FR Long shirts Fabric ：6 oz100% cotton knit fire resistant fabric with Flatlock stitchwhich not only meets the flame retardant needs, but is also comfortable, lightweight andbreathable. Safety standards：ATPV1 2 Cal/cm²CAT 2 Arc Rated Garment and UL certification（packaged with a sample for simple customer testing） What is flame resistant clothing？:Flame resistant shirts are resistant to combustion when exposed to flame or electric arc and will not continue to burn when removed from the ignition source, thus reducing your safety hazard. Applicable Population：Machine wash tested over 100 times and still fire retardant after washing, ideal for welding, electricians, forestry and industrial workers. In order to let you have a better shopping experience, you can check the size of the garment in the size chart in the product detail picture before purchasing, and choose the right garment for you according to your situation. FR High Visibility/High Vis Fire Resistant Long Sleeve