The flame persistency test is a reaction to fire complementary test for M classification of building and fitting materials. It is used for flexibleand rigid materials of any thickness which develop holes without combustion or with short time combustion during the main test.
This test allows to classify the material in M1, M2 or M3 categories. In case of combust or not dripping, the final classification will be made after the dripping test (NF P 92-505).
The flame propagation test is performed with the same apparatus and is used for M4 classification of flexible and rigid materials of any 

STANDARDS : NF P 92-504