(a) Purpose. The purpose of this standard is to reduce danger of injury and loss of life by providing, on a national basis, standard methods of testing and rating the flammability of textiles and textile products for clothing use, thereby prohibiting the use of any dangerously flammable clothing textiles.

(b) Scope. The Standard provides methods of testing the flammability of clothing and textiles intended to be used for clothing, establishes three classes of flammability, sets forth the requirements which textiles shall meet to be classified, and warns against the use of those textiles which have burning characteristics unsuitable for clothing. Hereafter, “clothing and textiles intended to be used for clothing” shall be referred to as “textiles.”

(c) Specific exceptions. This standard shall not apply to: (1) Hats, provided they do not constitute or form part of a covering for the neck, face, or shoulders when worn by individuals;

(2) Gloves, provided they are not more than 14 inches in length and are not affixed to or do not form an integral part of another garment;

(3) Footwear, provided it does not consist of hosiery in whole or part and is not affixed to or does not form an integral part of another garment;

(4) Interlining fabrics, when intended or sold for use as a layer between an outer shell and an inner lining in wearing apparel.

(d) Specific exemptions. Experience gained from years of testing in accordance with the Standard demonstrates that certain fabrics consistently yield acceptable results when tested in accordance with the Standard. Therefore, persons and firms issuing an initial guaranty of any of the following types of fabrics, or of products made entirely from one or more of these fabrics, are exempt from any requirement for testing to support guaranties of those fabrics:

(1) Plain surface fabrics, regardless of fiber content, weighing 2.6 ounces per square yard or more; and

(2) All fabrics, both plain surface and raised-fiber surface textiles, regardless of weight, made entirely from any of the following fibers or entirely from combination of the following fibers: acrylic, modacrylic, nylon, olefin, polyester, wool.

(e) Applicability. The requirements of this part 1610 shall apply to textile fabric or related material in a form or state ready for use in an article of wearing apparel, including garments and costumes finished for consumer use.

In addition to the definitions given in Section 2 of the Flammable Fabrics Act as amended (15 U.S.C. 1191), the following definitions apply for this part 1610.

(a) Base burn (also known as base fabric ignition or fusing) means the point at which the flame burns the ground (base) fabric of a raised surface textile fabric and provides a self-sustaining flame. Base burns, used to establish a Class 2 or 3 fabric, are those burns resulting from surface flash that occur on specimens in places other than the point of impingement (test result code SFBB) when the warp and fill yarns of a raised surface textile fabric undergo combustion. Base burns can be identified by an opacity change, scorching on the reverse side of the fabric, or when a physical hole is evident.

(b) Burn time means the time elapsed from ignition until the stop thread is severed as measured by the timing mechanism of the test apparatus.

(c) Dry cleaning means the cleaning of samples in a commercial dry cleaning machine under the conditions described in § 1610.6.

(d) Film means any non-rigid, unsupported plastic, rubber or other synthetic or natural film or sheeting, subject to the Act, or any combination thereof, including transparent, translucent, and opaque material, whether plain, embossed, molded, or otherwise surface treated, which is in a form or state ready for use in wearing apparel, and shall include film or sheeting of any thickness.

(e) Flammability means those characteristics of a material that pertain to its relative ease of ignition and relative ability to sustain combustion.

(f) Flame application time means the 1 second during which the ignition flame is applied to the test specimen.

(g) Ignition means that there is a self-sustaining flame on the specimen after the test flame is removed.

(h) Interlining means any textile which is intended for incorporation into an article of wearing apparel as a layer between an outer shell and an inner lining.

(i) Laundering means washing with an aqueous detergent solution and includes rinsing, extraction and tumble drying as described in § 1610.6.

(j) Long dimension means the 150 mm (6 in) length of test specimen.

(k) Plain surface textile fabric means any textile fabric which does not have an intentionally raised fiber or yarn surface such as a pile, nap, or tuft, but shall include those fabrics that have fancy woven, knitted or flock-printed surfaces.

(l) Raised surface textile fabric means any textile fabric with an intentionally raised fiber or yarn surface, such as a pile, including flocked pile, nap, or tufting.

(m) Refurbishing means dry cleaning and laundering in accordance with § 1610.6.

(n) Sample means a portion of a lot of material which is taken for testing or for record keeping purposes.

(o) Specimen means a 50 mm by 150 mm (2 in by 6 in) section of sample.

(p) Stop thread supply means 3-ply, white, mercerized, 100% cotton sewing thread, with a Tex size of 40 ±5.

(q) Surface flash means a rapid burning of the pile fibers and yarns on a raised fiber surface textile that may or may not result in base burning.

(r) Textile fabric means any coated or uncoated material subject to the Act, except film and fabrics having a nitro-cellulose fiber, finish, or coating, which is woven, knitted, felted or otherwise produced from any natural or manmade fiber, or substitute therefore, or combination thereof, of 50 mm (2 in) or more in width, and which is in a form or state ready for use in wearing apparel, including fabrics which have undergone further processing, such as dyeing and finishing, in garment form, for consumer use.

The Standard provides methods of testing the flammability of textiles from or intended to be used for apparel; establishes three classes of flammability; sets forth the requirements for classifying textiles; and prohibits the use of single or multi-layer textile fabrics that have burning characteristics that make them unsuitable for apparel. All textiles shall be tested before and after refurbishing according to § 1610.6. Each specimen cut from the textile shall be inserted in a frame, brushed if it has a raised-fiber surface, and held in a special apparatus at an angle of 45°. A standardized flame shall be applied to the surface near the lower end of the specimen for 1 second, and the time required for the flame to proceed up the fabric a distance of 127 mm (5 in) shall be recorded. A notation shall be made as to whether the base of a raised-surface textile fabric ignites or fuses.

(a) Class 1, Normal Flammability. Class 1 textiles exhibit normal flammability and are acceptable for use in clothing. This class shall include textiles which meet the minimum requirements set forth in paragraph (a)(1) or paragraph (a)(2) of this section.

(1) Plain surface textile fabric. Such textiles in their original state and/or after being refurbished as described in § 1610.6(a) and § 1610.6(b), when tested as described in § 1610.6 shall be classified as Class 1, Normal flammability, when the burn time is 3.5 seconds or more.

(2) Raised surface textile fabric. Such textiles in their original state and/or after being refurbished as described in § 1610.6(a) and (b), when tested as described in § 1610.6, shall be classified as Class 1, Normal Flammability, when the burn time is more than 7.0 seconds, or when they burn with a rapid surface flash (0.0 to 7.0 seconds), provided the intensity of the flame is so low as not to ignite or fuse the base fabric.

(b) Class 2, Intermediate flammability. Class 2 fabrics, applicable only to raised-fiber surface textiles, are considered to be of intermediate flammability, but may be used for clothing. This class shall include textiles which meet the minimum requirements set forth in paragraph (b)(2) of this section.

(1) Plain surface textile fabric. Class 2 is not applicable to plain surface textile fabrics.

(2) Raised surface textile fabric. Such textiles in their original state and/or after being refurbished as described in § 1610.6(a) and (b), when tested as described in § 1610.6, shall be classified as Class 2, Intermediate Flammability, when the burn time is from 4.0 through 7.0 seconds, both inclusive, and the base fabric starts burning at places other than the point of impingement as a result of the surface flash (test result code SFBB).

(c) Class 3, Rapid and intense burning. Class 3 textiles exhibit rapid and intense burning, are dangerously flammable and shall not be used for clothing. This class shall include textiles which have burning characteristics as described in paragraphs (c)(1) and (c)(2) of this section. Such textiles are considered dangerously flammable because of their rapid and intense burning.

(1) Plain surface textile fabric. Such textiles in their original state and/or after refurbishing as described in § 1610.6(a) and § 1610.6(b), when tested as described in § 1610.6, shall be classified as Class 3 Rapid and Intense Burning when the time of flame spread is less than 3.5 seconds.

(2) Raised surface textile fabric. Such textiles in their original state and/or after refurbishing as described in § 1610.6(a) and § 1610.6(b), when tested as described in § 1610.6, shall be classified as Class 3, Rapid and Intense Burning, when the time of flame spread is less than 4.0 seconds, and the base fabric starts burning at places other than the point of impingement as a result of the surface flash (test result code SFBB).

(a) Flammability apparatus. The flammability test apparatus consists of a draft-proof ventilated chamber enclosing a standardized ignition mechanism, sample rack, and automatic timing mechanism. The flammability apparatus shall meet the minimum requirements for testing as follows.

(1) Test chamber—(i) Test chamber structure. The test chamber shall be a metal, draft-proof ventilated chamber. The test chamber shall have inside dimensions of 35.3 cm high by 36.8 cm wide by 21.6 cm deep (14 in by 14.5 in by 8.5 in). There shall be eleven or twelve 12.7 mm diameter (0.5 in) holes equidistant along the rear of the top closure. The front of the chamber shall be a close fitting door with an insert made of clear material (i.e., glass, plexiglass) to permit observation of the entire test. A ventilating strip is provided at the base of the door in the front of the apparatus. The test chamber to be used in this test method is illustrated in Figures 1 and 2 of this part.

(ii) Specimen rack. The specimen rack provides support for the specimen holder (described in paragraph (a)(1)(iii) of this section) in which the specimen is mounted for testing. The angle of inclination shall be 45°. Two guide pins projecting downward from the center of the base of the rack travel in slots provided in the floor of the chamber so that adjustment can be made for the thickness of the specimen in relation to the test flame. A stop shall be provided in the base of the chamber to assist in adjusting the position of the rack. The specimen rack shall be constructed so that: It supports the specimen holder in a way that does not obstruct air flow around the bottom edge of the fabric specimen; and the fabric specimen is properly aligned with the igniter tip during flame impingement. The specimen rack to be used in this test method is illustrated in Figures 1 through 3 of this part. Movable rack: Refer to the manufacturers' instruction in relation to the adjustment procedure to move the rack into the appropriate position for the indicator finger alignment.

(iii) Specimen holder. The specimen holder supports and holds the fabric specimen. The specimen holder shall consist of two 2 mm (0.06 in) thick U-shaped matched metal plates. The plates are slotted and loosely pinned for alignment. The specimen shall be firmly sandwiched in between the metal plates with clamps mounted along the sides. The two plates of the holder shall cover all but 3.8 cm (1.5 in) of the width of the specimen for its full length. See Figures 1 and 3 of this part. The specimen holder shall be supported in the draft-proof chamber on the rack at an angle of 45°.

(iv) Indicator finger. The position of the specimen rack (described in paragraph (a)(1)(ii) of this section) shall be adjusted, so the tip of the indicator finger just touches the surface of the specimen. An indicator finger is necessary to ensure that the tip of the test flame will impinge on the specimen during testing. The indicator finger to be used in this test method is illustrated in Figures 1, 2 and 4 of this part.

(v) Ignition mechanism. The ignition mechanism shall consist of a motor driven butane gas jet formed around a 26-gauge hypodermic needle and creates the test flame. The test flame shall be protected by a shield. See Figure 5. The test flame is adjusted to 16 mm (0.625 in) and applied to the specimen for 1 second. A trigger device is located in the front of the apparatus, the pulling or pushing of which activates the test flame impingement and timing device. Electro-mechanical devices (i.e., servo-motors, solenoids, micro-switches, and electronic circuits, in addition to miscellaneous custom made cams and rods, shock absorbing linkages, and various other mechanical components) can be used to control and apply the flame impingement. See Figure 6 of this part.

(vi) Draft ventilator strip. A draft ventilator strip shall be placed across the front opening, sealing the space between the sliding door when in lowered position and the base on which the grid rack is attached. (See Figure 1 of this part.)

(vii) Stop weight. The weight, attached by means of a clip to the stop thread, in dropping actuates the stop motion for the timing mechanism. The weight shall be 30g ±5g (1.16 oz. ±0.18 oz).

(viii) Door. The door shall be a clear (i.e. glass or plexiglass) door, close fitting and allows for viewing of the entire test.

(ix) Hood. The hood or other suitable enclosure shall provide a draft-proof environment surrounding the test chamber. The hood or other suitable enclosure shall have a fan or other means for exhausting smoke and/or fumes produced by testing.

(2) Stop thread and thread guides—(i) Stop thread. The stop thread shall be stretched from the spool through suitable thread guides provided on the specimen holder and chamber walls.

(ii) Stop thread supply. This supply, consisting of a spool of 3-ply, white, mercerized, 100% cotton sewing thread, with a Tex size of 40 ±5 Tex, shall be fastened to the side of the chamber and can be withdrawn by releasing the thumbscrew holding it in position.

(iii) Thread Guides. The thread guides permit the lacing of the stop thread in the proper position exactly 127 mm (5 in) from the point where the center of the ignition flame impinges on the test specimen. The stop thread shall be 9.5 mm (0.37 in) above and parallel to the lower surface of the top plate of the specimen holder. This condition can be achieved easily and reproducibly with the use of a thread guide popularly referred to as a “sky hook” suspended down from the top panel along with two L-shaped thread guides attached to the upper end of the top plate of the specimen holder. Two other thread guides can be installed on the rear panel to draw the thread away from directly over the test flame. The essential condition, however, is the uniform height of 9.5 mm (0.37 in) for the stop thread and not the number, placement or design of the thread guides.

(iv) Stop weight thread guide. This thread guide shall be used to guide the stop thread when attaching the stop weight.

(3) Supply for test flame. (i) The fuel supply shall be a cylinder of chemically pure (c. p.) butane.

(ii) The fuel-tank control valve shall consist of a sensitive control device for regulating the fuel supply at the tank.

(iii) The flow control device, such as a manometer or flow meter, shall be sufficient to maintain a consistent flame length of 16 mm ( 5/8 in).

(4) Timing Device. The timing device consists of a timer, driving mechanism and weight. The timer, by means of special attachments, is actuated to start by connection with the gas jet. A trigger device (described in paragraph (a)(1)(v) of this section) activates the flame impingement, causing the driving mechanism to move the gas jet to its most forward position and automatically starts the timer at the moment of flame impact with the specimen. The falling weight, when caused to move by severance of the stop thread, stops the timer. Time shall be read directly and recorded as a burn time. Read burn time to 0.1 second. An electronic or mechanical timer can be used to record the burn time, and electro-mechanical devices (i.e., servo-motors, solenoids, micro-switches, and electronic circuits, in addition to miscellaneous custom made cams and rods, shock absorbing linkages, and various other mechanical components) can be used to control and apply the flame impingement.

(b) Specimen preparation equipment and materials—(1) Laboratory drying oven. This shall be a forced circulation drying oven capable of maintaining 105° ±3 °C (221° ±5 °F) for 30 ±2 minutes to dry the specimens while mounted in the specimen holders.

(2) Desiccator. This shall be an airtight and moisture tight chamber capable of holding the specimens horizontally without contacting each other during the cooling period following drying, and shall contain silica gel desiccant.

(3) Desiccant. Anhydrous silica gel shall be used as the desiccant.

(4) Automatic washing machine. The automatic washing machine shall be as described in § 1610.6(b)(1)(ii).

(5) Automatic tumble dryer. The automatic tumble dryer shall be as described in § 1610.6(b)(1)(ii).

(6) Commercial dry cleaning machine. The commercial dry cleaning machine shall be capable of providing a complete automatic dry-to-dry cycle using perchloroethylene solvent or hydrocarbon solvent and a cationic dry cleaning detergent as specified in § 1610.6(b)(1)(i).

(7) Dry cleaning solvent. The solvent shall be perchloroethylene, commercial grade, or hydrocarbon solvent, commercial grade.

(8) Dry cleaning detergent. The dry cleaning detergent shall be cationic class.

(9) Laundering detergent. The laundering detergent shall be as specified in § 1610.6(b)(1)(ii).

(10) Brushing device. The brushing device shall consist of a base board over which a small carriage is drawn. See Figure 7 of this part. This carriage runs on parallel tracks attached to the edges of the upper surface of the base board. The brush is hinged with pin hinges at the rear edge of the base board and rests on the carriage vertically with a pressure of 150 gf (0.33 lbf). The brush shall consist of two rows of stiff nylon bristles mounted with the tufts in a staggered position. The bristles are 0.41 mm (0.016 in) in diameter and 19 mm (0.75 in) in length. There are 20 bristles per tuft and 4 tufts per inch. See Figure 8 of this part. A clamp is attached to the forward edge of the movable carriage to permit holding the specimen on the carriage during the brushing operation. The purpose of the metal plate or “template” on the carriage of the brushing device is to support the specimen during the brushing operation. The template shall be 3.2 mm (0.13 in) thick. See Figure 9 of this part.

The test procedure is divided into two steps. Step 1 is testing in the original state; Step 2 is testing after the fabric has been refurbished according to paragraph (b)(1) of this section.

(a) Step 1—Testing in the original state. (1) Tests shall be conducted on the fabric in a form or state ready for use in wearing apparel. Determine whether the fabric to be tested is a plain surface textile fabric or a raised surface textile fabric as defined in § 1610.2 (k) and (l). There are some fabrics that require extra attention when preparing test specimens because of their particular construction characteristics. Examples of these fabrics are provided in paragraphs (a)(1)(i) through (vi) of this section along with guidelines for preparing specimens from these fabrics. This information is not intended to be all-inclusive.

(i) Flocked fabrics. Fabrics that are flocked overall are treated as raised surface textile fabrics as defined in § 1610.2(l). Flock printed fabrics (usually in a pattern and not covering the entire surface) shall be treated as plain surface textile fabrics as defined in § 1610.2(k).

(ii) Cut velvet fabrics. Cut velvet fabrics with a patterned construction shall be considered a raised surface textile fabric as defined in § 1610.2(l).

(iii) Metallic thread fabrics. Metallic thread fabrics shall be considered plain surface textile fabrics provided the base fabric is smooth. The specimens shall be cut so that the metallic thread is parallel to the long dimension of the specimen and arranged so the test flame impinges on a metallic thread.

(iv) Embroidery. Embroidery on netting material shall be tested with two sets of preliminary specimens to determine the most flammable area (which offers the greatest amount of netting or embroidery in the 150 mm (6 in.) direction). One set of netting only shall be tested and the other set shall consist mainly of embroidery with the specimens cut so that the test flame impinges on the embroidered area. Test the most flammable area according to the plain surface textile fabric requirements. The full test shall be completed on a sample cut from the area that has the fastest burn rate.

(v) Burn-out patterns. Flat woven constructions with burn-out patterns shall be considered plain surface textile fabrics as defined in § 1610.2(k).

(vi) Narrow fabrics and loose fibrous materials. Narrow fabrics and loose fibrous materials manufactured less than 50 mm (2 in) in width in either direction shall not be tested. If a 50 mm by 150 mm (2 in by 6 in) specimen cannot be cut due to the nature of the item, i.e. hula skirts, leis, fringe, loose feathers, wigs, hairpieces, etc., do not conduct a test.

(2) Plain surface textile fabrics:

(i) Preliminary trials. Conduct preliminary trials to determine the quickest burning direction. The specimen size shall be 50 mm by 150 mm (2 in by 6 in). Cut one specimen from each direction of the fabric. Identify the fabric direction being careful not to make any identifying marks in the exposed area to be tested. Preliminary specimens shall be mounted and conditioned as described in paragraphs (a)(2)(ii) through (iv) of this section and then tested following the procedure in paragraph (c) of this section to determine if there is a difference in the burning characteristics with respect to the direction of the fabric.

(ii) Identify and cut test specimens. Cut the required number of test specimens to be tested (refer to § 1610.7(b)(1)). Each specimen shall be 50 mm by 150 mm (2 in by 6 in), with the long dimension in the direction in which burning is most rapid as established in the preliminary trials. Be careful not to make any identifying marks in the exposed area to be tested.

(iii) Mount specimens. Specimens shall be placed in the holders, with the side to be burned face up. Even though plain surface textile fabrics are not brushed, all specimens shall be mounted in a specimen holder placed on the carriage that rides on the brushing device to ensure proper position in the holder. A specimen shall be placed between the two metal plates of a specimen holder and clamped. Each specimen shall be mounted and clamped prior to conditioning and testing.

(iv) Condition specimens. All specimens mounted in the holders shall then be placed in a horizontal position on an open metal shelf in the oven to permit free circulation of air around them. The specimens shall be dried in the oven for 30 ±2 minutes at 105° ±3 °C (221° ±5 °F), removed from the oven and placed over a bed of anhydrous silica gel desiccant in a desiccator until cool, but not less than 15 minutes.

(v) Flammability test. Follow the test procedure in paragraph (c) of this section and also follow the test sequence in § 1610.7(b)(1).

(3) Raised surface textile fabrics—(i) Preliminary trials. The most flammable surface of the fabric shall be tested. Conduct preliminary trials and/or visual examination to determine the quickest burning area. The specimen size shall be 50 mm by 150 mm (2 in by 6 in). For raised surface textile fabrics, the direction of the lay of the surface fibers shall be parallel with the long dimension of the specimen. Specimens shall be taken from that part of the raised-fiber surface that appears to have the fastest burn time. For those fabrics where it may be difficult to visually determine the correct direction of the lay of the raised surface fibers, preliminary tests can be done to determine the direction of the fastest burn time. For textiles with varying depths of pile, tufting, etc., the preliminary test specimens are taken from each depth of pile area to determine which exhibits the quickest rate of burning. A sufficient number of preliminary specimens shall be tested to provide adequate assurance that the raised surface textile fabric will be tested in the quickest burning area. Preliminary specimens shall be mounted and conditioned as described below and tested following the procedure in paragraph (c) of this section.

(ii) Identify and cut test specimens. Cut the required number of specimens (refer to § 1610.7(b)(3)) to be tested. Each specimen shall be 50 mm by 150 mm (2 in by 6 in), with the specimen taken from the direction in which burning is most rapid as established in the preliminary trials and/or visual examination. Be careful not to make any identifying marks in the exposed area to be tested.

(iii) Mount specimens. Prior to mounting the specimen, run a fingernail along the 150 mm (6 in) edge of the fabric not more than 6.4 mm (0.25 in) in from the side to determine the lay of the surface fibers. All specimens shall be mounted in a specimen holder placed on the carriage that rides on the brushing device. The specimens shall be mounted with the side to be burned face up and positioned so the lay of the surface fibers is going away from the closed end of the specimen holder. The specimen must be positioned in this manner so that the brushing procedure described in paragraph (a)(3)(iv) of this section will raise the surface fibers, i.e., the specimen is brushed against the direction of the lay of the surface fibers. The specimen shall be placed between the two metal plates of the specimen holder and clamped.

(iv) Brush specimens. After mounting in the specimen holder (and with the holder still on the carriage that rides on the brushing device) each specimen shall be brushed one time. The carriage is pushed to the rear of the brushing device, see Figure 7, and the brush, see Figure 8, lowered to the face of the specimen. The carriage shall be drawn forward by hand once against the lay of the surface fibers at a uniform rate. Brushing of a specimen shall be performed with the specimen mounted in a specimen holder. The purpose of the metal plate or “template” on the carriage of the brushing device is to support the specimen during the brushing operation. See Figure 9.

(v) Condition specimens. All specimens (mounted and brushed) in the holders shall be then placed in a horizontal position on an open metal shelf in the oven to permit free circulation of air around them. The specimens shall be dried in the oven for 30 ±2 minutes at 105° ±3 °C (221° ±5 °F) removed from the oven and placed over a bed of anhydrous silica gel desiccant in a desiccator until cool, but not less than 15 minutes.

(vi) Conduct flammability test. Follow the procedure in paragraph (c) of this section and follow the test sequence in § 1610.7(b)(3).

(b) Step 2—Refurbishing and testing after refurbishing. (1) The refurbishing procedures are the same for both plain surface textile fabrics and raised fiber surface textile fabrics. Those samples that result in a Class 3, Rapid and Intense Burning after Step 1 testing in the original state shall not be refurbished and shall not undergo Step 2.

(i) Dry cleaning procedure. (A) All samples shall be dry cleaned before they undergo the laundering procedure. Samples shall be dry cleaned in a commercial dry cleaning machine, using one of the following prescribed conditions:

(B) If necessary, ballast consisting of clean textile pieces or garments, white or light in color and consisting of approximately 80% wool fabric pieces and 20% cotton fabric pieces, shall be used.

(ii) Laundering procedure. The sample, after being subjected to the dry cleaning procedure, shall be washed and dried one time in accordance with section 9.2, section 9.4, section 12.2(A), Table I “(1) Normal,” “(IV) Hot,” and Table VI “(Aiii) Permanent Press” of AATCC LP1-2021 (incorporated by reference, see § 1610.6(b)(1)(iii)). Washing shall be performed in accordance with the detergent (powder) specified in section 9.4 of AATCC LP1-2021; parameters for water level, agitator speed, stroke length, washing time, spin speed, spin time, and wash temperature specified in Table I, “Standard Washing Machine Parameters,” “(1) Normal” and “(IV) Hot” of AATCC LP1-2021; and a maximum wash load as specified in section 9.2 of AATCC LP1-2021, which may consist of any combination of test samples and dummy pieces. Drying shall be performed in accordance with section 12.2(A) of AATCC LP1-2021, Tumble Dry, using the exhaust temperature and cool down time specified in Table VI, “Standard Tumble Dryer Parameters,” “(Aiii) Permanent Press” of AATCC LP1-2021.

(iii) AATCC LP1-2021, Laboratory Procedure for Home Laundering: Machine Washing, 2021, is incorporated by reference. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A read-only copy of the standard is available for viewing on the AATCC website. You may obtain a copy from the American Association of Textile Chemists and Colorists, P.O. Box 12215, Research Triangle Park, North Carolina 27709; telephone (919) 549-8141; www.aatcc.org. You may inspect a copy at the Office of the Secretary, U.S. Consumer Product Safety Commission, Room 710, 4330 East-West Highway, Bethesda, MD 20814, telephone (301) 504-7479, email [email protected], or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

(2) Testing plain surface textile fabrics after refurbishing. The test procedure is the same as for Step 1—Testing in the original state described in paragraph (a)(1) of this section; also follow the test sequence § 1610.7(b)(2).

(3) Testing raised fiber surface textile fabrics after refurbishing. The test procedure is the same as for Step 1—Testing in the original state as described in paragraph (a)(3) of this section; also follow the test sequence in § 1610.7(b)(4).

(c) Procedure for testing flammability. (1) The test chamber shall be located under the hood (or other suitable enclosure) with the fan turned off. Open the control valve in the fuel supply. Allow approximately 5 minutes for the air to be drawn from the fuel line, ignite the gas and adjust the test flame to a length of 16 mm ( 5/8 in), measured from its tip to the opening in the gas nozzle.

(2) Remove one mounted specimen from the desiccator at a time and place it in position on the specimen rack in the chamber of the apparatus. Thick fabrics may require adjustment of the specimen rack so that the tip of the indicator finger just touches the surface of the specimen.

(3) Adjust the position of the specimen rack of the flammability test chamber so that the tip of the indicator finger just touches the face of the mounted specimen.

(4) String the stop thread through the guides in the upper plate of the specimen holder across the top of the specimen, and through any other thread guide(s) of the chamber. Hook the stop weight in place close to and just below the stop weight thread guide. Set the timing mechanism to zero. Close the door of the flammability test chamber.

(5) Begin the test within 45 seconds of the time the specimen was removed from the desiccator. Activate the trigger device to impinge the test flame. The trigger device controls the impingement of the test flame onto the specimen and starts the timing device. The timing is automatic and stops when the weight is released by the severing of the stop thread.

(6) At the end of each test, turn on the hood fan to exhaust any fumes or smoke produced during the test.

(7) Record the burn time (reading of the timer) for each specimen, along with visual observation using the test result codes given in § 1610.8. If there is no burn time, record the visual observation using the test result codes. Please note for raised-fiber surface textile fabrics, specimens should be allowed to continue burning, even though a burn rate is measured, to determine if the base fabric will fuse.

(8) After exhausting all fumes and smoke produced during the test, turn off the fan before testing the next specimen.

(a) Preliminary and final classifications. Preliminary classifications are assigned based on the test results both before and after refurbishing. The final classification shall be the preliminary classification before or after refurbishing, whichever is the more severe flammability classification.

(b) Test sequence and classification criteria. (1) Step 1, Plain Surface Textile Fabrics in the original state.

(i) Conduct preliminary tests in accordance with § 1610.6(a)(2)(i) to determine the fastest burning direction of the fabric.

(ii) Prepare and test five specimens from the fastest burning direction. The burn times determine whether to assign the preliminary classification and proceed to § 1610.6(b) or to test five additional specimens.

(iii) Assign the preliminary classification of Class 1, Normal Flammability, and proceed to § 1610.6(b) when:

(A) There are no burn times; or

(B) There is only one burn time, and it is equal to or greater than 3.5 seconds; or

(C) The average burn time of two or more specimens is equal to or greater than 3.5 seconds.

(iv) Test five additional specimens when there is either only one burn time, and it is less than 3.5 seconds; or there is an average burn time of less than 3.5 seconds. Test these five additional specimens from the fastest burning direction as previously determined by the preliminary specimens. The burn times for the 10 specimens determine whether to:

(A) Stop testing and assign the final classification as Class 3, Rapid and Intense Burning, only when there are two or more burn times with an average burn time of less than 3.5 seconds; or

(B) Assign the preliminary classification of Class 1, Normal Flammability, and proceed to § 1610.6(b) when there are two or more burn times with an average burn time of 3.5 seconds or greater.

(v) If there is only one burn time out of the 10 test specimens, the test is inconclusive. The fabric cannot be classified.

(2) Step 2, Plain Surface Textile Fabrics after refurbishing in accordance with § 1610.6(b)(1).

(i) Conduct preliminary tests in accordance with § 1610.6(a)(2)(i) to determine the fastest burning direction of the fabric.

(ii) Prepare and test five specimens from the fastest burning direction. The burn times determine whether to stop testing and assign the preliminary classification or to test five additional specimens.

(iii) Stop testing and assign the preliminary classification of Class 1, Normal Flammability, when:

(A) There are no burn times; or

(B) There is only one burn time, and it is equal to or greater than 3.5 seconds; or

(C) The average burn time of two or more specimens is equal to or greater than 3.5 seconds.

(iv) Test five additional specimens when there is only one burn time, and it is less than 3.5 seconds; or there is an average burn time less than 3.5 seconds. Test five additional specimens from the fastest burning direction as previously determined by the preliminary specimens. The burn times for the 10 specimens determine the preliminary classification when:

(A) There are two or more burn times with an average burn time of 3.5 seconds or greater. The preliminary classification is Class 1, Normal Flammability; or

(B) There are two or more burn times with an average burn time of less than 3.5 seconds. The preliminary and final classification is Class 3, Rapid and Intense Burning; or

(v) If there is only one burn time out of the 10 specimens, the test results are inconclusive. The fabric cannot be classified.

(3) Step 1, Raised Surface Textile Fabric in the original state.

(i) Determine the area to be most flammable per § 1610.6(a)(3)(i).

(ii) Prepare and test five specimens from the most flammable area. The burn times and visual observations determine whether to assign a preliminary classification and proceed to § 1610.6(b) or to test five additional specimens.

(iii) Assign the preliminary classification and proceed to § 1610.6(b) when:

(A) There are no burn times. The preliminary classification is Class 1, Normal Flammability; or

(B) There is only one burn time and it is less than 4.0 seconds without an SFBB test result code, or it is 4.0 seconds or greater with or without am SFBB test result code. The preliminary classification is Class 1, Normal Flammability; or

(C) There are no base burns (SFBB) regardless of the burn time(s). The preliminary classification is Class 1, Normal Flammability; or

(D) There are two or more burn times with an average burn time of 0.0 to 7.0 seconds with a surface flash only. The preliminary classification is Class 1, Normal Flammability; or

(E) There are two or more burn times with an average burn time greater than 7.0 seconds with any number of base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(F) There are two or more burn times with an average burn time of 4.0 through 7.0 seconds (both inclusive) with no more than one base burn (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(G) There are two or more burn times with an average burn time less than 4.0 seconds with no more than one base burn (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(H) There are two or more burn times with an average burn time of 4.0 through 7.0 seconds (both inclusive) with two or more base burns (SFBB). The preliminary classification is Class 2, Intermediate Flammability.

(iv) Test five additional specimens when the tests of the initial five specimens result in either of the following: There is only one burn time and it is less than 4.0 seconds with a base burn (SFBB); or the average of two or more burn times is less than 4.0 seconds with two or more base burns (SFBB). Test these five additional specimens from the most flammable area. The burn times and visual observations for the 10 specimens will determine whether to:

(A) Stop testing and assign the final classification only if the average burn time for the 10 specimens is less than 4.0 seconds with three or more base burns (SFBB). The final classification is Class 3, Rapid and Intense Burning; or

(B) Assign the preliminary classification and continue on to § 1610.6(b) when:

(1) The average burn time is less than 4.0 seconds with no more than two base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(2) The average burn time is 4.0 to 7.0 seconds (both inclusive) with no more than 2 base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(3) The average burn time is greater than 7.0 seconds. The preliminary classification is Class 1, Normal Flammability; or

(4) The average burn time is 4.0 to 7.0 seconds (both inclusive) with three or more base burns (SFBB). The preliminary classification is Class 2, Intermediate Flammability; or

(v) If there is only one burn time out of the 10 specimens, the test is inconclusive. The fabric cannot be classified.

(4) Step 2, Raised Surface Textile Fabric After Refurbishing in accordance with § 1610.6(b).

(i) Determine the area to be most flammable in accordance with § 1610.6(a)(3)(i).

(ii) Prepare and test five specimens from the most flammable area. Burn times and visual observations determine whether to stop testing and determine the preliminary classification or to test five additional specimens.

(iii) Stop testing and assign the preliminary classification when:

(A) There are no burn times. The preliminary classification is Class 1, Normal Flammability; or

(B) There is only one burn time, and it is less than 4.0 seconds without an SFBB test result code; or it is 4.0 seconds or greater with or without an SFBB test result code. The preliminary classification is Class 1, Normal Flammability; or

(C) There are no base burns (SFBB) regardless of the burn time(s). The preliminary classification is Class 1, Normal Flammability; or

(D) There are two or more burn times with an average burn time of 0.0 to 7.0 seconds with a surface flash only. The preliminary classification is Class 1, Normal Flammability; or

(E) There are two or more burn times with an average burn time greater than 7.0 seconds with any number of base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(F) There are two or more burn times with an average burn time of 4.0 to 7.0 seconds (both inclusive) with no more than one base burn (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(G) There are two or more burn times with an average burn time less than 4.0 seconds with no more than one base burn (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(H) There are two or more burn times with an average burn time of 4.0 to 7.0 seconds (both inclusive) with two or more base burns (SFBB). The preliminary classification is Class 2, Intermediate Flammability.

(iv) Test five additional specimens when the tests of the initial five specimens result in either of the following: There is only one burn time, and it is less than 4.0 seconds with a base burn (SFBB); or the average of two or more burn times is less than 4.0 seconds with two or more base burns (SFBB).

(v) If required, test five additional specimens from the most flammable area. The burn times and visual observations for the 10 specimens determine the preliminary classification when:

(A) The average burn time is less than 4.0 seconds with no more than two base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(B) The average burn time is less than 4.0 seconds with three or more base burns (SFBB). The preliminary and final classification is Class 3, Rapid and Intense Burning; or

(C) The average burn time is greater than 7.0 seconds. The preliminary classification is Class 1, Normal Flammability; or

(D) The average burn time is 4.0 to 7.0 seconds (both inclusive), with no more than two base burns (SFBB). The preliminary classification is Class 1, Normal Flammability; or

(E) The average burn time is 4.0 to 7.0 seconds (both inclusive), with three or more base burns (SFBB). The preliminary classification is Class 2, Intermediate Flammability; or

(vi) If there is only one burn time out of the 10 specimens, the test is inconclusive. The fabric cannot be classified.

(a) The reported result shall be the classification before or after refurbishing, whichever is the more severe; and based on this result, the textile shall be placed in the proper final classification as described in § 1610.4.

(b) Test result codes. The following are definitions for the test result codes, which shall be used for recording flammability results for each specimen that is burned.

(1) For Plain Surface Textile Fabrics:

(i) DNI Did not ignite.

(ii) IBE Ignited, but extinguished.

(iii) _._sec. Actual burn time measured and recorded by the timing device.

(2) For Raised Surface Textile Fabrics:

(i) _._SFBB Time in seconds, surface flash base burn starting at places other than the point of impingement as a result of surface flash.

(ii) _._SFBB poi Time in seconds, surface flash base burn starting at the point of impingement.

(iii) _._SFBB poi* Time in seconds, surface flash base burn possibly starting at the point of impingement. The asterisk is accompanied by the following statement: “Unable to make absolute determination as to source of base burns.” This statement is added to the result of any specimen if there is a question as to origin of the base burn.

(iv) _._SF only Time in seconds, surface flash only. No damage to the base fabric.

(v) SF poi Surface flash, at the point of impingement only (equivalent to “did not ignite” for plain surfaces).

(vi) SF uc Surface flash, under the stop thread, but does not break the stop thread.

(vii) SF pw Surface flash, part way. No time shown because the surface flash did not reach the stop thread.