Abstract Thermal insulation can play a very important role in industrial fires. Certain insulation materials are inherently combustible and will increase the risk of fire. Other insulation materials may be non-combustible in themselves but may absorb combustible liquids. Some will provide good fire protection but under normal operating conditions, they can create major problems like corrosion under insulation. Therefore, for maximum fire safety, it is desirable to choose an insulation material that combines two important physical properties: non-combustibility and non-absorptivity. Several fire tests run on cellular glass resulted in a mathematical computer model. Thanks to this, both thermal and fire related problems can be solved with cellular glass insulation.