Thanks to modern toughened laminated glass technology, many would-be intruders now find that they have met their match in the glass panes which allow the architect to realise their ambitious design concept.

In toughened laminated glass, two (or more) panes of toughened glass are sandwiched, or laminated together, using an interlayer between the layers of glass. Toughened laminated glass can be damaged by impact, but although the toughened glass may still break into granular pieces, most will adhere to the interlayer. This reduces the risk from falling glass, and it also often allows the damaged pane of glass to remain in place until it can be replaced, avoiding the need to board over the damaged section.

Thanks to the development of more specialist interlayers, we are now able to add much greater strength and resistance to wilful damage. This has allowed architects to specify glass products which help to protect both people and property, in a range of applications from private homes to retail environments and from airports to maximum security facilities. Using glass panels with specialist interlayers, we can now provide glass products which withstand the two main standards for attack resistant glass; BS EN 356 and LPS1270. BS EN 356 is a long-established standard against which glass is rated for its resistance to manual attack. This is tested by dropping three metal balls of increasing weight onto the panel.

At ESG, we were the first in the UK to offer a LPS1270 compliant product in the form of ESG Secure. A newer standard, it was introduced a decade ago by The Loss Prevention Certification Board, to rate glass used in products such as security doors and windows. LPS1270 is applied specifically to the glass panel, while the actual door or window is tested in accordance with LPS 1175.

LPS1270 testing gives us a good idea how the glass will perform in real crime scenarios. This is essential; if we can predict a possible criminal attack, we can now specify a robust product that will withstand it.

LPS 1270 compliant products must pass a series of test, increasing in severity and using a range of tools or weapons that a determined criminal might use. In the first test, the aim is to make a small hole through which a wire or screwdriver to be inserted. These are often used by criminals to lift a latch or press a release bar in order to enter the property. In the second test, the aim is to achieve a hole large enough to put a hand through, either to steal an item within reach or to open a door. In the third test, the panel is repeatedly attacked until there is an opening large enough for an intruder to step through to enter the premises.

Each test is timed and recorded. As the tests increase in severity and duration, the would-be intruder is given time to rest when tired. They are also equipped with a range of increasingly forceful of tools, ranging from screwdrivers to high powered diamond drills.

The glass being tested is awarded a three-digit test rating from one to eight for each scenario. You might see a rating of 2-3-3 for example, meaning that the glass had scored two for the first test, three for second and three for hole that the intruder can step through. The tests are carried out uninterrupted by security alarms or the arrival of law enforcement officers. In a real-life scenario, most intruders would leave, or be apprehended, long before they can achieve their goal.

In most situations, a high security level of 3 to 4 is ideal and practical. The glass panel will withstand attacks from tools such as disc grinders, fire axes, hooligan bars, sledgehammers, circular and reciprocating saws, and 18-volt drills. The panel would, no doubt, be damaged and need replacing, but the intruder would not have accessed the building.

While level 4 is usually plenty, level 5 approved glass is also available. This more or less allows door manufacturers and specifiers the ability to design out crime. The intruder might try to breach the glass, but we can be confident that he won’t succeed.

The glass itself, of course, still provides light and style, remaining aesthetically pleasing despite its security credentials, providing the best of both design and security conscious worlds.