A<unk>  with a belt-pack filter-blower that feeds<unk>  to the elastomeric mask. A<unk> , gown, and biosafety cabinet in use in a BSL-3 laboratory. All parts of the<unk>  are visible: the waist unit holding the fan, filter, and battery; the hose; and the mask, in this case a flexible, loose-fitting one. A<unk>  with a rigid, tight-fitting mask A<unk>  <unk>  is a type of respirator used to safeguard workers against contaminated<unk> .<unk> s consist of a headgear-and-fan assembly that takes ambient<unk>  contaminated with one or more type of pollutant or pathogen, actively removes (filters) a sufficient proportion of these hazards, and then delivers the clean<unk>  to the user's face or mouth and nose. They have a higher assigned protection factor than filtering facepiece respirators such as N95 masks.<unk> s are sometimes called positive-pressure masks, blower units, or just blowers.
Powered air-purifying respirator
Flow-restricted, oxygen-powered ventilation device
Liquid ventilator
Exhalation delivery system
Elastomeric respirator
Open-source ventilator
Analytical nebulizer
Air filtration in operating rooms