Supplied-air respirators (SARs) supply clean air from a compressed air tank or through an air line. This air is not from the work room area. The air supplied in tanks or from compressors must meet certain standards for purity and moisture content (e.g., CSA Standard Z180.1-00: Compressed Breathing Air and Systems). Supplied-air respirators may have either tight-fitting or loose-fitting respiratory inlets. Respirators with tight-fitting respiratory inlets have half or full face pieces. Types with loose-fitting respiratory inlets can be hoods or helmets that cover the head and neck, or loose-fitting face pieces with rubber or fabric side shields. These are supplied with air through airlines.