Masks are advised during anesthetic management in poorly scavenged areas, during vaporizer filling and when removing inhalant from vaporizers for shipping equipment. They may be considered in large volume practices when high O2 flows are used (as in large animals) or if mask inductions are common.

Lightweight filter masks are designed for minor exposure to waste anesthetic gases. They are comfortable to wear and staff are likely to comply with recommendations for wearing these.

If significant pollution exists, such as following a large spill or a broken inhalant bottle, the small masks may not be effective. Larger filters are available as shown. This kind of mask should be considered by those at greater risk (pregnant staff). These larger masks are most effective when fitted properly to the individual.