Industrial Hygiene – Air Contaminants

Air Contaminants are commonly classified as either particulate or gas and vapor contaminants. This week we will discuss only the particulate air contaminants.

Particulate contaminants include dusts, fumes, mists, aerosols, and fibers.

Dusts are solid particles that are formed or generated from solid organic or inorganic materials by reducing their size through mechanical processes such as crushing, grinding, drilling, abrading or blasting.

Fumes are formed when material from a volatilized solid condenses in cool air. In most cases, the solid particles resulting from the condensation react with air to form an oxide. This typically occurs when welding or burning of metal.

Mist is a term applied to a finely divided liquid suspended in the atmosphere. Mists are generated by liquids condensing from a vapor back to a liquid or by breaking up a liquid into a dispersed state such as by splashing, foaming or atomizing. Aerosols are also a form of a mist characterized by highly reparable, minute liquid particles.

Fibers are solid particles whose length is several times greater than their diameter.

When engineering, work practice or administrative controls are not adequate to protect employees from dusts, fumes, mists, aerosols, and fibers the face mask with the P-100 cartridge is used for protection unless levels are extremely high, then a supplied air respirator must be used.

Hexavalent chromium is a health hazard that can occur when metal that contains chromium is ground or welded. It has been shown, by Industrial Hygiene sampling conducted for J.J. White, Inc., that both the welder and the fitter must use, as a minimum, a negative pressure respirator with the P-100 cartridge.

Lead exposures typically occur as particulate exposure either as a fine dust, if sanded or ground, or if heat is involved, exposure is in the form of a fume. J.J. White Inc. does not have a lead abatement program therefore, it is important that you do not disturb any painted surface that may contain lead.

Asbestos exposure typically occurs only as a dust exposure even if it is heated. As with the case of lead, J.J. White, Inc. doesn’t have an asbestos abatement program, it is important that you do not disturb any insulation, or other material that may contain asbestos.