Arsenic metal manufacturing source

Uses/Sources. In the electronics industry to manufacture gallium arsenide and gallium arsenide phosphide for semiconductors and as a dopant produced accidentally as a result of generation of nascent hydrogen in the presence of arsenic or by the action of water on a metallic arsenide... 

The presence of elements known to have adverse health effects in humans such as lead and arsenic is obviously undesirable in food. Environmental sources are the main contributors to contamination of food with most metals and other elements. Some elements (e.g. arsenic) are present naturally but the major sources of other elements (e.g. lead) in the environment are from pollution from industrial and other human activities. The presence of metals and other elements in food can also be the result of contamination from certain agricultural practices (e.g. cadmium from phosphate fertilisers) or manufacturing processes (e.g. tin in canned foods). 

For this reason, heavy metals and metal ions that are used as additives in plastics and rubber (as colorants, stabilisers, plasticisers and so on) should be monitored carefully, and their use as well as the amounts used should be well known and regulated. In addition to their existence in some of the additives used in plastics and rubbers, toxic heavy metals most of which are considered chronic poisons, such as arsenic, lead, mercury, cadmium, nickel, zinc and chromium, are frequently encountered in industrial processing and other manufacturing operations (their main industrial sources include paint, ink, plastic, rubber and plastic film production, leather tanning, wood preserving, battery manufacturing, and so on). 

The limits are very low at fractions of parts per billion. A similar table exists for mercury emission limits (EC directive 84/156/EEC) but with even stricter emission limits. In the UK cadmium legislation has recently become stricter, in line with the EC initiative. December 1993 saw the publication, in the UK, of the Department of the Environment Process Guidance Notes (IPR 4/22) related to the manufacture of zinc, lead, antimony, arsenic, beryllium, gallium, indium, palladium, platinum, selenium, tellurium, thallium and their compounds. The publication tabulates potential sources of metal emission and places a large emphasis on effective and efficient waste minimisation techniques. The document sets the scene for stricter legislation on metal emissions in the UK. 

The subj ect oiwipe sampling is not well defined in standard industrial hygiene reference books. The use of wipe sample datais open to interpretation.However, wipe sampling is of interest to the semiconductor industry because of certain metals used in the manufacturing process such as arsenic, antimony, chromium, and lead. A variation on this technique is also used in the evaluation of surface contamination with sealed radioactive sources (see Ch. 6, Radiation Safety). 

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