Product Fire Performance Requirements
ASTM E84 (Standard Test Method for Surface Burning Characteristics of Building Materials) is a standard test method to assess the spread of flame along the surface of a material. Often referred to as the “Tunnel Test,” E84 involves installing a sample of material 20 inches wide by 25 feet long in the ceiling of a horizontal test chamber. The material is exposed to a 4-foot-long gas flame at one end of the tunnel for a period of 10 minutes. The rate of flame front progression on the material is measured, then compared against that of a calibration material, followed by calculations to produce a flame spread index rating. Smoke from the fire in the tunnel is measured in the exhaust stack with a light beam then also compared against that of a calibration material to produce smoke-developed index ratings. Since ASTM E84 is a standard laboratory fire test on a single material, numerical ratings derived from E84 are not intended to reflect hazards presented by the test material under actual fire conditions.
Product manufacturers use flame retardants as one of many tools to ensure products comply with building code requirements for fire performance in residential and commercial applications. The term “flame retardant” most accurately refers to a function or a performance attribute, not a family of chemicals. A variety of different chemistries, with different properties and molecular structures, provide flame retarding attributes when used in certain products. In some product applications, it is possible to combine these chemicals to maximize effectiveness.
Flame retardants support an important layer of fire protection that helps save lives and property by affecting overall fire conditions, including ignition, fire growth and smoke generation that have direct implications on escape time and time available for emergency response.
Building codes have specific requirements for the use of foam plastic insulation in certain applications. For example, the building code contains provisions that allow omission of the prescribed thermal barrier separation of foam insulation from the interior of the building upon successful performance in certain full-scale tests of an assembly containing foam plastic.
Similarly, some insulation products have been formulated and tested for use in one- and two-hour fire resistance rated wall, floor/ceiling and roof assembly constructions of wood or masonry. The standard test used to qualify time-rated assemblies is ASTM E119.
ASTM E119 (Standard Test Method for Fire Tests of Building Construction and Materials) is used to determine the fire resistance of a complete assembly. For example, a wall rating is measured by constructing a 10-foot by 10-foot section of total wall system: framing, cavity insulation, sheathing, siding and gypsum board. The wall section is installed vertically on a gas furnace, then the wall system is exposed to flame heat for the desired rating time period (i.e., one, two, three or four hours), followed by a hose stream test. Failure points during time of fire exposure are as follows: flame penetration through the wall section, temperature rise on the unexposed side of the assembly beyond prescribed limits and structural failure or collapse of the assembly. A one-hour fire resistance rating means that a wall of the tested configuration will not collapse, nor transmit flame or excessive temperature while supporting a design load (if rated as loadbearing) for at least one hour. Floor/ceiling and roof constructions may also be tested in accordance with ASTM E119; however, these assemblies are tested horizontally. The building code defines fire resistance requirements in a building based on the construction type (I, II, III, IV or V) and other factors. Factors affecting the duration of fire resistance include occupancy designations, building location, automatic sprinkler systems and insurance criteria.
New research shows how product fire standards impact the severity of room content fires. Differences among country-specific fire codes in real-world scenarios can dramatically affect overall fire conditions, including ignition development, smoke generation, escape time and time available for emergency personnel response.
For detailed fire safety statistics please visit the following:
- The U.S. Fire Administration (USFA) collects data from a variety of sources to provide information and analyses on the status and scope of the fire problem in the United States.
- The Insurance Information Institute publishes helpful graphics and data here.
- The National Fire Protection Association maintains a robust data and analysis website here.