Bulletproof Glass

• By Michael S. Dorn
• 11/01/16

An increasingly common question from students, parents and campus employees involves the use of “bulletproof ” glass. Inaccurate media and social media discussions of active shooter and terrorist incidents have increased the level of fear among students, staff and parents.

While there has not yet been a series of attacks where aggressors have shot victims through windows in the U.S., such attacks are possible. The perceptions and realities make it natural for people to question whether or not ballistic protection for windows is appropriate. This issue comes up quite often when campus buildings are being or have been built with copious expanses of glass. There are specific situations where bulletproof glass is both appropriate and practical, but there are details to be considered.

Does Bulletproof Glass Exist?

As with the description of police body armor, the term “bullet resistant” is infinitely more accurate. While there are a variety of high-quality products that can help provide ballistic protection for windows, there are challenges with stopping a wide array of projectiles of different weights traveling at different speeds. For example, stopping a 300-grain monolithic bullet fired from a .375 Holland & Holland caliber game-hunting rifle requires a far higher degree of protection than would be required to stop a 115-grain hollow-point bullet fired from a 9mm handgun. Fortunately, outside of ivory poachers, criminals rarely utilize game rifles like the .375 Holland & Holland. In fact, I can’t recall a case where a criminal has used a game rifle to commit a crime in the U.S. during an attack. However, there are a lot of calibers between these two extremes that must be considered.

Most experts in the field focus their attention on handgun calibers and popular calibers for tactical rifles, such as the .223 Remington and the 7.62x39mm cartridges commonly used in the AR-15- and AK-47-style rifles. For higher risk settings, protection for high-powered cartridges like the 7.62 NATO caliber may be considered. If this all this sounds technical to you, that is because it is! The discussion could be far more technical if we go into detail on projectile types, velocities of specific cartridges and other details.

There are a variety of products that are capable of stopping multiple rounds from any of these weapons as long as they are designed for the purpose, properly installed and supported by framing that is strong enough to prevent the windows from simply flexing out of the frames due to impact. Unfortunately, the factors that need to be considered for these types of protection are at least as and even more complex than this extremely brief description of ballistics.

Common Challenges for Protecting Windows From Ballistic Threats

There are numerous challenges and considerations for protecting building occupants from ballistic threats involving glass. As with security, ballistic, fire, graffiti and wind protection approaches for windows, there are a host of highly technical considerations when selecting windows, laminates and glazing to provide ballistic protection. For example, while some laminates will stop bullets fired from specific types of firearms, glass on the inside surface of some of these products can shatter and shower nearby occupants with flying glass shards that can cause serious injury and in some cases, death. If laminates are applied only to the window surface and not applied on the entire glass surface, the window may break at the edges upon impact and fall on occupants. These are some of the many challenges that make it necessary to identify the manufacturers of quality products and to have competent distributors with the highly technical knowledge to recommend practical solutions and install them properly.

The Good News

Now that we have discussed a few potential pitfalls of ballistic glass, I must point out that there are, fortunately, some great companies that offer excellent products. There are also qualified installers who can guide you in navigating these rocky but important waters. We advise our clients to focus on the quality of manufacturers and installers when examining ways to protect windows from ballistic threats. Cost, type of size and function of the windows and other factors need to be carefully evaluated and balanced with other security needs to create a good fit for performance, budget and lifecycle of the protective approach.

This article originally appeared in the issue of .