The majority of multistoried high-rise buildings and public facilities (sports stadiums, airports, etc.) today have a steel skeleton. Although steel does not burn it still requires protection against fire as, without adequate protection, structural steelwork can reach a critical temperature of @ 500 °C within five minutes; and above this temperature steel starts to lose load bearing capability and may buckle or collapse, with disastrous consequences for the stability of the building it is supporting. Therefore the continued integrity of load-bearing steel structures is a key concern for building authorities.
A number of measures can be taken to protect steel from fire. These generally fall into the passive category and involve insulation techniques including encasing in concrete, or boxing within fire-resistant panels. However many designers these days prefer to showcase the steel skeletons of buildings - and for this, passive intumescent coatings are ideal.