Levels of Security Glazing, From Security Film to Bullet Resistant Glass

Glass is a building's weakest link. Bad actors see it as an easy entry point. Security glazing solves that by integrating into the existing building to delay, stop, and prevent disaster. But not every threat requires the same solution. Here's how the four DefenseLite security glazing levels compare, so you can choose the right protection for every opening.

The Four Levels of Security Glazing

Level I: Delayed Entry

RiotLite security film is the minimum recommendation for security glazing. Applied to existing glass and mechanically attached to the frame, it holds broken glass together and slows down smash-and-grab and vandalism. It's an economical way to cover many windows and is typically used for lower-risk openings and interior glass.

Level II: Access Denial

The DefenseLite polycarbonate shield is a 1/4" shield mounted to exterior framing over the existing glass. It flexes and absorbs impact instead of shattering, so attackers can't get through even after the glass behind it breaks. An anti-graffiti sacrificial layer protects the surface, and the system provides strong acoustic performance (STC 41 / OITC 33).

Level III: Prevent Forced Entry

DefenseLite Pro uses heavier polycarbonate and extrusions about twice as thick. It's tested to ASTM F3561 Level 8, the highest level of that standard, along with hurricane, blast, and active-shooter criteria. Choose Level III for primary entries, storefronts, and any opening where you need to stop a determined attacker.

Level IV: Ballistic Protection

BulletShield adds UL 752-rated ballistic protection to everything Level III provides. It's available in polycarbonate and glass-clad configurations and is the recommended choice for main entries and lobbies where active-shooter risk is a primary concern. Learn how bulletproof glass works.

Why System Testing Matters

Component testing evaluates individual materials in isolation. System testing evaluates the fully installed product, including frames, fasteners, connections, and installation methods, under real-world conditions. A component can perform well on its own and behave differently once combined with frames and adjacent materials. Both RiotLite and DefenseLite Pro were tested as complete systems, so tested performance reflects what you'll get in the field.

Determining the Best Solution

Which level is right for each application? It starts with understanding current risk factors, which requires evaluating every part of the building's elevations because the threat may vary from side to side. A qualified security glazing professional who offers multiple solutions can perform a threat assessment that often results in more than one recommendation, for the most effective and economical approach.

The system manufacturer should also factor in local climate to prevent long-term moisture and condensation. A vented overmount system eliminates moisture in the void between the shield and the glass, minimizing the pillowing and distortion common in rigid, non-vented overglaze systems. Every DefenseLite overlay is vented. See how FSJ Tactical applies these levels using the Zones of Defense.