Appliance inspections: the new STN 33 1630

In May 2025 the standard STN 33 1630:2025 Inspections and checks of electrical appliances and extension leads during their use was issued. It replaces two standards companies had worked with for two decades: STN 33 1610 of November 2002 and STN 33 1600 of December 1996.

Transition period until 1 May 2027

The old standards may be used in parallel with the new one until 1 May 2027. Nothing is burning before that date, but it is worth knowing which standard your inspection technician is working to right now. The inspection report should state the standard the inspection was carried out under. If it still says STN 33 1610, that is fine for now. After 1 May 2027 it will not be.

What the standard covers

The standard covers hand-held electrical appliances, electrical hand tools, other electrical appliances, extension leads and power supplies intended for use with electrical appliances. The range is 25 V to 1 000 V AC, 60 V to 1 500 V DC, and current up to 63 A.

In practice that is everything from a drill and an angle grinder through a kettle and a monitor to the extension lead in the office.

The main change: one document instead of two

Until now, appliances and hand tools sat in two separate standards with different logic and different tables of intervals. The new standard merges them into a single document and unifies the intervals for electrical hand tools.

What does not change matters just as much. The intervals are still set by a technical standard, not by law. There is no legal regulation saying a drill must be inspected every six months. The interval follows the group of use, that is how often and in what environment the appliance or tool is used. A tool on a construction site has a different interval from the same drill in a maintenance workshop.

Why this concerns a company when a standard is not a law

The employer is required to ensure that workplaces, routes, work equipment, materials and work procedures do not endanger the safety and health of employees, and to arrange the necessary maintenance and repairs for that purpose (Section 6(1)(d) of Act No. 124/2006 Coll.). An inspection under a technical standard is the usual way of demonstrating that this duty is met. During a labour inspection and during the investigation of an injury it is one of the first documents asked for.

An appliance inspection is not an inspection of dedicated technical equipment

These two are often confused. Professional inspections and professional tests of dedicated electrical technical equipment are carried out under Decree No. 508/2009 Coll. and concern the electrical installation, switchboards, lightning protection and similar equipment. Inspections of appliances and hand tools under STN are a separate matter. One does not replace the other.

What we recommend doing now

Three steps. Draw up a list of appliances and tools by site, find out when their current inspection expires, and agree with your technician that the next inspection will already follow STN 33 1630:2025. The transition then happens naturally and without a rush in 2027.

If you want this sorted

We carry out inspections of electrical appliances and of electrical hand tools for companies, including sites away from the head office. Have a look at inspections and checks of electrical appliances and inspections and checks of electric hand tools, or get in touch.