THE SPECTRUM OF CORROSION environments in the pulp and paper industry is perhaps greater than that encountered elsewhere in the chemical process industries [1]. Aqueous environments range from acidic to neutral to basic, and from reducing to oxidizing. High-temperature environments include molten salts and boiler flue gases. Many of these environments are unique to the pulp and paper industry. Figure 1 is a schematic diagram of an integrated pulp and paper mill. Process equipment includes pressure vessels, boilers, kilns, storage tanks, towers, and large machines with rolls that rotate at high speed. This paper reviews the corrosion testing methods used for each of the major pulp and paper process environments.