Volume 33, Number 7, July 1998


Veil of Security

Understanding the Effectiveness of Window Film in Security Applications

by Tara Taffera

Security glazing. It’s the umbrella term used to describe everything from hurricane-resistant, bullet-resistant and impact-resistant barriers to human resistant materials. But glass retailers selling security film should be aware that this product is a good choice for protection in some situations. So, before discussing the best applications for security film, it is important to consider whether or not the installation of security film is the best avenue to pursue in certain situations.


Although many in the window film industry believe window film may serve as a valuable security precaution against hurricanes, its effectiveness has not yet been accepted by some code officials. At a recent symposium of the Building Environment and Thermal Envelope Council (BETEC), Paul E. Beers from Glazing Consultants Inc., cited laminated glass and shutters as methods being used to comply with impact code requirements in Dade County, FL. "To the best of my knowledge, no retrofit film systems have received Dade County approval," said Beers.

However, Darrell Smith, executive director for the International Window Film Association, questions whether the Dade County codes are realistic for hazard mitigation of existing dwellings. "Dade County seems to discourage other means of protection, such as the use of safety and security film to lessen damage and injury in the event of glass breakage," said Smith.


A few individuals continue to use the terms, "bullet-proof" or "bullet-resistant" glass or window film, when appealing to potential customers or through company advertisements. It is important that retailers resist the temptation to use these buzz words when describing security film benefits. "There is no such thing as bullet-proof window film," said Brian Smith, national sales manager for Johnson Window Films in Carson, CA. "The importance of not overstating a product’s capabilities in advertising is very serious."

Choosing Film

When does film work as an effective security measure? Manufacturers say window film helps "hold shattered glass in place." They promote their film products as effective ways to prevent against smash-and-grab theft, to minimize damage caused by vandals and civil disturbances and to prevent damage to interior furnishings when tornados, hurricanes and earthquakes shatter windows and allow rain and high winds to penetrate the building interior. For example, MSC Specialty Films Inc., of Clearwater, FL, says its Armorgard film more than triples the strength of some glass when applied to existing windows. The company says if the protected glass does break, the film holds the broken pieces in place and keeps the window in its frame.

The federal government has used film to add increased security and protection to its buildings. For example, the J. Edgar Hoover FBI Headquarters building, the U.S. Attorneys, Federal Emergency Management Agency (FEMA), the United States Information Agency (USIA) and the Pentagon buildings in Washington, DC, were recently retrofit with security film. "It is often impossible or impractical to replace the glass so security film is a more obvious, practical and cost-effective alternative," said Peter Wolfenden of MSC Specialty Films Inc.

A Federal Customer

The General Services Administration is one government agency that speaks of the effectiveness of security film. Bruce Hall, GSA structural engineer, demonstrated the value of security film at the BETEC symposium by showing participants GSA blast testing results. Hall showed that windows enhanced with security film and attachment systems provided a significant hazard reduction over unprotected windows.

With the variety of security window films on the market and all manufacturers making similar claims concerning the level of protection, how can glass retailers know what type of security film is the most effective? In describing safety and security film, it is generally true that thinner film applications can generally provide a measure of safety while thicker films provide heavier security and more protection. Film standards are an effective means of measuring the level of protection.

Although there are several standards in existence, most film manufacturers strive to meet the standards set by the American National Standards Institute (ANSI Z97.1 test) and the Consumer Product Safety Commission (CPSC 16 CFR 1201 Category II test). Product literature produced by film manufacturers cites what films meet particular standards. The glass retailer should have an understanding of what these standards entail, so he or she is able to educate the customer on the benefits of security film. If not already at their disposal, retailers may want to request a copy of the safety film manufacturers independent impact test report from individual manufacturers.

Following is a brief explanation of the tests cited in ANSI and CPSC tests. The impact test method for both the CPSC and ANSI Z97.1 standards begins by placing a 34-inch by 76-inch specimen into the test frame. The specimen is held in the frame by placing a mounting frame over the specimen and bolting the mounting frame to the main frame. A 100-pound impactor is raised to the desired height and released (for the 400-foot-pound test the impactor is raised 48-inches or four-feet). The impact force is equal to the impactor weight multiplied by the height raised (again for a 48-inch drop height this is equal to four-feet by 100 pounds or 400-foot pounds). Products are considered to meet the safety standard of the test specimens meet one of several criteria.

Specimen Breakage

In general wording, these criteria are: the specimen does not break; the specimen breaks but has no opening larger than three inches in diameter; or no opening through which a four-pound ball will fall (CPSC); the specimen leaves the test frame after impact, but remains unbroken; or the specimen breaks into sufficiently small pieces that are not likely to cause cutting or piercing injuries (this break results when using tempered glass specimens).

Once the glass retailer is educated, it is important for he or she to educate the customer. "Homeowners and business owners frequently ask for a product without knowing what they really need. We, as manufacturers and dealers, need to ask ‘what are you trying to accomplish’ before we sell glass or film or any other product," said Virginia Kubler, director of sales and marketing for Courtaulds Performance Films Inc. Courtaulds conducts educational programs for its dealers and distributors once or twice a year, sending technicians to teach representatives how to sell its products and ensure that dealers understand how to talk to end-users about product choices.

With so many issues falling under the security glazing umbrella, it is important for the glass retailer to decipher what uses are truly the best for security film and also in the best interest of the customer.  

Tara Taffera is the managing editor of USGlass magazine and the editor of Window Film magazine


Copyright 1998 Key Communications, Inc. All rights reserved. No reproduction of any type without expressed written permission.