The standard classifies High-Visibility Safety Apparel (HVSA) as Performance Class 1, 2 or 3, depending on the amount of visible background and retroreflective material. These Performance Classes give users a way to specify HVSA that is appropriate for the work environment and hazards. The 2015 edition also establishes three types of garments:

• Type O (off-road), for non-roadway use, where workers are not exposed to high traffic or temporary control zones. Type O HVSA is Performance Class 1.
• Type R (roadway), for use where workers are exposed to traffic from public access highway rights-of-way or roadway temporary control zones. Type R HVSA may be Performance Class 2 or 3.
• Type P (public safety) for emergency and incident responders and law enforcement personnel who are exposed to struck-by hazards in roadway or off-road work environments. These garments provide additional options addressing competing hazards or the need for access to special equipment. Type P HVSA may be Performance Class 2 or 3

A microporus polyurethane layer which is impermeable and acts on the surface tension of water preventing it from filtrations through the micropore. At the same time allows the exit of water vapor molecules (perspiration) since it has a smaller size than the polyurethane microporus.

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