Protective clothing test methods

The puncture resistance test measures the pounds of force needed for an 8D nail to penetrate the outsole and sole plate under controlled travel rate and test ensemble. The test procedure and apparatus are described in Appendix E to Subpart L of 29 CFR 1910 and are used to evaluate footwear for fire brigades under 1910.156.

• Apparatus: a testing machine with a movable platform running at 1/4 inch/min (0.1 cm/sec), two rigid blocks (one drilled to hold an 8D nail at a 98° angle), a leather outsole piece, a new 8D nail for each determination, and a sole plate/sample assembly.
• Procedure: assemble the blocks, outsole sample, and sole plate so the nail can penetrate; start the machine and record the pounds of force required for complete penetration to the nearest five pounds; perform two determinations per sole plate and average the results; use a new nail for each determination.
• Reference: the method reproduces the specifications from the Military Specification for Fireman's Boots (MIL-B-2885D) as stated in Appendix E.

The trapezoid tearing test specimen must be a 3-inch by 6-inch rectangle with the long dimension parallel to the warp for warp tests and parallel to the filling for filling tests. These specimen requirements are specified in Appendix E to Subpart L of 29 CFR 1910 which supports protective clothing evaluations in connection with 1910.156.

• Location: specimens must be taken no nearer than one-tenth the cloth width from the selvage.
• Diversity: no two warp specimens may contain the same warp yarns and no two filling specimens may contain the same filling yarns.
• Marking: an isosceles trapezoid (altitude 3 in; bases 1 in and 4 in) is marked on each specimen and a center cut ~3/8 in made before testing.

You must test five specimens in each of the warp and filling directions and report the average tearing strength separately for warp and filling to the nearest 0.1 pound. This reporting requirement appears in Appendix E to Subpart L of 29 CFR 1910 and relates to protective clothing criteria referenced by 1910.156.

• Measurement: the tearing strength of the sample unit is the average of the five highest peak loads for 3 inches of separation.
• Units and precision: report averages to the nearest 0.1 pound (0.05 kg).
• Discarding invalid runs: specimens that slip, break at clamp edges, or otherwise produce outlier low values due to technique must be discarded and replaced.

The machine must hold the specimen with two clamps having one-inch by three-inch jaw faces, use six-ounce weight tension clamps, and pull at 12 ± 0.5 inches per minute. These apparatus and speed details are set forth in Appendix E to Subpart L of 29 CFR 1910 used for protective clothing testing under 1910.156.

• Clamps: jaws must have flat smooth gripping surfaces; edges rounded to ≤1/64 in; slipping specimens may have rubber-faced jaws.
• Gage length: distance between jaws is one inch at test start.
• Speed control: pulling clamp uniform movement, set to 12 ± 0.5 in/min (0.5 ± .02 cm/sec).

Vertical flame resistance testing requires rectangular specimens 2 3/4 inches by 12 inches (long axis parallel to warp or filling), and five specimens from each direction must be tested. These specimen and quantity requirements are described in Appendix E to Subpart L of 29 CFR 1910 which supports fire brigade protective clothing rules in 1910.156.

• Direction: long dimension parallel to warp for warp tests or to filling for filling tests; do not reuse yarns between specimens in the same direction.
• Number: test five specimens per direction (warp and filling) from each sample unit.
• Conditioning: all specimens must reach moisture equilibrium under the specified standard atmosphere before testing.

The vertical flame test requires a specified burner geometry, a control valve system delivering gas at 2.5 ± 0.25 psi at the burner inlet, and a synthetic gas mixture with the composition and properties listed in Appendix E. These apparatus and gas requirements are in Appendix E to Subpart L of 29 CFR 1910 and align with the flame-resistance testing used to support 1910.156.

• Burner: 3/8-inch inside diameter barrel, pilot tube ~1/16-inch diameter spaced 1/8-inch away, and positioning so the center of the barrel is directly below specimen center.
• Pressure: delivery rate to furnish gas under 2.5 ± 0.25 psi at the burner inlet; see 1910.156(g)(3)(vi)(A).
• Synthetic gas: 55 ± 3% H2, 24 ± 1% CH4, 3 ± 1% C2H6, 18 ± 1% CO; specific gravity ~0.365 ± 0.018 and B.T.U. content 540 ± 20 per cubic foot at 21 °C.

The burner flame is applied vertically at the middle of the lower edge of the specimen for 12 seconds while the specimen is suspended so its lower end is 3/4-inch above the burner. These exposure details are prescribed in Appendix E to Subpart L of 29 CFR 1910 and connect to protective clothing requirements in 1910.156.

• Positioning: specimen suspended vertically in the cabinet with entire length exposed and lower end 3/4-inch (1.9 cm) above the burner.
• Cabinet: testing must be in a draft-free area and the cabinet door remains shut during the test.
• Pilot: pilot flame adjusted to ~1/8-inch in height before insertion of specimen.

After-flame time is the time the specimen continues to flame after the burner is shut off and must be recorded to the nearest 0.2 second; char length is measured after flaming and glowing cease and reported to the nearest 0.1 inch—both reported as averages of the specimen results. These measurement and reporting rules are in Appendix E to Subpart L of 29 CFR 1910 which supports fire brigade clothing standards in 1910.156.

• After-flame: time measured to 0.2-second resolution.
• Char length: fold specimen lengthwise, locate highest peak of char, attach specified weight/hooks and apply gentle tearing; measure distance from lower end to tear along undamaged edge to 0.1-inch resolution.
• Reporting: average after-flame time and average char length from all specimens tested are the sample unit results; record all individual specimen values.

Appendix E specifies the total tearing weight to use in the char-length test based on the cloth's pre-treatment weight per square yard: 0.25 lb for 2.0–6.0 oz/yd², 0.5 lb for >6.0–15.0 oz/yd², 0.75 lb for >15.0–23.0 oz/yd², and 1.0 lb for >23.0 oz/yd². These table values are provided in Appendix E to Subpart L of 29 CFR 1910 that guide flame-resistance evaluation for 1910.156.

• Use the specified total tearing weight (hook + weight) corresponding to the cloth's weight per square yard.
• Convert units if needed using the S.I. conversions provided in the appendix.

Specimens must be brought to moisture equilibrium under the standard atmospheric conditions described in the appendix and exposed to the test flame within 20 seconds after removal from the conditioning atmosphere. This conditioning requirement is in Appendix E to Subpart L of 29 CFR 1910, which supports the protective clothing criteria in 1910.156.

• Standard atmosphere: follow paragraph (3)C of the appendix for the defined standard atmospheric conditions.
• Timing: start flame exposure within 20 seconds after taking the specimen out of the conditioning cabinet.
• Disputes: in case of measurement dispute, all testing will be conducted under the standard atmospheric conditions specified.

The testing machine must have an error not exceeding 2% up to a 50-pound load and 1% over 50 pounds, and its capacity must be such that the maximum breaking load is between 15% and 85% of rated capacity. These accuracy and capacity criteria are in Appendix E to Subpart L of 29 CFR 1910 used for evaluating protective clothing per 1910.156.

• Error tolerances: ≤2% error at readings ≤50 lb; ≤1% error for readings >50 lb.
• Rated capacity: design machine so breaking load lies between 15% and 85% of the machine's rated capacity.
• Recording: calibrated dial, scale, or chart must indicate applied load and elongation and retain the peak load reading after rupture.

If a specimen slips between the jaws, breaks at the jaw edges, or produces an anomalously low result due to faulty technique, that individual measurement must be discarded and another specimen tested. This handling of invalid tests is required by Appendix E to Subpart L of 29 CFR 1910 which underpins protective clothing testing in 1910.156.

• Replace the discarded specimen with a new one from the sample unit.
• Continue until the required number of valid specimen measurements (five per direction) are obtained.
• Document discarded runs and reasons in the test report.

You must report both the after-flame time (to nearest 0.2 s) and the char length (to nearest 0.1 in) for each individual specimen and give the average values for the sample unit. These reporting requirements are specified in Appendix E to Subpart L of 29 CFR 1910 and are used to demonstrate compliance with protective clothing requirements under 1910.156.

• Record each specimen's after-flame time and char length.
• Compute and report sample-unit averages for both metrics with the specified precision.
• Include all individual values in the test record.

Appendix E reproduces established federal and military textile and footwear test methods, specifically referencing Military Specification MIL-B-2885D for puncture resistance and Federal Test Method Standard 191 (Methods 5136 and 5903) for tearing and flame tests. The appendix itself is part of 29 CFR 1910 Subpart L that supports fire brigade protective clothing requirements in 1910.156.

• Puncture test: reproduced from "Military Specification For Fireman's Boots," MIL-B-2885D (1973, 1975 amendment).
• Tearing and flame tests: reproductions from "Federal Test Method Standard 191, Method 5136" and "Method 5903 (1971)."
• Use: these established methods are used to determine whether protective clothing meets the levels required by 1910.156 for fire brigades.

Labs must clear fumes and smoke from the test cabinet after each specimen and ensure precise timing (burner applied for 12 seconds; after-flame recorded to 0.2 s) before testing the next specimen. These procedural controls are specified in Appendix E to Subpart L of 29 CFR 1910 which supports protective clothing testing for 1910.156.

• Burner application: apply flame for exactly 12 seconds and then shut off.
• After each test: ventilate or clear the cabinet of smoke and fumes before inserting the next specimen.
• Recordkeeping: document timing, cabinet clearing actions, and any deviations in the test report.

The vertical flame test in Appendix E provides objective measures (after-flame and char length) that support evaluating whether protective clothing meets the performance criteria required for fire brigade garments under 1910.156(g)(3)(vi). Appendix E details the test apparatus and procedure to generate those measures within 29 CFR 1910 Subpart L.

• Purpose: supplies standardized test data used to judge flame resistance and material integrity for fire brigade clothing.
• Link to regulation: see 1910.156(g)(3)(vi)(A) for the regulatory cross-reference to test apparatus pressure and burner delivery.
• Compliance: manufacturers and employers rely on these measured outcomes when selecting garments to meet the protective performance expected under 1910.156.