I've heard that chromium can be harmful to my employees, and possibly for my customers. Can you tell me about chromium, and what the possible effects are from exposure?
Chromium can exist in oxidation states ranging from -2 to 6, but it is mostly found in the trivalent (CrIII) and hexavalent (CrVI) oxidation states. CrIII is naturally found in rocks, soils, plants, animals, and volcanic emissions. This form of chromium is believed by many to play a nutritional role in the human body. CrVI is the most toxic form of chromium and is produced in industrial environments when CrIII is heated in the presence of mineral bases and atmospheric oxygen—as in metal finishing processes. CrVI is found in the acid used in hot-dip galvanizing quench baths and has been used as a 0.15% wt. sodium chromate solution to prevent wet storage stain on hot-dip galvanized parts. It is the aggressive oxidizing behavior of chromium that makes exposure to CrVI such a dangerous health risk. A person can be exposed to chromium by eating or drinking contaminated food or water, breathing contaminated air, skin contact, or living near uncontrolled hazardous waste sites that contain chromium particles. Small amounts of CrVI that are ingested will not necessarily harm you, however, accidental ingestion of larger amounts can cause stomach upsets and ulcers, convulsions, kidney and liver damage, and even death. The levels of CrVI that cause these effects are far greater than those you might be exposed to in any type of food or regulated water sources. Chromium compounds in the air are mostly present as fine dust particles, which eventually settle over land.
© 2019 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of the AGA. Anyone making use of this information assumes all liability arising from such use.