VOCs?

VOCs are volatile organic compounds -- chemicals that evaporate easily and get into the air. Acetone, methane, toluene are examples of VOCs. VOCs aren't very good for the environment because they contribute to global warming.

What do VOCs have to do with paint?

Paint is made up of pigment (the color), and a binder that holds the pigment on the surface you're painting. You want the paint to be solid; however, you can't apply it as a solid. The answer is to disperse the pigment and the binders in a solvent. This makes the solid pigment and binder into a liquid, just as dissolving cocoa mix into water or milk turns the granular cocoa powder into liquid cocoa.

The purpose of the solvent in paints is to evaporate and allow the solid pigment and binder to bond to the surface. Latex paints use mostly water (although they do have some VOCs), which is why they take a long time to dry. Acrylic-urethane paints, like those used on cars, aren't soluble in water, so you have to use other types of solvents. Most of the solvents that dissolve these types of paints contain VOCs.

You can usually identify VOCs right away: volatile means that the molecules evaporate easily, so when you open a container with a VOC in it, you usually smell the VOC pretty quickly. The VOCs are what you smell in spray paint, for example.

The Solution

Scientists use chemistry to make solvents that are more environmentally friendly, but that still dissolve the pigment and binders. Dupont's Cromax^® Pro paint, which has been featured on the No. 24 car, is one example. This video feature from the American Institute of Physics shows how Benjamin Moore scientists use polymers to create low- or no-VOC latex paints. The lack of VOCs means that you don't get that characteristic paint smell when you open the can, or while the paint is drying.