ANSI standards for hard hats set combustibility or flammability criteria. He then measured their solubility in water and their specific gravity, and noted their combustibility. Disadvantages include combustibility (hard to extinguish) and significant smoke development. ASTM E1822-02b defines the combustibility of chairs when they are stacked. The elevated temperatures and pressures involved in curing increase the risks of potential combustibility. The resulting plaster has qualified to the A2 combustibility rating as per DIN4102. For an Authority Having Jurisdiction, combustibility is defined by the local code.