chromium 3 bromide (Cr3Br) is a compound with chromium as the dominant oxidation state and bromide as the second oxidation state. This form of chromium is much less toxic than the more commonly found hexavalent chromium compounds (Cr6+).
Hexavalent chromium and trivalent chromium are essentially the same element with different oxidation states. Hexavalent chromium is more toxic to humans and can cause gastrointestinal upset, kidney damage, and skin rashes in those who ingest it in large quantities.
A few hexavalent chromium (Cr6+) compounds are used as welding reagents in the steel industry. Hexavalent chromium releases ozone during welding, which can induce pulmonary and immunologic problems in some workers.
Some hexavalent chromium is also released during the recycling of metals such as aluminum and nickel. Hexavalent chromium can contaminate air, water and soil.
Most hexavalent chromium particles settle in the air within 10 days after they are emitted from manufacturing or disposal of products that contain chromium, or burning of fossil fuels. Soil hexavalent chromium often lingers in the soil for a long time, especially in contaminated areas of the world.
Hexavalent chromium can be found in the environment and has a wide range of environmental effects, including chronic toxicity to plants, birds and fish, and acute toxicity to animals. Some of these effects can be fatal, but others may result in a decline in the growth rate or death of plants and birds and low growth rates in animals such as dogs, cats and cattle.