Flame retardancy Test; In this test 1. 6 mm standard test stick is treated with the flame for some certain time and after the burner is turned off we have to count (by chronometer) that how long it takes until no flame is visible. The most important specifications in this test are that whether there are any falling particles and how many seconds takes it the fire to go off. Then it can be decided whether this material Vo or Vı or V2 flame retarded according to the UL - 94 standards.