Class I liquids shall not be kept inside of buildings except in sealed containers and approved safety cans of not more than one gallon capacity each, provided that, in rooms conforming herein in this chapter described, safety cans up to ten (10) gallons in size may be used, and in garages and manufacturing plants, the clerk may permit the use of approved portable wheeled tanks where the nature of the business requires such storage. Systems with arrangements for discharging class I liquids inside of buildings shall have discharge outlets located only in rooms conforming to this chapter. (1961 Code)