What Is UL 752?

UL 752 is the Underwriters Laboratories standard for bullet-resisting equipment. It defines the testing protocols and ballistic resistance levels used to classify architectural products — including windows, doors, wall panels, and glazing assemblies — against defined firearm threats. It is the primary U.S. specification benchmark for bullet-resistant building components in commercial and government construction.

The standard covers ten levels (1–10), each tied to a specific firearm, caliber, bullet weight, and shot count. Products tested and found compliant may carry a UL Listed designation, providing independent third-party verification of performance.

Key terminology. The correct specification term is bullet-resistant — not “bulletproof,” which implies absolute protection no architectural product can guarantee. A UL Listed designation confirms independent testing. BR Level (e.g., BR3) is the standard abbreviation in glazing specifications. No spall / Low spall are supplementary designations indicating the degree of interior fragment hazard when glazing is impacted.

Common misconceptions. Ballistic window film (typically 3–8 mils thick) does not meet UL 752 and cannot substitute for rated glazing, which ranges from ¾ inch to 4 inches thick. Rated glazing in an unrated frame is not a compliant ballistic system — frames must be rated as well. UL 752 and NIJ standards serve different purposes: UL 752 covers architectural building components; NIJ standards apply to body armor for law enforcement and military personnel.

UL 752 Ballistic Rating Levels — All 10 Explained

UL 752 organizes ballistic resistance into ten levels. Each level is defined by a specific firearm type, ammunition caliber, bullet weight, and the number of rounds fired at a defined distance. A product fails if penetration occurs.

Level 1 — 9mm Handgun

Level 1 tests resistance to three shots from a 9mm full metal copper jacket (FMCJ) round, 124-grain. The 9mm is the most widely owned handgun caliber in the United States and represents the baseline commercial threat. Level 1 is the most commonly specified protection level across retail, banking, pharmacy, and general commercial applications. Typical materials include laminated polycarbonate and lighter glass-clad polycarbonate assemblies.

Level 2 — .357 Magnum Handgun

Level 2 tests against three shots of .357 Magnum lead semi wadcutter (LSWC), 158-grain — a higher-energy round than Level 1. This level is appropriate for police station reception areas, government service windows, credit unions, and check cashing facilities where an elevated handgun threat is anticipated.

Level 3 — .44 Magnum Handgun

Level 3 is the highest handgun-class rating under UL 752, testing against three shots of .44 Magnum lead semi wadcutter (LSWC), 240-grain. Products at this level suit high-risk cashier environments, detention facility visitor areas, and high-security reception counters. Level 3 completes the handgun protection tier.

Level 4 — .30 Caliber Rifle

Level 4 marks the transition to rifle protection and requires resistance to one shot from a .30 caliber rifle, 150-grain. Rifle fire carries substantially greater velocity and penetrating force than handgun ammunition, requiring significantly thicker materials. Typical applications include military guard posts, perimeter security checkpoints, and high-security government facilities.

Level 5 — 7.62mm NATO Rifle

Level 5 addresses one shot from the 7.62×51mm NATO round (M80 ball, 147-grain) — a standard military battle rifle and light machine gun cartridge. This level is specified for embassy security glazing, military installations, and critical infrastructure control rooms where military-grade rifle threats are a design consideration.

Level 6 — 9mm Submachine Gun (5 Shots)

Level 6 tests resistance to five shots of 9mm FMCJ, 124-grain — the same round as Level 1, but fired five times rather than three. This level addresses sustained fire from submachine guns. Typical applications include tactical operations centers, law enforcement command stations, and detention facility control rooms.

Level 7 — 5.56mm Rifle (AR-15 / M16, 5 Shots)

Level 7 addresses five shots of 5.56×45mm ammunition (55-grain, M193 equivalent) — the caliber used in AR-15 pattern rifles and military M16/M4 weapons. This high-velocity, lighter-grain round presents a severe penetration challenge. Level 7 represents robust protection against the most commonly referenced rifle caliber in active threat scenarios in the United States. Applications include high-security government facilities and military bases.

Level 8 — 7.62mm High Velocity Rifle (5 Shots)

Level 8 is the highest level commonly specified for architectural applications, requiring resistance to five shots of high-velocity 7.62mm rifle fire, 150-grain. This is the upper boundary of what fiberglass composite panels and glass-clad glazing typically achieve in standard architectural formats. Applications include maximum security facilities, federal government installations, and armored transaction environments.

Levels 9 & 10 — Shotgun Threats

Level 9 tests against five shots of 12-gauge #4 lead buckshot — a high shot count addressing multiple pellet impacts. Level 10 addresses the 12-gauge rifled slug, a single high-mass projectile that presents a distinct penetration challenge through concentrated energy rather than velocity. Both levels are specified primarily for correctional facilities and guard stations where shotguns are standard security equipment.

Common Product Types Rated to UL 752

Fiberglass Composite Panels

Fiberglass composite panels are opaque ballistic panels for wall, partition, and structural assembly applications — the most widely used concealed ballistic protection product in commercial and government construction. Ballistic-grade fiberglass cloth is mechanically injected with thermoset resin and hydraulic hot-pressed into rigid flat sheets. The manufacturing process controls delamination to maximize projectile retention.

Panels range from 2.5 lb/ft² at Level 1 to 14.5 lb/ft² at Level 8 — significantly lighter than steel alternatives at equivalent protection levels. This weight advantage is critical in retrofit projects where structural capacity is limited. Panels are designed to be concealed behind drywall, millwork, or furniture; are fire-rated per ASTM E119; are available in Levels 1–8; and can be custom-cut using CNC waterjet and laser machinery. They are approved by the U.S. Marshal Service and General Services Administration. Fiberglass panels are interior-use products and are not suitable for exposed exterior applications.

Bullet-Resistant Glazing

Bullet-resistant glazing encompasses transparent and translucent assemblies for windows, transaction windows, vision panels, and storefront systems. Three primary compositions are used in architectural applications.

Laminated glass assemblies bond multiple glass plies with interlayer film. They offer superior scratch and weather resistance, are heavier than polycarbonate alternatives, and are well suited for exterior applications. Glass-clad polycarbonate (GCP) combines alternating layers of glass and polycarbonate bonded with interlayer film. The outer glass layers provide scratch resistance and optical clarity; the inner polycarbonate layers absorb energy and retain projectiles. GCP is rated Levels 1–10 and is suitable for both interior and exterior use. Polycarbonate and acrylic monolithic or laminated sheets are lightweight with excellent impact resistance but are prone to scratching unless an abrasion-resistant coating is applied. They are best suited for interior and lower-risk environments.

Some glazing products carry supplementary UL listings for no spall or low spall performance, which is an important safety consideration for occupied spaces near protected glazing.

Bullet-Resistant Doors, Windows & Transaction Systems

Bullet-resistant doors combine a rated door slab with rated frames and hardware to create a ballistic system assembly. They are available in wood, steel, and aluminum configurations and can include gun ports and vision panels. Complete system specification is essential — door, frame, and hardware must all be rated components.

Transaction systems are designed for environments where staff interact with the public through a secure barrier. They include fixed windows, operable transaction windows, deal trays, transaction drawers, package receivers, and speakers. Common applications include bank teller lines, pharmacy windows, courthouse clerk windows, police station lobbies, and check cashing facilities.

Codes, Standards & Certifications

UL 752 is the primary U.S. standard for bullet-resisting equipment. A UL Listed designation means the product has been independently tested by Underwriters Laboratories and found compliant — it is not a self-certification. For architects and building owners, UL Listing is the baseline third-party verification requirement.

ASTM E119 is the standard test method for fire resistance of building assemblies. Fiberglass composite panels tested per ASTM E119 provide fire resistance documentation required for certain occupancies and code-compliant assemblies.

ISO 9001 is the international quality management system standard. Manufacturers certified under ISO 9001 operate under third-party audited quality controls, ensuring manufacturing consistency across production runs — a requirement for many institutional and federal projects.

GSA Standards (General Services Administration) establish physical security design criteria for federally occupied and leased facilities, including explicit ballistic protection level requirements for certain occupancies. Products must carry GSA approval for use on these projects.

U.S. Marshal Service approval is required for products specified in federal court facilities and other facilities under USMS jurisdiction.

NIJ Standards (National Institute of Justice) govern ballistic resistance for personal protective equipment — body armor — used by law enforcement and military. NIJ levels are not comparable to UL 752 levels and do not apply to architectural building components.

IBC / ICC (International Building Code) does not specify UL 752 levels directly, but physical security requirements for certain occupancies — including courthouses, jails, and detention facilities — may reference ballistic resistance performance criteria that align with UL 752 levels.

Best Applications by Building Type

Schools. UL 752 Levels 1–3 are the standard specification range for K–12 and higher education security upgrades. Typical specifications include rated transaction windows at main office reception, bullet-resistant glazing in entry vestibule doors and sidelights, and concealed fiberglass panels behind reception counters.

Healthcare. Hospital emergency departments, psychiatric units, and pharmacy dispensary windows increasingly specify Level 1–2 rated glazing at nurse stations, pharmacy pick-up windows, and ED check-in areas.

Courthouses & Government Buildings. Among the most systematically secured building types in the U.S. Levels 1–5 are commonly specified across courtroom glazing, clerk windows, probation offices, and public lobbies. GSA and U.S. Marshal Service approvals are standard requirements for these projects.

Banks, Retail & Financial Services. The core commercial market for Levels 1–3. Cashier barriers, transaction windows, and teller line glazing address the most common handgun threats in high-cash environments including banks, convenience stores, pharmacies, check cashing facilities, and liquor stores.

Police Stations. Front desk reception, report windows, booking areas, and evidence room windows are typically specified at Levels 1–3 using fiberglass panels, transaction windows, and full ballistic barrier systems.

Military & High-Security Government. Military bases, embassies, federal buildings, and critical infrastructure control rooms may specify Levels 4–8 where rifle threats are anticipated based on security assessments.

Correctional Facilities. Control rooms, visitor windows, and guard stations are common applications for Levels 1–3 and, where shotgun threats are relevant, Levels 9–10.

Specifier Checklist

Before finalizing specifications for a ballistic protection project, confirm each of the following:

  • UL Listed certification confirmed — not a manufacturer self-certification claim
  • UL 752 level matched to the threat profile established by security design criteria or a qualified security consultant
  • GSA and/or U.S. Marshal Service approval confirmed for federal projects
  • Complete system specified: panels, glazing, frames, doors, and hardware all rated
  • ASTM E119 fire test documentation available for panel products in fire-rated assemblies
  • ISO 9001 certification confirmed for manufacturing quality assurance
  • No spall or Low spall designation confirmed for glazing in occupied spaces near protected glazing
  • Interior vs. exterior suitability confirmed — fiberglass panels are interior products
  • Custom fabrication capability confirmed for non-standard opening dimensions
  • BIM/Revit families and CSI MasterFormat specifications available for project integration
  • Lead time confirmed, especially for schedule-sensitive projects

Frequently Asked Questions

Can ballistic film replace bullet-resistant glazing?

No. Ballistic film (3–8 mils thick) can reduce spall and improve shatter resistance from low-level impacts but will not stop bullets. Rated bullet-resistant glazing is ¾ inch to 4 inches thick. If a product cannot meet a UL 752 ballistic standard, it is not bullet-resistant, and ballistic film does not qualify.

What is the difference between UL 752 and NIJ standards?

UL 752 applies to architectural building components — walls, glazing, doors — and rates them Levels 1–10 against specific firearm threats. NIJ standards apply to personal protective equipment, primarily body armor, for law enforcement and military personnel in dynamic environments. The two systems serve different product categories and are not interchangeable.

What does ‘no spall’ or ‘low spall’ mean?

Spall refers to glass fragments or material debris that break free from the interior face of a glazing assembly when a projectile impacts the exterior. A no spall designation means the tested assembly produced no hazardous interior fragments. Low spall indicates minimal and defined fragmentation. These designations are separately tested and listed by UL and are important safety considerations for any occupied space near protected glazing.

What protection level is appropriate for my application?

The appropriate level depends on the threat profile established through a security assessment. Handgun protection at Levels 1–3 is the correct specification for most commercial environments — banks, retail, healthcare, schools, and general government offices. Rifle protection at Levels 4–8 is appropriate where security assessments identify elevated threats, such as military installations, embassies, or maximum security facilities.

Is bullet-resistant glass different from standard laminated safety glass?

Yes. Standard laminated safety glass is designed to hold together when broken, reducing injury from accidental impacts. Bullet-resistant glazing is a multi-layer composite assembly — significantly thicker and more complex — engineered to absorb and distribute the energy of a projectile and prevent penetration. The two products are not interchangeable in security applications.

About Armortex®

Armortex® has manufactured bullet, blast, and forced entry resistant products since 1980 at its facility in Schertz, Texas. Products are tested to UL 752 Levels 1–10, ISO 9001 certified, approved by the U.S. Marshal Service and General Services Administration, and fire-tested per ASTM E119. Armortex® offers a full library of BIM/Revit families, CSI MasterFormat specifications, installation guides, and technical submittals for design professionals.

5926 Corridor Parkway, Schertz, TX 78154  |  1-800-880-8306  |  info@armortex.com  |  armortex.com