ASTM F3561: A new way to comprehensively evaluate forced-entry resistance

While security in education facilities has always been a significant issue for architects, school districts, and building teams to contend with, the urgency of need in K-12 settings has gone up at an alarming rate.

Pulling a shocking statistic from the authoritative K-12 School Shooting Database, the number of times a gun was fired or revealed or a bullet hit a K-12 school in the U.S. increased an astonishing 722% from 2015 to 2024. 

The extreme rise in the frequency of school shootings has created a need for a more comprehensive, systematic standard to support designs that more effectively resist unlawful entry.

While there are standards like ASTM F1233 for security glazing and systems and UL 972 for burglary resistance, these standards and others don’t function as a full-system testing standard for comprehensively analyzing resistance levels against an active shooter attack in school settings.

Filling this need for a comprehensive standard that evaluates the full glazing system—the glass, framing, anchoring, and hardware—for its ability to prevent entry, the industry has developed the ASTM F3561 Standard Test Method for Forced-Entry Resistance of Fenestration Systems After Simulated Active Shooter Attack.

What is ASTEM F3561?

ASTM F3561 evaluates a full system’s structural integrity and level of forced-entry resistance after being compromised by gunfire. The test reenacts a scenario where bullets are fired at the glass and shot at the locking hardware when applicable. The system is repeatedly impacted by a 100-pound pendulum at varying heights (and therefore impact speed and force) to simulate the force of an attacker attempting to smash their way through the system.

Because the ASTM F3561 ballistic impacts have specified velocities and a forced entry pendulum has a specified weight and drop height, variability and bias associated with human intervention are eliminated, producing a measurable and repeatable test.

The test is not timed, but rather evaluates an intruder’s ability to gain entry, correspondingly assigning a rating from Level 1 to Level 8. The ASTM F3561 rating determines how many standardized hits a system can take, which is a far more reliable metric for system design than guessing how long it would take an unknown attacker to get through. As a result, architects can better align their entrance system designs with a school district’s level of resistance requirements.

(To better understand why recognized tests are not timed and the difference between forced-entry and bullet resistance, read the white paper "Forced-Entry Resistance and ASTM F3561 in Educational Facilities.") 

The role of window film

While window film has its place in the fenestration security space, it’s important to understand that film’s main function is to retain broken glass fragments. While this does enhance glass safety, film does not strengthen the frame, anchors, glass bite, or hardware, all of which are essential for resisting forced entry.

Because film can meet some legislative mandates and is regarded as a lower initial cost, school districts are considering film products for security applications. While window film is better than no protection, especially in retrofit scenarios where replacing the glass and framing is not an option, it does not compare to a comprehensive, fully third-party-tested solution. Furthermore, it does not strengthen the frame, anchors, glass bite, or hardware, all of which are essential for resisting forced entry.

In comparison, a full ASTM F3561-certified system provides schools with documented proof that their glazing assemblies meet a recognized best-practice standard, offering a clear, defensible position if safety measures are ever called into question.

Best practices for ASTM F3561 systems

When designing with ASTM F3561-certified systems, there are a number of recommended best practices to ensure that the system will optimally enhance school security on the campus.

For starters, architects are encouraged to engage manufacturers and design-assist partners early in the process to help strike the right balance of performance, aesthetics, and budget. This process also helps the team evaluate which areas of a school demand higher-level protection — such as main entrances, vestibules, and administration areas — versus locations where lower-level resistance may be acceptable.

For new construction, specifying ASTM F3561 systems during schematic design also ensures coordination across Division 08 packages and avoids costly substitutions later.

For optimized outcomes, architects are encouraged to leverage manufacturer test reports and submittals as documentation for school boards, facility managers, and local code authorities. In addition, working with design-assist partners to match tested systems to the project’s budget, schedule, and aesthetic goals is an effective strategy.

An eye toward the future

Addressing a critical need for enhanced safety in schools, ASTM F3561 is emerging as the benchmark standard for fenestration security in educational settings. It provides the first repeatable, objective method for assessing the ability of a complete fenestration system to resist forced entry after ballistic weakening.

The standard is also gaining broader regulatory momentum. ASTM F3561 has been formally introduced for inclusion in the International Building Code (IBC) by the National Glass Association via code change proposal G88-25, targeting the 2027 IBC cycle — though initial mandatory requirements were disapproved and are pending modifications for reconsideration. The ASTM F3561 subcommittee continues to refine the standard to keep pace with evolving ammunition and weapons technology, as well as advancements in testing methodology.

As awareness of the standard continues to grow, more school districts are anticipated to move toward requiring tested systems in K-12 schools. For architects, this underscores the importance of staying informed and proactively integrating ASTM F3561-certified systems early in design to help clients navigate evolving expectations and risk profiles.

To download OBE's white paper "Forced-Entry Resistence and ASTM F3561 in Educational Facilities, click here.

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