Laboratory tests were made to determine the leaching effects of high purity water on plastics and other materials used in building or lining of high purity water storage tanks. Specifically tested were enamels used in painting interiors of condensate storage tanks, materials used for filter tubes, plastic and metal materials of construction, and miscellaneous coating and lining materials. Materials tested include polyethylene, epoxy resins, phenol-formaldehyde resins, cotton, cellulose acetate, glass fiber, mineral rubber with inert filler mixture, asphalt clay-cement mixture, polyvinyl over sprayed zinc and aluminum, sprayed zinc and aluminum, hydraulic cement, commercially pure aluminum, and coal tar enamels.