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Chromate carcinogenicity

Figure 6 The uptake reduction model for chromate carcinogenicity (after Wetterhahn). Possible sites for reduction of chromate include the cytoplasm, endoplasmic reticulum, mitochondria or the nucleus1443... Figure 6 The uptake reduction model for chromate carcinogenicity (after Wetterhahn). Possible sites for reduction of chromate include the cytoplasm, endoplasmic reticulum, mitochondria or the nucleus1443...
The carcinogenicity of chromium(VI) compounds has been well-documented in epidemiological studies and animal tests Chromium(VI) compounds were mutagenic in bacterial and mammalian cell systems whereas chromium(III) compounds were not active mutagens in the same test systems In subcellular assay systems both chromium(III) and chromium(VI) decreased the fidelity off. Coli DNA polymerase The differences in activity of chromium(VI) compared to chromium(III) in cellular and subcellular systems have been explained in terms of the uptake-reduction model of chromate carcinogenicity ... [Pg.95]

The NIOSH recommended exposure limit for carcinogenic hexavalent chromium is 1 lg/m Cr(VI) as a 10-h TWA, and for noncarcinogenic Cr(VI) the 10-h TWA is 25 lg/m Cr(VI), including a 15-min maximum exposure of 50 lg/m Cr(VI). According to NIOSH, the noncarcinogenic Cr(VI) compounds are chromic acid and the chromates and dichromates of sodium, potassium, lithium, mbidium, cesium, and ammonia. NIOSH considers any hexavalent chromium compound that does not appear on the preceding Hst carcinogenic (145). [Pg.142]

Recommendations by the ACGIH are classified as threshold limit values (TLV) based on 8-h TWA. Chromium metal and alloys, Cr(II) compounds and Cr(III) compounds, including chromite ore, have a TLV of 0.5 mg/m Cr in air. Water-soluble Cr(VI) compounds have a TLV of 0.05 mg/m Cr. Certain water-insoluble Cr(VI) compounds, ie, the chromates of 2inc, barium, calcium, lead, strontium, sintered chromic acid, and processing chromite ores, also have a TLV of 0.05 mg/m as well as a human carcinogen designation (145). [Pg.142]

The almost universal chromate oxidizers are claimed to be carcinogenic (Ref 67) for which... [Pg.989]

Connett PH, Wetterhahn KE (1983) Metabolism of the Carcinogen Chromate by Cellular Constituents. 54 93-124... [Pg.244]

Potassium chromate is a carcinogen, potassium permanganate is used as a germicide, and potassium hydrogen tartrate, commonly known as cream of tartar, is a white solid found in baking powder. Explain how potassium can have such diverse uses. [Pg.52]

Singh, J., Pritchard, D. E., Carlisle, D. L., McClean, J. A., Montaser, A., Orenstein, J. M. and Patierno, S. R. (1999). Internalization of carcinogenic lead chromate particles by cultured normal human lung epithelial cells formation of intracellular lead-inclusion bodies and induction of apoptosis, Toxicol. Appl. Pharmacol., 161, 240-248. [Pg.400]

The presence of lead and hexavalent chromium in these products is of chronic hazard concern and the EU has classified these pigments as harmful substances. Lead is soluble at stomach-acid concentrations and can accumulate in the organism. The results of a high lead intake include inactivation of enzymes and disturbances in the synthesis of haemoglobin. Hexavalent chromium compounds are considered to be carcinogenic. For these reasons the usage of lead chromate pigments has declined considerably in recent years. [Pg.81]

Preparations containing >0,5% lead chromate are required to be labelled according to EU Guideline 67/548/EEC (Annex I) as toxic (Symbol skull and crossbones) and beside others with the Risk phrases R 40 (limited evidence of carcinogenic effect), R 61 (may cause harm to the unborn child) and R 62 (possible risk of impaired fertility). [Pg.156]

Some compounds, such as strontium chromate and strontium fluoride, are carcinogens and toxic if ingested. Strontium-90 is particularly dangerous because it is a radioactive bone-seeker that replaces the calcium in bone tissue. Radiation poisoning and death may occur in people exposed to excessive doses of Sr-90. Strontium-90, as well as some other radioisotopes that are produced by explosions of nuclear weapons and then transported atmospherically, may be inhaled by plants and animals many miles from the source of the detonation. This and other factors led to the ban on atmospheric testing of nuclear and thermonuclear weapons. [Pg.78]

Cobaltous chromate (CoCrO ) is brownish-yellow to grayish-black (the color depends on its purity) is a dangerous carcinogen (causes cancer). [Pg.107]

Skin contact with tert-butyl chromate caused necrosis of the skin and death of rats. In another report exposed rats had an increase in respiratory rate and signs of mild narcosis. rCT r-Butyl chromate is considered to be an inferred carcinogen because it is a hexavalent chromium compound. ... [Pg.104]

Some less soluble hexavalent chromium compounds (lead chromate and zinc chromate pigments calcium chromate) are carcinogenic in rats, producing tumors at the sites of administration by several routes. Lead chromate also produces renal carcinomas after intramuscular administration in rats. ... [Pg.174]

The lARC has concluded that there is sufficient evidence in humans for the carcinogenicity of chromium(Vl) compounds as encountered in the chromate production, chromate pigment production, and chromate plating industries. In experimental animals there is sufficient evidence for the carcinogenicity of calcium chromate, zinc chromates, strontium chromate, and lead chromate. ... [Pg.174]

Toxicology. Lead chromate is a suspected human lung carcinogen and can cause chronic lead poisoning. [Pg.424]

Chronic animal studies have also yielded varying results. Intratracheal implantation of lead chromates in rats failed to significantly increase the carcinogenic response after 2 years. Intrapleural administration caused a 9% incidence of lung tumors in rats within 19-21 months. Intramuscular injection resulted in lymphomas, renal tumors, fibrosarcomas, and rhabdomyosarcomas at the site of injection in rats. ... [Pg.425]

The lARC has concluded that there is sufficient evidence in experimental animals and in humans for the carcinogenicity of lead chromate. ... [Pg.425]

The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for lead chromate is 0.05 mg/m as Pb and 0.012 mg/m as Cr with an A2-suspected human carcinogen designation. [Pg.425]

K. Wetterhahn Jennette, Microsomal reduction of the carcinogen chromate produces chromium(V),... [Pg.115]

X. Shi, N. S. Dalai, and V. Vallyathan, One-electron reduction of carcinogen chromate by micro-somes, mitochondria and Escherichia coir. Identification of Cr(V) and () [ radical, Arch. Biochem. Biophys., 290 (1991) 381-386. [Pg.116]

Barium chromate is a toxic substance and an EPA-confirmed human carcinogen. [Pg.85]

See other pages where Chromate carcinogenicity is mentioned: [Pg.228]    [Pg.11]    [Pg.228]    [Pg.11]    [Pg.141]    [Pg.149]    [Pg.349]    [Pg.440]    [Pg.653]    [Pg.41]    [Pg.190]    [Pg.129]    [Pg.460]    [Pg.576]    [Pg.577]    [Pg.108]    [Pg.109]    [Pg.456]    [Pg.97]    [Pg.390]    [Pg.226]    [Pg.70]    [Pg.184]    [Pg.162]    [Pg.108]    [Pg.109]    [Pg.456]    [Pg.41]   
See also in sourсe #XX -- [ Pg.947 ]



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