HIGH-HAZARD GROUP H
Philadelphia Code Subcode B, § 307
in effectSECTION 307 HIGH-HAZARD GROUP H
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[Revise Table B-307.1(1), Maximum Allowable Quantity Per Control Area of Hazardous Materials Posing a Physical Hazard, by deleting the “Flammable Gas” rows “Gaseous” and “Liquified” and replacing with the following, including the addition of note “r,” as follows:]
Material | Class | Group when the maximum allowable quantity is exceeded | Storage b | Use-closed systems | Use-open systems
Solid pounds (cubic feet) | Liquid gallons (pounds) | Gas (cubic feet at NTP) | Solid pounds (cubic feet) | Liquid gallons (pounds) | Gas (cubic feet at NTP) | Solid pounds (cubic feet) | Liquid gallons (pounds)
Flammable Gas | * * *
Gaseous
1A and 1B (High BV) r | H-2 | NA | NA | 1,000 d, e | NA | NA | 1,000 d, e | NA | NA
1B (Low BV) r | 162,500 d, e | 162,500 d, e
Liquified
1A and 1B (High BV) r | H-2 | NA | (150) d, e | NA | NA | (150) d, e | NA | NA | NA
1B (Low BV) r | (10,000) d, e | (10,000) d, e
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r. “High BV” Category 1B flammable gas has a burning velocity greater than 3.9 in/s (10 cm/s). “Low BV” Category 1B flammable gas has a burning velocity of 3.9in/s (10 cm/s) or less.
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[F] B-307.4 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 include, but not limited to, the following:
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[Replace “Flammable Gases” with the following:]
Category 1A Flammable gases.
Category 1B Flammable gases having a burning velocity greater than 3.9 inches per second (10 cm/s).
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[F] B-307.5 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:
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[Add the following:]
Category 1B Flammable gases having a burning velocity of 3.9 inches per second (10 cm/s) or less.
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Source: City of Philadelphia, The Philadelphia Code and Home Rule Charter (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/philadelphia/latest/philadelphia_pa/0-0-0-310775Fetched: 10/27/2026