453 Group L [sfm] — 2025 California Building Code

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

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.

The following terms are defined in Chapter 2:

LABORATORY SUITE.

[F] LIQUID TIGHT FLOOR.

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.

453.4.1 Separation of laboratory suites.

453.4.1.1 Laboratory suites shall be separated from other occupancies in accordance with Table 508.4.

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.

453.4.4 Emergency response equipment area. When required by the fire code official, an area for emergency response equipment shall be provided on each floor in an approved location. The area shall be a minimum of 50 square feet (4.6 m [2] ) , for spill mitigation supplies per California Fire Code 5001.3.3.4 in a location approved by the fire code official, and identified with signage.

Exception: The area size for spill mitigation supplies may be reduced by the fire code official when adequate supplies are provided.

453.4.5 Liquid tight floor. All portions of the laboratory suite where hazardous materials may be stored, dispensed, handled or used shall be provided with a liquid tight floor. The intersections of such floors shall have an integral coved base that extends upward onto the wall not less than 2 inches. Where the floor is designed to provide spill control or secondary containment the floor shall be designed in accordance with California Fire Code Section 5004.2.

453.4.6 Secondary power systems. A legally required standby power system shall have an automatic transfer time of not more than 10 seconds.

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SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

453.4.6.1 Required systems. Standby power shall be provided for all electrically operated equipment, systems and connected control circuits including: 1. Mechanical ventilation systems. See Section 453.4.7.2. 2. Temperature control systems required to prevent unsafe process excursions or chemical reactions. 3. Treatment systems and scrubbers.

4. Emergency Responder Radio Coverage (ERRCS). See Section 510 of the California Fire Code. 5. Electrically operated systems required elsewhere in this code and the California Fire Code.

453.4.7 Ventilation.

453.4.7.1 Compatibility. Incompatible materials shall not be conveyed in the same duct system. Combined products in mechani- cal exhaust ducts shall not create a physical hazard or reaction that could degrade the duct material. The building official may require a technical report in accordance with Section 453.7.1.

453.4.7.2 Fire dampers, smoke dampers and combination fire/smoke dampers. Fire dampers, smoke dampers or fire/smoke dampers shall not be permitted in mechanical exhaust duct systems used to maintain a safe laboratory environment. When the exhaust duct penetrates the laboratory suite boundary the exhaust duct shall be located within a horizontal or vertical assembly having a fire resistance rating equal to the fire barrier.

453.4.7.3 Reserved.

453.4.7.4 Laboratory suite exhaust air.

453.4.7.4.1 Exhaust air from laboratory suites shall not be recirculated.

453.4.7.4.2 Laboratory suite exhaust air shall be independently ducted to a point outside the building or an approved roof top structure.

Exception: Exhaust ducts serving separate laboratory suites may be connected to a common duct within a fire rated verti- cal shaft when the sub-duct extends vertically upward at least 22 inches.

453.4.7.4.3 Laboratory suite exhaust ducts shall not penetrate the fire barriers required by Section 453.4.1.

Exception: Where the exhaust duct is enclosed in a rated shaft in accordance with Section 713.

453.4.7.5 Ventilation rates. Mechanical exhaust ventilation systems shall provide a minimum ventilation rate not less than 1 cubic feet per minute per square foot [0.00508 m [3] /(s·m [2] ) ] of floor area, or 6 air exchanges per hour, whichever is greater. Systems shall operate continuously at the designed ventilation rate.

Exception: Refer to California Fire Code Section 5001.3 Performance-based design alternatives, as approved by the Fire Code Official.

453.4.7.6 Reserved.

453.4.7.7 Mechanical ventilation system balancing. Mechanical ventilation systems shall be designed and balanced such that during normal and emergency conditions the door opening forces comply with the requirements of Sections 1010.1.3 and Chapter 11B as applicable. Emergency conditions shall include: supply fan shutdown or failure, closing of smoke dampers or combination fire/smoke dampers, or emergency power.

453.6.1 Access to exits. Every room of a laboratory suite containing hazardous materials and having a floor area of 500 square feet (19 m2) or more shall have access to not less than two separate exits or exit-access doorways in accordance with Section 1006.2.

453.6.2 Door swing. All exit and exit-access doors serving areas with hazardous materials shall swing in the direction of exit travel, regardless of the occupant load served.

453.6.3 Panic hardware. Exit and exit access doors from areas with hazardous materials shall not be provided with a latch or lock unless it is panic hardware or fire exit hardware.

453.6.4 Buildings of four stories or more. A minimum of one exit shall be provided to serve the floor on each side of the 2-hour fire barrier and shall comply with the provisions of Chapter 10.

453.6.5 Reserved.

453.7.1 Multiple hazards. When a hazardous material has multiple hazards, all hazards shall be addressed and controlled in accor- dance with the provisions of this code and the California Fire Code.

SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

453.7.2 Percentage of maximum allowable quantities. The percentage of the maximum allowable quantity of hazardous materi- als per laboratory suite permitted for each story level within a building shall be in accordance with Table 453.7.2.1.

TABLE 453.7.2.1—HAZARDOUS MATERIALS QUANTITY PER LABORATORY SUITE

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.

453.7.3 Handling and transportation. The handling and transportation of hazardous materials shall be in accordance with Section 5003.10 of the California Fire Code.

Any story containing a Group L occupancy on the 11th story and above shall be provided with elevators and elevator lobbies in accordance with Sections 453.8.1 through 453.8.3.

453.8.1. An elevator that serves every story of the building shall be provided on each side of the 2-hour fire-smoke barrier.

453.8.2. An elevator lobby shall be provided on each side of the 2-hour fire-smoke barrier at each floor in accordance with Section 3006.

453.8.3. The elevator and its associated elevator lobbies and elevator machine rooms shall be pressurized in accordance with Section 909.6.

See California Fire Code Chapter 11, Section 1116 and California Existing Building Code.