Section 1615.3 - General requirements(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