What’s That You Don’t Smell? Paint

Until recently, a strong odor in latex paint was like a lot of things in life--it was unpleasant, but you put up with it to get the job done.

The primary odor-causing agent in latex paint is solvent, but things are changing. Today, you can buy low-odor interior latex paint that is essentially solvent-free, and industry experts say that low-odor exterior paints should debut in the near future. Certainly, this is a boon to painters everywhere who are sensitive to chemical odors. The problem is telling the difference between paints that are nominally low-odor because they meet federal specifications for solvent content and new varieties of paint that are formulated to have almost no solvent.

A can of high-quality latex paint contains a 20% binder by volume. In traditional latex paint, there is 1% to 7% solvent dissolved into the binder. New low-odor varieties of latex paint are essentially solvent-free, though they contain about the same amount of binder.

In traditional latex paint, globs of binder and particles of pigment are suspended in water. As the paint dries, the water evaporates and the solvent-softened binder globs become oval-shaped. When the water has completely evaporated, the globs of binder are coalesced and the remaining solvent evaporates. Solvent-free latex has soft binders. They coalesce without solvent.

Both types of paint form a high-quality, long-lasting film, but the solvent-free variety is good to know about if you’re chemically sensitive.

Paint manufacturers make a point of stressing that their products meet or exceed federal standards for volatile organic compounds (VOCs). Most high-quality latex paints meet this requirement. Hence, they are “low odor” or “low VOC” by nature. But this does not mean they are solvent-free or as close to it as possible.