The importance of safe isolation and other safety measures | NAPIT

The importance of safe isolation and other safety measures | NAPIT

Frank Bertie, Chief Technical Officer at NAPIT, covers the importance of safe isolation and the other essential safety measures required for electrical installations to avoid incidents and fatalities happening throughout the industry.

As Rules and Regulations have evolved, the requirements for controlling the operation of the installation through switches for isolation became part of the essential safety measures. Within the electrical industry there are still far too many cases of near misses and incidents both minor and major, with some incidents unfortunately leading to fatalities.

Inherent problems in electrical safety

Electricity can be dangerous with multiple connections within an energised electrical installation where the risk of electric shock is real and presents danger for those working on such systems. With all electrical training, safe isolation is an essential skill that anyone involved in electrical work must be familiar with and use as part of their work practices. There is more emphasis placed on the larger electrical installation, such as switchboards. The difference between a switchboard and a light switch is size, but both can result in electric shock if the correct safety procedures are not followed. Complacency is a big issue; whenever three-phase supplies are involved there seems to be more caution compared to domestic single-phase installations. There are still a high number of cases being highlighted where inappropriate methods of isolation (including the all too familiar insulation tape) is used to isolate a circuit, which has been part of the HSE inspection targets, when carrying out site visits and through industry awareness campaigns, see Fig 1.

During discussions with a contractor on a refurbishment of an existing building, where sections remained energised and the electricians were working between new and existing electrical installation, several near misses were reported. A follow up ‘toolbox talk’ on safe isolation revealed that out of 70+ electricians, only three had voltage indicators, with one of them being a volt stick, but no proving devices. Where the electricians were operating on a labour-only basis (self-employed), the main electrical contractor had not provided the tools for those electricians, assuming every electrician provided their own.

Legislation and Standards

Electrical safety, including the aspects of electrical safe isolation, are covered under the following:

The Health and Safety at Work Act 1974

Sets out general health and safety duties of employers, employees and the self-employed, including the requirements to co-operate with their employer.

Electricity at Work Regulations 1989

Provides specifics regarding safe working on electrical systems.

Regulation 12: Means for cutting off the supply and for isolation

In order to prevent danger, a suitable means shall be provided for:

● Cutting off the supply of electrical energy to electrical equipment

● Isolation of electrical equipment.

Regulation 13: Precautions for work on equipment made dead

Adequate precautions shall be taken to prevent electrical equipment, which has been made dead, from becoming electrically charged.

Regulation 14: Work on or near live conductors

No person shall be engaged in any work activity on or near any live conductors so as to prevent danger unless:

● It is unreasonable for it to be dead, and

● It is reasonable in all circumstances for him/her to be at work on or near it while it is live, and

● Suitable precautions are taken to prevent injury.

Regulation 16: Persons to be competent to prevent danger and injury

No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or injury unless they possess such knowledge or experience.

Management of Health and Safety at Work Regulations 1999

Places requirements on employers to make suitable and sufficient assessment of risk to the health and safety of their employees and other persons in connection with their operations within the workplace, wherever and whenever that work takes place.

BS 7671 Wiring Regulations

EAWR outlines the requirements for safe working and BS 7671 provides the requirements for the methods of isolation and switching for a variety of tasks such as:

● Isolation for the whole installation

● Isolation for every circuit

● Devices for isolation as detailed in table 537.4

● Mechanical maintenance

● Emergency switching

● Functional switching.

The type of installation shall determine the type and number of points of isolation; in the case of household or similar for operation by ordinary person, the isolator must interrupt both live conductors on a single-phase supply. For larger installations with multiple supplies, these will require a means of isolation for each supply with a linked switch or circuit-breaker.

Industry campaigning

Worrying statistics show that one in five installers do not carry a lock-out kit in their van or tool bag, and 25% of electricians rarely or never use a lock-out kit to isolate the electrical supply they are working on. In response to this need to raise awareness of Safe Isolation within the Workplace, Electrical Safety Roundtable (ESR), a leading industry forum, working with Louise Taggart, an influential health and safety campaigner, proposed that the sixth point of PPE was a lock-off kit. The 12 Easy Steps to Safe Isolation infographic was also created in light of this. NAPIT has always promoted the use of the correct procedures for safe working involving lock-off kits and two-pole voltage indicator with a proving unit, see Figs 2 and Fig 3.

  • Screen Shot 2022-02-03 at 10.21.46
  • Screen Shot 2022-02-03 at 10.21.58

Toolbox Talks

Employers have a duty to provide regular site specific toolbox talks with their employees on a range of topics, including safe isolation, to maintain safe working practices.


Safe Isolation has to be the most important aspect for anyone working on or near an electrical system. Being able to safely perform the most basic of tasks has to be the highest priority for employers, employees, duty holders and anyone else involved in the process. Industry must embrace fully the procedures for safe isolation and not use the excuse that it is time wasting or it is only a small job. Procedures for safe isolation can be found in our Inspection & Testing, On-Site Solutions and EICR Codebreakers publications, which are available to purchase via NAPIT Direct individually or as bundles.

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