5705.3.7 Rooms or buildings for quantities exceeding the maximum allowable quantity per control area.
Where required by Section 5705.3.5.3 or 5705.3.6.1, rooms or buildings used for the use, dispensing, or mixing of flammable and combustible liquids in quantities exceeding the maximum allowable quantity per control area shall be in accordance with Sections 5705.3.7.1 through 5705.3.7.6.3.
5705.3.7.1 Construction, location and fire protection.
Rooms or buildings classified in accordance with the International Building Code as Group H-2 or H-3 occupancies based on use, dispensing or mixing of flammable or combustible liquids shall be constructed in accordance with the International Building Code.
Group H-2 occupancy is the classification for a facility that uses or stores Class I, II or III liquids in open containers and systems, or in closed containers or systems under a pressure greater than 15 psig (103 kPa).
Group H-3 occupancy is the classification for a facility that uses or stores Class I, II or III liquids in closed containers or systems under a pressure of 15 psig (103 kPa) or less.
IBC Sections 414 and 415 give guidance for determining the construction requirements for these two occupancies.
5705.3.7.2 Basements.
In rooms or buildings classified in accordance with the International Building Code as Group H-2 or H-3, dispensing or mixing of flammable or combustible liquids shall not be conducted in basements.
The mixing and dispensing of flammable and combustible liquids in a basement could develop into a hazardous condition.
These operations are prohibited in a basement of a Group H-2 or H-3 occupancy.
5705.3.7.3 Fire protection.
Rooms or buildings classified in accordance with the International Building Code as Group H-2 or H-3 occupancies shall be equipped with an approved automatic fire-extinguishing system in accordance with Chapter 9.
New Group H-2 and H-3 occupancies must have an automatic sprinkler system according to Section 903.2.5.1 of the code. Any building that can be classified as a Group H-2 or H-3 occupancy that is not equipped with an automatic sprinkler system is in violation of the code.
5705.3.7.4 Doors.
Interior doors to rooms or portions of such buildings shall be self-closing fire doors in accordance with the International Building Code.
Interior fire-resistance-rated wall construction used to separate or isolate portions of a building must have fire-resistance-rated doors in the openings in the wall. A fire-resistance-rated interior door consists of the door, door frame, latches, locks,
hinges, closers, and any other hardware that is necessary for the door to function. The door is to be self-closing to ensure
that the door is not open during a fire. IBC Section 716 contains the criteria for the fire-resistance-rated door. Any obstruction
to the operation of or damage to this door that prevents the door from forming a barrier with the fire-resistance-rated
wall must be removed or repaired.
5705.3.7.5 Open systems.
Use, dispensing, and mixing of flammable and combustible liquids in open systems shall be in accordance with Sections 5705.3.7.5.1 through 5705.3.7.5.3.
Rooms and buildings where flammable and combustible liquids are dispensed, mixed or used in open containers or open systems must be designed and constructed in accordance with this section.
5705.3.7.5.1 Ventilation.
Continuous mechanical ventilation shall be provided at a rate of not less than 1 cfm per square foot [0.00508 m3/(s × m2)] of floor area over the design area. Provisions shall be made for the introduction of makeup air in such a manner as to include all floor areas or pits where vapors can collect. Local or spot ventilation shall be provided where needed to prevent the accumulation of hazardous vapors. Ventilation system design shall comply with the International Building Code and International Mechanical Code.
Exception: Where natural ventilation can be shown to be effective for the materials used, dispensed or mixed.
The requirements of this section for mechanical ventilation are identical to those in Section 5004.3. Mechanical ventilation is required to prevent the accumulation of vapors in concentrations in the flammable range. The exception allows the use of natural ventilation complying with Section 5004.3, which can be demonstrated to be effective for the flammable and combustible liquids being used.
5705.3.7.5.2 Explosion control.
Explosion control shall be provided in accordance with Section 911.
Refer to Section 911 for explosion control requirements. Deflagration venting in accordance with NFPA 68 is commonly used to comply with this requirement and must be designed to direct the force of an explosion out of the structure into an unoccupied area. However, Section 911 also references NFPA 69, which may require monitoring of gases and other methods to suppress factors contributing to the risk of explosion.
5705.3.7.5.3 Spill control and secondary containment.
Spill control shall be provided in accordance with Section 5703.4 where Class I, II or IIIA liquids are dispensed into containers exceeding a 1.3-gallon (5 L) capacity or mixed or used in open containers or systems exceeding a 5.3-gallon (20 L) capacity. Spill control and secondary containment shall be provided in accordance with Section 5703.4 where the capacity of an individual container exceeds 55 gallons (208 L) or the aggregate capacity of multiple containers or tanks exceeds 100 gallons (378.5 L).
Spill control complying with Section 5703.4 must be built into a room or a building where Class I, II or IIIA liquids are used in open containers or open systems that dispense the liquid into containers greater than 1.3 gallons (5 L), or are mixed or used in quantities greater than 5.3 gallons (20 L). In addition, secondary containment must be provided for individual containers greater than 55 gallons (208 L) or multiple containers with an aggregate capacity greater than 100 gallons (378.5 L). Section 5703.4 references Section 5004.2, which discusses the use of liquid-tight floors, curbs, dikes and drainage systems to divert the liquid to a location where it can be contained and safely handled.
5705.3.7.6 Closed systems.
Use or mixing of flammable or combustible liquids in closed systems shall be in accordance with Sections 5705.3.7.6.1 through 5705.3.7.6.3.
Rooms and buildings where flammable and combustible liquids are dispensed, mixed or used in closed systems must be designed and constructed in accordance with this section.
5705.3.7.6.1 Ventilation.
Closed systems designed to be opened as part of normal operations shall be provided with ventilation in accordance with Section 5705.3.7.5.1.
The requirements of this section for mechanical ventilation are identical to those in Section 5004.3. The mechanical ventilation is required to prevent accumulation of vapors in concentrations in the flammable range. Natural ventilation complying with Section 5004.3 that can be demonstrated to be effective for the flammable and combustible liquids being used is an acceptable alternative.
5705.3.7.6.2 Explosion control.
Explosion control shall be provided where an explosive environment can occur as a result of the mixing or use process. Explosion control shall be designed in accordance with Section 911.
Exception: Where process vessels are designed to contain fully the worst-case explosion anticipated within the vessel under process conditions considering the most likely failure.
Refer to Section 911 for explosion control requirements. Deflagration venting in accordance with NFPA 68 is commonly used to comply with this requirement and must be designed to direct the force of an explosion out of the structure into an unoccupied area. However, Section 911 also references NFPA 69, which may require monitoring of gases and other methods to suppress factors contributing to the risk of explosion.
The exception recognizes that a closed system can be designed to withstand the forces from an internal explosion. If the closed system is designed to resist the worst-case explosion, the room or building is considered to be in compliance with Section 911.
5705.3.7.6.3 Spill control and secondary containment.
Spill control shall be provided in accordance with Section 5703.4 where flammable or combustible liquids are dispensed into containers exceeding a 1.3-gallon (5 L) capacity or mixed or used in open containers or systems exceeding a 5.3-gallon (20 L) capacity. Spill control and secondary containment shall be provided in accordance with Section 5703.4 where the capacity of an individual container exceeds 55 gallons (208 L) or the aggregate capacity of multiple containers or tanks exceeds 1,000 gallons (3785 L).
Spill control complying with Section 5703.4 must be designed into a room or a building where flammable or combustible liquids are used in closed systems that dispense the liquid into containers greater than 1.3 gallons (5 L), or mixed or used in quantities greater than 5.3 gallons (20 L). In addition, secondary containment must be provided for individual containers greater than 55 gallons (208 L) or multiple containers with an aggregate capacity greater than 1,000 gallons (3785 L). Section 5703.4 references Section 5004.2, which discusses the use of liquid-tight floors, curbs, dikes and drainage systems to divert the liquid to a location where it can be contained and safely handled. This is identical to the requirement for an open system.