Testing Intumescent Coatings to the Extremes – through Hot and Cold to Explosions. Discussion of Blast Overpressure Testing as a Method of Evaluating an Intumescent Coating

Abstract Intumescent coating is an example of modern fireproofing methods. They are becoming increasingly popular due to the versatility they offer. As they are safety critical products, efficiency in fire alone is not enough for them to be declared fit for purpose. Apart from fire testing, intumescent coatings should be assessed to a variety of different tests to ensure they are suitable for harsh climates or complex structures. Coatings intended for the hydrocarbon market may have requirements of cryogenic insulation performance, weatherability without topcoat and they will need to perform in the event of an explosion. These large-scale tests must be conducted in combination with smaller scale tests that evaluate the mechanical characteristics of the coating, as well as making sure the in-can properties of the paint are acceptable. This article will discuss the blast overpressure test procedure as per ISO 23693 by evaluating a recent test program undertaken as part of an intumescent product development, and investigate the question - is the blast overpressure test the most extreme test you can perform on an intumescent coating?