Respirator (filtering device) – uses filters to remove contaminants in the workplace air , there are two main types:
Non-powered respirators – rely on the wearer’s breathing to draw air through the filter
Powered respirators – use a motor to pass air through the filter to give a supply of clean air to the wearer
Breathing apparatus (BA) – needs a supply of breathing-quality air from an independent source (e.g. air cylinder or air compressor)
Both respirators and BA are available in a range of different styles, which can be put into two main groups:
Tight-fitting facepieces (often referred to as masks) – rely on having a good seal with the wearer’s face. These are available as both non-powered and powered respirators and BA. Examples are filtering facepieces, half and full-face masks.
Loose-fitting facepieces – rely on enough clean air being provided to the wearer to prevent contaminant leaking in (only available as powered respirators or BA). Examples are hoods helmets, visors, blouses and suits.
WARNING: Only BA is suitable for use in oxygen deficient atmospheres.
Usually half mask, negative-pressure particulate respirator
Inspiratory effort of wearer draws air through filter
Filter comprises all or a significant portion of the facepiece
Airborne particles removed as inspired air passes through filter
NIOSH-certified CBRN air-purifying respirators with HEPA or P-100 filters provide the minimum acceptable level of protection against inhalation of particles for personnel working in environments likely to be contaminated with radioactive materials
Does not restrict mobility
Low cost (compared to other respirators)
Does not supply oxygen (cannot be used in low oxygen environments)
May only be used when air contaminant level is below the concentration limits of the filter
Fit testing required
Some contaminated air will leak into facepiece
Half mask models do not provide adequate eye protection