03/03/2006

Hexavalent chromium

Workers in many different occupations are exposed to hexavalent chromium.
Occupational exposures occur mainly among workers who handle pigments
containing dry chromate, spray paints and coatings containing chromate, operate
chrome plating baths, and weld or cut metals containing chromium, such as
stainless steel. Stainless steel welding involves the greatest exposure to
hexavalent chromium.

Chromium hexavalent (CrVI) compounds, often called hexavalent chromium, exist
in several forms. Chromates are often used as pigments for photography, and in
pyrotechnics, dyes, paints, inks, and plastics. They can also be used for
stainless steel production, textile dyes, wood preservation, leather tanning,
and as anti-corrosion coatings.

Calcium chromate, chromium trioxide, lead chromate, strontium chromate, and
zinc chromate are known human carcinogens. An increase in incidence of lung
cancer has been observed among workers in industries that produce chromate and
manufacture pigments containing chromate. An increased rate of lung cancer has
also been reported among producers and consumers of pigment containing
chromate. One study of chromium-nickel alloy foundry workers showed a
statistically significant increase in lung cancers.

There are several ways to reduce exposure to hexavalent chromium. Recommended
controls vary from operation to operation. The preferred approach is to use
engineering controls such as ventilation or equipment and process modification.
If these controls are not sufficient, other controls may be implemented,
including the use of respirators, eye protection, showering, and changing into
street clothes before leaving the plant.

Further info


AplusA-online.de - Source: U.S. Department of Labor Occupational Safety & Health Administration