Shining a New Light on Safety

Photoluminescent technology provides a new level of safety, as well as egress lighting.

• By John Sacht
• Jul 01, 2012

In 1931, the Empire State Building became the world's tallest building with a height of 1,250 feet and a staggering 102 floors. Today, the Empire State Building ranks 19th in the world and the tallest building, the Burj Khalifa in Dubai, stands 2,717 feet tall with 163 floors. As the height and number of high-rise buildings continue to increase, new devices and technologies are required to ensure safety during everyday operations and in the event of an emergency.

The standard signage and guardrails are no longer enough. Major advancements have taken place during the past 10 years, and more are on the way.

Prior to the Sept. 11, 2011, attacks, the World Trade Center deployed a new safety technology throughout the building: photoluminescent, or glow-in-the-dark, safety and egress markings. Unlike battery-operated safety technology, the photoluminescent technology remained visible for hours without any power source. While many lives were lost that day, the technology was credited with saving countless lives by lighting the way to safety.

Given its impact in the tragedy and other unrelated incidents, New York City passed New York Law 26 in 2004, which mandated the use of this technology in all building more than 72 feet high. Five years later, the International Building Code and International Fire Code also were revised to mandate the use of photoluminescent technology in new and existing high-rise buildings. Most recently, the maritime industry, via the International Convention for the Safety of Life at Sea, also mandated the use of photoluminescent materials for safety and rescue products.

Everyone from a temporary employee to a facility manager at a four-story office building can see the safety benefits of these technologies. What's not obvious on the surface are the cost-saving opportunities that they present. Photoluminescent technologies don't require expensive generators or other traditional power sources. The key ingredient in the products is phosphor, which contains rare earth elements that are found in mixed geological deposits throughout the world. After exposure to light, phosphor particles can absorb, store, and then emit light at a later time. An emerging subset of this is long-persistence phosphor (LPP), which can emit light for a much longer period of time. Like a sponge, LPP is able to absorb and hold the light energy, slowly releasing it to provide illumination over an extended period of time – up to 18 hours in some cases. These phosphors can be added to ink, dye, paint, coatings, and plastics to create low-maintenance, no-hassle safety solutions.

"Next-generation photoluminescent technology is really a marriage of physics and chemistry," explained Chuck Shuty, director of sales at phosphor manufacturer US Phosphor. "Phosphors, based upon solid state physics, can be modified to take on different characteristics. Depending on whether an end user needs a product that is especially bright, lasts a long time, or displays a different color, the solution is simply a matter of engineering the phosphor and formulation combination."

There are many examples of this technology's successful deployment. One such area is the stadium and arena industry. A facilities manager at a ballpark has a number of upper deck stairways that are steep and under lit. Luckily there have been no serious problems yet, but the issue needs to be addressed before the next season. Photoluminescent technology can be deployed to provide a cost-effective solution.

The traditional route might lead you to improve lighting, adding to the infrastructure and costing $1 million to $3 million, plus annual maintenance. Another option is to supplement existing lighting with photoluminescent products, which would cost as little as $200,000 for photoluminescent paint and labor, with no routine maintenance required for the first two to three years.

Brighter Subway Tunnels in Chicago
Similarly, the Chicago Transit Authority (CTA) faced a no-light/low-light dilemma that needed to be immediately addressed. When federal investigators were examining an equipment breakdown in 2006, they found what the Chicago Tribune called "deplorable, unsafe conditions in CTA tunnels and along subway emergency exits." The eventual result was an extensive subway safety upgrade, a key component of which included phosphor-based photoluminescent paint in about 50 subway emergency exits that line the transit system. It provides a clean tech network of "Emissive Safety Lighting."

"The emergency exits are no longer dark, dank and dirty. Photoluminescent/glow-in-the-dark paint had been brushed onto handrails, freshly painted white walls and stairs, directing passengers toward escape routes and ladders leading to the streets above, should accidents occur in the future," reported the Chicago Tribune.

Additionally, a CTA project manager shut off lights in an emergency exit at the Red Line subway near the North Clybourn station and "the green paint shined so brightly it appeared to be radioactive," the newspaper reported on Dec. 22, 2008.

It may glow like it's radioactive, but phosphor–based products are 100 percent environmentally friendly. Unlike some traditional safety and egress products, phosphor does not contain radioactive materials or toxic metals. Therefore, it presents very low health risk for the environment and for the personnel who handle it. The specific applications of this technology are broad, but coated, adhesive-backed films, markings, and signage dominate the safety and egress business. This is partly because they are mandated by building and marine codes, but also due to their lower installation cost and ease of application compared to paint products. Two firms, Jessup and Brady, manufacture coated products domestically and supply approximately 80 percent of the volume. Performance Indicator, LLC develops and licenses innovative and cutting-edge phosphor and formulation technologies that are deployed in coated products, compounded master batches, and fluids such as ink, plastisol, and paint. Paint covers the spectrum in cost and quality.

As our buildings, industries, and world continue to grow, safety and egress protocols are more important than ever. And no matter the facility, long-persistence phosphor-based products can provide another level of safety options at the right price.

This article originally appeared in the July 2012 issue of Occupational Health & Safety.