The authoritative public forum
  for Metal Finishing since 1989
  

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EXPOSURE LIMITS - HEXAVALENT CHROMIUM

I have learnt that hexavalent chromium (Cr6+) may have a heavy impact on the health of the workers.
Also I have learnt that, in general for many chemicals, values of environmental concentrations for safe exposure (TLV, PEL, STEL etc.) are defined.

My question is: As regards the Cr6+, the level, e.g., of TLV is the same whichever is the compound containing it, or not? If not, why? Thanks and best regards

p. cirese
officine galileo, campi bisenzio, italia

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2000

I don't know all the Cr(VI) compounds but Potassium Chromate and Potassium DiChromate have the same TLV (0.05 mg per cubic meter) and Permissible Exposure Limit PEL of 0.5 mg per cubic meter. This however is not the whole story.
their labeling is
Health 4 & 4
Flammability 0 & 0
Reactivity 2 & 3
Contact 3 & 3
Respectively, Cr(VI) is likely to be the most harmful component of a chemical, and hence define it's TLV - however how to handle the chemical and it's by/waste products will not be the same, and must be examined individually.After all different chemicals are different chemicals. Before using any chemical, investigate how you will handle, store and dispose of it. Also what procedures need to be in place in case of accident.

Ian Brooke
university - Glasgow, Scotland