Polymer flammability has no specific meaning; the flammability of a polymer is often defined by the method used to measure it (Nelson and Brindley 2000); flammability has been described as the ease with which a substance will ignite
(Quintiere 1997) but is also used to indicate the rate of fire growth after ignition: flammability is a function of both gas and solid phase chemistry (Zhang 2004). Fire tests are crucial to the development, screening and evaluation of materials with improved fire safety. Techniques employed to measure the ignition and burning behavior of a polymer are numerous. Some examples of fire tests are shown in Table 7, together with the individual fire properties they can quantify (Patel etal. 2012).
It can be seen from Table 7 that no single test covers all the parameters describing fire safety behavior, but many address more than one parameter. When selecting a test method, it is necessary to determine the end use of the product, and the likely fire scenarios. Aside from materials’ development, in fire testing, there are generally two end purposes:
- - To meet a regulatory requirement
- - To demonstrate that the material being tested will perform adequately in a specific
fire scenario (Babraukas 2000).
Understandably, manufacturers will optimize their materials in order to pass regulatory tests, and it is incumbent on the regulators to ensure that their tests continue to be appropriate to the types of fire retardant technologies being deployed.