CRSC · California Referenced Standards Code

What observations are made during the test (flame travel, sparks, combustion products)

A clean air filter is exposed to a 3-minute flame in a standard duct while observers watch for flames or sparks traveling downstream and measure smoke using a photoelectric cell. The code (§ 12‑71‑100) requires recording whether flames/sparks project beyond the discharge and computing the area under a smoke-density curve; small area and no sparks = Class 1, moderate area (≤6.0 in²) with no projecting sparks = Class 2.

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Last reviewed: July 6, 2026

What the code requires — plain English

The State Fire Marshal test for air filters requires that a clean (unused) filter be exposed to a controlled flame for 3 minutes while the tester records whether flame or sparks travel downstream, and the density, duration and character of the products of combustion (measured as an area under a smoke-density curve). The controlling rule is § 12-71-100 . All observations and measurements required by the standard are made while the filter is installed in the specified duct and airflow conditions.

The single most important observation: record whether flame or sparks are carried downstream beyond the filter, and quantify smoke by calculating the area under the smoke-density vs. time curve — those results determine classification. § 12-71-100

Requirements in detail

What to watch for (qualitative observations)

  • Flame travel / downstream travel of flame — observe both faces of the filter and the duct downstream for any flame movement away from the filter toward the discharge end. § 12-71-100 (b)(1) .
  • Sparks or projection — note any sparks or projected flaming particles that emerge downstream and whether they would ignite adjacent combustible material beyond the discharge end of the duct. § 12-71-100 (c) .
  • Products of combustion — observe the density, duration and character of smoke and other combustion products; these are quantified by the smoke-density measurement procedure. § 12-71-100 (b)(1)–(2) .

What to measure (quantitative observations)

  • Smoke density measurement is performed using a photoelectric cell and microammeter at the duct discharge; readings are recorded every 5 seconds for the first minute and every 10 seconds for the next two minutes, then converted to an area under the curve that represents smoke density. § 12-71-100 (b)(2)–(3) .
  • Classification depends on (a) absence/presence of flames or sparks and (b) the computed area under the smoke-density curve (square inches). § 12-71-100 (c) .

Decision-relevant table (quick reference)

Decision item / observation Required value / method Why it matters Code Reference
Test duration (flame applied) 3 minutes of flame exposure Observation window for flame/sparks and smoke measurement § 12-71-100 (b)(1)
Duct size / apparatus 21 in. square duct, 13½ ft long; filter frame for 20 × 20 in. filter Ensures standardized flow & observation geometry § 12-71-100 (a)(1–2)
Air velocity during test Approximately 200 linear feet per minute at discharge Controls convective transport of flames/sparks and smoke § 12-71-100 (a)(4)
Flame source Two 1-in pipe elbows producing yellow, wavering flames; ~4 ft³/min gas each Simulated flame attack on filter § 12-71-100 (a)(3)
Smoke measurement timing Read microammeter every 5 s (first 60 s), then every 10 s (next 120 s) Provides time-series to compute area under curve § 12-71-100 (b)(2)
Smoke metric Area under smoke-density curve (square inches on specified plot scale) Numerical criterion for classification § 12-71-100 (b)(3)
Class 1 threshold Area under curve < 1.5 in² AND no flames or sparks produced Highest classification — minimal combustion/smoke § 12-71-100 (c)(1)
Class 2 thresholds Area ≤ 6.0 in²; may burn moderately but must not project flames or extensive sparks beyond duct Moderate performance; limited consumption allowed § 12-71-100 (c)(2)
Adhesive coating flash point ≥ 325°F (Cleveland open cup) for liquid adhesives Prevents low-flash adhesives from creating additional hazard § 12-71-100 (d)

(Every table row is grounded in § 12-71-100 as cited above.)

How smoke area is obtained (brief)

  • The microammeter readings (drop in light intensity) are plotted vs. time on the prescribed scale (40 μA and 40 seconds per inch). The area under that plotted curve — measured by planimeter or calculated mathematically — is the smoke-density metric used in classification. § 12-71-100 (b)(2)–(3) .

Exceptions & special cases

  • Filters must be tested clean (unused); used/loaded filters are not the test condition described in § 12-71-100 (b)(1). Results do not apply to loaded filters unless another procedure is specified. § 12-71-100 (b)(1) .
  • A filter that emits flames or sparks during the test cannot qualify as Class 1 regardless of smoke area; Class 2 allows moderate burning provided no projection of flames or extensive sparks that would ignite adjacent combustibles beyond the duct occurs. If sparks/flames do project and could ignite adjacent combustibles, the unit does not meet Class 2 criteria. § 12-71-100 (c)(1)–(2) .
  • Adhesive coatings are separately constrained by a minimum flash point to avoid low-flash additives creating misleading or unsafe results. § 12-71-100 (d) .

If a test produces smoke area greater than 6.0 in² or projects ignition beyond the duct, the standard’s classification criteria are exceeded; the code does not list a higher class — the specimen fails the Class 1/2 classification per § 12-71-100 (c).

Common mistakes

  • Treating a short-lived ember or small char as harmless sparks without assessing whether it would ignite adjacent combustibles beyond the discharge end — the code explicitly considers that ignition potential. § 12-71-100 (c)(2) .
  • Failing to test clean filters (used filters can trap combustible deposits that change results) — the standard requires clean specimens. § 12-71-100 (b)(1) .
  • Incorrect timing of microammeter readings (not using 5 s and 10 s intervals), which corrupts the smoke-area calculation. § 12-71-100 (b)(2) .
  • Not using the required duct geometry or airflow (~200 fpm), which affects flame/spark transport and smoke measurement. § 12-71-100 (a)(1),(4) .
  • Miscomputing the plotted-scale conversion (the code specifies the plotting scale used) and then misreading the area in square inches. § 12-71-100 (b)(3) .

Worked example — concrete scenario

Scenario: A clean 20 × 20 in. filter is installed in the apparatus described in § 12-71-100 with the air velocity set to ~200 fpm. Flames are applied for 3 minutes and the downstream region is observed.

Observations:

  • No visible continuous flames or sparks exit the discharge end during or after the 3-minute flame exposure. (Qualitative pass for Class 1 flame/spark criterion.) § 12-71-100 (b)(1), (c)(1)
  • Microammeter readings are taken every 5 s (first minute) and every 10 s (next two minutes). After plotting the drop in light vs. time and computing the area under the curve using the standard plot scale, the measured area is 2.0 in².

Decision:

  • Because the area 2.0 in² is greater than the Class 1 threshold (< 1.5 in²), the filter cannot be Class 1 even though no sparks/flames projected downstream. § 12-71-100 (c)(1)
  • The area 2.0 in² is less than or equal to the Class 2 upper limit (≤ 6.0 in²), and since no projecting flames or extensive sparks occurred that would ignite adjacent combustibles, the filter is classified Class 2. § 12-71-100 (c)(2)

If instead sparks had projected beyond the discharge end in a manner that could ignite adjacent combustibles, the unit would fail the Class 2 criterion regardless of the 2.0 in² area. § 12-71-100 (c)(2)

Related provisions

  • § 12-71-100 — Description of test apparatus, method and classification for air filters (controlling section for this article) .
  • § 12-7A-1.5 — Summary of test method for exterior wall assemblies (observations required for sustained flaming / glow on the unexposed side) — related concept of timed observation and noting sustained flaming/glow. .
  • § 12-7A-1.10 — Required content of test reports for wildfire exposure tests, including notation of time/location of sustained flaming and observations of burning characteristics (useful for report-format parallels). .
  • § 12-7A-4A.7.3–7.4 — Decking test conduct and observation requirements (timed exposures and notes on location of flaming, glowing, and loss of material) — analogous observation practice for other SFM tests. .

(These related sections are included in the same CRSC document and provide analogous observation/reporting conventions used across State Fire Marshal standards.)

Code references

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

  • CRSC § 12-71 High 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.

    1. 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.
    2. 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.
    3. 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.
    4. 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.

    1. 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.

    2. 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.

    3. 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:

    1. 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] ).
    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 § 0.5 High relevance — show source text

    ** The horizontal airflow, measured at a horizontal distance of 20 inches (0.5 m) from the edge of the wall assembly, shall not exceed 1.64 ft/s (0.5 m/s). 3. Placement of test frame. Prior to testing, and without the test specimen in place, position the frame assembly under the exhaust hood and set the gas burner for the prescribed level of output. 4. Placement of specimen. Once the burner output is verified, position the specimen holder assembly at the desired test location under the collection hood.

    1. Test specimen. Insert the test specimen into the frame assembly, sealing all edges with ceramic wool.
    2. Ignition. Simultaneously ignite the gas burner and start the timer marking the beginning of the test. Control the burner to a constant 150 ± 8 kW output. Control the hood duct flow to collect all products of combustion.
    3. Flame exposure. Continue the flame exposure until flame penetration of the test specimen and sustained flaming on the unexposed side occurs or for a period of 10 minutes, then extinguish the burner.
    4. Observation. If sustained flaming on the unexposed side of the test specimen has not occurred, observe the unexposed side of the test specimen for an additional 60 minutes for evidence of sustained flaming or glowing combustion on the unexposed side. Terminate the observation prior to the completion of the 60-minute observation period if all evidence of flame, glow and smoke has disappeared.

    Note: An infrared thermometer has been found to be useful to detect the increase of temperature on the unexposed side of the test assembly. 9. Documentation. Perform photographic and/or video documentation before, during and after each test.

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    12-7A-1.10 Report. The report shall include the following:

    1. Name and address of the testing laboratory.

    2. Name and address of test sponsor.

    3. Description of the test specimen including construction details of the wall system, including details of individual components (such as type, thickness and installation method of any sheathing) and the manufacturer’s installation details and limitations as applicable.

    4. Number of specimens tested.

    5. Description of weathering, as applicable.

    6. Moisture content of hygroscopic elements of wall system construction at the time of testing.

    7. Details of the burner verification, including heat supply rate.

    8. Date of test, test identification number and date of report.

    9. The test results shall include:

    9.1. A notation of the time and location of sustained flaming on the unexposed side of the test specimen during the test, along with the sequence number of the test specimen. 9.2. A determination of the presence of glow on the unexposed side of the test specimen at the end of the 60-minute observation period. 9.3. Observations of the burning characteristics of the exposed surface of the test wall during and after the flame

    exposure.

    12-7A-1.11 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.

    1. Absence of flame penetration through the wall assembly at any time.
    2. Absence of evidence of glowing combustion on the interior surface of the assembly at the end of the 70-minute test.
  • CRSC § 4.4.2 High relevance — show source text

    All other measurement details shall be followed as specified in Sections 4.4.2, 4.4.3 and 4.4.4 of ASTM E108. Although ASTM E108 specifies calibration to be conducted with the 33-inch (840-mm) framework spacing used for the intermittent flame test set up, tests have shown that at the nominal 12 mph

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    setting, there was not difference in measured velocity between the 33- and 60-inch (838 mm and 1524 mm) framework spacing. 3.2. Mount the test specimen at a zero horizontal incline positioned 60 inches (1.5 m) from the front opening of the wind tunnel.

    3.3. Ignite the “A” brands as specified in Section 9.4 of ASTM E108 as reprinted here:

    1. Each 12- x 12-inch (300 x 300 mm) face for 30 seconds.
    2. Each 2.25- x 12-inch (57 x 300 mm) edge for 45 seconds.
    3. Each 12- x 12-inch (300 x 300 mm) face again for 30 seconds. 3.4. Center the burning brand laterally on the deck with the front edge 2.5 inches (64 mm) from the entering air edge of the deck.

    3.5. Continue the exposure for a 40-minute period or until all combustion of the deck boards ceases. The test shall be terminated immediately if flaming combustion accelerates uncontrollably (runaway combustion) or structural failure of any deck board occurs. Heat Release Rate is not monitored because of the impracticability with the specified airflow. 4. Observations. Note physical changes of the deck boards during the test, including deformation from the horizontal plane, location of flaming and glowing combustion, and loss of material (i.e., flaming drops of particles falling from the deck). It is desirable to capture the entire test with a video recorder to allow review of the details of performance.

    12-7A-4.8.4 Report. The report shall include description of the deck board material, and the time of any degradation (accelerated combustion, board collapse, flaming drops or particles falling from the deck).

    12-7A-4.8.5 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance:

    1. Absence of sustained flaming or glowing combustion of any kind at the conclusion of the 40-minute observation period.
    2. Absence of falling particles that are still burning when reaching the burner or floor.

    FIGURE 1 — DECK TEST ASSEMBLY (UNDER DECK-FLAME)

    FIGURE 2 — DECK TEST ASSEMBLY (BURNING-BRAND)

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    DECKING ALTERNATE METHOD A

    SFM STANDARD 12-7A-4A

  • CRSC § 436.5. High relevance — show source text

    DEPARTMENT OF HEALTH SERVICES

    Authority: Sections 102, 208 and 25811.

    Reference: Sections 102, 208 and 436.5.

    ALL HEALING ARTS X-RAY INSTALLATIONS

    Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.

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    12-71 AIR FILTERS

    STANDARD 12-71-1

    STATE FIRE MARSHAL

    DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS

    Sec. 12-71-100.

    (a) Test apparatus.

    1. 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.
    2. 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.
    3. 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.
    4. 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.

    1. 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.
  • CRSC § 7.1. High relevance — show source text

    1. Measurement of heat release rate. HRR is measured during the tests with a properly calibrated oxygen depletion calorimeter. Since HRR is typically a post-test analysis, this criterion for Acceptance may be determined at the end of the test.

    2. Burner positioning. Center the burner directly under the middle deck board, midway between the joists. The distance from the top of the burner to the bottom of the deck boards shall be 27 inches (690 mm).

    3. Moisture content. Measure the moisture content of the wooden members of the assembly using a moisture meter (ASTM D4444).

    4. Procedure.

    7.1. Ignition. Ignite the burner, controlling for a constant 80 ± 4 kW output. 7.2. Flame exposure. Continue the exposure for a 3-minute period. Extinguish the burner.

    7.3. Continued combustion. Continue observation for an additional 40 minutes or until all combustion has ceased. The test shall be terminated immediately if flaming combustion accelerates uncontrollably (runaway combustion) or structural failure of any deck board occurs. 8. Observations. Note physical changes of the deck boards during the test, including structural failure of any deck board, location of flaming and glowing ignition, and loss of material (i.e., flaming drops of particles falling from the deck). It is desirable to capture the entire test with a video recorder to allow review of the details of performance.

    12-7A-4A.7.4 Report. The report shall include a description of the deck board material and the time of any degradation (effective net peak heat release rate) during the test.

    12-7A-4A.7.5 Conditions of acceptance. Should one of the three replicates fail to meet the Condition of Acceptance, three additional tests may be run. All of the additional tests must meet the Condition of Acceptance with an effective peak heat release rate of less than or equal to 25 kW/ft [2] (269 kW/m [2] ).

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    12-8-1 FIRE-RESISTIVE STANDARDS FOR FIRE PROTECTION

    ROOM FIRE TEST FOR WALL AND CEILING MATERIALS

    STANDARD 12-8-100 ( SEE CHAPTER 35, CALIFORNIA BUILDING CODE )

    STATE FIRE MARSHAL

    Authority: Sections 13143, 13146.1, Health and Safety Code Reference: Sections 13108, 13143, 13146.1, Health and Safety Code

    SCOPE

    Sec. 12-8-101.

    (a) Basic. This standard is intended to evaluate, under a specified fire exposure condition, the contribution to room fire growth provided by wall ceiling and/or floor materials or assemblies. This standard is not intended to evaluate the fire endurance or flamespread of material or assemblies.

    Note: See State Fire Marshal (SFM) 7-1 and Uniform Building Code (UBC) Standard 8-1.

  • CRSC § 2.2. High relevance — show source text

    2.2. Gypsum board for mounting around the window once it is installed; 2.3. Pieces of gypsum cut into narrow strips for use as trim around the window; 2.4. Caulk to be used as per the window manufacturer's instructions. 3. Wall assembly. A noncombustible wall shall be used with a manufacturer or code-specified opening for the particular window. Install window in framed rough opening following manufacturer guidelines. Apply manufacturer-recommended caulk to nailing flange prior to installation. Use narrow strips of gypsum board as trim around window, covering the nail flange of the window. Any type of framing material may be tested. 3.1. Fit the window test assembly into the rear wall of the Wall Assembly Test Module, sealing all edges, including the soffit-to-wall joint. Ceramic wool or comparable material shall be used for sealing.

    12-7A-2.7 Conduct of tests.

    1. Burner output verification. Without the window in place, set the burner for 150 kW output. Conduct a verification run of 3 minutes to assure the heat release rate, and then turn off the burner.

    2. Test. Place the burner against the wall assembly at the center. Ignite the burner at the 150 kW output and control during the test for constant and uniform output. Optional radiometers can be placed behind the Wall Assembly Test Module to measure heat flux through the window glass.

    3. Duration and observations. The test shall be continued until flame-through occurs at the window. Flame-through can occur at the glass (glazing) and/or in the frame. At this point, the burner shall be extinguished and the assembly monitored for sustained combustion. Note the time elapsed and location of penetration if it occurs.

    4. Report. Report a description of the window unit, including the types of frames, cladding and panes being tested and details of the installation. Record when and how the glass breaks or flame-through occurs in the framing materials or sash, and/or

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    if the framing material deforms or otherwise suffers a loss of integrity such that the glass cannot be held in place, and a record of the time at which any of these events occur.

    12-7A-2.8 Conditions of Acceptance.

    1. Duration of direct flame exposure. To pass this test standard, the window and window assembly shall withstand 8 minutes of direct flame exposure with the absence of flame penetration through the window frame or pane, or structural failure of the window frame or pane.
    2. Flame penetration or structural failure. Flame penetration or structural failure of the flame or pane anytime during the test constitutes failure of this test standard.

    FIGURE 1 — SCHEMATIC OF THE WALL ASSEMBLY Test Module used for evaluating the fire performance of a window.

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    HORIZONTAL PROJECTION UNDERSIDE

    SFM STANDARD 12-7A-3

  • CRSC § 5.3. High relevance — show source text

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    5.3. Continued combustion. If penetration does not occur, continue observation for an additional 30 minutes or until all combustion has ceased.

    Note: An infrared thermometer has been found to be useful to detect the increase of temperature on the back side of the eaves and as an aid to identify the areas of potential combustion. 6. Observations. Note the time, location and nature of flame penetration.

    12-7A-3.9 Report. The report shall include a description of the eaves material, details of the construction of the eaves, moisture content of the framing and wood-based soffit elements as applicable, and point of flame penetration. Provide details on the time and reasons for early termination of the test.

    12-7A-3.10 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.

    1. Absence of flame penetration of the eaves or horizontal projection assembly at any time.
    2. Absence of structural failure of the eaves or horizontal projection subassembly at any time.
    3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.

    FIGURE 1 — EAVES TEST ASSEMBLY

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    DECKING

    SFM STANDARD 12-7A-4

    12-7A-4.1 Application. The minimum design, construction and performance standards set forth herein for unloaded decks are those deemed necessary to establish conformance to the provisions of these regulations. Materials and assemblies that meet the performance criteria of this standard are acceptable for use as defined in California Building Standards Code.

    12-7A-4.2 Scope. This standard evaluates the performance of decks (or other horizontal ancillary structures in close proximity to primary structures) when exposed to direct flames and brands. The under-deck flame exposure test is intended to determine the heat release rate (HRR) and degradation modes of deck or other horizontal boards when exposed to a burner flame simulating combustibles beneath a deck. The burning brand exposure test is intended to determine the degradation modes of deck or other horizontal boards when exposed to a burning brand on the upper surface.

    12-7A-4.3 Referenced document.

    1. ASTM D4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters.

    2. ASTM E108, Test Methods for Fire Tests of Roof Coverings.

    3. California Building Code, Chapter 7A.

    4. UL 790, Standard Test Methods for Fire Tests of Roof Coverings.

    12-7A-4.4 Definitions.

    1. Deck boards. Horizontal members that constitute the exposed surface of the ancillary structure.
    2. Deck surface area. The test specimen area defined by the overall specimen length and width after assembly.
    3. Heat release rate. The net rate of energy release as measured by oxygen depletion calorimetry.

    **12-7A-4.5 Test assembly.

  • CRSC § 12-7 High relevance — show source text
    1. Test Fixture. The test fixture shall be as described in SFM 12-7A-1, with the exception that the top soffit projection of the wall assembly fixture is modified to facilitate installation and removal of eave assemblies. Gypsum board (or equivalent) is used to create a noncombustible wall surface in the 4 x 8 ft. opening in the wall test fixture.
    2. Eaves assembly. Fit the eave assembly into the test module so that the horizontal surface of the assembly is 84 inches (2.1 m) from the top of the burner.
    3. Moisture content. Measure the moisture content of the wooden members of the assembly using a moisture meter (ASTM D4444), and for sheathing products, by methods outlined in ASTM D4442.
    4. Sealing. Seal the edges and ends with ceramic wool or comparable material to prevent flame penetration in these locations of the eave assembly.

    12-7A-3.8 Conduct of Tests.

    1. Airflow. The wall test shall be conducted under conditions of ambient airflow.

    2. Number of tests. Conduct the tests on three replicate eaves assemblies.

    3. Burner output verification. Without the eaves assembly in place, adjust the burner for 300 ± 15 kW output. Extinguish the burner.

    4. Burner positioning. Center the burner with respect to the width of the eaves wall assembly and 0.75 inch (20 mm) from the wall. The distance from the floor to the top of the burner shall be 12 inches (300 mm).

    5. Procedure.

    5.1. Ignition. Ignite the burner, controlling for a constant 300 ± 15 kW output. 5.2. Flame exposure. Continue the exposure until flame penetration of the eaves occurs or for a 10-minute period.

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    5.3. Continued combustion. If penetration does not occur, continue observation for an additional 30 minutes or until all combustion has ceased.

    Note: An infrared thermometer has been found to be useful to detect the increase of temperature on the back side of the eaves and as an aid to identify the areas of potential combustion. 6. Observations. Note the time, location and nature of flame penetration.

    12-7A-3.9 Report. The report shall include a description of the eaves material, details of the construction of the eaves, moisture content of the framing and wood-based soffit elements as applicable, and point of flame penetration. Provide details on the time and reasons for early termination of the test.

    12-7A-3.10 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.

    1. Absence of flame penetration of the eaves or horizontal projection assembly at any time.
    2. Absence of structural failure of the eaves or horizontal projection subassembly at any time.
    3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.

    FIGURE 1 — EAVES TEST ASSEMBLY

  • CRSC § 12-7 High relevance — show source text

    12-7A-1.2 Scope. This standard evaluates the performance of exterior walls of structures when exposed to direct flames.

    12-7A-1.3 Referenced documents.

    1. ASTM E2257, Test Method for Room Fire Test of Wall and Ceiling Materials and Assemblies.

    2. ASTM D4442, Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials.

    3. ASTM D4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters.

    4. California Building Code, Chapter 7A.

    12-7A-1.4 Definitions.

    1. Siding (cladding). Any material that constitutes the exposed exterior covering of an exterior wall and is applied over sheathing or is directly attached to the wall structural system.
    2. Sheathing. The material placed on an exterior wall beneath cladding or siding and is directly attached to the wall structural system.

    12-7A-1.5 Summary of test method.

    1. Direct flame exposure. This test method provides for the direct flame exposure of a wall specimen to a flame source centered at the base of a 4-foot by 8-foot (1220 mm by 2440 mm) test assembly.
    2. Gas burner. The method employs a gas burner to produce a diffusion flame in contact with the test wall assembly.
    3. Heat output. The gas burner produces a prescribed net rate of heat output of 8535 Btu/min (150 kW) for a period of 10 minutes, after which the flame exposure is terminated.
    4. Resistance to fire penetration. The test method measures the ability of the wall system to resist fire penetration from the exterior to the unexposed side of the test assembly under the conditions of exposure. Observations are made for the appearance of sustained flaming or glow on the unexposed side and/or sustained glowing on the unexposed side at the end of a 60-minute observation period.

    12-7A-1.6 Equipment. Unless otherwise noted, dimensions in the following descriptions shall be followed with a tolerance of ± 0.5 inch (13 mm).

    1. Wall assembly holding fixture. The test specimen support assembly shown in Figure 1 is designed to permit rapid installation and removal of wall assemblies, and to prevent edge penetration of fire at the margins of the wall assembly. It includes a sturdy frame assembly to hold the specimen and a simulated soffit that is noncombustible. The frame assembly permits a 4-foot by 8-foot (1220 mm by 2440 mm) prefabricated wall section to be inserted and to be sealed in such a way that protects the edges from fire. Side shields are situated near the vertical edges and to within 12 inches (304 mm) of the top of the test wall assembly as shown in Figure 1 to aid in minimizing extraneous drafts to the surface of the assembly.

    2. Burner.

    2.1. Burner details. The ignition source for the test shall be a gas diffusion burner with a nominal 4-inch-wide by 39-inchlong (100 mm wide by 1000 mm long) porous top surface of a refractory material, as shown in Figure 2. With the exception of top surface dimensions, the essential configuration of the burner is comparable to the burner design described in ASTM E2257. The burner enclosure shall be positioned so that it is centered relative to the width of the test wall.

  • CRSC § 12-7 High relevance — show source text

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    MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

    12-7A-1.10 Report. The report shall include the following:

    1. Name and address of the testing laboratory.

    2. Name and address of test sponsor.

    3. Description of the test specimen including construction details of the wall system, including details of individual components (such as type, thickness and installation method of any sheathing) and the manufacturer’s installation details and limitations as applicable.

    4. Number of specimens tested.

    5. Description of weathering, as applicable.

    6. Moisture content of hygroscopic elements of wall system construction at the time of testing.

    7. Details of the burner verification, including heat supply rate.

    8. Date of test, test identification number and date of report.

    9. The test results shall include:

    9.1. A notation of the time and location of sustained flaming on the unexposed side of the test specimen during the test, along with the sequence number of the test specimen. 9.2. A determination of the presence of glow on the unexposed side of the test specimen at the end of the 60-minute observation period. 9.3. Observations of the burning characteristics of the exposed surface of the test wall during and after the flame

    exposure.

    12-7A-1.11 Conditions of Acceptance. Should one of the three replicates fail to meet the Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet the Conditions of Acceptance.

    1. Absence of flame penetration through the wall assembly at any time.
    2. Absence of evidence of glowing combustion on the interior surface of the assembly at the end of the 70-minute test.

    40 2025 CALIFORNIA REFERENCED STANDARDS CODE

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    MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

    EXTERIOR WINDOWS

    SFM STANDARD 12-7A-2

    12-7A-2.1 Application. Exterior window assemblies that meet the performance criteria of this standard are acceptable for use as defined in the California Building Standards Code.

    12-7A-2.2 Scope. This standard evaluates the performance of exterior windows used in structures when exposed to direct flames.

    12-7A-2.3 Referenced documents.

    1. AAMA (for definitions) Training Manual, Residential & Light Commercial Window and Door Installation Training and Registration Program.
    2. CAWM 400-95, Standard Practice for Installation of Windows with Integral Mounting Flange in Wood Frame Construction.

    12-7A-2.4 Definitions.

    1. Frame (Jambs). This usually consists of two vertical members (side jambs) and two horizontal members (head and sill) that hold the sash. Frames and sash are typically made of steel, aluminum, vinyl, fiberglass, wood or a combination of these materials.

    2. Glazing. The glass in a window. It may include layers of plastic as well as glass.

    3. Sash. The fixed or movable parts of the window in which the panes of glass are set.

    12-7A-2.5 Test apparatus.

    1. Wall assembly test module. The module is designed to permit rapid installation and removal of window/wall assemblies, and is designed to prevent edge penetration of fire at the margins.
  • CRSC § 12-7 High relevance — show source text

    12-7A-4A.7.2 Test system preparation. See 12-7A-4 Figure No. 1.

    1. Deck support assembly. Assembly that holds the test deck over the burner.
    2. Baffle panels and joist support. Horizontal metal plates to support the deck joists along their full length, and also to confine burner flames to the underside of the deck boards located between the support joists.
    3. Back wall. Ceramic fiber board or another noncombustible panel product for the back wall material. Total height of the back wall is 8 feet (2.4 m).
    4. Ledger board. A 4-foot-long (1.2 m) simulated 2 x 6 ledger board shall be constructed of layers of ceramic fiber board (or other noncombustible panel product) and attached to the wall at a height slightly below the overhang of the rear deck board of the test deck.

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    MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE

    12-7A-4A.7.3 Conduct of tests.

    1. Airflow. The test is conducted under conditions of ambient airflow.

    2. Number of tests. Conduct the test on three replicate assemblies.

    3. Burner output verification. Without a deck in the apparatus, set the output of the burner to 80 ± 4 kW. Conduct a verification run of 3 minutes to ensure the heat release rate, and then turn off the burner.

    4. Measurement of heat release rate. HRR is measured during the tests with a properly calibrated oxygen depletion calorimeter. Since HRR is typically a post-test analysis, this criterion for Acceptance may be determined at the end of the test.

    5. Burner positioning. Center the burner directly under the middle deck board, midway between the joists. The distance from the top of the burner to the bottom of the deck boards shall be 27 inches (690 mm).

    6. Moisture content. Measure the moisture content of the wooden members of the assembly using a moisture meter (ASTM D4444).

    7. Procedure.

    7.1. Ignition. Ignite the burner, controlling for a constant 80 ± 4 kW output. 7.2. Flame exposure. Continue the exposure for a 3-minute period. Extinguish the burner.

    7.3. Continued combustion. Continue observation for an additional 40 minutes or until all combustion has ceased. The test shall be terminated immediately if flaming combustion accelerates uncontrollably (runaway combustion) or structural failure of any deck board occurs. 8. Observations. Note physical changes of the deck boards during the test, including structural failure of any deck board, location of flaming and glowing ignition, and loss of material (i.e., flaming drops of particles falling from the deck). It is desirable to capture the entire test with a video recorder to allow review of the details of performance.

    12-7A-4A.7.4 Report. The report shall include a description of the deck board material and the time of any degradation (effective net peak heat release rate) during the test.

  • CRSC § 1.5 High relevance — show source text
    1. 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.
    2. 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:

    1. 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] ).
    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.

    2025 CALIFORNIA REFERENCED STANDARDS CODE 107

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    108 2025 CALIFORNIA REFERENCED STANDARDS CODE

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    12-72-1 PROTECTIVE SIGNALING SYSTEMS

    STANDARD TEST PROCEDURES

    STANDARD 12-72-1

    STATE FIRE MARSHAL

    SCOPE

    Sec. 12-72-100.

    (a) Basic. This standard represents the minimum basic requirements for the construction and performance of the protective signaling systems to be listed under this classification. The minimum design, construction and performance standards set forth herein are those deemed as minimum necessary to establish conformance to the regulations of the State Fire Marshal as set forth in the California Electrical Code, and when applicable shall be reported on in their entirety by the approved testing laboratory.

    (b) Systems. This standard covers electrically operated devices and control units designed to transmit and sound alarms, supervisory and trouble signals to be employed in ordinary indoor locations in accordance with the Standards of the National Fire Protection Association for the Installation, Maintenance and Use of Proprietary, Auxiliary and Local Protective Signaling Systems, Remote Station, Nos. 72A, 72B, 72C and 72D, and the California Electrical Code. This includes combination protective signaling systems employing nonsupervised sounding circuits; combination fire alarm-communication, -program and -clock systems (hereinafter referred to as combination signaling systems); and audible devices used for both alarm and program or communication

    purposes.

Frequently asked questions

What exactly is counted as "projection of sparks" that would disqualify Class 2?

If sparks or flaming particles are projected downstream beyond the discharge end of the duct in a way that would ignite adjacent combustible materials, the unit fails the no-projection requirement in § 12-71-100 (c)(2). The code stresses ignition potential, not merely the presence of non-igniting ash.

How is the smoke “area” converted to square inches?

Microammeter readings (drop in light) are plotted vs. time on the specified scale (40 μA and 40 seconds per inch) and the resulting area under that curve is measured (planimeter or calculation) to give square inches — see § 12-71-100 (b)(2–3).

Must filters be totally uncoated for the test?

No — the standard allows liquid-adhesive coatings, but any liquid-adhesive coating used on filters must have a flash point of 325°F (163°C) Cleveland open cup or higher. § 12-71-100 (d)

If flames appear but do not reach the discharge end, can the filter be Class 1?

No. Class 1 requires that the filter “do not produce flames or sparks when attacked by flame.” Any flames or sparks produced during the test disqualify Class 1. § 12-71-100 (c)(1)

What if my smoke-area computation is borderline (e.g., 1.49 vs 1.51 in²)?

The standard defines numeric thresholds: < 1.5 in² for Class 1; ≤ 6.0 in² for Class 2. Report and document the measured area and the measurement method (plot scale, planimeter/calculation). If ambiguity remains, re-check the plotted data and measurement process per § 12-71-100 (b)(2–3).

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California Referenced Standards Code