The Significant Changes to the 2006 International Codes series has been developed by the International Code Council and published
by Thomson-Delmar Learning to accommodate the transition from the 2003 to the 2006 editions of the International Codes. To purchase books in the series, visit the Code Council website.
International Fire Code
SUBJECT: Definition for High-Hazard Group H-3
CHANGE TYPE: Clarification
202 General Definitions
High-Hazard Group H-3. Buildings and structures
that contain materials that readily support combustion
or present a physical hazard shall be classified
as Group H-3. Such materials shall include, but not
be limited to, the following:
Class I, II or IIIA flammable or combustible liquids
which are used or stored in normally
closed containers or systems pressurized
at less than 15 pounds per square inch
(103 kPa) gauge or less
Combustible fibers
Consumer fireworks, 1.4G (Class C Common)
Cryogenic fluids, oxidizing
Flammable solids
Organic peroxides, Classes II and III
Oxidizers, Class 3, that are used or stored in
normally closed containers or systems
pressurized at 15 pounds per square inch
gauge (103 kPa) or less
Oxidizers, Class 2
Oxidizing gases
Unstable (reactive) materials, Class 2
Water-reactive materials, Class 2
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CHANGE SIGNIFICANCE: In the 2003 edition, the International
Fire Code (IFC) was changed to place oxidizers
and flammable liquids at an equivalent level with respect
to occupancy classifications. All open-use conditions and
those storage and closed-use conditions involving vessels or systems pressurized
in excess of 15
psig were linked to
the H-2 occupancy
classification. Storage
and closed-use conditions in vessels
or systems having a
pressure less than 15
psig were linked to
the H-3 occupancy
classification. However,
neither the H-2
nor the H-3 provisions
addressed the
case of vessels or
systems with exactly
15 psig, presenting
an anomaly in the code. This was addressed by modifying
the H-3 definition to include the 15 psig case.
It should be noted that the provisions for storage and
closed use of Class 3 oxidizers at pressures not exceeding
15 psig were approved for publication in the 2003 IFC but were inadvertently omitted from early printings.
They were later added by errata and now appear in the
2006 edition. The text associated with this revision is
shown here in blue.
The original basis for the 15 psig threshold is American
National Standards Institute (ANSI) Standard B31.3,
Section 300.1.3, which excludes piping that operates
below that pressure and carrying certain nonhazardous
materials from having to comply with ANSI B31.3. Because
ANSI B31.3 uses 15 psig as a suitable breakpoint for application of that standard, that pressure was selected
as a basis for applicability of selected IFC hazardous
materials regulations, including the breakpoint
for H-2 versus H-3 occupancy classification for uses
containing sufficient quantities of flammable and combustible
liquids or oxidizers. |