At ambient temperatures, POLYROCK® is chemically resistant to most substances naturally occouring in the ground and a wide range of other substances such as sea water, dilute acids, alkalines and bleaching agents. Substances such as animal fats and diesel fuel will attack the surface of POLYROCK®,and organic solvent, petrol and concentrated acids can affect POLYROCK® to some degree. However, in all these cases the substance must be poresent in high concentrations to adversly affect POLYROCK®'s performance. Although such high concentrations are uncommon, POLYROCK® can be protected from chemical attack as an additional safeguard.