Back to overview

Fire hazard or electric shock: Be careful with old strings of lights


Testing strings of lights

When individual lamps of old strings of lights fail one after the other, the remaining filaments indeed shine brighter, but they also get unusually hot. During tests conducted by TÜV Rheinland, the temperatures of individual electric candles rose to up to 200°C, which constitutes an acute fire hazard. Due to the aging of plastics, strings of lights that use insulation which is no longer permitted today also pose a high risk of electric shock.

Check strings of lights for damage before use

In the fall of 2016, inspectors of TÜV Rheinland tested old strings of lights from private households that people were intending to use again at Christmas time. The problem is that by today’s standards, many of these strings of lights would not be allowed to be sold any more. The lamps become too hot, the insulation is no longer permitted and, in many cases, there are no safety instructions whatsoever. “All strings of lights, and very old ones in particular, should be inspected thoroughly for damage each time before they are used. If individual lamps of old strings of lights fail and there are no more original spare parts, the strings of lights must be properly disposed of,” says Rainer Weiskirchen from TÜV Rheinland.

This is why modern strings of lights with LED technology are replacing conventional light decorations with bulbs. And rightly so: People who decorate their balcony, Christmas tree or house with LEDs save electricity and money. “Despite the somewhat higher initial outlay, the investment is worthwhile because LED light decorations are more economical and extremely long-lasting. What’s more, they also perform better in terms of safety,” says Thomas Haupt, a product safety expert at TÜV Rheinland. In contrast, old strings of lights tend to be real electricity guzzlers.

Testing strings of lights

Labeling must be clearly identifiable

If strings, tubes or nets of lights are to last longer than just one Christmas season, they should be bought only from trustworthy retailers. It is also important for the safety instructions in the relevant local language and the name and address of the manufacturer to be displayed on the packaging. Another thing you should look for when purchasing lights is the GS mark . This stands for tested safety and is issued by service providers including TÜV Rheinland. For outdoor lighting, the code IP44 is very important. This shows the consumer that the lights are suitable for outdoor use and are weather-proof.

Use only power adapters with the GS mark

LED light decorations are generally safer than traditional strings of lights, because LEDs manage with safety extra-low voltage. This function is performed by an upstream safety power adapter, which reduces the power outlet voltage to a low voltage of just a few volts. The light decoration is therefore safe to touch. This means that the user is no longer at risk of an electric shock if a string of lights is damaged – which can happen when it is wound up and stored away or, in the case of low-quality plastic, after many years in storage. A safe string of lights should ideally have two test marks: One on the product and one on the power adapter. The GS mark is a further reliable indicator of tested safety.

Contact for media inquiries: Antje Schweitzer
+49 221 806 5597
Write an e-mail