What is the Difference Between Toughened Glass and Safety Backed Glass?

When designing a modern kitchen, choosing the right type of glass for your splashback is crucial for both safety and aesthetics. Two popular options are toughened glass and safety-backed glass. But what’s the difference between the two, and which one is best for your kitchen?

What is Toughened Glass?

Toughened glass, also known as tempered glass, is a type of safety glass that has been specially heat-treated to increase its strength. During the manufacturing process, the glass is heated to approximately 620°C and then rapidly cooled. This creates internal stresses that make it up to five times stronger than standard annealed glass. If it does break, toughened glass shatters into small, blunt pieces, reducing the risk of serious injury.

Toughened glass is known for its durability and ability to withstand high temperatures, making it an ideal choice for areas exposed to heat, such as behind a gas or electric hob.

What is Safety Backed Glass?

Safety-backed glass, often referred to as laminated glass, consists of two or more layers of glass bonded together with a durable interlayer, such as polyvinyl butyral (PVB). In the case of a break, the interlayer holds the glass shards in place, reducing the risk of injury.

Safety-backed glass also includes options like safety-backed mirrors, which come with a clear adhesive film on the back. This backing ensures that any broken pieces remain attached to the film, further minimising risks. While it cannot withstand high temperatures like toughened glass, it can be used behind induction hobs where heat exposure is less.

To summarise, we’ve put together an overview of the main and drawbacks of each of these popular glass types:

The Pros and Cons of Toughened Glass

Pros:

Strength: Up to five times stronger than standard glass, toughened glass is highly durable.

Heat Resistance: Suitable for high-heat environments, such as behind gas or electric hobs.

Safety: Shatters into small, blunt granules, reducing the risk of severe injuries.

Cons:

Post-Manufacture Alterations: Cannot be cut, drilled, or shaped after being toughened.

The Pros and Cons of Safety Backed Glass

Pros:

Safety: Laminated or backed with adhesive film, safety backed glass prevents shards from scattering upon breakage.

Cost-Effective: Safety backed mirror options are substantially cheaper than toughened glass.

Versatility: Comes in more colour options, making it ideal for decorative purposes.

Cons:

Heat Sensitivity: Cannot withstand high temperatures, limiting its use behind gas or electric hobs in your kitchen.

Weight: Laminated glass is heavier, requiring strong support structures.

When Can Each Be Used for a Glass Kitchen Splashback?

Toughened Glass: The go-to option for areas behind gas or electric hobs, toughened glass’s heat resistance makes it the safest choice. Toughened glass is also a consideration for busy areas of your kitchen, such as where you chop and prepare food.

Safety Backed Glass: Best used in areas not exposed to high heat, such as behind induction hobs. Safety-backed mirrors, in particular, are excellent for adding a decorative touch to your kitchen without compromising on safety.

Which Is Stronger: Laminated or Toughened Glass?

When it comes to strength, both toughened and laminated glass have unique qualities:

Toughened Glass: Toughened glass is exceptionally strong in terms of impact resistance and can handle significant physical stress.

Laminated Glass: Laminated glass excels in terms of security. Even when cracked, the interlayer holds the glass together, making it harder to penetrate.

For applications like kitchen splashbacks, toughened glass is often preferred due to its ability to withstand heat and high-impact resistance. However, laminated glass is ideal for areas where heat is not a concern and you may wish to consider a wider range of colour and design options.

How is Toughened Glass and Safety Glass Tested?

Toughened glass and safety glass are tested against rigorous standards to ensure their safety, durability, and suitability for various applications.

Testing Toughened Glass

Toughened glass must meet the requirements of BS EN 12150, the British Standard for thermally toughened soda lime silicate safety glass. Key tests include:

Thermal Treatment Verification:
Glass is subjected to the toughening process, where it is heated to approximately 620°C and rapidly cooled. To verify the process, the glass is inspected for surface compression and stress distribution using polarised light.

Fragmentation Test:
A sample is struck with a controlled force to ensure it breaks into small, blunt granules instead of sharp shards. This test confirms the safety feature of toughened glass and ensures compliance with safety regulations.

Impact Resistance:
The glass is subjected to impacts using weighted pendulums or spheres to test its ability to withstand force without breaking. This demonstrates the glass’s durability under various conditions.

Flatness and Surface Quality Check:
Toughened glass must meet specific standards for flatness and surface finish to ensure consistent performance and aesthetic quality.

Testing Laminated (Safety Backed) Glass

Laminated glass, often referred to as safety-backed glass, is tested according to BS EN 14449, which governs laminated safety lass. Tests include:

Adhesion Test:
This evaluates the bond strength between the glass layers and the interlayer (usually PVB). The layers must remain intact during and after impact.

Impact Resistance:
Laminated glass is subjected to impact tests, such as the soft body impact test, where a weighted bag simulating human impact strikes the glass. It ensures the glass holds together even when cracked, preventing shards from detaching.

Pendulum Test:
Laminated glass is tested with a pendulum to simulate impacts from various angles, ensuring compliance with safety standards for doors, partitions, and glazing.

Fragment Retention Test:
After the glass is broken, the ability of the interlayer to retain glass fragments is tested, demonstrating the safety backing’s effectiveness.

Both types of glass are also tested for:

Load Resistance:
To ensure they can handle weight or pressure without failure, particularly for structural applications.

Thermal Stress Resistance:
Toughened glass is tested for resistance to rapid temperature changes, while laminated glass is assessed for stability under prolonged exposure to varying temperatures.

Safety Certification:
Glass products must bear a CE Marking, indicating they meet European safety standards. Accredited laboratories conduct these tests to ensure compliance with British and European regulations.

Conclusion

Choosing between toughened and safety backed glass depends on your kitchen’s design and functional needs. Toughened glass is ideal for areas requiring heat resistance and impact strength, while safety backed glass is perfect for decorative purposes or low-heat zones.

Toughened glass is often required in certain areas of your kitchen to ensure you are compliant with building regulations. Laminated glass is commonly used in areas such as balustrades and radiator covers throughout your property.

By understanding their unique properties, you can make an informed decision that ensures safety, functionality, and style for your home. If you’re still unsure about the glass type you need, please ask a member of our team today!