Fortiflame Layer 4 fabric is a jersey knit blend of modacrylic/ rayon/nylon and spandex yarns at 8.0 oz./sq. yard. The fabric is inherently flame resistant and has 0 after flame or melt/drip during test method ASTM D 6413-11. The spandex blend provides the wearer with additional comfort and freedom of movement. Our fabric is soft against the skin, even while meeting these stringent standards. Fortiflame Layer 4 fabric will keep the wearer dry from excessive moisture and is treated with an antimicrobial to resist odors.