Cal. Code Regs. tit. 19 § 1237.3
(Large Scale Test). The specimens shall be conditioned by suspending them in an oven having mechanical air circulation, at temperatures of 140° to 145° F. for not less than one hour, nor more than one and one-half (1 ½ ) hours. Materials which distort or melt at the above oven exposure shall be conditioned at 60 to 80° F. and 25 percent to 50 percent relative humidity for not less than twenty-four (24) hours.
The apparatus for conducting the flame test shall consist of a sheet steel stack twelve inches (12") square transversely, seven feet (7') high, and supported one foot (1') above the floor on legs. The stack shall be open at the top and bottom and shall be provided with a door having an observation window of wired glass extending the full length.
Six specimens, each not less than five inches (5") x seven feet (7'), shall be subjected to the fire resistance test. One-half of each set of specimens shall be cut with the long dimension in the direction of the warp, and the other half with the long dimension in the direction of the filling. Two or more pieces may be sewn together to provide the necessary length.
The specimen shall be suspended vertically in the stack with its full width facing the observer so that the bottom of the specimen is four inches (4") above the top of a Bunsen burner having a three-eighths inch (3/8") diameter tube and placed on the floor below the stack. The gas supply to the burner shall be natural gas or a mixture of natural and manufactured gases having a heat value of approximately 800-1000 Btu per cubic foot. With a gas pressure of four and one-half inches (4 1/2") (108mm.) of water, the burner shall be adjusted to produce an eleven inch (11") oxidizing flame having an indistinct inner cone. The specimen shall be lightly restrained laterally with clamps and guide wires attached to its outer edges.
The flame shall be applied vertically near the middle of the lower end of the specimen for two (2) minutes and then withdrawn. Observations shall be recorded during and after the flame application to include duration of surface flaming and length of char.
The length of char shall be determined as described for small scale test specimens in Section 1237.1.
Cal. Code Regs. Tit. 19, § 1237.3