Dangerous reactions, inorganic

This analysis facilitates an a priori study, which enables us to be informed about the potential risks of dangerous reactions. This methodological study is now followed by two chapters on dangerous reactions focusing on first, inorganic, and then organic substances. 

The Code du travail and NFPA hazard codes are explained in Part I in the references that are concerned with each risk. For inorganic products the inflammability, reactivity and toxicity codes are mentioned. For organic products the toxicity code is the only one that is given. Indeed, the inflammability code can be found easily (see para 1.5.1) and the reactivity code is included in chapter 6 under dangerous reactions of inorganic products. 

Oxidizers may not themselves be combustible, but they may provide reaction pathways to accelerate the oxidation of other combustible materials. Combustible solids and liquids should be segregated from oxidizers. Certain oxidizers undergo dangerous reactions with specific noncombustible materials. Some oxidizers, such as calcium hypochlorite, decompose upon heating or contamination and self-react with violent heat output. Oxidizers include nitrates, nitric acid, nitrites, inorganic peroxides, chlorates, chlorites, dichromates, hypochlorites, perchlorates, permanganates, persulfates and the halogens. 

The contact of aluminium with certain inorganic or organic products may lead to dangerous reactions, including explosion, splashes, etc. Several lists are available that include substances capable of producing such reactions with aluminium. In fact, a close analysis of such lists shows that there is very often a confusion between finely divided aluminium such as powder or granules and metal in the form of cast products or wrought semi-products sheet, plate, profiles, bars, tubes, etc. This distinction is very important. Here are a few well-known facts ... 

The biomedical uses of polyphosphazenes mentioned earlier involve chemistry that could in principle be carried out on a classical petrochemical-based polymer. However, in their bioerosion reactions, polyphosphazenes display a uniqueness that sets them apart. This uniqueness stems from the presence of the inorganic backbone, which in the presence of appropriate side groups is capable of undergoing facile hydrolysis to phosphate and ammonia. Phosphate can be metabolized, and ammonia is excreted. If the side groups released in this process are also metabolizable or excretable, the polymer can be eroded under hydrolytic conditions without the danger of a toxic response. Thus, poljnners of this tjT are candidates for use as erodible biostructural materials or sutures, or as matrices for the controlled delivery of drugs. Four examples will be given to illustrate the opportunities that exist. 

Ten examples will be considered six of them are organic reactions and four inorganic. Seven of these reactions caused accidents, mentioned in the corresponding chapters. Two of them were chosen because they are known for not representing any danger and are commonly quoted in lectures. 

The many functions of hydrogen then allow it to be involved in many organic and inorganic acid/base and oxidation/reduction reactions. The danger is that its general role will allow its presence to be taken for granted, though the very presence of water (H20) is the basis of life. 

SAFETY PROFILE A poison. Flammable by chemical reaction an oxidizer. Explosive reaction with hydrogen peroxide, chlorine + ethylene. Reacts violently with molten potassium, molten sodium, S, (H2S + BaO + air). Forms explosive mixtures with nonmetals [e.g., phosphorus (impact-sensitive), sulfur (friction-sensitive)]. Incompatible with alkali metals, reducing materials. Dangerous when heated to decomposition it emits highly toxic fumes of Hg. See also MERCURY COMPOUNDS, INORGANIC. 

DOT CLASSIFICATION 5.1 Label Oxidizer SAFETY PROFILE Dangerous fire hazard by spontaneous chemical reaction. It is a very powerful oxidizer. Fires of this material should be handled like sodium peroxide fires. Moderate explosion hazard hy spontaneous chemical reaction. Explodes on contact with water, forming H2O2 and KOH. Violent reactions with air, Sb, As, O2, K. Vigorous reaction on contact with reducing materials. On contact with acid or acid fumes, it can emit toxic fumes. Incompatible with carbon, diselenium dichloride, ethanol, hydrocarbons, metals. When heated to decomposition it emits toxic fumes of K2O. See also PEROXIDES, INORGANIC. 

MlNEHAL ACIDS are inorganic acids derived from chemical reactions. The discoveries of all three acids below are attributed to Jabir Ibn Hay (8th C.), as is Aqua Regia. NEVER add water to an acid, the reaction can generate considerable heat, and may boil and spit dangerously, ALWAYS add acids carefully to water. ... 

The reaction mixtures from part (I) are oxidised with half-concentrated nitric acid silver can be regenerated from the silver nitrate solution by adding zinc. Danger Do not store ammoniacal silver nitrate solutions The bismuth salt solutions are treated with soda. The precipitates are transferred to the container used for collecting less toxic inorganic waste, and the clear solution is poured down the drain, as are the solutions of the reaction mixtures from parts (II) and (III). 

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