"General lighting fixtures are typically evaluated for risk of fire or electrical shock. They are subjected to different tests to review durability and ability to 'fail safely'. Egress lighting on the other hand can't fail and needs to work when you need it most. Thus UL 924 standards were developed which go above and beyond those of standard luminaires." -Electrician Chris
What is entailed in UL 924 testing of emergency lighting systems?
As the United States was settled, a patchwork of various codes came into effect across the various towns, cities, and counties. In time, it was recognized that uniformity was preferable. At least at the state level, there could be regulation and enforcement. "Best practices" could also be recognized. As this patchwork of codes began to coalesce, the best parts of earlier codes were adopted into a series of three model building codes (developed over three disparate regions - the east coast, the south, and the west coast). Since the early 1900's, these three models have been the basis for all building and fire codes in the United States. (Model codes have no actual authority, unless adopted in whole or part by a locality, such as a town, county, city, or even state). The East Coast and Midwest followed the Building Officials Code Administrators International (BOCA) National Building Code. The South and Southeast followed the Southern Building Code Congress International Standard Building Code. The West Coast followed the International Conference of Building Officials Uniform Building Code.
The development of building and fire codes in the U.S. Territories proceeded differently. For islands areas, especially in moist tropical climates, hurricanes or tropical storms, not fire, are often the most dangerous disasters. Also, many of the Territories were influenced by international (non-U.S.) regulations and codes. In some territories, only recently has the adoption of standardized codes been completed.
Today, all fifty U.S. states, the District of Columbia, and every U.S. Territory has adopted ICC model codes at the state or jurisdictional level in whole or as a basis for their building or fire codes. Thirty-Nine states have also adopted the NFPA 101®, Life Safety Code®. By enforcing these codes, Fire Code Officials (usually Fire Marshals), ensure that buildings are protected, exits are accessible, extinguisher and alarm systems are working properly, and all systems and services are correctly maintained in order to provide for maximum occupant and building safety.
International Fire Codes
By the early 1990's the importance of a single set of national model building codes led the three model code groups to join efforts and form the International Code Council (ICC). By 2000, the ICC had completed a series of model codes known as the International Codes. Among the new ICC codes are the International Building Code® which covers fire prevention as pertaining to the construction & design of new buildings, and the International Fire Code® which addresses the regulation of fire hazards in existing buildings, and the installation, testing and maintenance of fire protection in new and existing buildings. Just as the International Building Code® is a merger of the provisions of the National Building Code, Standard Building Code, and Uniform Building Code, the International Fire Code® is a merger of the provisions of the National Fire Prevention Code, the Standard Fire Prevention Code, and the Uniform Fire Code.
The National Fire Protection Association (NFPA) was originally founded in 1896 by insurance companies to standardize the new market of fire sprinkler systems. Eventually its scope grew to include all aspects of building design and construction, and was recognized worldwide for it's standards, particularly those dealing with fire fighting operations and equipment. It initially joined with the ICC to help develop the International Fire Code® but a series of disagreements led NFPA to withdraw and create a competing set of codes named the Comprehensive Consensus Codes (C3). C3 included NFPA 5000® as the central building code, and NFPA 101®, Life Safety Code® which detailed minimum requirements protecting occupants against toxic fumes, smoke, and fire in new and existing buildings.