Hazards of Chemicals and Gases
FLAMMABLE AND COMBUSTIBLE LIQUIDS
14 F rise in temperature. Outage space for gasoline of two percent of the capacity of the tank
or compartment is recommended, and permanent high-level markings should be installed.
Storage tanks should be provided with vents. Vent pipes of underground tanks storing Class I
flammable liquids should terminate outside buildings, higher than the fill pipe opening, and not
less than 12 feet above the adjacent ground level. They should discharge vertically upward, and
be located so that flammable vapors cannot enter building openings or be trapped under eaves
or other obstructions. Vent pipes from underground tanks storing Class II or Class III liquids
should terminate outside buildings and higher than the fill pipe opening. Vent outlets should be
above normal snow level.
Additional information concerning installation, protection, and spacing of storage tanks located
above ground, underground, or in areas subject to flooding is beyond the scope of this course.
If this information is desired, it may be found in the National Fire Protection Association
Flammable or combustible liquids in sealed containers represent a potential hazard rather than
an active hazard -- the possibility of fire from without. By the same reasoning, inside storage
rooms are undesirable. If they must be used, they should be isolated as much as possible, and
located at or above ground level. They should not be located over basements and should
preferably be along an exterior wall.
Every inside storage room shall be provided with either a gravity (low level intake) or a
continuous mechanical exhaust ventilation system. Mechanical ventilation must be used if
Class I liquids are contained or dispensed inside the room.
Storage cabinets have specific limits on the amount and class of flammable or combustible liquids
that may be stored in them. They must be constructed and sealed so as to be fire resistant.
Cabinets shall be labeled conspicuously -- FLAMMABLE-KEEP FIRE AWAY.
The most advisable storage facility is a separate building set some distance from normally
occupied plant areas. The construction can be similar to that specified for inside storage rooms.
The types and classes of flammable and combustible liquids stored will determine the best design
to be used.