Another form of fouling, which is common in the chemical process industry,
is corrosion and other chemical fouling. In this case, the surfaces are
fouled by the accumulation of the products of chemical reactions on the surfaces.
This form of fouling can be avoided by coating metal pipes with glass
or using plastic pipes instead of metal ones. Heat exchangers may also be
fouled by the growth of algae in warm fluids. This type of fouling is called
biological fouling and can be prevented by chemical treatment.