Iodate toxicity

Many silver compounds are unstable to light, and are thus shipped ia brown glass or opaque plastic bottles. Silver compounds that are oxidants, eg, silver nitrate and iodate, must be so identified according to U.S. Department of Transportation (DOT) regulations. Compounds such as silver cyanide, which is toxic owiag to its cyanide content, must carry a poison label. However, most silver compounds are essentially nontoxic. 

The procedure reported here is practical, uses readily available, non-toxic starting materials, and can be easily scaled up. No harmful by-products are formed during the synthesis, and sodium iodate, generated during the periodate cl avage, can be recycled into sodium metaperiodate.15... 

The use of iodate and periodic acid as oxidizers for noble metal CMP has also been attempted. Similar to W CMP, a surface oxidation or modification is required for the subsequent removal by mechanical force. For example, the potential use of ruthenium as bottom electrode capacitor for next-generation DRAM devices [40] has been explored. Owing to the fact that a dry-etch process can lead to the formation of toxic RUO4 [41], the possibility of using CMP to implement Ru has gained interest recently. The studies in this area have indicated that the formation of stable passive layers such as RUO2 [41,42] and RU2O5 [42] are important steps in the Ru CMP. 

DFG MAK 1.5mg/m3 DOT CLASSIFICATION 4.2 Label Spontaneously Combustible SAFETY PROFILE Moderately toxic by intravenous route. Experimental reproductive effects. It can cause a dust irritation, particularly to the eyes and mucous membranes. See also CARBON BLACK, SOOT. Combustible when exposed to heat. Dust is explosive when exposed to heat or flame or oxides, peroxides, oxosalts, halogens, interhalogens, O2, (NH4NO3 + heat), (NH4CIO4 240°), bromates, Ca(OCl)2, chlorates, (CI2 + Cr(OCl)2), CIO, iodates, IO5, Pb(N03)2, HgNOs, HNO3, (oils + air), (K + air), Na2S, Zn(N03)2. Incompatible with air, metals, oxidants, unsaturated oils. 

SAFETY PROFILE Salts of iodic acid. Variable toxicity. Generally eye, skin, and mucous membrane irritants. Powerful oxidizers. Similar to bromates and chlorates. Contamination of iodates with organic matter may produce explosive mixtures. Iodates are used in bread as an improving agent for the dough. When heated to decomposition they emit toxic fumes of I . See also specific compounds. 

MERCURIC THIOCYANATE (592-85-8) Hg(SCN)i Moderately unstable solid. Possible violent reaction with strong oxidizers strong acids organic peroxides, peroxides and hydroperoxides potassium chlorate potassium iodate, silver nitrate, sodium chlorate, nitric acid. Incompatible with ammonia, chlorates, hydrozoic acid, methyl isocyanoacetate, nitrates, nitrites, perchlorates, sodium peroxyborate, trinitrobenzoic acid, urea nitrate. When heated, this material swells to many times its original bulk. Attacks aluminum in the presence of moisture. Decomposes above 329°F/165°C, releasing toxic mercury and cyanide fumes, and sulfur and nitrogen oxides. On small fires, use dry chemical powder (such as Purple-K-Powder), alcohol-resistant foam, or COj extinguishers. MERCURIC (Spanish) (7439-97-6) see mercury. 

SODIUM RHODANIDE (540-72-7) NaSCN Exposure to light causes slow decomposition, forming cyanide, sulfur oxides, and nitrous vapors. Violent reaction, possibly explosion, with strong oxidizers, organic peroxides, nitric acid. Incompatible with acids, bases, chlorates, anunonia, amines, amides, alcohols, glycols, caprolactam, nitrates, peroxides and hydroperoxides, potassium chlorate, potassium iodate, silver nitrate, sodium chlorate. Contact with sulfuric acid forms toxic carbonyl sulfide gas. Forms explosive mixture with sodium nitrate. Thermal decomposition releases oxides of sulfur and nitrogen. 

EXPLOSION and FIRE CONCERNS flammable in the form of dust when exposed to heat or flame when heated or on contact with acid or acid fumes, it emits highly toxic fumes dangerous when water solutions of arsenicals are in contact with active metals such as iron, zinc, aluminum flammable by chemical reaction with bromates, chlorates, iodates, peroxides, lithium, silver nitrate, nitric acid, potassium permanganate, chromium trioxide, chlorine trifluoride, chlorine oxide, bromine trifluoride, bromine pentafluoride, bromine azide use foam, carbon dioxide, or dry chemical for firefighting purposes.. 

The observation of toxicity of iodine mainly focused on the iodide or iodate, which is normally present in iodized salt, milk, water and leachate of foodstuffs. However, the toxicity of some other species of iodine may be much higher than that of iodide and iodate. For the prevention of iodine deficiency disorders, iodized oil was used as an injection or administered orally in many countries iodized oil is normally produced by binding iodine atoms to the polyunsaturated fatty acid in the oil (Zimmermann et al, 2000). After administration, it was supposed that iodine is released gradually as iodide to maintain a constant supply of iodine to the body. Experience in the past decades shows that the utilization of iodized oil is safe. However, acute poisoning of iodized oil to children who are orally administered was reported in China in 1998 this may be related to the species of iodine, which may be more toxic than iodide or iodate. Iodine has been used as an effective, simple, and cost-efficient means of water disinfection (Backer and Hollowell, 2000), in which the active disinfectant species are elemental iodine and hypo-iodous acid. Doses of iodine below 1 mg/1 kill bacteria within minutes. Elemental iodine and hypoiodous acid remain in the disinfected water, which may be toxic to humans. 

Iodide and iodate have a low toxicity and high bioavailability, whereas the toxicity of elemental iodine and periodate is high. The bioavailability of organic iodine, especially iodine associated with macromolecules, is low. 

The oxidation of halides results in the formation of highly soluble and potentially toxic species, including perchlorate, iodate and bromate. The presence of these chemicals in drinking water supplies has become an important issue for municipal water supplies, as well as for the bottled water industry. These species are not only present in many source waters, but also can be formed or introduced during water treatment. 

Iodate is generally considered to be an important component of the human diet, as it is rapidly reduced to iodide in the body and iodide is essential for thyroid function (Burgi et ai, 2001). However, high levels of iodate (>600 mg/day) have been shown to cause damage to the retina, resulting in ocular toxicity (Burgi et ai, 2001). 

Blood iodine levels were elevated at subtoxic doses of iodine, indicating adequate exposure. Iodine toxicity manifested itself as reduced performance. Since iron supplementation prevented it, this toxicity may have resulted from an apparent interference of iodate or iodine, respectively, with iron uptake or utiftzation. NOELs for pigs were observed at 400 parts per million (ppm) calcium iodate added to hog mash calves were more susceptible with a NOEL of only 25 ppm. The toxic signs were attributed either to iron deficiency or to general iodine toxicity. 

All these smdies are, in part, incomplete nonetheless, they may be sufficient to derive adequate safety factors for overt organ toxicity by iodate (not iodine ). 

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