Electrical Hazards 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 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.
Most countries have detailed regulations governing the standards to
which electrical installations must conform. In the United...