Paints and coatings are applied as a fluid, and they dry or cure in place. During that process a carrier evaporates, leaving the active agents in place. For most products this carrier was traditionally a volatile organic solvent that turned into an airborne volatile organic compound (VOC) as it evaporated. As with caulks and adhesives, air quality regulations and health concerns have driven a shift toward waterborne products. Evaporating water isn’t a health concern, though other components of the coating or adhesive still generally release some VOCs.
Paints and coatings have their greatest effect on indoor air quality during and immediately after installation. The health hazard is particularly acute for installers. Most conventional products off-gas VOCs, and other chemicals that are added to enhance the performance or extend shelf life of the product. Little scientific data is available on the health effects of many of these chemicals—and even less on the effects of exposure to a combination of such chemicals that may occur in buildings. Quality substitutions, which are lower in toxicity or nontoxic, are available for all of these products.