Hexavalent chromium is a toxic form of the element chromium which is today recognised as a human genotoxic carcinogen. Individuals experiencing long-term exposure to airborne hexavalent chromium particles have a significantly increased risk of developing respiratory cancers.
Other hexavalent chromium exposure health effects are nose, throat, lung and respiratory tract irritations when breathed at high levels, and irritation and damage to eyes and the skin if high concentrations of the particles come into contact with these organs.
Work activities involving hexavalent chromium which can result in toxic levels of exposure include:
- Welding, cutting and hard-facing of stainless steel
- Manual metal arc welding of high chromium steels
- Chrome plating
- Refractory production
- Addition of cement to gravel and sand to make concrete
- Leather tanning
- Timber preservation using copper chrome arsenate
- Chromate use in the textile industry
- Chrome pigment use, such as in dyes, paints, inks and plastics
The number of persons exposed or potentially exposed to hexavalent chromium in New Zealand is unknown. However, over 75,000 New Zealand workers in the construction industry have worked in areas where there is a chance they have been exposed.