Careless work with electricity can lead to safety risks. On the one hand, this relates to use of electricity as a power source for machines and tools. On the other hand, it concerns the safe handling and correct maintenance of machines and tools.

The aim of the toolbox is:
To provide information on the different designs of electrical equipment which are used in the workplace. In particular, information about the forms of protection, otherwise referred to as insulation.

Electrical risks can be sub-divided into the following:

• Electric current passing through the body;
• Hazard of fire and explosion;
• Secondary accidents, for example, a bang on the head as a result of falling after an electric shock.

The technical requirements for installations are detailed in the Dutch standards NEN 1010 - Safety provisions for the construction of low-voltage installations.

The Dutch Working Conditions (ARBO wet) and the Dutch Working Conditions Decree (ARBO besluit 3.5) prescribes that the employer must authorize employees for certain E-activities by formally providing them with a declaration of authority. (een aanwijzing of bevoegdheidsverklaring ). Such a statement clearly states what one is allowed (and therefore also what is not) in relation to knowledge, skills and experience.

Working Conditions Decree 3.5, art. 1: 'Work and operating activities on electrical installations that may pose hazards are carried out by expert, sufficiently trained and authorized employees'.

For electrically powered machines, equipment, tools and lighting, classes have been established. This classification relates to the design (insulation). In addition, protection against contact and the water tightness are specified in a code. This code consists of the letters IP followed by a two-digit number. Symbols are added to older items of equipment. At the bottom of this page an overview of all these.

Equipment in protection classes I and II is powered by an electric current of 220 - 230 Volt. Class III equipment is powered by a safe current of 42 Volt or extremely safe current of 24 Volt.

This safe or extremely safe current is attained through the use of safety transformers. Sometimes it might be necessary to power tools at 220 Volt, but this is attained by means of an isolation transformer. This applies in particular when working in crawl spaces.
A combination of safety and insulation transformer is also referred to as a combi transformer. The figure below indicates the use of the different possible applications.