CBC · California Building Code
What defines a Group L laboratory suite and when Section 453 applies
If a building contains one or more defined Group L "laboratory suites," CBC § 453 applies: each suite is limited to 10,000 sq ft, is intended for a single tenant (or must name a responsible party), requires specific fire‑resistance separations, and ties hazardous‑material limits to per‑suite tables; the enforcing agency can require a technical report to detail hazard controls.
Last reviewed: July 5, 2026
What the code requires — 2-4 sentences
Section 453 of the CBC applies when a building, structure, or portion thereof contains one or more Group L laboratory suites: the Section 453 provisions are written to govern those laboratory suites (see § 453.1). The enforcing agency may also require a technical opinion/report (hazardous materials management plan and engineering controls) prepared by an approved qualified person (see § 453.1.1). In short: if you have a defined "laboratory suite" in a building, § 453 applies and sets the limits and construction/separation requirements for that suite.
Requirements in detail
Core applicability and definitions
- What triggers § 453: any building or portion of a building that contains one or more laboratory suites as defined in Chapter 2 is subject to the requirements of Section 453 (see § 453.1). The code also notes these provisions are optional and may be applied to buildings or structures; Group B laboratory provisions remain available under Section 304 where appropriate (see § 453.1).
- Definition: a "laboratory suite" is the Group L occupancy space described in Chapter 2 (laboratory suite definitions and cross‑references appear in Chapter 2).
Mandatory numeric and tenancy limits
- Maximum gross floor area per individual laboratory suite: 10,000 square feet. If any individual suite exceeds that, it does not meet the § 453.3.1 limit (see § 453.3.1).
- Laboratory suite tenancy: an individual laboratory suite shall not serve more than a single tenant; an exception allows a suite to have a responsible party or department that is accountable for all hazardous materials within the suite (see § 453.3.2).
Construction and separation requirements (selection)
- Separation between laboratory suites: laboratory suites shall be separated from other laboratory suites by a fire barrier with not less than a 1‑hour rating (see § 453.4.1.2).
- Separation from control areas: minimum 2‑hour fire‑resistance rating, with a limited exception permitting 1‑hour on floor levels below the 4th story (see § 453.4.1.3 and its exception).
- Where a floor contains more than one suite on the 4th story and above, a 2‑hour fire barrier is required dividing the floor; that barrier must be continuous exterior wall to exterior wall and satisfy area/number distribution requirements (see § 453.4.3.1 and subsections).
- For Group L occupancies on the 11th story and above, additional fire‑smoke barrier, elevator lobby, and elevator pressurization requirements apply (see § 453.4.3.2 and § 453.8).
Hazardous materials and quantities
- The laboratory‑suite concept in § 453 ties the allowable aggregate quantities of hazardous materials to an individual "suite" — the specific allowable quantities and limits are set in the CBC tables referenced by § 453 (Table 453.7.3.1 and related tables). The text indicates that increases normally allowed for fully sprinklered buildings do not apply to Group L occupancies (see the table notes and related statements).
Decision‑relevant summary table
| Decision dimension | Key value / threshold | Code Reference |
|---|---|---|
| Max gross floor area per individual lab suite | 10,000 sq ft | § 453.3.1 |
| Single‑tenant requirement | One tenant per suite (exception: responsible party/department permitted) | § 453.3.2 |
| Separation between suites | 1‑hour fire barrier between suites | § 453.4.1.2 |
| Separation from control areas | 2‑hour fire‑resistance (1‑hour exception below 4th story) | § 453.4.1.3 (exception) |
| When a 2‑hour floor divider is required | Any story with >1 lab suite on 4th story and above | § 453.4.3.1 |
| Sprinkler‑system quantity increases | Not applicable to Group L (i.e., sprinkler increases do not raise allowable hazmat limits) | Table notes / related text |
| Technical report (enforcing agency may require) | Qualified opinion/report/HMMP prepared by approved person | § 453.1.1 |
Exceptions & special cases
- The CBC explicitly allows an exception to the single‑tenant rule: a suite may instead designate a responsible party/department to manage all hazardous materials for that suite; that is not the same as full multi‑tenant occupancy without a single accountable entity (see § 453.3.2).
- The 2‑hour separation to control areas is reduced to 1 hour on floors below the 4th story per the exception in § 453.4.1.3. Evaluate building height and floor level when applying separation rules.
- The CBC notes its Section 453 provisions are “optional and may apply” and refers back to Group B laboratory rules where applicable (see § 453.1). That means the authority having jurisdiction could apply § 453, defer to Group B provisions, or require additional measures via § 453.1.
Common mistakes
- Misclassifying small lab rooms as Group L suites: not every lab room is a Group L “laboratory suite” for § 453 purposes—check the Chapter‑2 definition and whether the aggregate/suite concept applies.
- Ignoring the 10,000 sq ft limit: designing a contiguous lab area larger than 10,000 sq ft and treating it as a single suite will conflict with § 453.3.1.
- Assuming sprinkler systems automatically allow larger hazardous material quantities: the CBC explicitly states sprinkler increases for hazmat quantities are not applicable to Group L occupancies (see table notes).
- Overlooking required technical reports: the enforcing agency may mandate a technical opinion/report; leaving that until plan review can delay approvals (see § 453.1.1).
Worked example — concrete scenario
Scenario: An owner proposes a research floor with a single contiguous lab area of 9,500 sq ft containing three lab workrooms, two shared equipment rooms, offices, and storage for hazardous chemicals; one tenant will occupy and control the whole area.
Application of § 453:
- Because the area is a contiguous Group L laboratory suite within a building, § 453 applies (see § 453.1).
- The gross floor area is 9,500 sq ft, which is less than the 10,000 sq ft limit, so the suite size complies with § 453.3.1.
- The suite will serve a single tenant—compliant with § 453.3.2; if multiple tenants were proposed, the owner would need to establish a single responsible party or separate the space into distinct suites.
- The owner intends to store flammable liquids; allowable quantities must be determined against the CBC tables referenced by § 453 (Table 453.7.3.1 and related tables). Because Group L does not benefit from sprinkler‑based increases, designing storage assumptions must use the base allowable amounts in the tables (table content for numeric quantities must be checked in the CBC table itself).
- If the floor is the 5th story and the building contains multiple lab suites on that floor, the developer must provide a 2‑hour fire barrier dividing the floor as required by § 453.4.3.1. If the project is on the 2nd floor, certain exceptions reduce separation requirements (see § 453.4.1.3 exception).
Note: the exact allowable quantities of each hazardous material are specified in the CBC tables referenced by § 453 (Table 453.7.3.1 / Table 453.7.2.1). Those table values were not included in the retrieved excerpts here and must be consulted directly in the CBC to size storage and determine compliance.
Related provisions
- § 453.1 — Scope; when Section 453 applies (see § 453.1).
- § 453.1.1 — Technical report (enforcing agency may require HMMP/technical opinion).
- § 453.3.1 — Gross floor area limit per laboratory suite (10,000 sq ft).
- § 453.3.2 — Tenant limitation / responsible‑party exception.
- § 453.4.1.2 / § 453.4.1.3 — Separation between suites and separation from control areas (ratings and exceptions).
- § 453.4.3.1 / § 453.4.3.2 — Floor division and fire‑smoke barrier requirements (including 11th story+ rules).
- Table references for hazardous materials quantities (see Table 453.7.3.1 and related table notes regarding sprinkler systems).
- Chapter 2 definitions, including “laboratory suite” (see § 202 and related definitions).
Code references
Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:
CBC § 453.7.3.1 High relevance — show source text
KEY BOX. A secure device with a lock operable only by a fire department master key, and containing building entry keys and other keys that may be required for access in an emergency.
[A] LABELED. Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, approved agency or other organization concerned with product evaluation that maintains periodic inspection of the production of such labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.
LABORATORY. [SFM] A room, building or area where the use and storage of hazardous materials are utilized for testing, analysis, instruc- tion, research or developmental activities.
LABORATORY SUITE. [SFM] A laboratory suite is a Group L occupancy space within a building or structure, which may include multiple laboratories, offices, storage, equipment rooms or similar support functions, where the aggregate quantities of hazardous materials stored and used do not exceed the quantities set forth in the California Building Code Table 453.7.3.1 (see the California Building Code Section 453).
LABORATORY SUITE. A fire-rated enclosed laboratory area that will provide one or more laboratory spaces, within a Group B educational occupancy, that are permitted to include ancillary uses such as offices, bathrooms and corridors that are contiguous with the laboratory area, and are constructed in accordance with Chapter 38.
LANDSCAPED ROOF. An area over a roof assembly incorporating planters, vegetation, hardscaping or other similar decorative appurtenances that are not part of the roof assembly.
LEVEL OF EXIT DISCHARGE. See “Exit discharge, level of.”
LIFE SAFETY SYSTEMS. Systems, devices and equipment that enhance or facilitate evacuation, smoke control, compartmentation and/or isolation.
LIMITED SPRAYING SPACE. An area in which operations for touch-up or spot painting of a surface area of 9 square feet (0.84 m [2] ) or less are conducted.
LIQUEFIED NATURAL GAS (LNG). A fluid in the liquid state composed predominantly of methane and which may contain minor quantities of ethane, propane, nitrogen or other components normally found in natural gas.
LIQUEFIED PETROLEUM GAS (LP-gas). A material which is composed predominantly of the following hydrocarbons or mixtures of them: propane, propylene, butane (normal butane or isobutane) and butylenes.
LIQUID. A material having a melting point that is equal to or less than 68°F (20°C) and a boiling point which is greater than 68°F (20°C) at 14.7 pounds per square inch absolute (psia) (101 kPa). Where not otherwise identified, the term “liquid” includes both flammable and combustible liquids.
LIQUID OXYGEN AMBULATORY CONTAINER. A container used for liquid oxygen not exceeding 0.396 gallons (1.5 liters) specifically designed for use as a medical device as defined by 21 USC Chapter 9 that is intended for portable therapeutic use and to be filled from its companion base unit, a liquid oxygen home care container.
CBC § 2-25 High relevance — show source text
way.
[BE] INTERIOR EXIT STAIRWAY. An exit component that serves to meet one or more means of egress design requirements, such as required number of exits or exit access travel distance, and provides for a protected path of egress travel to the exit discharge or public
way.
[BG] INTERIOR FINISH. Interior finish includes interior wall and ceiling finish and interior floor finish.
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DEFINITIONS
[BG] INTERIOR FLOOR-WALL BASE. Interior floor finish trim used to provide a functional or decorative border at the intersection of walls and floors.
[BG] INTERIOR WALL AND CEILING FINISH. The exposed interior surfaces of buildings, including but not limited to: fixed or movable walls and partitions; toilet room privacy partitions; columns; ceilings; and interior wainscoting, paneling or other finish applied structurally or for decoration, acoustical correction, surface insulation, structural fire resistance or similar purposes, but not including trim.
IRRITANT. A chemical which is not corrosive, but which causes a reversible inflammatory effect on living tissue by chemical action at the site of contact. A chemical is a skin irritant if, when tested on the intact skin of albino rabbits by the methods of CPSC 16 CFR Part 1500.41 for an exposure of four or more hours or by other appropriate techniques, it results in an empirical score of 5 or more. A chemical is classified as an eye irritant if so determined under the procedure listed in CPSC 16 CFR Part 1500.42 or other approved techniques.
[A] JURISDICTION. The governmental unit that has adopted this code.
KEY BOX. A secure device with a lock operable only by a fire department master key, and containing building entry keys and other keys that may be required for access in an emergency.
[A] LABELED. Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, approved agency or other organization concerned with product evaluation that maintains periodic inspection of the production of such labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.
LABORATORY. [SFM] A room, building or area where the use and storage of hazardous materials are utilized for testing, analysis, instruc- tion, research or developmental activities.
LABORATORY SUITE. [SFM] A laboratory suite is a Group L occupancy space within a building or structure, which may include multiple laboratories, offices, storage, equipment rooms or similar support functions, where the aggregate quantities of hazardous materials stored and used do not exceed the quantities set forth in the California Building Code Table 453.7.3.1 (see the California Building Code Section 453).
LABORATORY SUITE. A fire-rated enclosed laboratory area that will provide one or more laboratory spaces, within a Group B educational occupancy, that are permitted to include ancillary uses such as offices, bathrooms and corridors that are contiguous with the laboratory area, and are constructed in accordance with Chapter 38.
LANDSCAPED ROOF. An area over a roof assembly incorporating planters, vegetation, hardscaping or other similar decorative appurtenances that are not part of the roof assembly.
CBC § 37.47 High relevance — show source text
[BS] JOINT. The opening in or between adjacent assemblies that is created due to building tolerances, or is designed to allow independent movement of the building in any plane caused by thermal, seismic, wind or any other loading.
[A] JURISDICTION. The governmental unit that has adopted this code.
KEY STATION. [DSA-AC] Certain rapid and light rail stations, and commuter rail stations, as defined under criteria established by the Department of Transportation in 49 CFR 37.47 and 49 CFR 37.51, respectively.
KICK PLATE. An abrasion-resistant plate affixed to the bottom portion of a door to prevent a trap condition and protect its surface.
KITCHEN OR KITCHENETTE. [DSA-AC] A room, space or area with equipment for the preparation and cooking of food.
[BF] L RATING. The air leakage rating of a through penetration firestop system or a fire-resistant joint system when tested in accordance with UL 1479 or UL 2079, respectively.
[A] LABEL. An identification applied on a product by the manufacturer that contains the name of the manufacturer, the function and performance characteristics of the product or material and the name and identification of an approved agency, and that indicates that the representative sample of the product or material has been tested and evaluated by an approved agency (see Section 1703.5, “Manufacturer’s designation” and “Mark”).
[A] LABELED. Equipment, materials or products to which has been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, approved agency or other organization concerned with product evaluation that maintains periodic inspection of the production of the above-labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose. [HCD 1 & HCD 2] “ Labeled” means equipment or materials to which has been attached a label, symbol or other identifying mark of an organization, approved by the Department, that maintains a periodic inspection program of production of labeled products, installations, equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
LABORATORY. [SFM] A room, building or area where the use and storage of hazardous materials are utilized for testing, analysis, instruc- tion, research or developmental activities.
LABORATORY SUITE. [SFM] A laboratory suite is a Group L Occupancy space within a building or structure, which may include multiple laboratories, offices, storage, equipment rooms or similar support functions, where the aggregate quantities of hazardous materials stored and used do not exceed the quantities set forth in Table 453.7.2.1 (see Section 453).
LADDER. A series of vertically separate treads or rungs either connected by vertical rail members or independently fastened to an adja- cent vertical pool wall.
LAVATORY. A fixed bowl or basin with running water and drainpipe, as in a toilet or bathing facility, for washing or bathing purposes. (As differentiated from the definition of “Sink”.) LEVEL AREA. [HCD 1-AC] A specified surface that does not have a slope in any direction exceeding [1] / 4 inch (6.4 mm) in 1 foot (305 mm) from the horizontal (2.083-percent gradient).
CBC § 453.7.2.1 High relevance — show source text
[HCD 1 & HCD 2] “ Labeled” means equipment or materials to which has been attached a label, symbol or other identifying mark of an organization, approved by the Department, that maintains a periodic inspection program of production of labeled products, installations, equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
LABORATORY. [SFM] A room, building or area where the use and storage of hazardous materials are utilized for testing, analysis, instruc- tion, research or developmental activities.
LABORATORY SUITE. [SFM] A laboratory suite is a Group L Occupancy space within a building or structure, which may include multiple laboratories, offices, storage, equipment rooms or similar support functions, where the aggregate quantities of hazardous materials stored and used do not exceed the quantities set forth in Table 453.7.2.1 (see Section 453).
LADDER. A series of vertically separate treads or rungs either connected by vertical rail members or independently fastened to an adja- cent vertical pool wall.
LAVATORY. A fixed bowl or basin with running water and drainpipe, as in a toilet or bathing facility, for washing or bathing purposes. (As differentiated from the definition of “Sink”.) LEVEL AREA. [HCD 1-AC] A specified surface that does not have a slope in any direction exceeding [1] / 4 inch (6.4 mm) in 1 foot (305 mm) from the horizontal (2.083-percent gradient).
[BS] LANDSCAPED ROOF. An area over a roof assembly incorporating planters, vegetation, hardscaping or other similar decorative appurtenances that are not part of the roof assembly.
LEVEL OF EXIT DISCHARGE. See “Exit discharge, level of.”
LICENSING AGENCY. [OSHPD 1 , 1R, 2, 3, 4 & 5 ] (See Chapter 12, Section 1224.3 for defined term.)
[F] LIFE SAFETY SYSTEMS. Systems, devices and equipment that enhance or facilitate evacuation, smoke control, compartmentation and isolation.
LIFT, PLATFORM (WHEELCHAIR). [HCD 1-AC] See “Platform (Wheelchair) Lift”.
[BF] LIGHT-DIFFUSING SYSTEM. Construction consisting in whole or in part of lenses, panels, grids or baffles made with light-transmitting plastics positioned below independently mounted electrical light sources, skylights or light-transmitting plastic roof panels. Lenses, panels, grids and baffles that are part of an electrical fixture shall not be considered as a light-diffusing system.
[BS] LIGHT-FRAME CONSTRUCTION. Construction whose vertical and horizontal structural elements are primarily formed by a system of repetitive wood or cold-formed steel framing members.
[BF] LIGHT-TRANSMITTING PLASTIC ROOF PANELS. Structural plastic panels other than skylights that are fastened to structural members, or panels or sheathing and that are used as light-transmitting media in the plane of the roof.
CBC § 452.1.5 High relevance — show source text
_ The egress system shall comply with the requirements of Section 709 for smoke barriers. 3.6. The building is equipped with an automatic sprinkler system throughout.
452.1.5 Special hazards. School classrooms constructed after January 1, 1990, not equipped with automatic sprinkler systems, which have metal grilles or bars on all their windows and do not have at least two exit doors within 3 feet (914 mm) of each end of the classroom opening to the exterior of the building or to a common hallway used for evacuation purposes, shall have an inside release for the grilles or bars on at least one window farthest from the exit doors. The window or windows with the inside release shall be clearly marked as emergency exits.
452.1.6 Class I, II or III-A flammable liquids shall not be placed, stored or used in Group E occupancies, except in approved quantities as necessary in laboratories and classrooms and for operation and maintenance as set forth in the California Fire Code.
SECTION 453—GROUP L [SFM]
453.1 Scope. The provisions of this section shall apply to buildings or structures, or portions thereof, containing one or more Group L laboratory suites as defined in Section 202.
The provisions of this section are optional and may apply to buildings or structures. See Section 304 for Group B Laboratories.
453.1.1 Technical report. The enforcing agency may require a technical opinion and report to identify and develop methods of protection from the hazards presented by the hazardous materials. A qualified person, firm or corporation, approved by the enforcing agency, shall prepare the opinion and report, and shall be provided without charge to the enforcing agency. The opinion and report may include, but is not limited to, the preparation of a hazardous material management plan (HMMP); chemical analysis; recommen- dations for methods of isolation, separation, containment or protection of hazardous materials or processes, including appropriate engineering controls to be applied; the extent of changes in the hazardous behavior to be anticipated under conditions of exposure to fire or from hazard control procedures; and the limitations or conditions of use necessary to achieve and maintain control of the
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SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE
hazardous materials or operations. The report shall be entered into the files of the code enforcement agencies. Proprietary and trade secret information shall be protected under the laws of the state or jurisdiction having authority.
453.2 Definitions. The following terms are defined in Chapter 2:
LABORATORY SUITE.
[F] LIQUID TIGHT FLOOR.
453.3 Laboratory suite requirements. 453.3.1 The gross floor area of an individual laboratory suite shall not exceed 10,000 square feet (929 m [2] ).
453.3.2 An individual laboratory suite shall not serve more than a single tenant.
Exception: An individual laboratory suite shall have a responsible party or department for all hazardous materials within a suite.
453.4 Construction.
453.4.1 Separation of laboratory suites.
CBC § 307.1 High relevance — show source text
Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings_
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
_a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2).CBC § 307.1 High relevance — show source text
5_|75|20|20|20|NP|NP| |Above grade
plane|3|100|UL|UL|UL|UL|NP| |Above grade
plane|1, 2|100|UL|UL|UL|UL|UL| |Below grade
plane|1|75c|10|10|10|10|10| |Below grade
plane|2|50d|5|5|5|5|5| |Below grade
plane|3 and below|0|NP|NP|NP|NP|NP| |UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
_a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2).CBC § 453.4.1.2 High relevance — show source text
453.4.1.2 Laboratory suites shall be separated from other laboratory suites by a fire barrier having a fire-resistance rating of not less than 1-hour.
453.4.1.3 Laboratory suites shall be separated from control areas by a minimum 2-hour fire-resistance rating in accordance with Sections 707 and 711.
Exception: Laboratory suites shall be separated from control areas by a minimum 1-hour fire-resistance rating on floor levels below the 4th story.
453.4.1.4 Horizontal separation. The floor construction of the laboratory suite and the construction supporting the floor of the laboratory suite shall have a minimum 2-hour fire-resistance rating in accordance with Section 711.
Exceptions: 1. The floor construction of the laboratory suite and the construction supporting the floor of the laboratory suite are allowed to be 1-hour fire-resistance rated in buildings of Type IIA, IIIA and VA construction. 2. When an individual laboratory suite occupies more than one story, the intermediate floors contained within the suite shall comply with the requirements of Table 601.
453.4.2 Reserved.
453.4.3 Fire barrier and fire-smoke barrier.
453.4.3.1 Fire barrier. A fire barrier having a fire resistance rating of not less than 2-hours shall divide any story containing more than one laboratory suite on the 4th story and above.
453.4.3.1.1 Fire barriers shall be continuous from exterior wall to exterior wall,
453.4.3.1.2 The fire barrier shall divide the floor so that the square footage on each side of the 2-hour fire barrier is not less than 30 percent of the total floor area, and
453.4.3.1.3 The number of laboratory suites on each side of the 2-hour fire barrier shall not be less than 25 percent of the total number of laboratory suites on the floor.
453.4.3.2 Fire-smoke barrier. Any story containing a Group L occupancy on the 11th story and above shall be subdivided by a fire- smoke barrier constructed as a fire barrier having a fire-resistance rating of not less than 2 hours and shall also comply with the smoke barrier requirements of Section 709.
The 2-hour fire-smoke barrier shall be in accordance with Sections 453.4.3 through 453.4.3.2.3.
453.4.3.2.1 A minimum of one door opening shall be provided in the 2-hour fire-smoke barrier for emergency access.
453.4.3.2.2 Each side of the 2-hour fire-smoke barrier shall be designed as a separate smoke zone designed in accordance with Section 909.6.
453.4.3.2.3 T he area on each side of the 2-hour fire- smoke barrier shall be served by a minimum of one exit enclosure in accor- dance with Section 1022.
CBC § 307.1 Medium relevance — show source text
b_**|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE| |STORY|STORY|PERCENTAGE OF MAXIMUM
ALLOWABLE QUANTITY PER
LABORATORY SUITEa, b|Type IA|Type IB|Type IIA,
IIIA, IV|Type IIB, IIIB,
VA|Type VB| |Above grade
plane|Above 20|0|NP|NP|NP|NP|NP| |Above grade
plane|15 to 20|25|4|NP|NP|NP|NP| |Above grade
plane|11, 12, 13, 14|50|8|NP|NP|NP|NP| |Above grade
plane|7, 8, 9, 10|50|16|NP|NP|NP|NP| |Above grade
plane|6|75|20|20|NP|NP|NP| |Above grade
plane|4, 5|75|20|20|20|NP|NP| |Above grade
plane|3|100|UL|UL|UL|UL|NP| |Above grade
plane|1, 2|100|UL|UL|UL|UL|UL| |Below grade
plane|1|75c|10|10|10|10|10| |Below grade
plane|2|50d|5|5|5|5|5| |Below grade
plane|3 and below|0|NP|NP|NP|NP|NP| |UL = Unlimited, NP = Not permitted
a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
areas.|UL = Unlimited, NP = Not permitted
_a.CBC § 311.3.1 Medium relevance — show source text
Asbestos
Beverages up to and including 20-percent alcohol
Cement in bags
Chalk and crayons
Dairy products in nonwaxed coated paper containers
Dry cell batteries
Electrical coils
Electrical motors
Empty cans
Food products
Foods in noncombustible containers
Fresh fruits and vegetables in nonplastic trays or containers
Frozen foods
Glass
Glass bottles, empty or filled with noncombustible liquids
Gypsum board
Inert pigments
Ivory
Meats
Metal cabinets
Metal desks with plastic tops and trim
Metal parts
Metals
Mirrors
Oil-filled and other types of distribution transformers
Public parking garages, open or enclosed
Porcelain and pottery
Stoves
Talc and soapstones
Washers and dryers
311.3.1 Public parking garages. Public parking garages shall comply with Section 406.4 and the additional requirements of Section 406.5 for open parking garages or Section 406.6 for enclosed parking garages.
SECTION 312—UTILITY AND MISCELLANEOUS GROUP U
312.1 General. Buildings and structures of an accessory character and miscellaneous structures not classified in any specific occupancy shall be constructed, equipped and maintained to conform to the requirements of this code commensurate with the fire and life hazard incidental to their occupancy. Group U shall include, but not be limited to, the following:
Agricultural buildings
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OCCUPANCY CLASSIFICATION AND USE
Aircraft hangars, accessory to a one- or two-family residence (see Section 412.4)
Barns
Carports Communication equipment structures with a gross floor area of less than 1,500 square feet (139 m [2] )
Fences more than 7 feet (2134 mm) in height
Grain silos, accessory to a residential occupancy
Livestock shelters
Private garages
Retaining walls
Sheds
Stables
Tanks
Towers
312.1.1 Greenhouses. Greenhouses not classified as another occupancy shall be classified as Use Group U.
312.2 Private garages and carports. Private garages and carports shall comply with Section 406.3.
312.3 Residential aircraft hangars. Aircraft hangars accessory to a one- or two-family residence shall comply with Section 412.4.
SECTION 313—LABORATORIES GROUP L [SFM]
313.1 Group L Laboratories. [SFM] Group L occupancy includes the use of a building or structure, or a portion thereof, containing one or more laboratory suites as defined in Section 453.
SECTION 314—ORGANIZED CAMPS GROUP C [SFM]
314.1 Organized Camps Group C. [SFM] An organized camp is a site with programs and facilities established for the primary purpose of providing an outdoor group living experience with social, spiritual, educational or recreational objectives, for five days or more during one or more seasons of the year.
2025 CALIFORNIA BUILDING CODE 3-19
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3-20 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Frequently asked questions
Who decides whether § 453 or Group B lab provisions apply?
The enforcing agency (AHJ) determines applicability; § 453 itself notes the section is optional and may be applied, and the AHJ may request a technical report per § 453.1.1.
Is a 9,900 sq ft contiguous lab automatically one suite under § 453?
Yes—if the contiguous area meets the laboratory‑suite definition and is under 10,000 sq ft, it meets the size limit in § 453.3.1; other requirements (separation, hazmat limits, tenancy) still apply.
Can sprinkler protection be used to increase allowable chemical quantities in a Group L suite?
No. The CBC indicates that allowable hazardous‑material increases for fully sprinklered buildings are not applicable to Group L occupancies—do not assume sprinkler increases raise the table quantities.
If two tenants share a suite, is that allowed?
An individual laboratory suite shall not serve more than a single tenant; the code provides an exception allowing a responsible party or department to be designated for hazardous materials in the suite—this does not equate to unfettered multi‑tenant occupancy without a clear, single accountable entity. See § 453.3.2.
Where do I find the allowable quantities for specific hazardous materials?
Allowable quantities are in the CBC tables referenced by § 453 (e.g., Table 453.7.3.1 and Table 453.7.2.1). Those tables must be consulted directly—table numeric values were not included in the retrieved excerpts here.
More in California Building Code
- Administration & Permits
- Energy Efficiency
- Existing Buildings
- Occupancy Classification & Use
- Hazardous Materials & Occupancies
- Types of Construction
- Fire-Resistance & Fire Safety
- Interior Finishes
- Means of Egress
- Accessibility
- Exterior Walls
- Roofing & Roof Assemblies
- Structural Design
- Special Inspections & Tests
- Foundations & Soils
- Concrete
- Masonry
- Steel
- Wood
- Elevators & Conveying Systems
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