Cal. Code Regs. tit. 19 § 1323
Flame-retardant application concerns shall attach to the certificate submitted to the State Fire Marshal's office not less than one two-inch (2") x six-inch (6") test sample of the fabric or material treated by them, excepting only where such sample cannot be taken without defacing finished converted goods such as curtains, drapes, flats, etc. No exception is permitted for yardage goods.
Test specimens of approved registered fabrics and materials shall be submitted to the State Fire Marshal. The wide variation in fire resistant quality of registered products, ranging from noncombustible to flameproof, militates against setting a single test size and frequency. In general, a one foot (1') by three foot (3') specimen of each unit or lot of fabric and film production bearing the production or lot number shall be submitted by the producer directly to the State Fire Marshal. For other special fabrics and materials, the sample size and test frequency will be specified on an individual basis to the concern in whose name the product is registered.
Cal. Code Regs. Tit. 19, § 1323