Inorganic colorants, hazards

A great deal of frustration has arisen over the way hazardous chemicals are defined by OSHA. Most people feel more comfortable if there is a specific list of chemicals to which they can refer, but there is no such list provided under the Hazard Communication Standard. In addition, chemicals that were not previously considered hazardous because they are virtually inert or are not harmful to humans by contact with skin are now considered a dust hazard (particularly inorganic, nontoxic, noncombustible dusts that can enter the body via the respiratory system). This is where the regulation of colorants under OSHA occurs via the Hazard Communication Standard. 

Many plastics converters prefer to utilize colorants other than those that present potential health hazards. Colorants of these types are commonly restricted by legislation that limits their use. Many of the most weatherfast and heat stable inorganic pigments contain significant levels of heavy metals, specifically hexavalent chromium, lead, mercury, and cadmium, so... 

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