The American National Standards Institute (ANSI) is one of the key regulatory organizations that govern the standards for safety vests, reflective safety jackets, and other high-visibility clothing. In the U.S. the Standard for High-Visibility Safety Apparel provides consistent guidelines for selecting and using safety vests and other apparel that provide high visibility under any light conditions by day and under illumination by vehicle headlights in the dark.

The High-Visibility Safety Apparel standard offers performance specifications for reflective materials, including minimum amounts, background material, placement, care labeling, and test methods. In simplest terms, the standard provides for a high degree of reflective material incorporated into garments, which helps improve visibility and safety.

Regulatory standards on high-visibility clothing specify three classes of garments based on work environment.

Class 1 safety vests and other garments are intended for workers who have ample separation from vehicular traffic that does not exceed 25 mph and in activities that permit full and undivided attention to approaching traffic. Class 1 garments must have a minimum of 155 square inches of reflective tape. The reflective tape amounts can be made up of the appropriate amount of 2-inch tape 1 3/8-inch tape. The Standard recommends Class 1 garments for workers such as delivery vehicle drivers, parking service attendants, shopping cart retrievers, sidewalk or roadside maintenance workers, and workers in warehouses with equipment traffic.

Class 2 safety vests are for users who need greater visibility in poor weather conditions and whose activities occur near roadways where traffic speeds exceed 25 mph, backgrounds are complex, and tasks divert attention from approaching vehicle traffic. Class 2 safety apparel must have a minimum of 201 square inches of reflective tape of 2-inch tape or 12.2 linear feet of 1 3/8-inch tape. The standard recommends Class 2 safety vests and other garments for workers such as accident site investigators in less-hazardous situations, airport baggage handlers, emergency responders in less-hazardous situations, forestry workers, high-volume parking or toll-gate personnel, law enforcement personnel, railway workers in less-hazardous environments, roadway construction workers in less-hazardous locations, and school crossing guards.

Class 3 safety vests and other garments provide the highest level of visibility to workers in high-risk environments that involve high task loads, a wide range of weather conditions, and traffic exceeding 50 mph. In these environments, workers need to be as conspicuous as possible and class 3 safety vests and clothing help people stand out. Class 3 garments provide coverage to the arms or legs as well as the torso and can include safety pants, safety jackets, coveralls or rain wear. The wearer must be conspicuous and identifiable as a person through the full range of body motions at a minimum of 1280 feet. Class 3 safety vests and other garments must have a minimum of 310 square inches of 2-inch reflective tape. No narrower tape is allowed. The standard recommends Class 3 garments for workers such as accident site investigators, emergency responders, railway workers, roadway construction personnel, survey crews, and flagging crews.