PRIOR TO THE 1960s, THE COATINGS INDUSTRY enjoyed a somewhat predictable regulatory and economic environment. The paint formulator selected solvents based on evaporation rate, solubility parameter, density, flammability, and, of course, cost. There was no apparent need to consider the relative photochemical reactivity of these materials, nor was there any appreciable incentive to reduce the solvent content of commercially acceptable coatings. It was recognized that objectionable odors were released from some paints and coatings. Further, air emissions resulting from the evaporation of solvents during high-temperature processing of oils and resins caused occasional complaints from persons living near the coatings plant. The prevailing view of this period was summarized by Francis Scofield in his article in the 13th edition of the Paint Testing Manual entitled “Atmospheric Pollutants” . These “nuisance” types of pollution are a continuing problem but, in general, can be dealt with by dilution and dispersion of the objectionable materials to bring the concentration below a level that can be detected by the neighboring citizenry. Fortunately, most of the materials used by the paint industry are not toxic at concentrations significantly below the range at which they can be detected by the human nose, and sophisticated analytical procedures are rarely needed to deal with these “nuisance” problems. Since the 1960s, societal concern about health and the environment has increased appreciably. Actions taken by federal and state legislative bodies have resulted in a steady avalanche of new laws and associated regulations that affect virtually all of the chemical industry. Some of the federal laws administered by the U.S. Environmental Protection Agency (EPA) that impact the coatings industry are shown in Table 1. They are designed to control the emission of pollutants to air, to water, and to soil. In addition, among the new federal standards administered by the Occupational Safety and Health Administration are those that require manufacturers—including those making paints and coatings—to evaluate the hazards of products they make and to provide appropriate safety information to employees and users through the Material Safety Data Sheet (MSDS) and product labels: • Hazard Communication Standard (HCS), 1983 • Occupational Exposure to Hazardous Chemicals in Laboratories, 1990 The discussion in this section will focus on the Clean Air Act and its amendments that, in the authors' opinions, have had (and will continue to have) the greatest impact on coatings. However, it should be noted that regulatory activities in specific regions of the United States (for example, the state of California and the Ozone Transportation Commission—that includes 12 states in the U.S. Northeast plus the District of Columbia) have resulted in the development of VOC emissions rulings (see section on “Other Important U.S. Regulatory Activities”), which are more stringent than those enacted through EPA. In addition, other regions of the world are developing or have already enacted regulations addressing the emissions of volatile organic compounds.