ASTM F1506 standard for FR clothing
Geared to those in the electrical industry, the ASTM F1506 standard covers performance specifications for apparel worn by electrical workers who are exposed to electric arcs and related thermal hazards, including open flame and radiant heat. To comply with this standard, flame-resistant materials must:
Not melt, drip, or continue burning for more than two seconds after the flame source is removed.
Meet performance specifications after 25 washes/dry-cleanings.