Toxicity indium

Acute indium poisonings are rare due to the low absorption of this metal from the gastrointestinal tract and moderate absorption from inhalation. However, in animal experiments indium toxicity is often related to the chemical form and route of exposure. Insoluble indium oxides were found to be more toxic to mice than ionic indium when expressed as lethality per quantity of... 

G. Normandeau, 1990. Cadmium free gold solders An update Indium toxicity and potential workplace exposures. In Proceedings of the Santa Fe Symposium on Jewelry Manufacturing Technology, ed. D. SchneUer, 239-292. Albuquerque, NM Met-Chem Research. 

Intermetallic compounds with gallium are used as semiconductors. Indium is used to coat other metals to protect against corrosion, especially in engine bearings it is also a constituent of low-metal alloys used in safety sprinklers. The toxicity of thallium compounds has limited the use of the metal, but it does find use as a constituent of high-endurance alloys for bearings. 

There is evidence that indium has a low order of toxicity however, care should be taken until further information is available. 

Some metals used as metallic coatings are considered nontoxic, such as aluminum, magnesium, iron, tin, indium, molybdenum, tungsten, titanium, tantalum, niobium, bismuth, and the precious metals such as gold, platinum, rhodium, and palladium. However, some of the most important poUutants are metallic contaminants of these metals. Metals that can be bioconcentrated to harmful levels, especially in predators at the top of the food chain, such as mercury, cadmium, and lead are especially problematic. Other metals such as silver, copper, nickel, zinc, and chromium in the hexavalent oxidation state are highly toxic to aquatic Hfe (37,57—60). 

Soldered joints present their own characteristic corrosion problems usually in the form of dissimilar metal attack often aided by inadequate flux removal after soldering. Such joints have always been a source of concern to the electrical industry. Lead-containing solders must be used with caution for some types of electrical connection since PbfOHjj.PbCOj may be found as a corrosion product and can interrupt current flow. Indium has been found to be a useful addition to Sn-Pb solders to improve their corrosion resistanceHowever, in view of the toxicity of lead and its alloys, the use of lead solders, particularly in contact with potable waters and foodstuff s, is likely to decline. 

Indium metal dust, particles, and vapors are toxic if ingested or inhaled, as are most of the compounds of indium. This requires the semiconductor and electronics industries that use indium compounds to provide protection for their workers. 

There are no reports of toxicity in humans. When indium was applied to the skin there was no evidence of irritation. 

Blazka ME, Dixon D, Haskins E, et ah Pulmonary toxicity to intratracheally administered indium trichloride in Fischer 344 rats. Eundam Appl Toxicol 22 231-239, 1994... 

Nakajima M, Takahashi H, Sasaki M, et ah Species differences in the developmental toxicity of indium between rats and mice. Teratology 62(3) 41A, 2000... 

Most of the surveys on metals and metalloids in food have concentrated on those elements that are known to be toxic, or where there are possible concerns about their levels in food. In the course of collecting the data, information on other metals is often collected in addition. Other metals that have been included in the UK Government s surveillance are zinc, antimony, chromium, cobalt, indium, nickel, thallium and tin. 

Hart MM, Adamson RH. 1971. Antitumor activity and toxicity of salts of inorganic group Ilia metals Aluminum, gallium, indium, and thallium. Proc Natl Acad Sci U S A 68 1623-1626. 

Other metals in group 13 have not been investigated nearly as extensively as aluminium. Recently, however, indium and gallium complexes have been shown to be active initiators in particular, indium complexes are quite desirable due to their low toxicity and water tolerance [65-67]. Table 3 illustrates some selected examples of interesting Ga and In initiators. 

Gallium(III) and indium(III) radionuclides are used widely for radiodiagnosis. As with all complexes used for such purposes, rapid and stable binding of the toxic radionuclide is essential. Molecular mechanics modeling has been used to predict the stability of gallium(III) and indium(III) complexes of bis(aminoetha-nethiol) ligands and to attempted a prediction of the coordination numbers of the complexes 5121. 

The classical electronics solder alloy (Sn + 37 wt% Pb) contains the inhalation-toxic element lead and is being replaced in electronics for health reasons. A Pb-free solder is Sn-3.5wt% Ag indium and bismuth alloys are other eutectic-forming alloying additives to Sn. The classical brazing alloy is at the Cu-Ag eutectic (Ag-F 28.1 w% Cu) and is well suited for mechanically strong contacts with Cu and its alloys. 

Tanaka, A. (2004). Toxicity of indium arsenide, gallium arsenide and aluminum gallium arsenide. Toxicol. Appl. Pharmacol. 198 405-11. 

SAFETY PROFILE Experimental teratogenic and reproductive effects. A severe skin irritant. When heated to decomposition it emits toxic fumes of NO.. See also INDIUM and NITRATES. 

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