701 Ammonium dichromate Ammonium dichromate is a chemical compound of hexavalent chromium. It has been used in pyrotechnics. Hexavalent chromium refers to chemical compounds that contain the element chromium in the +6 oxidation state. Chromium(VI) is more toxic than other oxidation states of the chromium atom because of its greater ability to enter cells and higher redox potential. (L16, L51) 7789-09-5 24600 Cr2H8N2O7 251.914170 Orange crystals. 180°C Inhalation (L16) ; oral (L16) ; dermal (L16) Hexavalent chromium's carcinogenic effects are caused by its metabolites, pentavalent and trivalent chromium. The DNA damage may be caused by hydroxyl radicals produced during reoxidation of pentavalent chromium by hydrogen peroxide molecules present in the cell. 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. It has been shown to induce carcinogenesis by overstimulating cellular regulatory pathways and increasing peroxide levels by activating certain mitogen-activated protein kinases. It can also cause transcriptional repression by cross-linking histone deacetylase 1-DNA methyltransferase 1 complexes to CYP1A1 promoter chromatin, inhibiting histone modification. Chromium may increase its own toxicity by modifying metal regulatory transcription factor 1, causing the inhibition of zinc-induced metallothionein transcription. (A12, L16, A34, A35, A36) Chromium is absorbed from oral, inhalation, or dermal exposure and distributes to nearly all tissues, with the highest concentrations found in kidney and liver. Bone is also a major storage site and may contribute to long-term retention. Hexavalent chromium's similarity to sulfate and chromate allow it to be transported into cells via sulfate transport mechanisms. 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. Chromium is almost entirely excreted with the urine. (A12, L16) LD50: 22 mg/kg (Oral, Rat) (L16) LD50: 30 mg/kg (Intravenous, Rat) (T22) LD50: 763 mg/kg (Dermal, Rabbit) (L16) L C50: 82 mg/m3 over 4 hours (Inhalation, Rat) (L16) 1 to 3 grams for an adult human (hexavalent chromium). (A119) 1, carcinogenic to humans. (L135) Ammonium dichromate is used in pyrotechnics, as a mordant for dyeing pigments, in the manufacturing of alizarin, and chrome alum, in leather tanning and in oil purification. (L51) Intermediate Inhalation: 0.0002 mg/m3 (L134) Chronic Inhalation: 0.00009 mg/m3 (L134) Hexavalent chromium is a known carcinogen. Chronic inhalation especially has been linked to lung cancer. Hexavalent chromium has also been know to cause reproductive and developmental defects. (A12) Breathing hexavalent chromium can cause irritation to the lining of the nose, nose ulcers, runny nose, and breathing problems, such as asthma, cough, shortness of breath, or wheezing. Ingestion of hexavalent chromium causes irritation and ulcers in the stomach and small intestine, as well as anemia. Skin contact can cause skin ulcers. (L16) There is no know antidote for chromium poisoning. Exposure is usually handled with symptomatic treatment. (L16) 2009-03-26T19:26:29Z 2014-12-24T20:22:36Z Sulfate transporter (P50443) Sulfate anion transporter 1 (Q9H2B4) (A12) C013811 Ammonium dichromate true Sulfate transporter (P50443) Sulfate anion transporter 1 (Q9H2B4) (A12) [NH4+].[NH4+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O Cr2H8N2O7 InChI=1S/2Cr.2H3N.7O/h;;2*1H3;;;;;;;/q;;;;;;;;;2*-1/p+2 InChIKey=JOSWYUNQBRPBDN-UHFFFAOYSA-P 252.0649 251.914174428 Exogenous Solid 23002