All textile fabrics (except those with a nitro-cellulose fiber, finish or coating) intended or sold for use in wearing apparel, and all such fabrics contained in articles of wearing apparel, shall be subject to the requirements of the Act, and shall be deemed to be so highly flammable as to be dangerous when worn by individuals if such fabrics or any uncovered or exposed part of such articles of wearing apparel exhibits rapid and intense burning when tested under the conditions and in the manner prescribed in subpart A of this part 1610.

Notwithstanding the provisions of paragraph (a)(1) of this section, coated fabrics, except those with a nitro-cellulose coating, may be tested under the procedures outlined in part 1611, Standard for the Flammability of Vinyl Plastic Film, and if such coated fabrics do not exhibit a rate of burning in excess of that specified in § 1611.3 they shall not be deemed to be so highly flammable as to be dangerous when worn by individuals.

All film, and textile fabrics with a nitro-cellulose fiber, finish or coating intended or sold for use in wearing apparel, and all film and such textile fabrics referred to in this rule which are contained in articles of wearing apparel, shall be subject to the requirements of the Act, and shall be deemed to be so highly flammable as to be dangerous when worn by individuals if such film or such textile fabrics or any uncovered or exposed part of such articles of wearing apparel exhibit a rate of burning in excess of that specified in part 1611, Standard for the Flammability of Vinyl Plastic Film.