Respirable and Total Dust

NIOSH 0500/0600

Dusts are solid particles, ranging in size from below 1 µm up to at least 100 µm, which may be or become airborne, depending on their origin, physical characteristics, and ambient conditions.

Airborne dusts are of particular concern because they are well known to be associated with classical widespread occupational lung diseases such as the pneumoconiosis, as well as with systemic intoxications such as lead poisoning, especially at higher levels of exposure. But, in the modern era, there is also increasing interest in other dust-related diseases, such as cancer, asthma, allergic alveolitis, and irritation, as well as a whole range of non-respiratory illnesses, which may occur at much lower exposure levels.

Types of dust found in the work environment include:

• mineral dusts, e.g., crystalline silica, asbestos, coal, and cement.
• metallic dusts, such as lead, cadmium, nickel, and beryllium.
• other chemical dusts, e.g., bulk chemicals and pesticides.
• organic and vegetable dusts, flour, wood, cotton and tea dusts, pollens.
• biohazards, such as viable particles, molds, and spores.

NIOSH 0500 gravimetrically calculates the total dust concentration while NIOSH 0600 samples only the respirable portion of solid particles present with use of specific sampling devices such as cyclones or parallel particle impactors (PPI’s). Respirable particulate fraction is that fraction of inhaled airborne particles that can penetrate beyond the terminal bronchioles into the gas-exchange region of the lungs (< 4 micrometers).