52.(1) of Division A) or the Scope of Subsection 4.1.1 of Division B.
My apologies if my references are slightly off as I’m referencing the National Fire Code of Canada.
I don’ have a copy available to me at the moment, but I would check CSA B149.1 – Natural Gas & Propane Code.