The storage place shall be located where contents of leaking containers cannot run over the surface to any point within 100 feet of the above-mentioned places and structures.
NOTE: Certain petroleum gases, such as butane and propane, are compressed to liquid form in pressure tanks. When a tank containing liquefied petroleum gases leaks or is ruptured, the contents vaporize in the atmosphere. These vapors are heavier than air and will flow downhill over the surface of the ground much like water until the vapors are diffused. For this reason tanks containing liquefied petroleum gases must be stored at locations which are in compliance with the provisions of this section.
Cal. Code Regs. Tit. 8, § 7064