Acetylides, hazards

Silver acetylide is a more powerful detonator than the copper derivative, but both will initiate explosive acetylene-containing gas mixtures [1]. It decomposes violently when heated to 120-140°C [2], Formation of a deposit of this explosive material was observed when silver-containing solutions were aspirated into an acetylene-fuelled atomic absorption spectrometer. Precautions to prevent formation are discussed [3], The effect of ageing for 16 months on the explosive properties of silver and copper acetylides has been studied. Both retain their hazardous properties for many months, and the former is the more effective in initiating acetylene explosions [4],... 

Monocaesium and monorubidium acetylides ignite with cone, sulfuric acid [1]. Other carbides are hazardous in contact [2],... 

Silver is a white, ductile metal occurring naturally in its pure form and in ores (USEPA 1980). Silver has the highest electrical and thermal conductivity of all metals. Some silver compounds are extremely photosensitive and are stable in air and water, except for tarnishing readily when exposed to sulfur compounds (Heyl et al. 1973). Metallic silver is insoluble in water, but many silver salts, such as silver nitrate, are soluble in water to more than 1220 g/L (Table 7.3). In natural environments, silver occurs primarily in the form of the sulfide or is intimately associated with other metal sulfides, especially fhose of lead, copper, iron, and gold, which are all essentially insoluble (USEPA 1980 USPHS 1990). Silver readily forms compounds with antimony, arsenic, selenium, and tellurium (Smith and Carson 1977). Silver has two stable isotopes ( ° Ag and ° Ag) and 20 radioisotopes none of the radioisotopes of silver occurs naturally, and the radioisotope with the longest physical half-life (253 days) is "° Ag. Several compounds of silver are potential explosion hazards silver oxalate decomposes explosively when heated silver acetylide (Ag2C2) is sensitive to detonation on contact and silver azide (AgN3) detonates spontaneously under certain conditions (Smith and Carson 1977). 

A lab method of prepn is described in Ref 6. Its toxicology, fire hazard, storage and handling are discussed in Ref 7. It was claimed (Ref 3) that the ignition sensitivity life of igniter compds contg cuprous acery-lide(or other metallic acetylides) is improved by the addition of small amounts of abietic acid... 

According to Sax (Ref 23) acetylene is si toxic and its fire hazard is great when exposed to heat or flame. Its expl hazard is moderate when exposed to heat or flame or when it undergoes spontaneous chetn reactions. At high ptess it may decomp explosively even ax moderate temps. It can react vigorously with oxidizing materials and it forms expl compds on contact with Cu or Ag(see Acetylides)... 

Only one of the acetylides(cuprous acetylide) has found application in industry as an ingredient of electric detonators. Some acetylides, as for instance, that of silver, arc probably suitable for use in primers and detonators. They also may be incorporated in LA-based compositions for expl rivets in order to reduce their ignition point(Ref 6) According to Sax(Ref 6) the toxicity of acetylides is unknown, but their expln hazards are considered to be the same as those of fulminates and azides. The acetylides must be handled with extreme care and In storage they must be kept cool and wet. Metal powders, such as finely divided Cu or Ag, should be excluded. Shipping regulations are the same as for other primary and initiating explosives Refs l)Beil 1,238-40,(104 6),[217-20] ... 

The use of very fast ign agents involves, in most cases, considerable danger from the hazard of static elecy. It has been found that ign compds which have a negligible induction period(or so -called fast compds) are susceptible to initiation by static elecy. Particularly susceptible to static elecy is Cu acetylide Ref W.H.Aughey, L.A.Burrows W.E.Lawson,... 

The ultimate product obtained by oxidising cuprous acetylide could be formulated thus. Although infrared suggested a cumulene structure, not that shown above, it retains the hazards of its progenitor. 

Metal Acetylides or Carbides. Monocesium and monorubidium acetylides ignite on contact with concentrated sulfuric acid.14 Hazardous reactions occur with other carbides.12... 

Copper, aluminum, and their alloys should not be used in handling vinylidene chloride. Copper can react with acetylenic impurities to form copper acetylides, whereas aluminum can react with the vinylidene chloride to form aluminum chloralkyls. Both compounds are extremely reactive and potentially hazardous. 

DOT CLASSIFICATION Forbidden SAFETY PROFILE Severe explosion hazard. A more powerful detonator than copper acetylide. Explodes when heated to 120-140°C. Formed when silver-containing soludons contact acetylene. Upon decomposidon it emits acrid smoke and irritadng fumes. See also SILVER COMPOUNDS and ACETYLIDES. 

Acetylene is a reactive material that poses a fire and explosion hazard. Its lower and upper explosive limits in air are 2.5% and 93%, respectively. Acetylene reacts with active metals (e.g., copper, silver, and mercury) to form explosive acetylide compounds. Acetylene manufactured from calcium carbide can contain impurities such as phosphine and arsine that are responsible for the ethereal to garlic-like odor of commercial acetylene and pose a greater human... 

SULFUROUS OXIDE (7446-09-5) SO, Noncombustible liquefied gas under pressure or liquid. Contact with air forms hydrogen chloride fumes. Violent reaction with water or steam, forming sulfurous acid, a medium-strong acid and corrosion hazard. Reacts violently with acetylene, acrolein, alcohols, aluminum powder alkali metals (i.e., potassium, sodium) amines, ammonia, bromine pentafluoride butadiene caustics, cesium acetylene carbide chlorates, chlorine trifluoride chromium powder copper or copper alloy powders chlorine, diethylzinc, fluorine, ethylene oxide lead dioxide lithium acetylene carbide diamino-, metal powders monolithium acetylide-ammonia nitryl chloride potassium acetylene carbide potassium acetylide, potassium chlorate rubidium carbide silver azide sodium acetylide staimous oxide. Decon oses in... 

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