![]() People who are allergic to chromium may have asthma attacks after breathing high levels of chromium (III) in air. However, all forms of chromium can be toxic at high levels. Trivalent chromium compounds are considerably less toxic than the hexavalent compounds and are neither irritating nor corrosive under normal conditions. This depends on how much chromium a person has been exposed to, for how long, the nature of the chromium compound(s), and current state of health. Australia's chromium (III) compounds emission report.The National Pollutant Inventory ( NPI) holds data for all sources of chromium (III) compounds emissions in Australia. ![]() Chromium (VI) compounds are dealt with elsewhere in the NPI. Pure chromium metal (oxidation state of 0) which dissolves readily in non-oxidising mineral acids such as hydrochloric and sulfuric acids is not found in nature. Water solubility of chromium and its salts ranges from low to high, e.g chromium (III) oxide is insoluble in water, and chromic (III) acetate, chromium (III) nitrate and chromium (III) sulfate are soluble in water. Although each form can be converted to the other form under certain conditions, chromium (III) is not oxidised to chromium (VI) in the natural soil environment. Compared to chromium (III), chromium (VI) is assumed to be about 100 to 1000 times more toxic. Chromium is chiefly found in its trivalent form in natural environments, except in sea water where chromium in its hexavalent state is prevailing, but at extremely low concentrations. Another oxidation state of practical importance is chromium (VI) (CASR# 1), but whilst there are some natural sources for chromium (VI), the majority originates from industrial activities. Chromite is the most important chromium ore mined for the recovery of chromium. The most stable oxidation state of the element chromium is chromium (III), found in chromite. All chromium compounds have no taste or odour. Chromium chloride is a hygroscopic compound with melting point of 1152☌ and specific gravity of 2.8. Chromium acetate is a grey-green to blue green pasty mass. Chromic oxide is a bright green hygroscopic powder with melting point of 2435☌, boiling point of 4000☌ and specific gravity of 5.2. Properties vary widely depending on the particular compound. ![]() Synonyms: Chromic ion, Chromium ion, Trivalent chromiumĬhromium sulfate (CASR# 1) Physical propertiesĬhromium is a white, hard, lustrous and brittle metal that is extremely resistant to ordinary corrosive agents. Chromic sulfate is used in tanning, green paints, inks and text dyes and in ceramics. Chromium (III) nitrate is used in the preparation of chrome catalysts, in textile printing operations, and as a corrosion inhibitor. Chromium (III) acetate is used to fix certain textile dyes, to harden photographic emulsions and as a catalyst. More specifically, chromium (III) oxide is used as a paint pigment, a fixative for certain textile dyes and as a catalyst. Chromium (III) compounds are employed as pigment, as catalyst, as tanning agent in the tanning industry, in the production of pure chromium metal and chromium (VI) compounds, and in the production of refractory bricks. More applications are in the photographic industry (sensitiser), in industrial water treatment (including treatment of cooling tower water), as medicinal astringents and antiseptics, and in nuclear and high temperature research. protective coatings for automotive and equipment accessories), as dyes, as inorganic paint pigments, for leather tanning, as fungicides and wood preservatives, and as catalysts. Chromium compounds are used for chrome plating (e.g. Chromium metal is used as an alloying element to harden steel and to manufacture stainless steel.
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