1. Introduction
The hazardous nature of electricity is well known and the Electricity at Work Regulations are intended to ensure that electrical equipment is constructed, used, inspected and maintained so as not to present danger.
The regulations and their supporting standards can be technically complex and require specialist knowledge but the under-pinning principles follow those discussed in BMF's Guide to Members. Conformance to BS 7671 (the "Wiring Regulations") is of particular importance.
Application of the appropriate level of competence is core to ensuring electrical safety but this does not mean it is entirely a matter for specialists. The principles of safety management still need to be applied and some aspects of equipment inspection (e.g. for portable equipment) can be done with a minimum of instruction.
The requirements under the Electricity at Work regulations are closely related to those under the Provision and Use of Work Equipment Regulations. Refer to Specialised Topic Guide 1.
2. Nature of the Hazards
Apart from contact with live parts, electrical hazards can also result in fires or explosions. The normal domestic voltage of 230v ac (alternating current) can kill.
Fires are commonly started by poor electrical installations or inadequate maintenance, and fires or explosions by sparking electrical equipment or static discharges igniting flammable vapours or dusts.
The risks are greater when the equipment is used or installed in harsh conditions such as cramped or confined spaces, damp conditions, or with a lot of earthed metalwork.
3. Duties and Responsibilities
The principal duty-holder is the employer but any person with potentially dangerous sources of electricity 'within his control' is also considered a duty-holder.
There is also an obligation to maintain equipment where a danger would otherwise exist.
4. Risk Assessment
The risk assessment should pay particular attention to where and how electrical equipment is used, for example:
- In wet conditions where unsuitable equipment and its surroundings could become live
- Outside use where there is greater risk of damage, particularly to flexible leads
- In cramped spaces with a lot of earthed metalwork where an electrical fault could easily result in a shock
- Where an electrical fault could lead to a fire or explosion
The risk assessment should consider the use and practicability of safer alternatives such as pneumatic or hydraulic tools, or of lower voltages, an example of the latter being the use on construction sites of 110volt supplies via centre-tapped to earth transformers.
5. Suitability of Equipment
(a) Environment
Equipment must be suitable for the conditions under which it operates including factors such as:
- Mechanical damage
- Weather
- Temperature and pressure
- Liquids
- Dirty conditions
- Corrosion
- Flammable substances
- Explosions
The 'IP' rating system is in common use in respect of protection from solid objects and moisture.
(b) Insulation and Earthing together with isolation of the supply provides protection against short circuits and overloads. For equipment operating at 230volts or higher an RCD (residual current device) can provide additional safety.
(c) Installations should be to a suitable standard, i.e. BS7671 (See further information)
6. Use of equipment
Equipment must be used within its capacity and rating where otherwise it might cause danger.
7. Working on Electrical Equipment
A sufficient level of competence, that is, having the appropriate technical knowledge and experience, is essential in all cases. It is preferable to render the equipment dead, proved dead, and isolated from the supply, all carried out under a safe system of work. These arrangements are often formalised in a 'Permit to Work' system.
Work carried out in the vicinity of overhead or underground power-lines is the subject of special guidance. Over half the fatalities from electrical accidents are from contact with overhead lines. Refer to further information below.
8. Inspection, Testing and Maintenance
(a) General. All electrical equipment and installations must be maintained to prevent danger. Most risks can be controlled by simple visual checks to look for signs of wear or damage, but this must be backed-up by testing as necessary.
Equipment repairs and alterations will require a higher degree of competence in order to understand the risks and take appropriate precautions.
Any suspect or faulty equipment must be taken out of use, labelled 'Do Not Use' and kept secure.
The frequency of inspections and any necessary testing will depend on the type of equipment, how often it is used and its environment. More detailed guidance can be found under Further Information.
(b) Portable Appliance Testing
This area has been the source of confusion and even misrepresentation particularly in respect of low risk environments such as offices. There are no specific inspection intervals defined in law.
Guidance published by the HSE in INDG 236 (see Further Information) applies to office and other low risk environments:
- 95% of faults in office environments can be detected by visual inspection by a person with simple training; essentially switch-off and un-plug.
- Users should be encouraged to report signs of damage.
- Equipment which is earthed should have an occasional combined inspection and test, including the plugs and leads, to confirm a continuous earth path. This can be done by a suitably trained member of staff.
- Suggested frequencies for equipment (other than battery power or voltages less than 50 volts ac.) vary from 6 months to four years, with combined tests and inspections of earthed equipment between 1 and 5 years.
9. Further Information
British Standard BS 7671. Requirements for Electrical Installations is also known as the IEE Wiring Regulations. They relate principally to the design, selection, erection, inspection and testing of electrical installations, permanent or temporary, in and about buildings generally and to agricultural and horticultural premises, construction sites and caravans and their sites. Compliance with BS 7671 is likely to achieve compliance with relevant aspects of the 1989 Regulations.
Memorandum of Guidance on the Electricity at Work regulations. HSR25. HSE
Maintaining portable and transportable electrical equipment HSG107. HSE
Maintaining portable electrical equipment in offices and other low-risk environments. INDG236. HSE
Avoidance of danger from overhead electric powerlines. General Guidance Note GS38. HSE
Electrical safety at places of entertainment. General Guidance Note GS50
Lighting at Work. HSG38. HSE
Avoiding danger from underground services. HSG47. HSE
Electricity at Work: Safe Working Practices. HSG85. HSE
Electrical safety on construction sites. HSG141. HSE
Electrical safety and you. INDG231. HSE
Consult the HSE website www.hse.gov.uk for more information on a wide range of topics related to electrical safety. Appendix 2 to HSR25 gives references to non-HSE standards published by such as the British Standards Institute and IEC.
This information is copyright of the BMF July 2009 and must not be re-published