Safety Glass

How to tell if your windows are Safety glass?.

The most reliable way to check is to look for a permanent mark etched or sandblasted onto the glass. Check all four corners, usually near the frame or under the trim. In the UK, safety glass will be marked with standards such as BS EN 12150 for toughened glass or BS EN 14449 for laminated glass. You may also see a CE mark, BSI Kitemark, or words like Safety, Toughened, or Laminated. If the marking is faint, use a torch held at an angle to make it easier to see. You can also examine the edges of the glass if they are exposed. Toughened safety glass has smooth, rounded, and polished edges with no sharp cuts. Laminated safety glass will show a thin, clear plastic layer sandwiched between two sheets of glass when you look at the edge. Ordinary standard glass typically has sharp, rough, or flat-cut edges. Another simple method is the polarized light test. Look through a pair of polarized sunglasses or view your phone screen through the glass while rotating it. Toughened safety glass will reveal faint dark lines, stripes, or wavy patterns caused by internal stress, while ordinary glass will remain clear and even in appearance..

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Kite Marks

If your window has a BS kite mark it will be Safety glass.

A tap test can also help tell the difference. Lightly tap the glass with a soft hard object like a pen handle — avoid using metal. Safety glass produces a clear, high-pitched ping or ringing sound. Ordinary glass makes a dull, flat thud noise instead. When looking along the surface of the glass at an angle, toughened safety glass often has very slight, gentle waviness or ripples, which happens during the manufacturing heating process. Standard glass usually appears perfectly flat and smooth. You can also judge based on where the window is located, following UK building regulations. Safety glass is legally required in specific areas: any window where the bottom edge is less than 800mm from the floor, glass within 300mm of doors or side panels, glass near stairways, and in bathrooms or other low-level areas. If your window is in one of these positions, it should be fitted with safety glass. Please note that breaking or drilling the glass to test it is not recommended, as it is destructive, dangerous, and completely unnecessary. Would you like me to explain the key differences between toughened and laminated safety glass.