The Commodity Standards Division, by means of assembled conferences or letter referenda, or both, assists the sponsor group in arriving at a tentative standard of practice and thereafter refers it to the other elements of the same industry for approval or for constructive criticism that will be helpful in making any necessary adjustments.

The method or procedure under which commercial standards are established consists of six principal steps, i. e., request, tentative proposal, adjustment, recommendation, acceptance, promulgation.

Establishment of a commercial standard is initiated only by a written request for the cooperation of the Commodity Standards Division. Requests come most frequently from trade associations, technical societies, or user interests. In a few instances, requests have been submitted by a responsible firm engaged in the production of the commodity, later supported by the concurrent action of other interests. The organization making the request is expected to submit a proposal, or information necessary to the drafting of a proposed standard, to serve as a basis for discussion by others concerned.

The tentative proposal is pretented to representative firms or organizations for advance comment leading to preliminary adjustment, followed by circulation more widely for comment and adjustment by the entire industry. When the original proposal has been adjusted to meet the desires of the majority, it is circulated to the entire trade for written acceptance.

Individual firms make known their approval of the proposal by authorizing one of their officers to fill in an acceptance form worded as follows: "We believe that the commercial standard CS (serial number) constitutes a useful standard of practice, and we individually plan to utilize it as far as practicable in the (a) production, (b) distribution, or (c) purchase of (name of commodity). We reserve the right to depart from it as we deem advisable. We understand, of course, that only those articles which actually comply with the standard in all respects can be identified or labeled as conforming thereto."

If acceptances are received representing at least 65 percent of the volume of business and representative of all interests (producer, distributor, and user), and there is no active valid opposition, the Department of Commerce promulgates the standard as a voluntary standard of the trade, issued as one of a printed series of commercial standards. The Department reserves the right to withhold promulgation if evidence is presented that promulgation is not in the public interest.

The regular procedure of the Division assures continuous servicing of each effective commercial standard, through review and revision, whenever, in the opinion of the industry, changing conditions warrant such action.

Coincident with the establishment of a commercial standard, a standing committee, representative of production, distribution, testing, purchase, and general interests, is appointed. That committee reviews all suggestions for revision of the commercial standard and endeavors to reconcile differences. The final recommendation of the standing committee is circulated for written acceptance, as in the procedure for the establishment of previous editions of the standard. Commercial standards are printed and made available by the Department of Commerce through the Government Printing Office and the Department of Commerce field offices.

Each commercial standard is wholly advisory. Effected persons or organizations may conform or diverge as they prefer. The Department of Commerce has no regulatory powers with reference to the subject.

FLAMMABILITY OF CLOTHING TEXTILES

COMMERCIAL STANDARD CS191-53

(Effective date, January 30, 1953)

TS-5170

January 15, 1953

NOTE. All fabrics of natural or regenerated cellulose, as well as certain types of finished and unfinished fabrics made from other natural or synthetic fibers, are combustible. Some combustible fabrics, when used for clothing, are potentially dangerous to the wearer because of the speed and intensity of flame with which the fabric burns, its ease of ignition, and because of the design of the garment. Two of these factors, the ease of ignition and the speed of flame spread, can be measured with the instrument described.

It is suggested that measurement of these two factors, together with visual observation of flame intensity, will permit the separation of various fabrics into three classes of flammability, thus assisting in a judgment of fabric suitability for clothing.

1. PURPOSE

1.1 The purpose 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 discouraging the use of any dangerously flammable clothing textiles.

2. SCOPE

2.1 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 so classified, and warns against the use of those textiles which have burning characteristics unsuitable for clothing.

2.2 Specific exceptions.-This standard shall not apply to

a. Hats, gloves, and footwear.

b. Interlining fabrics.2

3.1 Flammability.—

3. REQUIREMENTS

3.1.1 Normal flammability, class 1.-This class shall include textiles which meet the minimum requirements set forth in paragraphs 3.1.1.1. or 3.1.1.2. Textiles meeting these requirements are generally accepted by the trade as having no unusual burning characteristics.

3.1.1.1 Textiles without nap, pile, tufting, flock, or other type of raised fiber surface. Such textiles in their original state, and/or after being dry-cleaned and washed as described in paragraphs 4.4 and 4.5, when tested as described in paragraph 4, shall be classified as class 1, normal flammability, when the time of flame spread is 4 seconds or more.

3.1.1.2 Napped, pile, tufted, flocked, or other textiles having a raised fiber surface. Such textiles in their original state and/or after being dry cleaned and washed as described in paragraphs 4.4 and 4.5, when tested as described in paragraph 4, shall be classified as class 1, normal flammability, when the time of flame spread is more than 7 seconds, or when they burn with a rapid surface flash (from 0 to 7 seconds), provided the intensity of the flame is so low as not to ignite or fuse the base fabric.

3.1.2 Intermediate flammability, class 2.-This class shall include textiles which meet the minimum requirements set forth in paragraph 3.1.2.1. Textiles meeting these requirements are recognized by the trade as having flammability characteristics between normal and rapid and intense burning.

3.1.2.1 Napped, pile, tufted, flocked, or other textiles having a raised fiber surface. Such textiles in their original state and/or after being dry-cleaned and washed as described in paragraphs 4.4 and 4.5, when tested as described in paragraph 4, shall be classified as class 2, intermediate flammability, when the time of flame spread is from 4 to 7 seconds, both inclusive, and the base fabric ignites or fuses.

3.1.3 Rapid and intense burning, class 3.-This class shall include textiles which have burning characteristics as described in paragraphs 3.1.3.1 and 3.1.3.2. Such textiles are considered dangerously flammable and recognized by the trade as being unsuitable for clothing because of their rapid and intense burning.

3.1.3.1 Textiles free from nap, pile, tufting, flock, or other type of raised fiber surface. Such textiles in their original state and/or after being drycleaned and washed as described in paragraphs 4.4 and 4.5, when tested as described in paragraph 4, shall be classified as class 3, rapid and intense burning, when the time of flame spread is less than 4 seconds.

3.1.3.2 Napped, pile, tufted, flocked, or other textiles having a raised fiber surface. Such textiles in their original state and/or after being dry-cleaned

1 Hereinafter "clothing and textiles to be used for clothing" shall be referred to as "textiles." 2 Interlining fabrics are not considered dangerously fammable when used as interlinings. When used for other purposes, they should be tested and rated as any other fabrics.

and washed, as described in paragraphs 4.4 and 4.5, when tested as described in paragraph 4 shall be classified as class 3, rapid and intense burning, when the time of flame spread is less than 4 seconds and when the intensity of flame is such as to ignite or fuse the base fabric.

4.1 Test specimens.—

4. METHODS OF TEST

4.1.1 Number and size of specimens required.-Five specimens, each measur ing 2 inches by 6 inches, are required for each test.

4.1.2 For textiles without a raised fiber surface the long dimension shall be that in which they burn most rapidly and the more rapidly burning surface shall be tested. To establish the long dimension and the surface, preliminary tests are made as described in paragraph 4.7 with specimens cut in different directions. 4.1.3 For textiles having a raised fiber surface, the direction of the lay of the surface fibers shall be parallel with the long dimension of the specimens. For this type of textiles with varying depths of pile, tufting, etc., the specia lens are taken from that part and tested on that surface which has the fastest rate of burning.

4.1.4 If the specimens in the preliminary test, when tested as described in paragraph 4.7 do not ignite or are very slow burning, or could have a fireretarding finish, a swatch large enough to provide the specimens required for the test, with allowance for shrinkage in dry-cleaning and washing, as subjected to the dry-cleaning and washing procedures described in paragraphs 4.4 and 4.5. The specimens for the flammability test are then taken from it.

4.1.5 The specimens required for testing, each 2 x 6 inches, are marked out on the back (or under side) of each sample with the long dimension in the direction in which burning is most rapid, as established in the preliminary trials. The end of the specimen toward which and on the face of which burning is most rapid is identified by attaching a staple to it. The specimens are then cut out.

Staple

Direction in which fabric burns most rapidly

FIGURE 1. Specimen showing staple.

4.2 Flammability tester.—The flammability tester consists of a draft-proof ventilated chamber enclosing a standardized ignition medium, sample rack, and automatic timing device.

4.2.1 Draftproof chamber with vented top (A, Fig. 2). This metal chamber prevents air circulation around the specimen rack and flame, but permits free ventilation for rapid oxidation. The chamber is 141⁄2 inches wide by 8%1⁄2 inches deep and 14 inches in height. There are 12 half-inch holes equidistant along the rear of the top closure. A ventilating strip is provided at the base of the 'sliding glass door in the front of the apparatus.

4.2.2 Specimen rack (B, Fig. 2).—The specimen rack provides supports for the frames in which the specimens are mounted. The angle of inclination is 45 degrees. 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 flame front. A stop is provided in the base of the chamber to assist in adjusting the position of the rack.

This apparatus is manufactured by the United States Testing Company, 1415 Park Avenue, Hoboken, N. J., Blueprints of working plans for the manufacture of this apparatus are available at a nominal charge from the American Association of Textile Chemists and Colorists, care of Lowell Textile Institute, Lowell, Mass.

33167-53-13

4.2.3 Specimen holder (C, Fig. 2).-The specimen holder consists of two 18-inch matched metal plates with clamps mounted along the sides, between which the specimen is fixed. The plates are slotted and loosely pinned for alignment. The two plates of the holder cover all but 11⁄2 inches of the width of the specimen for its full length. The specimen holder is supported in the draftproof chamber on the rack at an angle of 45 degrees. Five specimen holders are provided.

4.2.4 Indicating finger (D, Fig. 2).-The forepart of this finger touches the specimen when the rack is adjusted. By means of this finger the thickness of the specimen is compensated for in the throw of the gas nozzle.

4.2.5 Control knobs (not shown).-There are two of these knobs which hold the rack in test position. The knobs can be reached under the stage of the cabinet and permit forward and backward movements of the rack when loosened. 4.2.6 Ignition medium (F, Fig. 2).-The ignition medium consists of a springmotor-driven gas jet formed around a 26-gauge hypodermic needle. A trigger located in the front of the apparatus serves to wind the spring motor when the machine is placed in operation. The gas jet is protected by a copper shield.

4.2.7 Stop cord (G, Fig. 2).-This cord, stretched from the spool (P, Fig. 2) through suitable thread guides provided on the specimen frame and chamber

walls, permits the lacing of the cord in the proper position exactly 5 inches from the point where the center of the ignition flame impinges on the test specimen. The stop cord consists of a No. 50 mercerized sewing thread and measures the rise and spread of the flame from the test specimen.

4.2.8 Pulley or eye (H, Fig. 2).-Support and guide for stop cord.

4.2.9 Stop weight (I, Fig. 2).—The weight, attached by means of a clip to the stop cord, in dropping actuates the stop motion.

4.2.10 Slide door control (J, Fig. 2). This knob moves the catch mechanism used to hold the sliding door in an open position for insertion of test specimen racks.

4.2.11 Slide door (K, Fig. 2).—A glass door in its normal position slides in the grooves at the front of the cabinet.

4.2.12 Fuel control valve (L, Fig. 2).-Consists of a sensitive control device for regulating the fuel supply at the tank. The valve ends in a 1⁄2-inch male connection for attachment to the standard Butane tank of 2 pounds capacity.

4.2.13 Flow meter (V, Fig. 2).—A flowmeter is used to bring the fuel supply to test level by means of the control valve. The flowmeter consists of a U-shaped glass tube cut into the gas line in a manner to register the gas pressure delivered to the microburner. Attached to the case wall behind the flowmeter is a movable metal plate with two parallel horizontal lines properly spaced for the desired flame length. When the pressure is off the plate is so regulated that the liquid level in both sides of the U-shaped tube meets the lower line. When the test is made the pressure is so adjusted that the higher liquid level in the U-shaped tube meets the upper line.

4.2.14 cp Butane container1 (M, Fig. 2).-This fuel supply is a No. 4 cylinder of cp Butane.

4.2.15 Stopwatch and timing mechanism (N, Fig. 2).—This watch, by means of special attachments, is actuated to a start by connection with the gas jet (F, Fig. 2). A driving mechanism on rear of cabinet (S, Fig. 2) moves the gas jet to its most forward position and automatically starts the timing at the moment of flame impact. The falling weight (I, Fig. 2), when caused to move by severance of cord (C, Fig. 2), stops the watch. Timing is read directly.

4.2.16 Starting lever (O, Fig. 2).—This lever is operated from left to right in one stroke and is released to operate the gas jet.

4.2.17 Cord supply (P, Fig. 2).-This supply, consisting of a spool of No. 50 mercerized cotton sewing thread, is fastened to the side of the chamber and can be withdrawn by releasing the thumbscrew holding same in position.

4.2.18 Cord loop (Q, Fig. 2).—At a point behind the stop cord (G, Fig. 2) on the rear panel, there is installed another loop to draw the cord away from directly over the flame.

4.2.19 Draft ventilator strip (R, Fig. 2).—A draft ventilator strip is 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.

4.3 Brushing device."

4.3.1. This device consists of a baseboard over which a smaller carriage is drawn. This carriage runs on parrallel tracks attached to the edges of the upper surface of the baseboard. The brush is hinged with pin hinges at the rear edge of the baseboard and rests on the carriage vertically with a pressure of 150 grams.

4.3.2 The brush consists of two rows of stiff nylon bristles mounted with the tufts in a staggered position. The bristles are 0.016 inch in diameter and 0.75 inch in length. There are 20 bristles per tuft and tufts per inch. A clamp is attached to the forward edge of the movable carriage to permit holding the specimen on the carriage during the brushing operation.

Butane, C. P. No. 4 cylinders containing 2 pounds. Butane may be obtained from, among others, the Matheson Company, Inc., East Rutherford, N. J. See footnote 3.