index loi of at least 27 u201c flame retardant u201d u201c flame resistant u201d u201c fire resistant u201d or u201c fire resistance u201d may also refer to the flame reference standard astm d6413 99 for textile compositions flame persistent test nf p 92 504 and similar standards for flame resistant fibers and textiles fire resistance may also be tested by measuring the after burning time in accordance with the ul test subject 94 in this test the tested materials are given classifications of ul 94 v 0 ul 94 v 1 and ul 94 v 2 on the basis of the results obtained with the ten test specimens briefly the criteria for each of these ul 94 v classifications are as follows ul 94 v 0 the average burning and or glowing time after removal of the ignition flame should not exceed 5 seconds and none of the test specimens should release and drips which ignite absorbent cotton wool ul 94 v 1 the average burning and or glowing time after removal of the ignition flame should not exceed 25 seconds and none of the test specimens should release any drips which ignite absorbent cotton wool ul 94 v 2 the average burning and or glowing time after removal of the ignition flame should not exceed 25 seconds and the test specimens release flaming particles which ignite absorbent cotton wool fire resistance may also be tested by measuring after burning time these test methods provide a laboratory test procedure for measuring and comparing the surface flammability of materials when.