Electrical Hazards, risks of injury or death arising from exposure to electricity. Electricity is essential to daily life, providing heat and light and powering appliances in homes and factories. It must, however, be treated with great care, because the consequences of an electrical fault can be serious and sometimes fatal. Generally voltages greater than 50 volts can present a serious hazard and currents of more than about 50 milliamps flowing through the human body can lead to death by electrocution.
A shock occurs when a "live" part of some device is touched, so that current passes through the body. Its severity depends on many factors, including the body's conductivity (the ease with which electricity passes through it). The conductivity is usually small, but can be increased if the body or clothing is wet. The risk of injury also increases according to the size of the voltage or current, or the duration of contact. There is a risk of electrocution (death by electric shock) if current passes across the heart. For example, if one foot is touching wet ground, the risk is greater if the arm on the opposite side touches a high-voltage source than it would be if the arm on the same side did so.
Current passing into the body generates heat, which burns the tissue. Electricity can also present less direct risks. Burns are caused when hot surfaces on electrical appliances are touched, and some appliances present a risk of injury from moving parts. Fires are caused when wires or cables overheat, melting their covering of insulation and setting fire to any combustible material nearby.
Numbers of Accidents
Official figures show that 31 people died in electric current accidents in homes in England and Wales in 1992, and around 13,000 people were injured in electrical accidents in and around ...
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Current passing into the body generates heat, which burns the tissue. Electricity can also present less direct risks. Burns are caused when hot surfaces on electrical appliances are touched, and some appliances present a risk of injury from moving parts. Fires are caused when wires or cables overheat, melting their covering of insulation and setting fire to any combustible material nearby.
Numbers of Accidents
Official figures show that 31 people died in electric current accidents in homes in England and Wales in 1992, and around 13,000 people were injured in electrical accidents in and around the home. Most were males between 15 and 64 years of age, carrying out do-it-yourself and maintenance work. Several deaths were caused by people touching the live end of a cable cut by an electric lawnmower.
Electrical faults in the home cause around 25,000 fires each year, killing or injuring over 2,000 people.
Electrical Installations
Most countries have detailed regulations governing the standards to which electrical installations must conform. In the United Kingdom the Wiring Regulations (BS 7671), produced by the Institution of Electrical Engineers (IEE) and the British Standards Institution (BSI), prescribe the wiring standards to be adopted. The Electrical Contractors Association (ECA) and the National Inspection Council for Electrical Installation Contracting (NICEIC) require their members to observe these requirements to minimize any danger.
Electrical Products
In Britain, domestic electrical products must satisfy the requirements of the Electrical Equipment (Safety) Regulations (1994), which were made under the Consumer Protection Act (1987), and implement the Low Voltage Directive (73/23/EEC) of the European Union (EU). The technical interpretation of the legal requirements is provided by a standard for electrical products, EN 60 335, which is harmonized among EU member countries, and manufacturers are encouraged to seek independent third-party quality assurance for their products, such as that provided by the BSI and BEAB (British Electrotechnical Approvals Board).
In Britain, following a campaign by RoSPA, the Royal Society for the Prevention of Accidents, all domestic electrical appliances must now be supplied complete with a fitted plug. A non-rewirable or moulded plug is preferred, which must be approved by a recognized body such as BSI.
Accident Prevention
In the home, appliances, plugs, and cables must be checked for damage regularly and replaced or repaired by an expert when necessary. Electrical wiring should be inspected every five years by experts, such as those recognized by the ECA and the NICEIC.
Children must be warned to keep away from railways, electricity sub-stations, and factories, and fishing-rods, especially those made of carbon fibre, and kites must not be used near overhead power lines.
Anyone using electrical equipment out of doors should ensure that the supply is protected by an RCD (residual current device), which detects any current to earth and so will protect the user against the danger of serious electric shock by disconnecting the supply in the event of a fault occurring.
In the home, fuses, which are a rather crude method of protecting the distribution system against excessive current, have largely been replaced by the more precise MCB (miniature circuit-breaker), and RCDs are now usually incorporated to provide added safety from the danger of electric shock.
