Introduction

The emergence of new photoluminescent technologies and groundbreaking changes to the New York City Building Code have combined to set a precedent for providing buildings and facilities with a new benchmark for evacuation safety. Today's safety engineers must be familiar with the principles that are now well established for photoluminescent directional safety way guidance systems so they can incorporate them into new and existing facilities in ways that will provide a higher level of safety for occupants. This presentation will give the background for why this technology was developed and how it has been implemented in New York City.

Background

9/11: Planes hit the World Trade Center's twin towers. In less than 2 hours several thousand people escape. Whether in light or darkness, many survivors credit their lives with the buildings' photoluminescent egress path markings, markings which had been installed for evacuation safety purposes following the 1993 bombing.

Because of 9/11, the New York City Department of Buildings (DOB) convened the World Trade Center Building Code Task Force in March 2002. Its purpose was to recommend ways to amend the building code for improved safety in commercial high-rise structures. This task force issued its recommendations in February 2003 and in June 2004: Local Law 26, containing most of its recommendations, was unanimously approved by the City Council and signed collectively into law by Mayor Bloomberg. The first recommendation to take effect is the mandatory installation of continuous photoluminescent directional egress path marking systems in the stairwells of all Class E commercial buildings 75 feet tall or higher.

Reference Standard 6-1: Photoluminescent Exit Path Markings.

To fulfill Local Law 26 by July 1, 2006, the DOB wrote Reference Standard 6-1.1 This standard, termed "RS 6-1," is a minimum standard that specifies the physical properties of the materials, size, and placement location of each component. The standard sets forth photoluminescent marking requirements for signs, handrails, steps, and demarcation lines that outline the egress path.

These systems provide essential directional information in the stairwells and transfer corridors under normal lighting conditions. However, their primary function becomes most evident in a power failure and, in particular, if back-up power systems fail. Photoluminescent markings function in darkness and obscurity to give occupants the visual clues they need to find the stairwell entry door and travel along the egress path to the building's final exit.

Material Physical Characteristics

The first section of RS 6-1 specifies the physical characteristics of the photoluminescent materials that can be used to meet the code. Local Law 26 states, "The markings shall be washable, nontoxic, non-radioactive, and if subjected to fire must be self-extinguishing when the flame is removed."2

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