Tillman® Flame Resistant FR7A® Cotton Sleeves. 9 oz, green flame resistant cotton sleeves. 23″ length. Made from flame resistant, washable, 100% FR7A® cotton. Offers protection from sudden flame exposure, light duty welding and sparks. 9 oz flame resistant 100% cotton fabric meets ASTM D6413-10. ASTM D6413-10 is used to determine a pass/fail criteria for ASTM F1506, which requires a maximum char length of 6 inches.