Chromium (VI) compounds (chromates and dichromates) are known carcinogens. Although the quantities handled in school laboratories are very much smaller than those used in industrial settings, and students are not likely to be exposed for long term, extreme caution should be used with these compounds in an educational setting.
Because students do not have extensive safety training, are also likely to be less careful than adults, and since the use of these compounds creates disposal problems, they should not be used in most teaching situations.
Click here to go to Internet related sources of information.