How do I recognize TSG safety glass?

How to prevent undesirable scratches

When completing your window cleaning tasks, you may well come across tempered safety glass, or TSG for short. This type of safety glass is made up of a single, specially heat-treated pane which is extremely scratch-prone. When cleaning such glass, you must be particularly careful because TSG safety glass is under extremely high tension and has an undulating surface. We explain to you how you can recognize TSG with an ingenious trick.

Your lighter will show you the difference

For reasons of safety, a TSG pane is installed in many areas where shattered glass may present a real risk of injury. When it is broken, it shatters into small, cube-shaped fragments. The reason? The pane is heated up to more than 600°C and then abruptly cooled with a quick blast of air in a special manufacturing process. This ensures that the areas closer to the surface cool down faster than the core and the glass is thus placed under an increased amount of tension. Due to this stored energy, TSG glass shatters into blunt-edged fragments when broken and the risk of major cuts is thus considerably reduced. This property has ensured that TSG has been used for side windows in car manufacture for many decades and is now increasingly being used for functional glass in the home..


The following trick will help you to recognize the safety glass: hold the flame of a lighter in front of the pane; if there is a double reflection, it is TSG glass. And this means great care is needed! Since TSG is more delicate, it also scratches more easily – particularly if there are small particles on cleaning devices. Even the smallest sand and dust particles can scratch the sensitive surface. We thus recommend that you proceed with the utmost caution and use absolutely clean and professional cleaning devices – manufactured by UNGER, of course!

You are guaranteed to get the quality that pros are so accustomed to in their everyday working lives. Put your trust in our tools, too!