The Toxicity of Latex Paint

Paint toxicity is a concern for any household with small children because while no one would intentionally ingest paint, toddlers can do things like lick the walls or even sample fresh paint from an open can or a paintbrush. Besides that, everyone breathes fumes from freshly applied paint as it off-gasses.

Paint toxicity is difficult to measure, and no standard exists that applies to all types. It's safe to say, however, that there are fewer health risks associated with latex (water-based) paints than there are with solvent-based (oil-based or alkyd) paints. There are still some, however, depending on the formulation of the specific product.

All paints have three primary components: binders, pigments, and a solvent. While the solvent in latex paint is water, which is harmless by itself, it's usually combined with a coalescing agent, such as a glycol or glycol ether to emulsify the binder, which is either polyvinyl acetate (PVA) or acrylic polymers and copolymers. The most common pigment is white titanium dioxide, and there may be others, such as iron oxides, zinc oxide, and carbon black.

Besides the primary components, many latex formulations include additives, and the one of most concern is mercury, which is a mildewcide. The use of mercury for interior paints was banned in 1990, but it still might be found in some exterior formulations, which is a good reason not to use exterior paint indoors. Other common additives include triclosan —which replaces mercury as a mildewcide — calcium carbonate to flatten the sheen, driers to accelerate drying time, and others. Additives typically make up 5 percent of the ingredients in a can of paint.

The binders in latex paint are nontoxic, but PVA is a known skin irritant. Ethylene glycol is toxic, and ingesting it in large quantities is considered a medical emergency. You would have to drink a large quantity of fresh paint to get a toxic dose of ethylene glycol, however, and that's unlikely, even for children. It isn't present in dried paint, but you can inhale it while spreading the paint, and because of this, some people may experience mild reactions, such as dizziness, mild nausea, sore throat, and headaches.

When it comes to pigments, the one of most concern is titanium dioxide for two reasons: It's in 70 percent of latex paint products, and it's a known carcinogen. Other pigments, such as iron oxide, can also produce reactions in sensitive people when inhaled. Add to this the possible harmful effects of inhaling mildewcides, bactericides, and other additives that may be part of a specific paint formulation.

These days, most latex paints are formulated to be low in volatile organic compounds (VOCs), which usually means they contain a lower concentration of emulsifiers, like ethylene glycol, but it's virtually impossible for a paint to give off no VOCs while it's drying. They are one of many sources of indoor air pollution. You can generally avoid ill effects by wearing a respirator while painting, providing adequate ventilation, and staying out of the room you just painted until the paint finishes off-gassing, which usually takes about 24 hours.

Once the paint has dried, it poses little danger to toddlers because the harmful pigments and additives are locked into the mixture by the binder, which is inert and harmless. Children could be harmed by eating paint chips that have fallen on the ground, and anyone sanding a painted wall should wear a respirator to avoid inhaling sanding dust. However, ingesting small amounts of paint chips or sanding dust is unlikely to cause any ill effects.