EI – Integrity and insulation
E – Integrity. This is the ability of a test component to stop fire from spreading to an unexposed side as a result of penetration of flames or smoke.
I – Insulation. This is the ability of a test component to restrict the temperature rise of the non-heated side to below specified levels during the fire, which is not more than +140°C up to +180°C.
EW – Integrity and radiation reduction
E – Integrity. This is the ability of a test component to stop fire from spreading to an unexposed side as a result of penetration of flames or smoke.
W – Reduction of thermal radiation. This is the ability of a test component to resist fire exposure on one side only, so as to reduce the probability of the transmission of fire as a result of significant radiated heat either through the element or from its unexposed surface to neighbouring objects.
All the above-mentioned parameters are followed by as a time limit in minutes. The number after a given symbol shows the time the performance criteria is fulfilled during a standardized fire test. Ex: EI30, EI60, EI90 etc.