Electricity

The main harm is electric shock, caused by direct contact with a conductor, such as the bare wires of a live appliance. A shock can also lead to another injury: someone who gets a shock while changing a light bulb may fall from the ladder. Electricity also causes burns and fire.

Most deaths and injuries are caused by poorly maintained equipment, work near overhead power lines, contact with underground cables during excavation, work on or near domestic supplies, and unsuitable equipment in explosive atmospheres, such as car spray booths. Most could be avoided by careful planning and simple precautions.

As a duty holder, find out what electrical work your team does. They may be working near electricity, using electrical equipment such as power tools, or working on electrical equipment and installations. In all cases, make sure the risks are assessed, people are trained and the controls are adequate.

• Working near electricity. Train people to recognise wiring, which is sometimes not obvious, to ask for and use an up to date map of gas, water and electricity services, to find and mark underground services, to ask for power to be turned off, and to follow the advice of a competent person.
• Using electrical equipment. Develop a procedure so that the equipment is suitable for its use and for the supply, is in good condition, is used with a circuit breaker between it and the supply, and is used by trained people.
• Working on electrical equipment. Plan the work thoroughly, let only competent people do it, and meet the relevant national or industry standards.

A case study: an ungrounded mixing motor

A 17 year old assistant pool manager was electrocuted when she touched an ungrounded electric motor. She was adding soda ash to the pool water to adjust the pH. Standing barefoot on the wet concrete floor of the pump room, she filled a plastic drum with water, plugged in the mixing motor and switched it on. While adding soda ash she touched the live motor with her left hand, which gave the current a path to earth. She died.

People in control of work are responsible for keeping equipment in a safe condition and for giving workers the information and instruction they need. The motor should have been earthed and protected. The room should have had drainage so that water did not collect, and a dry floor and insulating footwear might have prevented the death.

A study aid, not published or endorsed by IOSH or OSHA. Laws and limits differ between countries.