(a) Summary of test method. Five conditioned specimens, 8.9 × 25.4 cm. (3.5 × 10 in.), are suspended one at a time vertically in holders in a prescribed cabinet and subjected to a standard flame along their bottom edge for a specified time under controlled conditions. The char length is measured.

(b) Test criteria. The test criteria when the testing is done in accordance with §1615.4 Test procedure are:

(1) Average char length. The average char length of five specimens shall not exceed 17.8 cm. (7.0 in.).

(2) Full specimen burn. No individual specimen shall have a char length of 25.4 cm. (10 in.).

[40 FR 59903, Dec. 30, 1975, as amended at 43 FR 4853, Feb. 6, 1978]