The main environmental problems associated with electrical appliance and equipment manufacture involve pollution and treatment of materials discarded during the manufacturing processes, together with the recycling, where possible, of the complete product when it has reached the end of its life.
The exhaust of air contaminated with acid, alkali, lead, cadmium and other potentially harmful materials into the atmosphere and the pollution of water from the manufacturing of batteries should be prevented as far as possible, and where this is not possible it should be monitored to ensure compliance with relevant legislation.
The use of batteries can generate public health concerns. Leaking lead-acid or alkaline batteries can result in burns from the electrolyte. Recharging large lead-acid batteries can produce hydrogen gas, a fire and explosion hazard in enclosed areas. Release of thionyl chloride or sulphur dioxide from large lithium batteries can involve exposure to sulphur dioxide, hydrochloric acid mist, burning lithium and so on, and has caused at least one fatality (Ducatman, Ducatman and Barnes 1988). This could also be a hazard during manufacture of these batteries.
Battery manufacturers have become aware of increasing environmental concern from the disposal of batteries containing toxic heavy metals by putting them in landfills or incinerating them with other garbage. Leakage of toxic metals from waste dumps or alternatively escaping from the chimneys of waste incinerators can result in water and air contamination. The manufacturers therefore recognized the need to reduce the mercury content of batteries, in particular, within the limits allowable by modern technology. The campaign for mercury elimination commenced in advance of the legislation introduced in the European Union, the EC Battery Directive.
Recycling is another way to deal with environmental pollution. Nickel-cadmium batteries can be recycled relatively easily. The recovery of cadmium is very efficient and it is re-used in the construction of nickel-cadmium batteries. The nickel will subsequently be used in the steel industry. The initial economics suggested that the recycling of nickel-cadmium batteries was not cost effective, but advances in technology are expected to improve the situation. Mercuric oxide cells, which are covered by the EC Battery Directive, have been used primarily in hearing aids, and are being replaced typically with lithium or zinc-air batteries. Silver oxide cells are recycled, especially by the jewellery industry, due to the value of the silver content.
When recycling harmful materials, care has to be taken similar to that exercised during the manufacturing processes. During the recycling of silver batteries, for example, workers may be exposed to mercury vapour and silver oxide.
The repair and recycling of lead-acid batteries can result not only in lead poisoning among the workers, and sometimes their families, but also in extensive lead contamination of the environment (Matte et al. 1989). In many countries, particularly in the Caribbean and Latin America, lead car battery plates are burned to produce lead oxide for pottery glazes.
Electric Cable Manufacture
Electric cable manufacture has three major sources of pollution: solvent vapours, potential release of toluene di-isocyanate from enamelled wire manufacture and environmental emissions during the manufacture of materials used in cables. All of these require appropriate environmental controls.
Electric Lamp and Tube Manufacture
The major environmental concerns here are the waste disposal and/or recycling of mercury-containing lamps and the disposal of PCBs from the ballasts of fluorescent lamps. Glass manufacturing can also be a significant source of emission of nitrogen oxides into the atmosphere.
Domestic Electric Appliances
Since the electric appliance industry is to a large extent an assembly industry, environmental issues are minimal, with the major exception being paints and solvents used as surface coatings. Standard pollution control measures should be instituted in accordance with environmental regulations.
The recycling of electrical appliances involves separation of the recovered equipment into different materials such as copper and mild steel which can be reused, which is discussed elsewhere in this Encyclopaedia.