The following are some code requirements
and recommendations that apply to many warehouse operations.
Smaller warehouses may not legally require them, automated
sprinkler should be considered as standard requirement in
Storage should be maintained at least 18 inches below sprinkler
In racked storage, transverse flue spaces of at least 3
inches should be maintained. Transverse flue space is the
space to either side of a racked pallet.
In racked storage, longitudinal flue spaces of at least
6 inches should be maintained. Longitudinal flue space is
the space between the rows of back-to-back rack. It is important
to note that the flue space is measured as the distance
between the loads, not the distance between the racks. In
a standard pallet rack configuration you will usually have
3 inches of pallet overhang, calculating this into the flue
space would require the rows of rack to be at least 12 inches
Most warehouses meeting the above flue space requirements
do not require in-rack sprinkler systems. Racking with solid
decking, storage configurations that prevent maintaining
the flue spaces, storage of high hazard materials, or storage
greater than 40 feet in height will probably require in-rack
Dead end aisles must not be more than 50 feet in length.
In solid piled floor storage there must be an aisle at least
every 100 feet and within 50 feet of walls when materials
are stored against the wall. Essentially this means that
any portion of the solid piled storage should be within
50 feet of an aisle.
During restocking operations using manual stocking methods
(using stock carts, rolling ladders, etc.) a minimum unobstructed
aisle width of 24 inches or ½ the aisle width, whichever
is greater, must be maintained.
During mechanical stocking operations a minimum unobstructed
aisle width of 44 inches must be maintained.
Automated material handling equipment such as carousels
and ASRS units will have additional code requirements to
prevent the equipment’s motion from spreading a fire.
Smoking is prohibited in warehouses and no smoking signs
Battery charging areas have specific code requirements including
ventilation, acid neutralization, eye wash stations, and
spill control systems.
Liquid Propane fuel cylinders used on LP forklifts should
not be stored within 20 feet of fire exits and are limited
to a maximum quantity of 300 lbs per storage location. This
is the equivalent of six 43 lb cylinders or nine 33lb cylinders.
Empty cylinders are considered full for this calculation.
If additional storage locations are required they must be
separated by a minimum of 300 feet.
Plastics. Plastic content is the single storage characteristic
most likely to contribute to a class IV or Class V high-hazard
commodity classification. The classification is based upon
the type of plastic and the overall content, measured by
percent by weight for unexpanded plastics and percent by
volume and weight for expanded plastics. This is where operational
changes such as changing packaging materials from paper
based to polystyrene or changing from wooden to plastic
pallets can have a substantial impact.
Aerosols. “Rocketing” is a term used to describe
the ability of aerosol containers to propel themselves across
a warehouse, carrying a trail of fire behind them. There
is a whole series of codes dedicated to the storage requirements
for aerosol products. Depending upon the chemical content
and the amount of aerosols stored (measured by weight),
separation areas, chain-link fence enclosures, fire walls,
and additional sprinkler protection may be required.
Hazardous Materials. Flammable liquids, solids, and gasses,
explosives, oxidizers, and reactive materials fall under
the category of Hazardous materials and have their own series
of codes that apply. You’re definitely going to need
some expert guidance when storing these types of materials.