They cannot supply oxygen in an oxygen deficient atmosphere. In addition to the filtering elements, the backpack assembly consists of a battery powered blower assembly, which keeps air moving to the face piece. Organic Dusts are derived from material formed by living organisms and contain carbon. Sawdust is an organic dust. They are usually referred to as Nuisance Dust.
Inorganic Dusts are usually mineral, such as asbestos, silica and coal dust.
These dusts enter the body through inhalation and slowly convert and degenerate healthy lung tissue into useless fibrous or scar tissue. These dusts are considered more dangerous than the fibrosis producing dusts. Whether inhaled into the lungs or ingested through the mouth, these dusts dissolve and enter the blood stream to travel through it and injure almost any organ in the body. Metal fumes, resulting when metals are subjected to high temperature. Welding fume is an example of metal fume.