Arc classification test.
Three samples are needed for the arc test in order to determine the after-flame average with regard to which incident energy is equal to, or greater than, ATPV or EBT.
For single-layered arc test samples:
• Woven and knit fabric: After-flame ≤ 5 s
Arc classification ≥ 5 cal/cm² (20.9 J/cm²):
• No melting or dripping.
The test may be made after three consecutive washes, followed by drying, in accordance with the manufacturer’s care instructions. If no care instructions are provided, the fabric must be washed based on the AATCC 135 (3, IV A iii) method, followed by drying.