Many of the industrial applications of reinforced plastics are to replace metals such as steel, which will rust and corrode even in relatively mild chemical envirunments. Galvanizing will resist weathering, but will be damaged in acidic conditions. Paints and coatings may be applied to steel to provide protection against weathering and mild chemical exposure. Coatings based on polyesters, epoxies and other polymers may be may be filled with flake glass to increase durability and reduce permeability or may be reinforced with glass fibres such as chopped-strand mat for tank linings. Unfortunately as temperatures rise, permeation may become a problem and pinholes may allow the ingression of the chemicals. The use of stainless steels will allow many chemicals to be stored even at higher temperatures, but certain chemicals, such as chlorine and its compounds, will attack even the higher grades of stainless steel. Industries such as pulp and paper make extensive use of chlorine compounds in bleaching and were an obvious target for reinforced plastics applications. Most pulp and paper mills will have their own chemical plant to produce many of the aggressive chemicals used in bleaching, including chlorine, chlorine dioxide and sodium hypochlorite. After decades of working with the design of equipment and piping in the composites industry, a wealth of information has been gathered. In order to know the best choice of materials for each application in various industries, knowledge is necessary to understand of the performance and behaviour of metals. These include aluminium, copper, brasses, bronzes, steels, stainless steel alloys, Monel metal, Hastelloy, titanium and even exotic metals such as tantalum. We maintain a comprehensive database of information on metals’ and alloys’ properties and their resistance to chemicals.