Because organic matter can burn in rock wool products, organic matter content must be strictly controlled.

Because the rock wool products in the process of production to join a certain amount of modified phenolic resin, this is a kind of organic resin, though its ignition point higher than that of other organic resin (approximately 240 degrees), after all, still can burn, and its burning temperature is lower than that of mineral wool products of thermal shrinkage temperature under load, therefore must strictly limit the content of the modified phenolic resin, organic matter content in the general requirements mineral wool products highest do not exceed 4%, for Marine rock wool products more strict in this respect, for less than 3%.