CRSC · California Referenced Standards Code
Are kitchen/grease filters required to be Class I per SFM 12-71-1
For SFM‑regulated applications, the CRSC test **§ 12‑71‑100** (SFM 12‑71‑1) defines Class I (no flames/sparks; smoke‑area < 1.5 in²) and the California Mechanical Code requires grease filters used in those applications to be Class I when tested to that standard; check the adopted code listings and the § 1.11.0 scope to confirm applicability.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
For air filters, the State Fire Marshal’s test standard SFM 12‑71‑1 is codified at § 12‑71‑100 of the California Referenced Standards Code (CRSC). The CRSC defines the test apparatus, test method, and classification criteria that produce Class I or Class 2 filter ratings (see § 12‑71‑100). The California Mechanical Code then requires that grease filters used in SFM‑regulated applications be Class I when tested per SFM 12‑71‑1 (see § 509.2.3 and § 509.2.3.4 of the Mechanical Code) .
If the grease filter is used in an application regulated by the State Fire Marshal (per the list referenced in the codes), it must pass the SFM 12‑71‑1 test as a Class I filter (no flame/sparks and smoke-area < 1.5 in²) — § 12‑71‑100.
Requirements in detail
Key defined terms (first mentions)
- Class I — filters that “do not produce flames or sparks when attacked by flame” and produce an area under the smoke‑density curve of less than 1.5 square inches per the classification criteria in § 12‑71‑100(c)(1).
- Class 2 — filters that burn moderately or emit moderate smoke but do not project flames/sparks beyond the duct and develop smoke‑area not more than 6.0 square inches, per § 12‑71‑100(c)(2).
- SFM 12‑71‑1 / § 12‑71‑100 — the CRSC section that specifies the test duct, burner arrangement, airflow, test duration, smoke measurement and classification.
Test apparatus & method (what the CRSC actually requires)
- Test duct: 21 in. square by 13.5 ft long with a 20 × 20 in. nominal filter frame. Air velocity set to approximately 200 linear feet per minute. Flames applied by two burners about 18 in. from the filter. Test duration: 3 minutes. See § 12‑71‑100(a), (b).
- Smoke measurement: photoelectric cell and microammeter measure light drop; the area under the plotted smoke‑density curve quantifies smoke production (used for classification). See § 12‑71‑100(b)(2)‑(3).
Classification criteria (decision thresholds)
| Decision dimension | Value / threshold | Notes | Code Reference |
|---|---|---|---|
| No flames or sparks downstream | required for Class I | Clean (unused) filters are tested | § 12‑71‑100(c)(1) |
| Smoke area for Class I | < 1.5 in² | Area under smoke‑density curve measured during test | § 12‑71‑100(c)(1) |
| Smoke area for Class 2 | ≤ 6.0 in² | Class 2 may burn moderately but must not project flames/sparks beyond discharge | § 12‑71‑100(c)(2) |
| Test air velocity | ≈ 200 ft/min | Set at discharge end during test | § 12‑71‑100(a)(4) |
| Flame exposure duration | 3 minutes | Flames applied while observing faces and downstream condition | § 12‑71‑100(b)(1) |
| Adhesive coatings flash point | ≥ 325°F (Cleveland open cup) | Applies to liquid adhesive coatings on filters | § 12‑71‑100(d) |
| Where Class I is required (by mechanical code) | SFM‑regulated applications listed in Section 1.11.0 | Mechanical Code requires grease filters be Class I when tested per SFM 12‑71‑1 for SFM‑regulated uses (also a DPH note) | § 509.2.3 and § 509.2.3.4 (Cal. Mechanical Code) |
How the Mechanical Code ties in
- The Mechanical Code states grease filters “shall be Class I when tested in accordance with the test method in Title 24, Part 12, Chapter 12‑71, SFM Standard 12‑71‑1” for applications listed in Section 1.11.0 regulated by the Office of the State Fire Marshal. It also contains a DPH‑tagged clause requiring Class I when tested per SFM 12‑71‑1. See § 509.2.3 and § 509.2.3.4 (Mechanical Code) for the requirement language and scope note.
Exceptions & special cases
- Listed hood assemblies and listed grease removal devices are installed per their listings and manufacturer instructions; some listing conditions can allow different separation distances or arrangements — see Mechanical Code § 509.1 and related exceptions. The Mechanical Code allows listed devices to be installed per their listing even if different from the prescriptive text.
- Mesh filters: mesh type filters shall not be used unless evaluated as an integral part of a listed exhaust hood or listed with a primary filter per UL 1046 — see § 509.1.1 (Mechanical Code). That means not every mesh filter is acceptable even if it passes a lab test.
- Scope qualification: the CRSC describes the test and classification, but the Mechanical Code (and DPH tagging) determine when a grease filter must be Class I in actual installations. The precise set of “applications listed in Section 1.11.0” referenced by the Mechanical Code was not present in the retrieved excerpts; verify the applicable list in the adopted code/administrative material for project jurisdiction (the CRSC excerpt references that list).
Common mistakes
- Saying “all kitchen filters everywhere must be Class I.” — Incorrect. The CRSC defines the SFM test and classification; the Mechanical Code then requires Class I for SFM‑regulated applications (those listed in Section 1.11.0). Residential range hoods or non‑listed applications may not be covered by this mandatory statement. Check the Mechanical Code scope and the Section 1.11.0 list for applicability.
- Confusing the test standard with listing standards: a manufacturer’s listing (e.g., UL or other) and the SFM test are separate processes. The Mechanical Code requires filters to be “listed” and in SFM‑regulated uses also to be Class I under SFM 12‑71‑1. Always ask for the specific listing/test report.
- Assuming “mesh filter allowed if tested” — Mesh filters are restricted by § 509.1.1 unless they are part of a listed assembly or listed in conjunction with a primary filter per UL 1046.
Worked example — concrete scenario
Scenario: A commercial pizza restaurant installs a Type I canopy hood with removable metal grease filters. The project is in a building type and occupancy that appears on the SFM list referenced by the Mechanical Code.
- The manufacturer provides an SFM 12‑71‑1 report showing: no downstream flames/sparks during the 3‑minute test and an area under the smoke curve of 1.2 in².
- Under § 12‑71‑100(c)(1) that result qualifies the unit as Class I (since 1.2 in² < 1.5 in²) .
- Because the Mechanical Code § 509.2.3 requires grease filters to be Class I when tested per SFM 12‑71‑1 for SFM‑regulated applications, the installer can accept the filter for use in this SFM‑regulated hood (subject to listing and installation provisions) .
- If a different filter test report showed 3.5 in², that would be Class 2 (≤ 6.0 in² but > 1.5 in²) and would not meet the Mechanical Code’s Class I requirement for SFM‑regulated uses; a different filter/listing would be required per § 12‑71‑100(c) and § 509.2.3.
Related provisions
- § 12‑71‑100 — SFM Standard 12‑71‑1 test apparatus, test method and classification criteria (CRSC).
- § 12‑71‑100(a) — Test apparatus dimensions and set‑up.
- § 12‑71‑100(b) — Test method, flame exposure and smoke measurement procedure.
- § 12‑71‑100(c) — Classification thresholds for Class I and Class 2.
- § 12‑71‑100(d) — Adhesive coating flash‑point requirement for filters.
- Cal. Mechanical Code § 509.2.3 and § 509.2.3.4 — require grease filters to be Class I when tested per SFM 12‑71‑1 for SFM‑regulated applications (and DPH reference). These are the implementing building‑code provisions that make the CRSC test relevant to installations.
If you need: (a) the exact list of “applications listed in Section 1.11.0” referenced by the Mechanical Code, or (b) a sample acceptance checklist (manufacturer’s test report items to verify), tell me which and I’ll pull or draft that next. Note: the Section 1.11.0 list was not included in the retrieved excerpts, so confirm that list in your adopted code package or local amendments.
Code references
Grounded in the retrieved California Referenced Standards Code — click a citation to read the verbatim passage:
CRSC § 509.2.3 High relevance — show source text
509.2.3 Grease Filters. Grease filters shall be listed
and constructed of steel or other non-combustible material, and shall be of rigid construction that will not distort or crush under normal operation, handling, cleaning, or replacement. [SFM] For applications listed in Section 1.11.0 regulated by the Office of the State Fire Marshal, grease filters shall be Class I when tested in accordance with the test method in Title 24, Part 12, Chapter 12-71, SFM Standard 12-71-1.
509.2.3.1 Arrangement. Grease filters shall be arranged so that all exhaust air passes through the grease filters. [NFPA 96:6.2.3.4]
509.2.3.2 Accessibility. Grease filters shall be easily accessible for removal. [NFPA 96:6.2.3.5]
509.2.3.3 Angled Installation. Grease filters shall be installed at an angle not less than 45 degrees (0.79 rad) from the horizontal. [NFPA 96:6.2.3.6]
509.2.3.4 [DPH] Grease filters shall be Class I when tested in accordance with the test method in
SFM 12-71-1.
509.2.4 Grease Drip Trays. Grease filters shall be equipped with a grease drip tray beneath their lower edges. [NFPA 96:6.2.4.1]
509.2.4.1 Size and Pitch. Grease drip trays shall be kept to the minimum size needed to collect grease. Grease drip trays shall be pitched to drain into an enclosed metal container having a capacity not exceeding 1 gallon (4 L). [NFPA 96:6.2.4.2, 6.2.4.3]
114 2025 CALIFORNIA MECHANICAL CODE
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EXHAUST SYSTEMS
509.2.5 Grease Filter Orientation. Grease filters that require a specific orientation to drain grease shall be clearly so designated on the face of the filter as to be visible with the filter installed, or the hood or filter shall be constructed so that filters cannot be installed in the wrong orientation. [NFPA 96:6.2.5]
509.3 Solid-Fuel Grease Removal Devices. Where solid-fuel cooking equipment is provided with grease removal devices, these devices shall be in accordance with Section 517.0.
510.0 Exhaust Duct Systems.
510.1 General. Ducts shall not pass through fire walls.
[NFPA 96:7.1.1]
510.1.1 Fire Hazards. All ducts shall lead directly to the exterior of the building, so as not to unduly increase any fire hazard. [NFPA 96:7.1.2]
510.1.2 Interconnection. Duct systems shall not be interconnected with any other building ventilation or exhaust system. [NFPA 96:7.1.3]
CRSC § 509.2 High relevance — show source text
(2) Where a grease removal device is listed for separation distances less than those required in Section
509.2 and Section 509.2.1, the listing requirements shall be permitted. [NFPA 96:6.2.1.4]
(3) Grease removal devices supplied as part of listed hood assemblies shall be installed in accordance with the terms of the listing and the manufacturer’s instructions. [NFPA 96:6.2.1.5]
509.2.2 Grease Removal Device Protection. Where the distance between the grease removal device and the appliance flue outlet (heat source) is less than 18 inches (457 mm), grease removal devices shall be protected from combustion gas outlets and from direct flame impingement occurring during normal operation of cooking appliances producing high flue gas temperatures.
[NFPA 96:6.2.2.1]
509.2.2.1 Installation. This protection shall be permitted to be accomplished by the installation of a steel or stainless steel baffle plate between the heat source and the grease removal device. [NFPA 96:6.2.2.2]
509.2.2.2 Size and Location. The baffle plate shall be sized and located so that flames or combustion gases travel a distance not less than 18 inches (457 mm) from the heat source to the grease removal device. [NFPA 96:6.2.2.3]
509.2.2.3 Clearance. The baffle shall be located not less than 6 inches (152 mm) from the grease removal device. [NFPA 96:6.2.2.4]
509.2.3 Grease Filters. Grease filters shall be listed
and constructed of steel or other non-combustible material, and shall be of rigid construction that will not distort or crush under normal operation, handling, cleaning, or replacement. [SFM] For applications listed in Section 1.11.0 regulated by the Office of the State Fire Marshal, grease filters shall be Class I when tested in accordance with the test method in Title 24, Part 12, Chapter 12-71, SFM Standard 12-71-1.
509.2.3.1 Arrangement. Grease filters shall be arranged so that all exhaust air passes through the grease filters. [NFPA 96:6.2.3.4]
509.2.3.2 Accessibility. Grease filters shall be easily accessible for removal. [NFPA 96:6.2.3.5]
509.2.3.3 Angled Installation. Grease filters shall be installed at an angle not less than 45 degrees (0.79 rad) from the horizontal. [NFPA 96:6.2.3.6]
509.2.3.4 [DPH] Grease filters shall be Class I when tested in accordance with the test method in
SFM 12-71-1.
509.2.4 Grease Drip Trays. Grease filters shall be equipped with a grease drip tray beneath their lower edges. [NFPA 96:6.2.4.1]
CRSC § 25.4 Medium relevance — show source text
@ 16″|—|32″
(287)|25″
(356)|36″
(263)|29″
(345)|21″
(428)|29″
(367)|20″
(484)|—|23″
(471)|—|—| |2 × 12 @ 12″|—|42″
(209)|31″
(263)|—|37″
(253)|27″
(317)|36″
(271)|27″
(358)|17″
(447)|31″
(348)|19″
(462)|—| |2 × 12 @ 8″|—|48″
(136)|45″
(169)|—|48″
(164)|38″
(206)|—|40″
(233)|26″
(294)|36″
(230)|29″
(304)|18″
(379)| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f. See Section R301.2.2.6, Item 1, for additional limitations on cantilevered floor joists for detached one- and two-family dwellings in Seismic Design Category D0, D1 or D2 and
townhouses in Seismic Design Category C, D0, D1 or D2.
g. Linear interpolation shall be permitted for building widths and ground snow loads other than shown.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f.CRSC § 12-7 Medium relevance — show source text
Fire tests of building
construction and materials.|SFM|Part 2, Section 703| |Chapter 12-7-2|Reserved||| |Chapter 12-7-3|Fire-resistive standards.
Fire testing furnaces.|SFM|Part 9, Section 3001| |Chapter 12-7-4|Fire-resistive standards.
Fire door assembly tests.|SFM|Part 2, Section 716| |Chapter 12-7-5|Fire-resistive standards. Interior
finish of decorative material.|SFM|Part 2, Chapter 8
Part 9, Chapter 8| |Chapter 12-7A|Materials and construction methods for
exterior wildfire exposure|SFM|Part 7, Chapter 5| |Chapter 12-8-1|Fire-resistive standards for fire protection|SFM|Part 2, Sections 408.14 and 435.6.2| |Appendix 12-8-1A|Calculation of the total rate of heat and carbon
monoxide or carbon dioxide production|SFM|| |Appendix 12-8-1B|Guide to mounting techniques for wall and
ceiling interior finish material|SFM|| |Chapter 12-10-1|Exits. Power-operated exit doors.|SFM|Part 2, Sections 408.4.2, 1010.1.4.2, 1010.1.9.1| |Chapter 12-10-2|Exits. Single-point latching or locking devices.|SFM|Part 2, Section 1010.2.2
Part 9, Section 1010.2.2| |Chapter 12-10-3|Exits. Emergency exit and panic hardware.
|SFM|Part 9, Section 1009.12| |Chapter 12-11A,
12-11B|Detectable warning products and directional
surfaces|DSA|Part 2, Sections 1112A.9, 1116A.5, 11B-247,
11B-406.5.12, 11B-705, 11B-810.5.2| |Chapter 12-12|Reserved||| |Chapter 12-13|Standards for insulating material|CA/SFM|Part 2.5, Section R302.10.1
Part 6, Section 110.8
Part 9, Section 720, Table 721.1(1)
Part 11, Section A5.504.4.8| |Chapter 12-16-1|California standard for earthquake-actuated
automatic gas shutoff systems|DSA|Part 2, Chapters 16 and 16A
Part 5, Section 1211.8| |Chapter 12-16-2|California standard for residential excess flow
actuated automatic gas shutoff valves|DSA|Part 5, Section 1209.1| |Chapter 12-31C|Radiation shielding|DPH|Part 2, Section 3102C| |Chapter 12-71|Air filters|SFM|Part 4, Sections 401.2, 509.2.3, 509.2.3.4
Part 6, Section 120.1| |Chapter 12-72-1|Protective signaling systems.
Standard test procedures.|SFM|| |Chapter 12-72-2|Protective signaling systems.CRSC § 12-71 Medium relevance — show source text
STATE FIRE MARSHAL
DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS
Sec. 12-71-100.
(a) Test apparatus.
- The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
- One end of the duct is tapered to the discharge of a variable-speed blower and the other end is open to discharge. A metal filter frame is provided near the middle of the length of the duct to receive one 20 by 20 inches (508 mm by 508 mm) (nominal) filter unit. Two tightfitting doors, located to permit access to the filter frame, are each provided with a mica window to permit observation of both faces of the filter and conditions in the duct downstream from the filter.
- Two 1-inch (25 mm) pipe elbows, about 18 inches (457 mm) from the base of the test filter, form gas burner outlets adjusted to provide yellow, wavering flames. The burners consume approximately 4 cubic feet (approximately 1,000 Btu/cubic feet) of gas per minute.
- With the filter in place the air velocity is adjusted to approximately 200 linear feet per minute as measured at the discharge end of the duct by an Alnor Velometer Anemometer.
(b) Test method.
Filters are tested clean, that is, unused. The flames are applied for 3 minutes during which time observations are made of both faces of the filter as to the downstream travel of flame or sparks and the density, duration and character of the products of combustion.
Smoke density is measured as the drop in light intensity on a microammeter by means of photoelectric cell mounted a few inches below and about 12 inches (305 mm) inside the discharge end of the duct. The light source, stabilized for light intensity, is mounted 1 inch (25 mm) above the duct directly above the photoelectric cell. The microammeter readings are recorded every 5 seconds for the first minute and every 10 seconds for the next 2 minutes.
The differences between these readings and the readings taken before the test are plotted against time (the scale being 40 μA and 40 seconds to the inch) with the resulting area under the curve being measured by use of a planimeter or calculated mathematically. This area is a measure of the smoke density produced during the test.
(c) Classification. As a result of the tests, air filter units are classified as Class 1 or 2 as indicated below:
- Class 1 air filter units are those which, when clean, do not produce flames or sparks when attacked by flame and which develop areas under the smoke density curves that are less than 1.5 square inches (967 mm [2] ).
- Class 2 air filter units are those which, when clean, burn moderately when attacked by flame or emit moderate amounts of smoke or both. These units, although they may be consumed to some extent, do not project flames or extensive sparks that would ignite adjacent combustible materials beyond the discharge end of the duct during the test and do not develop areas under the smoke density curves that are more than 6.0 square inches (3871 mm [2] ).
(d) Adhesive coatings. Liquid-adhesive coatings used on filters shall have a flash point of 325°F (163°C) Cleveland open cup tester, or higher.
CRSC § 120.1 Medium relevance — show source text
Provide the higher rate where periods of heavy use are expected to occur. The lower rate shall be permitted to be used otherwise.
E – Rate is for a toilet room intended to be occupied by one person at a time. For continuous systems operation during hours of use, the lower rate shall be permitted to be used.
Otherwise the higher rate shall be used.
F – See other applicable standards for exhaust rate.
G – For continuous system operation, the lower rate shall be permitted to be used. Otherwise the higher rate shall be used.
H – Rate is per showerhead.
Notes:
1. For spaces not included in this table, the spaces in Table 120.1-B shall apply.|A – RESERVED.
B – RESERVED.
C – Exhaust shall not be required where two or more sides comprise walls that are at least 50 percent open to the outside.
D – Rate is per water closet, urinal or both. Provide the higher rate where periods of heavy use are expected to occur. The lower rate shall be permitted to be used otherwise.
E – Rate is for a toilet room intended to be occupied by one person at a time. For continuous systems operation during hours of use, the lower rate shall be permitted to be used.
Otherwise the higher rate shall be used.
F – See other applicable standards for exhaust rate.
G – For continuous system operation, the lower rate shall be permitted to be used. Otherwise the higher rate shall be used.
H – Rate is per showerhead.
Notes:
1. For spaces not included in this table, the spaces in Table 120.1-B shall apply.|TABLE 160.2-D—AIRSTREAMS OR SOURCES
[ASHRAE 62.1:TABLE 6-3]Col2 DESCRIPTION AIR CLASS Commercial kitchen grease hoods 4 Commercial kitchen hoods other than grease 3 Hydraulic elevator machine room 2 Refrigerating machinery rooms 3 TABLE 160.2-E—DEMAND-CONTROLLED LOCAL VENTILATION EXHAUST AIRFLOW RATES AND CAPTURE EFFICIENCY Col2 APPLICATION COMPLIANCE CRITERIA Enclosed kitchen or nonenclosed kitchen Vented range hood, including appliance-range hood combinations shall meet either the capture
efficiency (CE) or the airflow rate specified in Table 160.2-G, as applicable.Enclosed kitchen or nonenclosed kitchen Other kitchen exhaust fans, including downdraft: 300 cfm (150 L/s). Bathroom 50 cfm (25 L/s) 210 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—MANDATORY REQUIREMENTS
TABLE 160.2-F—CONTINUOUS LOCAL VENTILATION EXHAUST AIRFLOW RATES Col2 APPLICATION AIRFLOW Enclosed kitchen 5 ach, based on kitchen volume Bathroom 20 cfm (10 L/s) CRSC § 509.0 Medium relevance — show source text
509.0 Grease Removal Devices in Hoods.
509.1 Grease Removal Devices. Listed grease filters or other listed grease removal devices intended for use with commercial cooking operations shall be provided. Listed grease filters and grease removal devices that are removable but not an integral component of a specific listed exhaust hood shall be listed in accordance with UL 1046 and shall be designated on the filter. {NFPA 96:6.1.1, 6.1.2} 509.1.1 Grease Filters, Mesh-Type. Mesh filters shall not be used unless evaluated as an integral part of a listed exhaust hood or listed in conjunction with a primary filter in accordance with UL 1046. {NFPA 96:6.1.3}
509.2 Installation. The distance between the grease removal device and the cooking surface shall be as great as possible but not less than 18 inches (457 mm). [NFPA 96:6.2.1.1]
509.2.1 Vertical Distance. Where grease removal devices are used in conjunction with solid fuel or solid fueltype broilers, including gas or electrically heated charbroilers, a minimum vertical distance of 4 feet (1219 mm) shall be maintained between the lower edge of the grease removal device and the cooking surface. [NFPA 96:6.2.1.2]
Exceptions:
(1) For cooking equipment without exposed flame and where flue gases bypass grease removal devices, the minimum vertical distance shall be permitted to be reduced to not less than 6 inches (152 mm). [NFPA 96:6.2.1.3]
(2) Where a grease removal device is listed for separation distances less than those required in Section
509.2 and Section 509.2.1, the listing requirements shall be permitted. [NFPA 96:6.2.1.4]
(3) Grease removal devices supplied as part of listed hood assemblies shall be installed in accordance with the terms of the listing and the manufacturer’s instructions. [NFPA 96:6.2.1.5]
509.2.2 Grease Removal Device Protection. Where the distance between the grease removal device and the appliance flue outlet (heat source) is less than 18 inches (457 mm), grease removal devices shall be protected from combustion gas outlets and from direct flame impingement occurring during normal operation of cooking appliances producing high flue gas temperatures.
[NFPA 96:6.2.2.1]
509.2.2.1 Installation. This protection shall be permitted to be accomplished by the installation of a steel or stainless steel baffle plate between the heat source and the grease removal device. [NFPA 96:6.2.2.2]
509.2.2.2 Size and Location. The baffle plate shall be sized and located so that flames or combustion gases travel a distance not less than 18 inches (457 mm) from the heat source to the grease removal device. [NFPA 96:6.2.2.3]
509.2.2.3 Clearance. The baffle shall be located not less than 6 inches (152 mm) from the grease removal device. [NFPA 96:6.2.2.4]
509.2.3 Grease Filters. Grease filters shall be listed
CRSC § 508.5.2.1 Medium relevance — show source text
2025 CALIFORNIA MECHANICAL CODE 113
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EXHAUST SYSTEMS
508.5.2.1 Installation. Noncanopy-type commercial cooking hoods shall be installed with the edge of the hood set back not more than 1 foot (305 mm) from the edge of the cooking surface, and the vertical distance between the lip of the hood and the cooking surface shall not exceed 3 feet (914 mm). 508.5.2.2 Capacity. In addition to other requirements for hoods specified in this section, the volume of air exhausting through a noncanopy-type hood to the duct system shall be not less than 300 cubic feet per minute per lineal foot [(ft [3] /min)/ft)] [0.464 (m [3] /s)/m] of cooking equipment. Listed noncanopy exhaust hoods and filters shall be sized and installed in accordance with the terms of their listing and the manufacturer’s installation instructions.
508.5.3 Labeling. Type I hoods shall bear a label indicating the exhaust flow rate in cubic feet per minute per lineal foot [(m [3] /s)/m].
508.6 Solid-Fuel Hood Assemblies. Where solid-fuel cooking equipment is to be used, the solid-fuel hood assembly shall be in accordance with Section 517.0.
508.7 Exhaust Outlets. An exhaust outlet within an unlisted hood shall be located so as to optimize the capture of particulate matter. Each outlet shall serve not more than a 12 foot (3658 mm) section of an unlisted hood.
509.0 Grease Removal Devices in Hoods.
509.1 Grease Removal Devices. Listed grease filters or other listed grease removal devices intended for use with commercial cooking operations shall be provided. Listed grease filters and grease removal devices that are removable but not an integral component of a specific listed exhaust hood shall be listed in accordance with UL 1046 and shall be designated on the filter. {NFPA 96:6.1.1, 6.1.2} 509.1.1 Grease Filters, Mesh-Type. Mesh filters shall not be used unless evaluated as an integral part of a listed exhaust hood or listed in conjunction with a primary filter in accordance with UL 1046. {NFPA 96:6.1.3}
509.2 Installation. The distance between the grease removal device and the cooking surface shall be as great as possible but not less than 18 inches (457 mm). [NFPA 96:6.2.1.1]
509.2.1 Vertical Distance. Where grease removal devices are used in conjunction with solid fuel or solid fueltype broilers, including gas or electrically heated charbroilers, a minimum vertical distance of 4 feet (1219 mm) shall be maintained between the lower edge of the grease removal device and the cooking surface. [NFPA 96:6.2.1.2]
Exceptions:
(1) For cooking equipment without exposed flame and where flue gases bypass grease removal devices, the minimum vertical distance shall be permitted to be reduced to not less than 6 inches (152 mm). [NFPA 96:6.2.1.3]
(2) Where a grease removal device is listed for separation distances less than those required in Section
CRSC § 8.2 Medium relevance — show source text
2 ft**|Hvs ≤ 8.2 ft|8.2 ft <****Hvs ≤ 16.4 ft|8.2 ft <****Hvs ≤ 16.4 ft|16.4 ft <****Hvs|16.4 ft <****Hvs| |Vbz/Az ≤
(CFM/ft2)|As/Al
≤ 0.5|As/Al
> 0.5|As/Al
≤ 0.5|As/Al
> 0.5|As/Al
≤ 0.5|As/Al
> 0.5| |0.2|2.0|1.3|1.3|0.8|0.9|0.6| |0.4|4.0|2.6|2.5|1.6|1.8|1.2| |0.6|6.0|3.9|3.8|2.5|2.7|1.7| |0.8|8.0|5.2|5.0|3.3|3.6|2.3| |1.1|11.0|7.1|6.9|4.5|4.9|3.2|For SI unit: 1 cubic foot per minute = 0.0283 m [3] /min, 1 cubic foot per minute per square foot = 5.08 [(L/s)/m [2] ], 1 square foot = 0.0929 m [2], 1 foot = 304.8 mm,
Where:
Vbz = breathing zone outdoor airflow, per Table 402.1. Az = zone floor area, the net occupiable floor area of the ventilation zone. Hvs = vertical separation between the center of the top and bottom openings’ free operable area; in case of multiple horizontally spaced pairs of openings, use shortest distance encountered. As = openable area of smallest opening (top or bottom); in case of multiple horizontally spaced pairs of top-and-bottom openings, use aggregated areas. Al = openable area of largest opening (top or bottom); in case of multiple horizontally spaced pairs of top-and-bottom openings, use aggregated areas.
Volumetric airflow rates used to estimate required operable area are based on the following:
Dry-air density of 0.075 lbda/ft [3] (1.2 kgda/m [3] ) at a barometric pressure of 1 atm (101.3 kPa) and an air temperature of 70°F (21°C)
Temperature difference between indoors and outdoors of 1.8°F (1°C)
Gravity constant of 32.2 ft/s [2] (9.81m/s [2] )
Window discharge coefficient of 0.6
ical ventilation systems shall include controls, manual or automatic, that enable the fan system to operate wherever the spaces served are occupied. The system shall be designed to maintain minimum outdoor airflow as required by Section 403.0 under any load conditions.
CRSC § 5704.2.7.4 Medium relevance — show source text
5704.2.7.4 Emergency venting. Stationary, above-ground tanks shall be equipped with additional venting that will relieve excessive internal pressure caused by exposure to fires. Emergency vents for Class I, II and IIIA liquids shall not discharge inside buildings. The venting shall be installed and maintained in accordance with Section 22.7 of NFPA 30 except as modified by Section 5703.6.2.2.
Exceptions:
- Tanks larger than 12,000 gallons (45 420 L) in capacity storing Class IIIB liquids that are not within the diked area or the drainage path of Class I or II liquids do not require emergency relief venting.
- Emergency vents on protected above-ground tanks complying with UL 2085 containing Class II or IIIA liquids are allowed to discharge inside the building.
5704.2.7.5 Tank openings other than vents. Tank openings for other than vents shall comply with Sections 5704.2.7.5.1 through 5704.2.7.5.8.
5704.2.7.5.1 Connections below liquid level. Connections for tank openings below the liquid level shall be liquid tight.
5704.2.7.5.2 Filling, emptying and vapor recovery connections. Filling, emptying and vapor recovery connections to tanks containing Class I, II or IIIA liquids shall be located outside of buildings in accordance with Section 5704.2.7.5.6 at a location free from sources of ignition and not less than 5 feet (1524 mm) away from building openings or lot lines of property that can be built on. Such openings shall be properly identified and provided with a liquid-tight cap that shall be closed when not in use.
Filling and emptying connections to indoor tanks containing Class IIIB liquids and connected to fuel-burning equipment shall be located at a finished ground level location outside of buildings. Such openings shall be provided with a liquid-tight cap that shall be closed when not in use. A sign in accordance with Section 5003.6 that displays the following warning shall be permanently attached at the filling location:
TRANSFERRING FUEL OTHER THAN
CLASS IIIB COMBUSTIBLE LIQUID TO THIS TANK CONNECTION IS A VIOLATION
OF THE FIRE CODE AND IS STRICTLY
PROHIBITED
5704.2.7.5.3 Piping, connections and fittings. Piping, connections, fittings and other appurtenances shall be installed in accordance with Section 5703.6.
5704.2.7.5.4 Manual gauging. Openings for manual gauging, if independent of the fill pipe, shall be provided with a liquidtight cap or cover. Covers shall be kept closed when not gauging. If inside a building, such openings shall be protected against liquid overflow and possible vapor release by means of a spring-loaded check valve or other approved device.
5704.2.7.5.5 Fill pipes and discharge lines. For top-loaded tanks, a metallic fill pipe shall be designed and installed to minimize the generation of static electricity by terminating the pipe within 6 inches (152 mm) of the bottom of the tank, and it shall be installed in a manner that avoids excessive vibration.
CRSC § 106.11.2.1 Medium relevance — show source text
Solar reflectance may also be certified by other supervisory entities approved by the Energy Commission pursuant to Title 24, Part 1, California Administrative Code.
TABLE A5.106.11.2.1—VALUES OF SOILING RESISTANCE, ß, BY PRODUCT TYPE Col2 Col3 PRODUCT TYPE CRRC PRODUCT CATEGORY ß Field-applied coating Field-applied coating 0.65 Other Not a field-applied coating 0.70 A5.106.11.2.2 Thermal emittance. Roofing materials shall have a CRRC initial or aged thermal emittance as determined in accordance with ASTM E408 or C1371 equal to or greater than those specified in Table A5.106.11.2.2 for Tier 1 and Table A5.106.11.2.3 for Tier 2.
Thermal emittance may also be certified by other supervisory entities approved by the Energy Commission pursuant to Title 24, Part 1, California Administrative Code.
TABLE A5.106.11.2.2 [BSC]—TIER 1 Col2 Col3 Col4 Col5 ROOF SLOPE CLIMATE ZONE MINIMUM AGED SOLAR REFLECTANCE THERMAL EMITTANCE SRI ≤ 2:12 1–16 0.63 0.75 75 > 2:12 1–16 0.20 0.75 16 A5.106.11.2.3 Solar reflectance index alternative. Solar Reflectance Index (SRI) equal to or greater than the values specified in Table A5.106.11.2.2 for Tier 1 and Table A5.106.11.2.3 for Tier 2 may be used as an alternative to compliance with the aged solar reflectance values and thermal emittance.
SRI values used to comply with this section shall be calculated using the Solar Reflectance Index (SRI) Calculation Worksheet (SRI-WS) developed by the California Energy Commission or in compliance with ASTM E1980-11 as specified in the California Energy Code, Section 110.8(i)3. Solar reflectance values used in the SRI-WS shall be based on the aged reflectance value of the roofing product or the equation in section A5.106.11.2.1 if the CRRC certified aged solar reflectance are not available. Certified Thermal emittance used in the SRI-WS may be either the initial value or the aged value listed by the CRRC.
Solar reflectance and thermal emittance may also be certified by other supervisory entities approved by the Commission pursuant to Title 24, Part 1, California Administrative Code.
Note: The Solar Reflectance Index Calculation Worksheet (SRI-WS) is available by contacting the Energy Standard Hotline at 1-800-772-3300, website at www.energy.ca.gov or by email at Title24@ energy.state.ca.us.
CRSC § 12-16 Medium relevance — show source text
CHAPTER 12-16-1 ENGINEERING REGULATIONS—QUALITY
AND DESIGN OF THE MATERIALS OF
CONSTRUCTION . . . . . . . . . . . . . . . . . . . 101
CHAPTER 12-16-2 ENGINEERING REGULATIONS—QUALITY
AND DESIGN OF THE MATERIALS OF
CONSTRUCTION . . . . . . . . . . . . . . . . . . . 103
CHAPTER 12-31C RADIATION SHIELDING STANDARDS . . 105
CHAPTER 12-71 AIR FILTERS. . . . . . . . . . . . . . . . . . . . . . . 107
CHAPTER 12-72-1 PROTECTIVE SIGNALING SYSTEMS . . . 109
CHAPTER 12-72-2 PROTECTIVE SIGNALING SYSTEMS . . . 123
CHAPTER 12-72-3 PROTECTIVE SIGNALING SYSTEMS . . . 133
HISTORY NOTE APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
2025 CALIFORNIA REFERENCED STANDARDS CODE vii
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
viii 2025 CALIFORNIA REFERENCED STANDARDS CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PART 12 CROSS REFERENCE TABLE
(Cross reference table is nonregulatory, intended only as an aid to the code user.)
PART 12
STANDARDSUBJECT ADOPTING
AGENCYASSOCIATED TITLE 24
BUILDING STANDARDChapter 12-3 Releasing systems for security bars in
dwellingsSFM Part 2, Sections 1031.2.1, 1031.6, 1032.7
Part 2.5, Sections R319.1.1 and R319.4.4
Part 9, Sections 1031.2.1, 1031.6, 1032.7
Appendix 4 Section 452.1.5 and Title 19 provisions 4.1, 4.2, 4.3,
4.4, 4.5, 4.6 reprinted in Part 9
Part 10, Section 505.4Chapter 12-4A Laboratory animal quarters standards DPH Part 2, Section 1236 Chapter 12-4-1 Stage and Platforms SFM Part 2, Sections 410.2.7, 410.2.7.1, 410.2.7.2
Part 9, Sections 105.6.51, 4809Chapter 12-7-1 Fire-resistive standards.
Frequently asked questions
Are residential kitchen range hood filters required to be Class I?
Not necessarily. The CRSC defines the Class I test (SFM 12‑71‑1), but the Mechanical Code requirement for Class I applies to SFM‑regulated applications (see § 509.2.3). Many residential hoods are outside that SFM scope — check the Mechanical Code scope and local enforcement.
If a filter is UL‑listed, is the SFM 12‑71‑1 Class I test still needed?
The Mechanical Code requires listed grease filters; for certain SFM‑regulated uses it additionally requires the filter be Class I when tested per SFM 12‑71‑1. So a UL listing does not automatically substitute unless the listing specifically shows compliance with SFM 12‑71‑1 or the product’s listing/listing conditions cover the requirement. Verify the listing details.
What numerical evidence proves a Class I result?
A SFM 12‑71‑1 test report showing (1) no flames or sparks downstream during the 3‑minute flame exposure and (2) an area under the smoke‑density curve < 1.5 in² meets the Class I criterion per § 12‑71‑100(c)(1).
Who enforces the Class I requirement on a project?
The building official / plan reviewer enforces the Mechanical Code installation and listing requirements; where the application falls under State Fire Marshal jurisdiction (per the referenced list), the SFM/CRSC test requirement will be enforced as part of code compliance and listing verification. See § 509.2.3 and § 12‑71‑100.
What if a manufacturer uses adhesive coatings on filters?
Liquid adhesive coatings on filters must have a flash point of 325°F (163°C) or higher (Cleveland open cup) per § 12‑71‑100(d). Verify coating data on the manufacturer’s submittal.
More in California Referenced Standards Code
- Administration and scope — CRSC Chapter 12 overview
- Air filter standards (Chapter 12‑71)
- Building and facility access / accessibility standards (Chapters 12‑11A, 12‑11B)
- Engineering regulations — quality and design of construction materials (12‑16 series)
- Exits and means of egress (Chapters 12‑10 series)
- Protective signaling systems and detectors (Chapters 12‑72‑1, ‑2, ‑3)
- Radiation shielding standards (Chapter 12‑31C)
- Referenced standards index / cross‑reference table (Part 12 listing of referenced standards)
- Releasing systems for security bars (egress-release standards)
- Standards for insulating materials (Chapter 12‑13)
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