CBC · California Building Code

Explosion control, venting and barricade options for explosion hazards

If you store or use hazardous materials in quantities above the CBC maximums, § 414.5.1 and Table 414.5.1 tell you whether the building must have barricade construction, deflagration venting/explosion prevention, or that venting is not allowed — the table gives the method by material/class and the CBC directs you to the California Fire Code for the technical design and installation.

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Last reviewed: July 5, 2026

What the code requires — 2-4 sentences

The California Building Code requires that explosion control be provided where quantities of hazardous materials exceed the maximum allowable quantities in Table 307.1(1) or where a space is occupied for activities that create explosion hazards. The Building Code directs that explosion control be provided in accordance with the California Fire Code and specifies the method (barricade construction, deflagration venting, or prohibition) by material/class in Table 414.5.1 (§ 414.5, § 414.5.1) . In short: check Table 414.5.1 to see which method the CBC requires for your material, and follow the California Fire Code for the technical design and installation where the CBC defers to it (§ 414.5.1) .

Requirements in detail

Scope and trigger

  • When explosion control is required: where quantities exceed the MAQ in Table 307.1(1) or where a room/space is occupied for explosion-hazard operations (see § 414.5.1) .
  • The CBC itself does not supply the vent design criteria; it requires the explosion control “in accordance with the California Fire Code” and points the designer to that code and referenced standards (see Table 414.5.1 notes and § 414.5.1) .

Decision matrix (quick reference)

The table below summarizes the decision-relevant dimensions in Table 414.5.1: material/hazard category, whether barricade construction is required, whether deflagration venting or prevention systems are required or not permitted, and the CBC code reference.

Material / Hazard Category Barricade construction? Deflagration venting or prevention systems? Code Reference
Combustible dusts Not required Required Table 414.5.1; § 414.5.1
Cryogenic flammables Not required Required Table 414.5.1; § 414.5.1
Explosives — Division 1.1 Required Not required Table 414.5.1; § 414.5.1
Explosives — Division 1.2 Required Not required Table 414.5.1; § 414.5.1
Explosives — Division 1.3 Not required Required Table 414.5.1; § 414.5.1
Explosives — Division 1.4 Not required Required (note: consumer fireworks excluded per footnote) Table 414.5.1; § 414.5.1
Explosives — Division 1.5 & 1.6 Required Not required Table 414.5.1; § 414.5.1
Flammable gas (gaseous or liquefied) Not required Required (with limited exceptions for low burning velocity gases) Table 414.5.1; § 414.5.1
Flammable liquids (Class IA, IB) Not required Required Table 414.5.1; § 414.5.1
Organic peroxides (certain classes) Required Not permitted Table 414.5.1; § 414.5.1
Oxidizers / Unstable-reactive (certain classes) Required Not permitted Table 414.5.1; § 414.5.1
Water‑reactive materials (classes listed) Not required Required (where they can form explosive mixtures) Table 414.5.1; § 414.5.1
Special uses (grain processing, energy storage, acetylene generators, LP-gas distribution, etc.) Not required Required Table 414.5.1; § 414.5.1

(For the exact classification and any additional rows, consult Table 414.5.1 in the CBC — the table lists many materials and the required method; entries above are representative summaries taken from Table 414.5.1) .

What “required” and “not permitted” mean in practice under the CBC

  • “Required” in the barricade column means the CBC mandates barricade construction as the explosion-control method for that hazard/class when explosion control is triggered by quantity or use — designers must show this protection in the construction documents (§ 414.5.1; Table 414.5.1) .
  • “Required” in the venting/prevention column means the CBC requires explosion (deflagration) venting or a prevention system per the California Fire Code for that hazard/class; the CBC defers the technical standards for venting/prevention to the Fire Code and referenced NFPA standards (§ 414.5.1; Table 414.5.1) .
  • “Not permitted” means that venting/prevention is explicitly disallowed for that type of hazard — barricade or other means must be used (§ 414.5.1; Table 414.5.1) .

Exceptions & special cases

  • Explosion control is only required when quantities exceed the MAQ in Table 307.1(1) or when the occupancy/use creates explosion hazards; if quantities are below MAQ, Table 414.5.1 does not by itself trigger control measures (§ 414.5.1) .
  • Table footnotes (a, b, c, etc.) clarify scope and exceptions: for example, footnote a directs you to § 414.1.3 for reporting/information requirements; footnote b cross‑references the California Fire Code for design of venting/prevention; footnote c explains when combustible dusts are considered hazardous and subject to the requirement. These footnotes are part of Table 414.5.1 — see the table notes for specific conditions and exclusions (Table 414.5.1 notes) .
  • Some occupancy-specific exceptions are noted (for example: explosion venting is not required for Group H-5 fabrication areas that comply with Chapter 27 and the CBC; see Table 414.5.1 notes) — follow the table footnotes and the Fire Code for these special cases (§ 414.5.1; Table 414.5.1 notes) .
  • Where the CBC requires explosion control, the actual vent design, vent sizing, vent placement, barricade design, and prevention-system design are handled by the California Fire Code and consensus standards (NFPA 68, NFPA 69, NFPA 495, etc.). The CBC directs compliance with those documents via Table 414.5.1 (see the table notes and § 414.5.1) .

Common mistakes

  • Treating Table 414.5.1 as a design manual: the table tells you which method the CBC requires, not how to size vents or build barricades. The Fire Code and referenced NFPA standards contain the technical design rules — the CBC points you there (§ 414.5.1) .
  • Assuming venting is allowed for detonative hazards: Table 414.5.1 shows that for detonation-type hazards the CBC can require barricades and explicitly mark venting “Not permitted” — do not use deflagration venting for detonation protection when the table forbids it (§ 414.5.1; Table 414.5.1) .
  • Failing to check MAQ trigger: explosion control is only triggered when quantities exceed the MAQ in Table 307.1(1) or when operations are classified as explosion-hazard uses — verify quantities against Table 307.1(1) and document the calculation on the plans (§ 414.5.1; § 414.1.3) .
  • Overlooking the required report: § 414.1.3 requires a report that identifies maximum expected quantities and the proposed methods of protection; omitting that report or key information is a common plan-review deficiency (§ 414.1.3) .

Worked example — applying the rule with numbers (illustrative)

Scenario (illustrative example only — check Table 307.1(1) for your code MAQ): A manufacturing room will store flammable liquid Class IB, and the project team expects to store 300 gallons on the floor of the room. Step-by-step:

  1. Determine the MAQ from CBC Table 307.1(1) for Class IB flammable liquids. (You must look up the actual MAQ in Table 307.1(1); this example assumes the MAQ is lower than 300 gallons for demonstration — the CBC requires using the value in Table 307.1(1)) (§ 414.5.1) .
  2. If the expected 300 gallons exceeds the MAQ from Table 307.1(1), explosion control is required in accordance with CBC § 414.5.1 and Table 414.5.1; for flammable liquids Class IA/IB Table 414.5.1 lists deflagration venting or explosion prevention systems as the required method (barricade not required) — so the designer must provide venting or an approved prevention system (per the California Fire Code) and show that on the construction documents (§ 414.5.1; Table 414.5.1) .
  3. Design detail: the CBC tells you which method is required but not the vent sizes or vent pressure ratings — those are in the California Fire Code and NFPA standards (the CBC cross‑references the Fire Code in Table 414.5.1 notes) — coordinate the vent/prevention design with the fire code official and follow NFPA 68/69 as required (§ 414.5.1; Table 414.5.1 notes) file.
  4. Document submission: include the report required by § 414.1.3 (maximum expected quantities and the proposed explosion control method) and label the drawings to show the vent locations or the prevention system and demonstrate compliance with the Fire Code design criteria (§ 414.1.3; § 414.5.1) file.

Note: the numeric “300 gallons” above is an illustrative example only. Always use the actual MAQ values listed in Table 307.1(1) when determining whether explosion control is triggered (§ 414.5.1) .

Related provisions

  • Hazardous materials general rules and information submittal: § 414.1.3 (report identifying maximum expected quantities and methods of protection) .
  • Ventilation requirements for spaces where explosive dusts/vapors can be emitted: § 414.3 (mechanical ventilation where required) .
  • Group H and special-use requirements: See Section 415 for detailed Group H provisions and special occupancies referenced by Table 414.5.1 (see index cross-references and Table 414.5.1 notes) .
  • Cross-reference to the California Fire Code for technical venting/prevention design and NFPA standards: Table 414.5.1 notes and § 414.5.1 direct you to the California Fire Code (see the table footnotes) .

Code references

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

  • CBC § 414.5.1 High relevance — show source text

    [F] 414.5.1 Explosion control. Explosion control shall be provided in accordance with the California Fire Code as required by Table 414.5.1 where quantities of hazardous materials specified in that table exceed the maximum allowable quantities in Table 307.1(1) or where a structure, room or space is occupied for purposes involving explosion hazards as required by Section 415 or the California Fire Code .

    [F] TABLE 414.5.1—EXPLOSION CONTROL REQUIREMENTSa, h Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade construction Explosion (deflagration) venting or
    explosion (deflagration) prevention systemsb
    HAZARD CATEGORY
    Combustible dustsc — Not Required Required
    Cryogenic flammables — Not Required Required
    Explosives Division 1.1 Required Not Required
    Explosives Division 1.2 Required Not Required
    Explosives Division 1.3 Not Required Required
    Explosives Division 1.4j Not Required Required
    Explosives Division 1.5 Required Not Required
    Explosives Division 1.6 Required Not Required
    Flammable gas Gaseous Not Required Requiredk
    Flammable gas Liquefied Not Required Requiredk
    Flammable liquid IAd Not Required Required
    Flammable liquid IBe Not Required Required
    Organic peroxides U Required Not Permitted
    Organic peroxides I Required Not Permitted

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    SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

    [F] TABLE 414.5.1—EXPLOSION CONTROL REQUIREMENTSa, h—continued Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade construction Explosion (deflagration) venting or
    explosion (deflagration) prevention systemsb
    Oxidizer liquids and solids 4 Required Not Permitted
    Pyrophoric gas — Not Required Required
    Unstable (reactive) 4 Required Not Permitted
    Unstable (reactive) 3 Detonable Required Not Permitted
    Unstable (reactive) 3 Nondetonable Not Required Required
    Water-reactive liquids and solids 3 Not Required Required
    Water-reactive liquids and solids 2g Not Required Required
    SPECIAL USES
    Acetylene generator rooms — Not Required Required
    Electrochemical energy storage
    systemi    		 — Not Required Required
    Energy storage systemi — Not Required Required
    Grain processing — Not Required Required
    Liquefied petroleum gas-distri-
    bution facilities    		 — Not
  • CBC § 911.1 High relevance — show source text

    SECTION 911—EXPLOSION CONTROL

    911.1 General. Explosion control shall be provided in the following locations:

    1. Where a structure, room or space is occupied for purposes involving explosion hazards as identified in Table 911.1.
    2. Where quantities of hazardous materials specified in Table 911.1 exceed the maximum allowable quantities in Table 5003.1.1(1).

    Such areas shall be provided with explosion (deflagration) venting, explosion (deflagration) prevention systems or barricades in accordance with this section and NFPA 68, NFPA 69 or NFPA 495 as applicable. Deflagration venting shall not be utilized as a means to protect buildings from detonation hazards.

    TABLE 911.1—EXPLOSION CONTROL REQUIREMENTSf Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade
    construction    		 Explosion (deflagration) venting or
    explosion (deflagration) prevention systems
    Hazard Category Hazard Category Hazard Category Hazard Category
    Combustible dustsa — Not required Required
    Cryogenic fluids Flammable Not required Required

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    TABLE 911.1—EXPLOSION CONTROL REQUIREMENTSf—continued Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade
    construction    		 Explosion (deflagration) venting or
    explosion (deflagration) prevention systems
    Hazard Category Hazard Category Hazard Category Hazard Category
    Explosives Division 1.1 Required Not required
    Explosives Division 1.2 Required Not required
    Explosives Division 1.3 Not required Required
    Explosives Division 1.4i Not required Required
    Explosives Division 1.5 Required Not required
    Explosives Division 1.6 Required Not required
    Flammable gas Gaseous Not required Requiredh
    Flammable gas Liquefied Not required Requiredh
    Flammable liquids IAb Not required Required
    Flammable liquids IBc Not required Required
    Organic peroxides Unclassified detonable Required Not permitted
    Organic peroxides I Required Not permitted
    Oxidizer liquids and solids 4 Required Not permitted
    Pyrophoric Gases Not required Required
    Unstable (reactive) 4 Required Not permitted
    Unstable (reactive) 3 detonable Required Not permitted
    Unstable (reactive) 3 nondetonable Not required Required
    Water-reactive liquids and solids 3 Not required Required
    Water-reactive liquids and solids 2e Not
  • CBC § 25.4 High relevance — show source text

    explosion hazards existd|Detonation|Required|Not permitted| |Where explosion hazards existd|Deflagration|Not required|Required| |For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h.

  • CBC § 3.9 High relevance — show source text

    Control areas shall be separated from each other by not less than a 1-hour fire barrier.
    b. The building shall be equipped throughout with an approved automatic sprinkler system with a minimum sprinkler design density of Ordinary Hazard Group 2 in the area
    where flammable gases are stored or displayed.
    c. Where storage areas exceed 50,000 square feet in area, the maximum allowable quantities area is allowed to be increased by 2 percent for each 1,000 square feet of area in excess
    of 50,000 square feet, up to not more than 100 percent of the table amounts. Separation of control areas is not required. The aggregate amount shall not exceed 80,000 pounds.
    d._ Low Burning Velocity_(Low BV) Category 1B flammable gas has a burning velocity of 3.9 in/s or less.|

    [F] 414.3 Ventilation. Rooms, areas or spaces in which explosive, corrosive, combustible, flammable or highly toxic dusts, mists, fumes, vapors or gases are or have the potential to be emitted due to the processing, use, handling or storage of materials shall be mechanically ventilated where required by this code, the California Fire Code or the California Mechanical Code .

    Emissions generated at workstations shall be confined to the area in which they are generated as specified in the California Fire Code and the California Mechanical Code .

    [F] 414.4 Hazardous material systems. Systems involving hazardous materials shall be suitable for the intended application. Controls shall be designed to prevent materials from entering or leaving process or reaction systems at other than the intended time, rate or path. Automatic controls, where provided, shall be designed to be fail safe.

    [F] 414.5 Inside storage, dispensing , handling and use. The inside storage, dispensing and use of hazardous materials shall be in accordance with Sections 414.5.1 through 414.5.3 of this code and the California Fire Code .

    [F] 414.5.1 Explosion control. Explosion control shall be provided in accordance with the California Fire Code as required by Table 414.5.1 where quantities of hazardous materials specified in that table exceed the maximum allowable quantities in Table 307.1(1) or where a structure, room or space is occupied for purposes involving explosion hazards as required by Section 415 or the California Fire Code .

    [F] TABLE 414.5.1—EXPLOSION CONTROL REQUIREMENTSa, h Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade construction Explosion (deflagration) venting or
    explosion (deflagration) prevention systemsb
    HAZARD CATEGORY
    Combustible dustsc — Not Required Required
    Cryogenic flammables — Not Required Required
    Explosives Division 1.1 Required Not Required
    Explosives Division 1.2 Required Not Required
    Explosives Division 1.3 Not Required Required
    Explosives Division 1.4j Not Required Required
    Explosives Division 1.5 Required Not Required
    Explosives Division 1.
  • CBC § 2506.2 High relevance — show source text

    Vertical and horizontal assemblies

    2504

    Wallboard Table 2506.2, 2508.2, 2508.2.1, 2508.4, 2510.5.2.1 Water-resistant backing board 2506.2, 2509.2

    Habitable Space 1208 Handrails 1014 Alternating tread devices 1011.14 Assembly aisles 1030.16 Construction 1014.5, 1014.6, 1014.7 Extensions 1014.7 Glazing 2407 Graspability 1014.4 Guards 1015.3 Height 1014.2 Loads 1607.9

    Location 1014.1, 1014.8, 1014.9,

    1014.10

    Ramps 1012.8 Stairs 1011.11

    Hardboard 1403.3.2, 2303.1.7 Hardware (see Doors and Locks and Latching) Hardwood

    Fastening 2304.10 Quality 2303.3 Veneer 1403.3.2 Hazardous Materials 307, 414, 415 Compliance with California Fire Code 307.2

    Control areas 414.2

    Explosion control 414.5.1, Table 414.5.1, 415.11.6.5, 426.1.4 Mercantile occupancies 309.2 Reporting 414.1.3 Sprinkler protection Table 414.2.5.1, Table 414.2.5.2, 415.4, 415.11.12,

    903.2.5

    Ventilation 414.3, 415.9.1.7, 415.11.1.6, 415.11.1.8.1, 415.11.3.2, 415.11.6.8, 415.11.7.4, 415.11.8, 415.11.11, 1202.6 Weather protection 414.6.1 Hazardous Occupancy (Group H), (see Hazardous Materials) 307, 414, 415 Alarms and detection 415.11.2, 415.11.4, 415.11.6.9, 415.11.8, 415.3, 415.5, 907.2.5, 908.1, 908.2 Area 503, 505, 506, 507, 508 Dispersing 414.5, 414.6, 415.6 Gas detection systems 415.11.7 Group provisions H-1 (detonation) 307.3, 415.6.2, 415.7, 415.6.4.1, 415.7.1 H-2 (deflagration) 307.4, 415.8, 415.9 H-3 (physical hazard) 415.10, 307.5, 415.8 H-4 (health hazard) 307.6, 415.10 H-5 (semiconductor) 307.7, 415.11 Height 415.7, 415.8.1, 415.9.1.1, 426.1.1, 503, 504, 505, 506 Incidental uses 509

  • CBC § 4-40 High relevance — show source text

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    [F] TABLE 414.5.1—EXPLOSION CONTROL REQUIREMENTSa, h—continued Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade construction Explosion (deflagration) venting or
    explosion (deflagration) prevention systemsb
    Oxidizer liquids and solids 4 Required Not Permitted
    Pyrophoric gas — Not Required Required
    Unstable (reactive) 4 Required Not Permitted
    Unstable (reactive) 3 Detonable Required Not Permitted
    Unstable (reactive) 3 Nondetonable Not Required Required
    Water-reactive liquids and solids 3 Not Required Required
    Water-reactive liquids and solids 2g Not Required Required
    SPECIAL USES
    Acetylene generator rooms — Not Required Required
    Electrochemical energy storage
    systemi    		 — Not Required Required
    Energy storage systemi — Not Required Required
    Grain processing — Not Required Required
    Liquefied petroleum gas-distri-
    bution facilities    		 — Not Required Required
    Where explosion hazards existf Detonation Required Not Permitted
    Where explosion hazards existf Deflagration Not Required Required
    a. See Section 414.1.3.
    b. See the_California Fire Code_.
    c. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information
    prepared in accordance with Section 104.2.2 of the_California Fire Code_. See definition of "Combustible dust" in Chapter 2.
    d. Storage or use.
    e. In open use or dispensing.
    f. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the hazardous materials
    or as a result of the dispensing or use process.
    g. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    h. Explosion venting is not required for Group H-5 fabrication areas complying with Section 415.11.1 and the_California Fire Code_.
    i. Where explosion control is required in Section 1207 of the_California Fire Code_.
    j. Does not apply to consumer fireworks, Division 1.4G.
    k. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second (10 cm/s).    		 a. See Section 414.1.3.
    b. See the_California Fire Code_.
    c. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information
    prepared in accordance with Section 104.2.2 of the_California Fire Code_. See definition of "Combustible dust" in Chapter 2.
    d.
  • CBC § 910.5 High relevance — show source text

    910.5 Maintenance and testing. Maintenance and testing of smoke and heat vents and mechanical smoke removal systems shall be in accordance with Sections 910.5.1 and 910.5.2. A written record of inspection, testing and maintenance that includes the date, identification of personnel involved, any unsatisfactory result, corrective action taken and replaced parts shall be maintained on the premises.

    910.5.1 Smoke and heat vents. Smoke and heat vents shall be maintained in an operative condition. Inspection, testing and maintenance shall be in accordance with NFPA 204 except as follows:

    1. Mechanically operated smoke and heat vents shall be inspected annually and operationally tested not less than every 5

    years. 2. Gravity dropout smoke and heat vents shall be inspected annually. 3. Fused, damaged or painted fusible links shall be replaced.

    910.5.2 Mechanical smoke removal systems. Mechanical smoke removal systems shall be maintained in accordance with NFPA 204 and the equipment manufacturer’s instructions except as follows:

    1. Systems shall be inspected and operationally tested annually.
    2. Testing shall include the operation of all system components, controls and ancillary equipment, such as makeup air openings.
    3. A written schedule for routine maintenance and operational testing shall be established and testing shall be conducted in accordance with the schedule.

    SECTION 911—EXPLOSION CONTROL

    911.1 General. Explosion control shall be provided in the following locations:

    1. Where a structure, room or space is occupied for purposes involving explosion hazards as identified in Table 911.1.
    2. Where quantities of hazardous materials specified in Table 911.1 exceed the maximum allowable quantities in Table 5003.1.1(1).

    Such areas shall be provided with explosion (deflagration) venting, explosion (deflagration) prevention systems or barricades in accordance with this section and NFPA 68, NFPA 69 or NFPA 495 as applicable. Deflagration venting shall not be utilized as a means to protect buildings from detonation hazards.

    TABLE 911.1—EXPLOSION CONTROL REQUIREMENTSf Col2 Col3 Col4
    MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS
    MATERIAL CLASS Barricade
    construction    		 Explosion (deflagration) venting or
    explosion (deflagration) prevention systems
    Hazard Category Hazard Category Hazard Category Hazard Category
    Combustible dustsa — Not required Required
    Cryogenic fluids Flammable Not required Required

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    |TABLE 911.

  • CBC § 1207.6.3. High relevance — show source text

    Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|

  • CBC § 1207.6.3. High relevance — show source text

    A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|For SI: 1 inch per second = 25.4 mm/s.
    a. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard
    based on information prepared in accordance with Section 104.2.2. See definition of “Combustible dust” in Chapter 2.
    b. Storage or use.
    c. In open use or dispensing.
    d. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the
    hazardous materials or as a result of the dispensing or use process.
    e. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    f. Explosion venting is not required for Group H-5 Fabrication Areas complying with Chapter 27 and the_California Building Code_.
    g. Where explosion control is required in Section 1207.6.3.
    h. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second.
    i. Does not apply to consumer fireworks, 1.4G.|

    911.2 Required deflagration venting. Areas that are required to be provided with deflagration venting shall comply with the following:

    1. Walls, ceilings and roofs exposing surrounding areas shall be designed to resist a minimum internal pressure of 100 pounds per square foot (psf) (4788 Pa). The minimum internal design pressure shall be not less than five times the maximum internal relief pressure specified in Item 5 of this section.
    2. Deflagration venting shall be provided only in exterior walls and roofs.

    Exception: Where sufficient exterior wall and roof venting cannot be provided because of inadequate exterior wall or roof area, deflagration venting shall be allowed by specially designed shafts vented to the exterior of the building. 3. Deflagration venting shall be designed to prevent unacceptable structural damage. Where relieving a deflagration, vent closures shall not produce projectiles of sufficient velocity and mass to cause life threatening injuries to the occupants or other persons on the property or adjacent public ways.

    9-68 2025 CALIFORNIA FIRE CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    1. The aggregate clear area of vents and venting devices shall be governed by the pressure resistance of the construction assemblies specified in Item 1 of this section and the maximum internal pressure allowed by Item 5 of this section.
    2. Vents shall be designed to withstand loads in accordance with the California Building Code . Vents shall consist of any one or any combination of the following to relieve at a maximum internal pressure of 20 pounds per square foot (958 Pa), but not less than the loads required by the California Building Code : 5.1. Exterior walls designed to release outward.

    5.2. Hatch covers.

  • CBC § 415.11.1 High relevance — show source text

    Storage or use.
    e. In open use or dispensing.
    f. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the hazardous materials
    or as a result of the dispensing or use process.
    g. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    h. Explosion venting is not required for Group H-5 fabrication areas complying with Section 415.11.1 and the_California Fire Code_.
    i. Where explosion control is required in Section 1207 of the_California Fire Code_.
    j. Does not apply to consumer fireworks, Division 1.4G.
    k. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second (10 cm/s).|a. See Section 414.1.3.
    b. See the_California Fire Code_.
    c. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information
    prepared in accordance with Section 104.2.2 of the_California Fire Code_. See definition of "Combustible dust" in Chapter 2.
    d. Storage or use.
    e. In open use or dispensing.
    f. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the hazardous materials
    or as a result of the dispensing or use process.
    g. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    h. Explosion venting is not required for Group H-5 fabrication areas complying with Section 415.11.1 and the_California Fire Code_.
    i. Where explosion control is required in Section 1207 of the_California Fire Code_.
    j. Does not apply to consumer fireworks, Division 1.4G.
    k. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second (10 cm/s).|a. See Section 414.1.3.
    b. See the_California Fire Code_.
    c. Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information
    prepared in accordance with Section 104.2.2 of the_California Fire Code_. See definition of "Combustible dust" in Chapter 2.
    d. Storage or use.
    e. In open use or dispensing.
    f. Rooms containing dispensing and use of hazardous materials where an explosive environment can occur because of the characteristics or nature of the hazardous materials
    or as a result of the dispensing or use process.
    g. A method of explosion control shall be provided where Class 2 water-reactive materials can form potentially explosive mixtures.
    h. Explosion venting is not required for Group H-5 fabrication areas complying with Section 415.11.1 and the_California Fire Code_.
    i. Where explosion control is required in Section 1207 of the_California Fire Code_.
    j. Does not apply to consumer fireworks, Division 1.4G.
    k. Not required for Category 1B Flammable Gases having a burning velocity not exceeding 3.9 inches per second (10 cm/s).|

  • CBC § 3.3.44.2 Medium relevance — show source text

    Amend Section 3.3.44.2 and amend publications to read as follows:

    3.3.44.2 Open Station.* A station that is constructed such that it is directly open to the atmosphere and smoke and heat are allowed to disperse directly into the atmosphere.

    The following enclosed areas in open stations are permitted:

    1. Ticket/pass booths not exceeding 150 square feet (13.9 m [2] ) in area. 2. Mechanical and electrical spaces typically not used for human occupancy and necessary for the operation of a fixed guideway transit system. Such spaces shall be limited to two per level. 3. Restrooms not exceeding 150 square feet (13.9 m [2] ) in area. A maximum of four restrooms are permitted per level.

    Add a new definition as 3.3.44.3 to read as follows:

    3.3.44.1.1 Underground Station. A station or portion thereof that is located beneath the surface of the earth or of the water.

    Amend Section 5.2.2.1 to read as follows:

    5.2.2.1 Building construction for all new enclosed stations shall be not less than Type IA, Type IB or Type IIA construction and shall not exceed in area or height the limits specified in the California Building Code Table 503, for the station configuration or as determined by fire hazard analysis of potential fire exposure hazards to the structure.

    Add Section 5.2.2.1.1 –5.2.2.1.3 to read as follows:

    5.2.2.1.1 Underground stations shall be a minimum Type IA or Type IB constructions.

    5.2.2.1.2 Open stations may be of Type IIB construction and shall not exceed in area or height as required by Table 503 for Type IIA.

    5.2.2.1.3 Open at grade stations may be of any construction type allowed by the California Building Code.

    Delete Section 5.2.2.2.

    Amend Section 5.2.4.3 to read as follows:

    5.2.4.3 Ancillary Spaces. Fire resistance ratings of separations between ancillary occupancies shall be established as required by the California Building Code.

    35-36 2025 CALIFORNIA BUILDING CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    REFERENCED STANDARDS

    Amend Section 5.2.4.3.1 to read as follows:

    5.2.4.3.1 The following areas shall be separated by a two-hour fire barrier:

    1. Electrical control rooms, auxiliary electrical rooms and associated battery rooms

    2. Trash rooms

    3. Train control rooms and associated battery rooms

    4. Fan rooms

    5. Emergency generator rooms

    Amend Section 5.2.4.5 to read as follows:

    5.2.4.5 Separation Between System and Nonsystem Occupancies.* All station public areas shall be fire separated from adjacent non-system occupancies by a one hour fire barrier, unless otherwise required by other provisions of the California Building Code.

    Amend Section 5.3.1.1 to read as follows:

  • CBC § 910.4.3.1 Medium relevance — show source text

    910.4.3.1 Makeup air. Makeup air openings shall be provided within 6 feet (1829 mm) of the floor level. Operation of makeup air openings shall be manual or automatic. The minimum gross area of makeup air inlets shall be 8 square feet per 1,000 cubic feet per minute (0.74 m [2] per 0.4719 m [3] /s) of smoke exhaust.

    910.4.4 Activation. The mechanical smoke removal system shall be activated by manual controls only.

    910.4.5 Manual control location. Manual controls shall be located where they are able to be accessed by the fire service from an exterior door of the building and separated from the remainder of the building by not less than 1-hour fire barriers constructed in accordance with Section 707 of the California Building Code or horizontal assemblies constructed in accordance with Section 711 of the California Building Code, or both.

    910.4.6 Control wiring. Wiring for operation and control of mechanical smoke removal systems shall be connected ahead of the main disconnect in accordance with Section 701.12E of the California Electrical Code and be protected against interior fire exposure to temperatures in excess of 1,000°F (538°C) for a period of not less than 15 minutes.

    910.4.7 Controls. Where building air-handling and mechanical smoke removal systems are combined or where independent building air-handling systems are provided, fans shall automatically shut down in accordance with the California Mechanical Code . The manual controls provided for the smoke removal system shall have the capability to override the automatic shutdown of fans that are part of the smoke removal system.

    910.5 Maintenance and testing. Maintenance and testing of smoke and heat vents and mechanical smoke removal systems shall be in accordance with Sections 910.5.1 and 910.5.2. A written record of inspection, testing and maintenance that includes the date, identification of personnel involved, any unsatisfactory result, corrective action taken and replaced parts shall be maintained on the premises.

    910.5.1 Smoke and heat vents. Smoke and heat vents shall be maintained in an operative condition. Inspection, testing and maintenance shall be in accordance with NFPA 204 except as follows:

    1. Mechanically operated smoke and heat vents shall be inspected annually and operationally tested not less than every 5

    years. 2. Gravity dropout smoke and heat vents shall be inspected annually. 3. Fused, damaged or painted fusible links shall be replaced.

    910.5.2 Mechanical smoke removal systems. Mechanical smoke removal systems shall be maintained in accordance with NFPA 204 and the equipment manufacturer’s instructions except as follows:

    1. Systems shall be inspected and operationally tested annually.
    2. Testing shall include the operation of all system components, controls and ancillary equipment, such as makeup air openings.
    3. A written schedule for routine maintenance and operational testing shall be established and testing shall be conducted in accordance with the schedule.

    SECTION 911—EXPLOSION CONTROL

    911.1 General. Explosion control shall be provided in the following locations:

    1. Where a structure, room or space is occupied for purposes involving explosion hazards as identified in Table 911.1.
    2. Where quantities of hazardous materials specified in Table 911.1 exceed the maximum allowable quantities in Table 5003.1.1(1).

Frequently asked questions

When does the CBC require explosion control (summary)?

When quantities of hazardous materials exceed the maximum allowable quantities in Table 307.1(1) or when the space is occupied for explosion‑hazard activities; see § 414.5.1 and Table 414.5.1 .

Does Table 414.5.1 tell me how to size vents or barricades?

No. Table 414.5.1 identifies which method (barricade vs venting vs not permitted) the CBC requires by material/class; the technical design and sizing are done in the California Fire Code and referenced NFPA standards, as the CBC directs in § 414.5.1 and the table notes file.

Can I use deflagration venting for detonations?

No — for detonative hazards Table 414.5.1 and its notes indicate venting is not permitted where the table lists “Not Permitted”; the CBC requires barricade construction or other measures in those cases (§ 414.5.1; Table 414.5.1) .

What documentation do I need to submit with plans?

The CBC requires a report identifying the maximum expected quantities of hazardous materials and the proposed methods of protection (control areas, fire protection systems, explosion control) prepared by a qualified person, per § 414.1.3, and show compliance with Table 414.5.1 where triggered file.

Are there occupancy-specific exceptions (for example semiconductor fabrication)?

Yes. Table 414.5.1’s footnotes identify occupancy-specific exceptions (for example, certain Group H-5 fabrication areas) — check the table notes and applicable chapters for those exceptions (§ 414.5.1; Table 414.5.1 notes) .

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