Flame resistance. Charred length ≤ 150 mm (6 inches).
Five samples must be analysed in each direction in the original state and after 5 washes.
Whether the impermeable clothing is constructed with a single layer of material or a multi-layered system of materials, a sample of one layer of the various layers of the impermeable clothing that has been constructed must be subjected to all thermal tests. If the manufacturer does not provide cleaning instructions, the garments must be washed three times in accordance with Method 135 of the AATCC, followed by drying.