The term ‘safety’ is applied to glazing used to reduce the risk of accident by impact, fracture, shattering, or in a fire.
Depending on the location of your windows or doors, you may find that safety glass is a legal requirement.
What is safety glass?
Safety glass is glass that prevents injury to a person or animal if it is broken. It is more commonly used in doors but is a legal requirement in the UK for certain locations in your home.
There are different types of safety glass:
- Toughened Glass
- Laminated Glass
- Wired Glass (also called Pyroshield safety clear/textured)
Toughened glass looks like ordinary glass but receives a special heat treatment process to toughen it. As suggested by its name, it is much stronger than ordinary glass. Toughened glass also disintegrates on impact into small granular pieces, which are not sharp, reducing the risk of injury.
Laminated glass consists of two or more sheets of ordinary glass, which are attached together by a plastic interlayer. The plastic layer provides a barrier and on impact any broken shards of glass will remain attached to the plastic thus reducing the risk of injury. The glass has a slight tint of green to it due to the plastic interlayer.
Wired glass has a network / mesh of wires embedded in it. This isn’t generally used for windows or doors.
Although different types of safety glass will react differently to impact, they have all been tested to ensure that they don’t break into sharp shards of glass which could be dangerous to nearby people or animals.
These tests involve measuring impacts from a bag containing lead shot swinging into the glass at different levels of force. As long as the glass remains safe it is categorised as Class A, B or C with A being the highest grade of safety glass. Toughened glass is Class A, wired glass is Class C and laminated glass can be either Class A, B or C.
All safety glass should have a marking showing that the glass complies to safety requirements (European Standards EN 12600 or British Standards BS 6202).
When is safety glass required?
Safety glass is required in critical locations in domestic buildings. Locations deemed at risk of accidental human impact are deemed as critical locations.
For doors, this is any glazing which is between the finished floor level and 1500mm above floor level.
In door side panels, this is deemed as any glazing that is within 300mm of either side of a door edge and which is between the finished floor level and a height of 1500mm above the floor level.
Finally, for windows this is defined as any glass which is between the finished floor level and a height of 800mm above floor level.
Where only part of the glass unit falls within a critical location, the whole glass unit must comply with the safety glass legislation (British Standard BS 6202).
The diagram below gives examples of glazing in windows, partitions, walls, doors, and side panels. ‘Critical locations’ are shaded in the diagram below. Any glazing within a shaded area must comply with British Standards and be safety glass.
In the case of the diagram above, items 2, 3, 5, 6, 7, 9, 10, 11 and 12 would all require safety glass as all or part of the glass unit needs to comply with the legislation.
What are the benefits of toughened vs laminated glass?
Although both toughened and laminated glass help prevent injury if the glass is broken, they are very different products and therefore offer different benefits.
Laminated glass can also work as security glass, helping to prevent intruders from breaking into a property by providing an extra layer of security. The plastic interlayer can also help reduce noise, by using acoustic laminate glass, and reduce the transference of UV and solar gain.
In contrast, toughened glass will always meet the highest grade of safety due to the glass shattering into small pieces without jagged edges. It is also stronger than most other types of glass, making it harder to break. Toughened glass is also more resistant to heat and temperature variations.