Safe use, strorage and disposal of paint

Paint is a common product we all have in our homes that can become a household hazardous waste when it is not properly stored or disposed.

The following information will help you make decisions on how to avoid health and environmental hazards from using, storing and disposing of paint.

Composition of paints and their hazards

Most paint has four components: resin, solvent, pigment and additives. To determine the hazardous ingredients of paint, request a Material Safety Data Sheet from the retailer when you buy it.

The resin is the main ingredient and forms a coating or film on the surface being painted. This typically non-hazardous component includes linseed, acrylic or other synthetic resins.

The solvent keeps the paint in a liquid form until the solvent evaporates after the paint is applied. The solvent in oil-based paint is derived from a petroleum distillate and can include such hazardous ingredients as mineral spirits, toluene and xylene. The solvent in latex paint is water.

Pigments provide the color and opacity or covering power. The major pigments used presently are titanium oxide, iron oxide, calcium sulfate, clay or silicates. These pigments are relatively nontoxic. Some highly colored pigments may contain heavy metals such as chromium, cadmium or arsenic.

Paints purchased before 1977 may contain lead in the pigment. Lead, also a heavy metal, is poisonous. Do not use paint purchased prior to 1977. To determine if the painted surfaces in your home contain lead, contact your local health department or a lead paint removal contractor.

Paint may also have additives. Some types of additives include stabilizers that prevent paint deterioration in the can, dryers that assist in the formation of the paint coating, thickeners that aid in application, and preservatives that inhibit the growth of molds. The additives can range in composition, including both hazardous and non-hazardous ingredients.

How to determine if stored paint is usable

• If the paint will mix when stirred, it is probably usable. Oil-based paint can be usable for up to fifteen years. Latex paint is usable if it is less than ten years old and has not been repeatedly frozen and thawed.
• The best way to determine if latex paint is usable after it has been frozen is to brush the paint on newspaper. If there are lumps, the paint is not usable.

How to store paint so that it will remain usable

• Store the tightly sealed paint can upside-down, so that the paint will form a seal around the lid.
• Store paint cans in dry areas that will not freeze.
• Store paint cans away from sources of spark or flame.

What to do with usable, leftover paint

• Avoid having leftover paint by buying only the amount you need to do the job. Consult with the retailer to determine the surface area and the amount of paint needed to cover this area.
• Use up any leftover paint. Some suggested ways to do this include applying another coat to the surface until the paint is gone, painting a doghouse or other small structure, or using it as a primer coat for another project.
• If you cannot use it up, see if a friend or neighbor is willing to use it. Other groups to contact to see if they need usable latex paint include theater groups, community betterment groups, schools, daycare centers and graffiti removal projects. Before sharing usable latex paint, determine if it contains mercury. If it does, inform your recipient and suggest they use it only for exterior surfaces.
• Your community may sponsor a paint exchange for usable paint. If not, organize a paint exchange between members of local clubs, service organizations or other groups. Inform participants of the paint exchange that latex paint containing mercury should be used only on exterior surfaces. As a general rule, for paint to be usable by someone else, at least 1/3 of a gallon should remain in the original can with a legible label.

Before you hold the paint exchange, identify an organization or outlet that will accept the paint that is not taken, such as theater groups, community betterment groups or schools. For more ideas or guidelines on how to hold a paint exchange, contact the Household Hazardous Waste Project.

What to do with unusable paint

• Never put liquid paint into the trash or pour it down the drain unless instructed to do so by local waste officials. Paint disposed of this way can contaminate our water resources and the environment.
• Take the paint to your community's household hazardous waste collection. This is the best option for all unusable paint. If your community does not have a household hazardous waste collection, ask your local city, county and state officials to provide one.
• As a last resort, small amounts of paint can be solidified. If the paint is latex, you can solidify it following the instructions below, then place it in the trash destined for the landfill. Because of the increased health and safety risks involved in solidifying oil-based paints, contact your local city or county officials for other proper disposal methods