The challenge of solvent substitution in coatings.

A brief outline of the role of solvents in surface coatings is given, to provide the background to the problems encountered in solvent substitution. The direct substitution of one solvent by another is relatively straightforward. Computer programs greatly simplify the process. However, the real challenge lies with the reduction in solvent use, through the development of low solvent coatings. While this is a process that has been going on for many years, there is no doubt that recent regulatory pressures regarding both occupational health and environmental standards have made it the single most important challenge for the industry. Examples are discussed of the development of high solids, low solvent industrial coatings as well as water borne industrial coatings. Although there has been rapid progress in recent years, there is no prospect in sight for the complete elimination of solvents. Good workplace hygiene must therefore remain a key element in the safe use of coatings.