What is the difference between reaction to fire and fire resistance?
A. Reaction to fire assesses how a specific material or composite product reacts when exposed to heat which can be in the form of direct flame impingement, radiant heat or high temperatures. Typical parameters normally measured include ignitability, flame spread and rate of heat release. In the UK and Ireland reaction to fire is assessed by several parts of BS 476 including Parts 4,6,7,& 11. Over the next few years these tests are being replaced by the Euroclassification system. All these tests are relatively small scale and do not allow insulated panels to be tested in realistic as-installed configurations. A much more relevant reaction to fire test is the LPCB test LPS 1181. This is a large scale test which tests the panels in a realistic situation.The advantage of LPS 1181 is that the grading system covers both reaction to fire and resistance to fire, Resistance to fire is a measure of the passage of heat and flame through the thickness of a material and the test structure comprises
