Last reviewed 23 December 2016
Yuletide, bright lights and new household appliances go hand-in-hand. However, electrical safety is a domestic and industrial priority throughout the year. Jon Herbert looks at best practice.
Electricity kills and injures, often severely. Of 144 industrial deaths recorded in the UK in 2015/16, six were due to electric shock, of which four were in the construction industry.
However, by constantly building up awareness and taking methodical precautions, employers can protect workers from this hidden hazard.
Which is why long-term electrical safety could be a good item to add to your Christmas wish list at a time of the year when it might be all too easy for almost anybody to be momentarily distracted.
Although good electrical safety draws on well-applied common sense — plus not giving into temptation and taking an easy shortcut on the one occasion when familiarity breeds dangerous contempt — a reminder of the basics is advisable at any time of the year.
It is also important to remember that electrical safety is an integral part of running a successful business and key to UK health and safety law.
Electrical failures often have knock-on effects. Not only can workers suffer serious direct injuries, they are often victims to domino risks, such as falling from height. Fires and their toxic emissions may be additional threats.
The key questions that managers have to ask themselves are: what are the hazards, what do I have to do to prevent them and who is officially competent to carry out the work involved?
It is important to remember that overhead power lines regularly pose dangers; electricity may flash over from power lines to machinery and equipment even though no direct contact is made. Similarly, assume that buried cables could be present when excavating any hole or trench in open ground, pavements, or close to buildings.
Detailed professional advice should always be sought by anyone involved with electrical equipment use, or responsible for electrical safety. However, the following points are meant as a broad guide to what is needed.
The main working hazards associated with electricity are shock and burns resulting from contact with live components, injury from electric arcing, and explosions when mains or static electricity ignites inflammable dust, liquids or vapours. An example here could be the atmosphere within a spray booth.
As mentioned earlier, electrical injuries can be compounded by a loss of balance or instability near moving machinery, or when working on scaffolding or ladders.
A full risk assessment into equipment type, use and the working environment should also look for cables that are not correctly connected, loose wires crossing floors, a lack of clear off-switch labelling, plug sockets with overloaded adapters, plus other obvious non-conformities that can result in overheating, eg incorrectly fitted fuses.
All electrical equipment should be suitable for its intended task. It must also be operated correctly and used solely for its stated and intended purposes.
Other factors to be aware of are wet conditions that can make equipment and its surroundings live. Fuses, circuit breakers and other safety devices must be rated properly for the installations they are fitted to protect.
Wherever possible, isolators and fuse boxes should be kept locked. At the same time, switches and isolators must be quick and easy to access in an emergency. Staff should also be encouraged to report any potential hazards they see, including damage and defects. It doesn’t matter if they are wrong.
Maintenance is meant to prevent danger. All electrical equipment and installations including portable appliances (with the possible exemption of low-power devices such as laptop computers) need to be checked and maintained properly.
That includes repairing, or withdrawing from use, damaged plugs or connections, plus cables repaired with tape and bare wires. Burn marks or staining should be investigated as they can indicate overheating.
It is also important to inspect and test all installations with fixed wiring.
The major caveat is that all work must be carried out by a competent person or persons. This is defined as someone with the appropriate training, skills and knowledge who will have usually completed an electrical apprenticeship and have related practical experience.
More advanced and specialised maintenance of high-voltage switchgear, or control system changes, will require additional training and experience.
Expert guidance is available from many sources.
Making quite sure that equipment has been de-energised before work starts is essential, unless working on live circuits is unavoidable. In which case ensuring against arc flashes, choosing the right personal protective equipment and testing test tools first is vital.
As good practice, lock out or tag out procedures should also be used as protection against someone else unwittingly powering up equipment while maintenance or repairs are being carried out. Making sure that no one becomes part of a live circuit while holding test equipment is an important point, too.
It is also worth considering that test tool safety features continue to improve and investing in upgraded kit is usually advisable.
Home safe home
Portable electrical equipment is responsible for some 25% of all electrical injuries. Faulty electrical leads cause around 2000 fires every year.
Property owners are responsible for the overall safety of electrical installations, which must be installed in line with the Institution of Engineering and Technology (IET) Wiring Regulations 17th Edition (BS 7671:2008 Incorporating Amendment 3:2015) where appropriate. The IET Wiring Regulations have the status of being a Code of Practice. While they are non-statutory, they can be used in a court as evidence of the standard to be achieved.
It is recommended that installations are tested at least once every five years, or after any changes have been made, with visual inspections made more often.
Periodic testing should include verifying earthing system effectiveness, polarity, earth fault loop impedance, insulation resistance, isolation and switching device functionality, residual current devices, overcurrent circuit breakers and fuses.
A certificate showing test results needs to be issued.
Visual inspections should cover safety, wear and tear, corrosion, damage, excessive loading, age, external factors such as structural building changes, or altered tenant activities, plus the suitability of units such as protective devices.
In residential settings in particular, two types of fault are common. The first is electrical insulation failures around copper conductors in cables due to rubber becoming brittle with age, or rodents chewing through the insulation, for example.
The second cause is overheating which occurs when installations are overloaded. A very common example is the use of multi-adapters or multi-socket extension leads. These are not risks in themselves if used correctly with low-power items. However, if too many appliances are connected, excessive heat generated in copper conductors can break down insulation and cause a short circuit.
So, for electrical safety, it’s a simple checklist: risk assessment, maintenance, competent persons — and attentiveness.