The American National Standards Institute (ANSI) established road worker reflective clothing standards in 1999 and revised these standards in 2004. The standards provided in ANSI/ISEA 107-2004 set voluntary guidelines for high-visibility clothing in three classes: 1, 2 and 3. Each class specifies minimum size, background color, reflectivity and placement of reflective material.
Class 2 standards are for safety apparel and headwear with high visibility. Targeted employees are construction and utility workers, police and emergency personnel, firefighters, road workers and airport ramp workers. Guidelines for garments include shirts, vests, outerwear and rainwear, safety vests and headwear to improve visibility in daylight, low-light conditions and at night.