We have discussed the Maximum Allowable Quantity (MAQ) extensively over the years, but a lot of facilities just can’t stay within the confines of a MAQ so what are they to do? Well, it an easy answer but it is not so easy to meet! In this article, I will explain the four (4) H occupancies and what it means to have an H occupancy – focusing on H-2 and H-3, as these are the most common ones my clients deal with. So let’s begin with defining the four (4) H occupancies…
High-hazard Group H-2
Buildings and structures containing materials that pose a DEFLAGRATION HAZARD or a hazard from ACCELERATED BURNING shall be classified as Group H-2.
Such materials shall include, but not be limited to, the following:
- Class I, II, or IIIA flammable or combustible liquids that are used or stored in
- NORMALLY OPEN containers or systems; OR
- CLOSED containers or systems pressurized at MORE THAN 15 psig
- Combustible dust where manufactured, generated, or used in such a manner that the concentration and conditions create a fire or explosion hazard
- Cryogenic fluids, flammable
- Flammable gases
- Organic peroxides, Class I
- Oxidizers, Class 3, that are used or stored in
- NORMALLY OPEN containers or systems; OR
- CLOSED containers or systems pressurized at MORE THAN 15 psig
- Pyrophoric liquids, solids, and gases, non-detonable
- Unstable (reactive) materials, Class 3, non-detonable
- Water-reactive materials, Class 3
High-hazard Group H-3
Buildings and structures containing materials that readily support combustion or that pose 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 that are used or stored in NORMALLY CLOSED containers or systems pressurized at 15 psig OR LESS
- Combustible fibers, other than densely packed baled cotton, where manufactured, generated or used in such a manner that the concentration and conditions create a FIRE OR EXPLOSION HAZARD
- Consumer fireworks, 1.4G (Class C, Common)
- Cryogenic fluids, oxidizing
- Flammable solids
- Organic peroxides, Class II and III
- Oxidizers, Class 2
- Oxidizers, Class 3, that are used or stored in normally closed containers or systems pressurized at 15 psig or less
- Oxidizing gases
- Unstable (reactive) materials, Class 2
- Water-reactive materials, Class 2
High-hazard Group H-4
Buildings and structures containing materials that are HEALTH HAZARDS shall be classified as Group H-4.
Such materials shall include, but not be limited to, the following:
- Corrosives
- Highly toxic materials
- Toxic materials
High-hazard Group H-5
Semiconductor fabrication facilities and comparable research and development areas in which HAZARDOUS PRODUCTION MATERIALS (HPM) are used and the aggregate quantity of materials is in excess of those listed in Tables 307.1(1) and 307.1(2) shall be classified as Group H-5.
Such facilities and areas shall be designed and constructed in accordance with Section 415.11.
So once we have determined which H Group our area should meet we then begin looking at the Building Code requirements for the area. Buildings and structures with an occupancy in Group H shall comply with the applicable provisions of Section 414 and the International Fire Code.
Group H occupancies shall be provided with:
- AUTOMATIC FIRE DETECTION SYSTEM in accordance with Section 907.2
- AUTOMATIC SPRINKLER SYSTEM in accordance with Section 903.2.5
- EMERGENCY ALARMS for the detection and notification of an emergency condition
- An approved manual emergency alarm system shall be provided in buildings, rooms, or areas used for the storage of hazardous materials.
- Emergency alarm-initiating devices shall be installed outside of EACH INTERIOR EXIT OR EXIT ACCESS DOOR of storage buildings, rooms, or areas.
- Activation of an emergency alarm-initiating device shall SOUND A LOCAL ALARM TO ALERT OCCUPANTS OF AN EMERGENCY SITUATION involving hazardous materials.
- An approved manual emergency alarm system shall be provided in buildings, rooms, or areas used for the storage of hazardous materials.
Dispensing, use, and handling
Where hazardous materials having a hazard ranking of 3 or 4 in accordance with NFPA 704 are TRANSPORTED THROUGH CORRIDORS, INTERIOR EXIT STAIRWAYS OR RAMPS, OR EXIT PASSAGEWAYS, there shall be an:
- emergency telephone system,
- a local manual alarm station, OR
- an approved alarm-initiating device at not more than 150-foot (45 720 mm) intervals and at each exit and exit access doorway throughout the transport route.
- The signal shall be RELAYED TO AN APPROVED CENTRAL, PROPRIETARY, OR REMOTE STATION service or constantly attended on-site location and shall initiate a local audible alarm.
- Emergency alarm systems shall be electrically supervised and monitored by an approved central, proprietary, or remote station service or shall initiate an audible and visual signal at a constantly attended on-site location.
- Emergency alarm systems shall be provided with EMERGENCY OR STANDBY POWER in accordance with Section 2702.2.
Fire separation distance
In Groups H-2 and H-3, NOT LESS THAN 25% of the perimeter wall of the occupancy shall be an EXTERIOR WALL.
Exceptions:
1. Liquid use, dispensing and mixing rooms having a floor area of not more than 500 square feet (46.5 m2) need not be located on the outer perimeter of the building where they are in accordance with the International Fire Code and NFPA 30.
2. Liquid storage rooms having a floor area of not more than 1,000 square feet (93 m2) need not be located on the outer perimeter where they are in accordance with the International Fire Code and NFPA 30.
3. Spray paint booths that comply with the International Fire Code need not be located on the outer perimeter.
Group H occupancy minimum fire separation distance
Regardless of any other provisions, buildings containing Group H occupancies shall be SET BACK TO THE MINIMUM FIRE SEPARATION DISTANCE as set forth in Sections 415.6.1.1 through 415.6.1.4.
Distances shall be measured from the WALLS ENCLOSING THE OCCUPANCY TO LOT LINES, including those on a public way.
Distances to assumed lot lines established for the purpose of determining exterior wall and opening protection are not to be used to establish the minimum fire separation distance for buildings on sites where explosives are manufactured or used where separation is provided in accordance with the quantity distance tables specified for explosive materials in the International Fire Code.
- Group H-1 occupancies shall be set back not less than 75 feet and not less than required by the International Fire Code.
- Group H-2 occupancies shall be set back not less than 30 feet where the area of the occupancy is greater than 1,000 square feetand it is not required to be located in a detached building.
- Group H-2 and H-3 occupancies shall be set back not less than 50 feet where a DETACHED BUILDING IS REQUIRED (see Table 415.6.2).
Group H-2 and H-3 occupancies containing materials with explosive characteristics shall be separated as required by the International Fire Code. Where separations are not specified, the distances required shall be determined by a technical report issued in accordance with Section 414.1.3.
Detached buildings for Group H-1, H-2, or H-3 occupancy
The storage or use of hazardous materials in excess of those amounts listed in Table 415.6.2 shall be in accordance with the applicable provisions of Sections 415.7 and 415.8.
Where a detached building is required by Table 415.6.2, wall and opening protection based on fire separation distance is NOT required.
Special provisions for Group H-2 and H-3 occupancies
Group H-2 and H-3 occupancies containing quantities of hazardous materials in excess of those set forth in Table 415.6.2 shall be in detached buildings used for manufacturing, processing, dispensing, use or storage of hazardous materials.
Materials listed for Group H-1 occupancies in Section 307.3 are permitted to be located within Group H-2 or H-3 detached buildings provided that the amount of materials per control area do NOT EXCEED THE MAXIMUM ALLOWED QUANTITY specified in Table 307.1(1).
Group H-2 or H-3 occupancies containing materials that are in themselves BOTH PHYSICAL AND HEALTH HAZARDS in quantities exceeding the maximum allowable quantities per control area in Table 307.1(2) shall comply with requirements for Group H-2, H-3, or H-4 occupancies as applicable.
Hazardous materials other than those listed in Table 415.6.2 shall be allowed in manufacturing, processing, dispensing, use, or storage areas when separated from incompatible materials in accordance with the provisions of the International Fire Code.