Filtering respiratory protective devices The filtering APVRs are protective devices to be used in environments with oxygen values between 18 and 21%V and for non-IDLH filterable contaminants, with an olfactory threshold clearly lower than the TLV/TWA.
Among these are:
Half masks : they protect the respiratory tract, but not the eyes
Full Face Masks : protect the respiratory tract and cover the face
Emergency respirators : compact and sealed in a blister, they are used in the open field for emergency evacuation
Turbofans : they relieve the operator of the inhalation effort and provide an incomparable comfort of use
Filtration takes place through special filters, specific for each contaminant.
Insulating respiratory protective devices These devices are independent of the surrounding atmosphere and are used if it is not possible or insufficient to filter the air present in the confined space or if it is suspected of being polluted. They are generally referred to as self-contained breathing apparatus and can be connected to air cylinders to be carried on the shoulder or to external tanks connected by pipes.