Paint is something we all have to live with, because it's on the walls of just about every structure we have an occasion to venture into nowadays. Paint is made of three basic types of ingredients: binders, solvents, and pigments. Pigments are the chemicals that give the paint color. Binders are chemical elements that bind or glue the pigments to the surface, and solvents are liquids that thin the binders so that they, along with the pigments, can be applied to the surface.
The paint dries and becomes a permanent coating on the surface when the solvent evaporates. In the past, the best type of paint used oil or oil-compatible alkyd compounds as a binder. This made the most durable and colorful paint that could be commercially produced. The problem with oil paint was, and still is, that the solvents needed to mix with the oil and then evaporate so that the paint will dry give off very toxic fumes as they evaporate. These oil based paint solvents in the technical jargon belong to a class of materials known as Volatile Organic Compounds, or VOCs. There are all kinds of other chemicals in paint such as drying agents, pigment suspension agents, gloss agents, chemicals to help the paint stay level and not form drips and runs, etc., and some of these chemicals are also VOCs.
In the recent past, it became evident that a lot of the paint that people were using was emitting poisonous fumes for as much as several years after the paint was applied. This was not long after the time that Americans discovered that lead in paint was poisoning and leading to serious mental disabilities in our children.
The paint companies, not wanting to have a repeat of the bad publicity and courtroom expense that was the result of the lead paint debacle, started to develop safer alternatives. Latex paint, which had been developed because it was a much cheaper (but inferior) way to get pigment on the interior walls of houses, was made the subject of intense R&D. Latex/acrylic and vinyl/acrylic blends and acrylic enamel paints were formulated which eventually had all of the qualities of the best oil based paints, but were water based, and therefore had little or no VOCs evaporating out as they dried. The industry set up its own certification for low VOC paints, known as the "Green Seal". The Environmental Protection Agency also got into the act and set up parameters for how VOC levels were to be determined. Paint with VOCs below 5 grams/liter can legally be called "Zero VOC", Green Seal designated paints must have VOC contents below 100g/L for gloss or semi-gloss finish and 50 g/L for flat finish.
Because many municipalities have outlawed high VOC paints, and because of consumer demand, most paint manufacturers now produce a low VOC line of paints, and some of the biggest have given up manufacturing high VOC paints at all. This is really good news - something that American industry is doing right.