Written By: Brad Campbell | February 16, 2023
Glass is one of the most vulnerable points in any building. Standard storefront windows or glass entryway doors can shatter with a single impact, leaving occupants and assets exposed to theft and armed attacks. Ballistic glass offers a high-security glazing solution that can resist bullets, forced entry, and other impacts.
Unlike traditional commercial glass, ballistic-grade glazing is designed to absorb energy from bullets, slow penetration, and provide a critical barrier between people and potential threats.
Understanding what ballistic glass is, how it works, and technical standards, like UL 752 ratings, is crucial when selecting the right glass security solution for your building.
Ballistic glass, also known as bullet-resistant glass, is a type of multi-layered security glazing designed to resist projectiles from firearms. It is used in environments where enhanced threat protection is required, including high-risk retail spaces, schools, banks, government buildings, and healthcare facilities.
Ballistic glass can be constructed from:
The layers work together to slow, deform, and stop a projectile, reducing the likelihood of penetration. The design mitigates active threats and allows occupants to react, evacuating or barricading themselves safely inside until the authorities arrive and neutralize the threat.
Ballistic glass relies on engineering principles that manage kinetic energy. When a bullet strikes, the impact is absorbed and dispersed across multiple layers:
Even with advanced materials and layering techniques, it’s important to remember that ballistic glass is not impervious. Its primary function is to delay penetration, providing critical time to respond to a threat, and to provide access denial to keep attackers out of the building.
When a projectile strikes glass, the impact can cause fragments to break off the interior, or safe-side, surface. These fragments, known as spall, can be dangerous, especially in confined spaces where occupants are sheltering.
Effective ballistic glazing isn’t only about stopping bullets; it must also prevent spalling to protect building occupants inside the protected area.
Ballistic glass assemblies manage this risk through spall-control technology. In a low-spall construction, the interior surface may release minimal, lightweight debris that is unlikely to cause serious injury. This is acceptable in certain commercial applications where complete debris elimination isn’t mandatory.
However, environments such as schools, government facilities, financial institutions, or secure reception areas often require no-spall performance, meaning the glazing completely contains all fragments on impact.
Polycarbonate layers play a critical role in achieving no-spall protection. Their ability to flex and absorb energy prevents glass particles from detaching and ensures the interior surface (the “safe side”) remains intact.
The UL 752 standard is the benchmark for evaluating ballistic glass. This system classifies glass based on its ability to stop bullets of specific calibers, types, and velocities. Ratings range from Level 1, which resists small-caliber handgun rounds, to Level 10, capable of stopping high-powered rifle rounds.
| UL 752 Level | Ammunition Type | Number of Shots |
| 1 | 9mm | 3 |
| 2 | .357 Magnum | 3 |
| 3 | .44 Magnum | 3 |
| 4 | .30-06 Rifle | 1 |
| 5–10 | Assault rifles, high-powered rifles, & multi-shot 9mm firearms | Varies |
These ratings allow architects, building owners or managers, and security consultants to match ballistic-grade security glass to specific threat scenarios, ensuring that the protection level aligns with the potential risk.
Non-ballistic security glass is also known as containment-grade security glass. While these materials can resist high-force impacts and reduce the risk of injury from broken shards of glass, they don’t withstand bullets and thus have no UL 752 rating.
Despite the fact that containment-grade security glazing doesn’t slow or stop bullets, it can still be used for active threat mitigation. This is because even if it gets riddled with bullets, it can retain its shape and strength, preventing an attacker from forcing entry.
Understanding these distinctions is critical for developing an effective layered security strategy. Many businesses and facilities can benefit from installing a combination of both ballistic and non-ballistic security glazing.
Ballistic glass provides a layered defense against a range of threats:
Ballistic-rated glass is also highly resistant to tools commonly used in break-ins, including hammers, crowbars, bricks, and rocks. Many bullet-resistant glazing materials are also tested and certified for forced entry resistance according to protocols like ASTM test standards. Retrofitting storefronts or commercial properties with this glass can deter and prevent theft, reduce property damage, and discourage repeated forced entry attempts.
Active threat scenarios, including targeted armed attacks, are a critical worst-case security consideration for schools, offices, and public facilities. Ballistic glass can not only stop bullets, potentially saving lives during the first few moments of an attack, but also delay or prevent access, giving occupants time to react and emergency personnel time to arrive.
Ballistic glass is highly customizable. With such a wide choice of material composition, thickness, and UL 752 ratings, it can be matched to specific security needs, from high-risk retail shops facing potential armed robbery to high-security government facilities.
Unlike metal barriers, ballistic glass maintains visual transparency and natural light transmission, allowing secure areas to remain welcoming while still being protected.
Ballistic glass is versatile and used in a wide range of facilities, including:
Retrofits of existing structures or integration into new construction are both feasible, making ballistic glass suitable for modern security upgrades without drastic architectural changes.
Retrofit ballistic glazing systems are engineered to fit into existing framing using specialized framing adapters.
Compared to full window or door replacements, retrofits reduce costs, shorten installation timelines, and minimize disruptions to normal operations, all while providing a substantial security boost. This approach is highly efficient for retail storefronts, schools, offices, and other buildings where replacing every window or door is cost- or time-prohibitive.
A retrofit is typically feasible when the existing framing is structurally sound and capable of supporting the added weight and thickness of ballistic-grade glazing. In some cases, particularly with older or damaged frames or when upgrading to very high UL 752 levels, new framing may be required to maintain proper anchoring and performance.
Ballistic glass is an essential component of many modern commercial security strategies. From retail stores to schools and government facilities, it provides protection where it matters most, impeding threats and safeguarding people and property.
Whether your goal is deterring smash-and-grab theft, improving forced-entry resistance, or preparing for active threats, ballistic glass is a versatile, cost-effective solution, especially when you choose a retrofittable solution like Riot Glass.
Contact Riot Glass today to explore our ballistic-grade glazing options or schedule a free consultation with our security experts. Protecting your property starts with the right glass!
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