It may be oxidized to hexavalent chromium, a known carcinogen. ( 10)Ĭhromium in its trivalent state is not very toxic. ( 8)Ĭhromium nitrate is used in the production of alkali metal-free catalysts and in pickling. Chromium (III) compounds are not classifiable as to their carcinogenicity to humans (Group 3). Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). Nitrites, nitrates, and their metabolites are excreted in the urine. The major metabolic pathway for nitrate is conversion to nitrite, and then to ammonia. In vivo conversion of nitrates to nitrites can occur in the gastrointestional tract under the right conditions, significantly enhancing nitrates' toxic potency. Intake of some amount of nitrates and nitrites is a normal part of the nitrogen cycle in humans. Chromium is almost entirely excreted with the urine. Inside the cell, hexavalent chromium is reduced first to pentavalent chromium, then to trivalent chromium by many substances including ascorbate, glutathione, and nicotinamide adenine dinucleotide. Hexavalent chromium's similarity to sulfate and chromate allow it to be transported into cells via sulfate transport mechanisms. Bone is also a major storage site and may contribute to long-term retention. ( 5, 13, 1, 6, 2, 3, 4)Ĭhromium is absorbed from oral, inhalation, or dermal exposure and distributes to nearly all tissues, with the highest concentrations found in kidney and liver. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. Nitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. Nitrate's toxicity is a result of it's conversion to nitrite once in the body. Chromium may increase its own toxicity by modifying metal regulatory transcription factor 1, causing the inhibition of zinc-induced metallothionein transcription. It can also cause transcriptional repression by cross-linking histone deacetylase 1-DNA methyltransferase 1 complexes to CYP1A1 promoter chromatin, inhibiting histone modification. It has been shown to induce carcinogenesis by overstimulating cellular regulatory pathways and increasing peroxide levels by activating certain mitogen-activated protein kinases. Trivalent chromium may also form complexes with peptides, proteins, and DNA, resulting in DNA-protein crosslinks, DNA strand breaks, DNA-DNA interstrand crosslinks, chromium-DNA adducts, chromosomal aberrations and alterations in cellular signaling pathways. chromium coordination entity ( CHEBI:86204 ).These are inorganic compounds in which the largest oxoanion is nitrate, and in which the heaviest atom not in an oxoanion is a transition metal. ()=O.()=O.()=Oīelongs to the class of inorganic compounds known as transition metal nitrates. Nitrite is a toxic compound known to cause methemoglobinemia. Trivalent chromium (chromium(III)) however, is biologically necessary for sugar and lipid metabolism in humans. ( 12)) due to its greater ability to enter cells and higher redox potential. Chromium is most toxic in its +6 oxidation state (chromiumNitrite is a toxic compound known to cause methemoglobinemia. It is found naturally occuring in rocks, animals, plants, and soil, and is usually mined as chromite ore. Chromium is a chemical element which has the symbol Cr and atomic number 24. It is used in the production of alkali metal-free catalysts and in pickling. In case of fire: Store in a well-ventilated place.Chromium nitrate is a nitrate of chromium. Call a POISON CENTER or doctor/physician if you feel unwell. Remove contact lenses, if present and easy to do. IF IN EYES: Rinse cautiously with water for several minutes. IF INHALED: Remove to fresh air and keep at rest in a position comfortable for breathing. IF ON SKIN: Wash with plenty of soap and water. Wear protective gloves/protective clothing/eye protection/face protection. Contaminated work clothing should not be allowed out of the workplace. Use only outdoors or in a well-ventilated area. Wash face, hands and any exposed skin thoroughly after handling Do not eat, drink or smoke when using this product. Avoid breathing dust/fume/gas/mist/vapours/spray. Take any precaution to avoid mixing with combustibles. Toxic to aquatic life with long lasting effects.
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