Paints

Paint is composed of four basic materials:

• solvent – The liquid that carries the solid components of paint, providing the correct consistency for application by brush, roller, spray or dipping. The most common solvents used in architectural paints are water and organic solvents.
• binder – The binder or resin forms the solid film that remains after the solvent has evaporated, binding the pigment particles together.
• pigment – This component gives paint color and opacity. Pigments are normally present as fine solid particles dispersed in the binder and solvent.
• additives – Additivies improve paint’s production, storage, application, and other performance properties.

Conventional paints are generally classified into two categories:

• oil-based – In oil-based paints (e.g., alkyd) the carrier is a solvent (linseed oil, petroleum distillate, alcohol, ketone, ester, glycol ether) consisting of volatile organic compounds (VOCs.). VOCs are emitted during application of the coating and as the coating dries. VOCs reacts with sunlight to contribute to smog.
• water-based – Water-based paints (e.g., latex paints) are an alternative to oil-based paints. The volatile organic compound (VOC) content of water-based paints is significantly lower than conventional solvent-based paints, thereby reducing VOC emissions.

Paint has the potential to cause both health and environmental impacts. Low-level exposure to paint may irritate or burn the eyes, nose, throat, and skin and cause reactions such as headaches, dizziness, or nausea. These symptoms are generally mild and will subside once the immediate exposure has ceased. However, high levels of exposure to some paint components, even for a short period of time, can cause severe and lasting impacts such as kidney or liver damage, or respiratory problems. Substances found in some oil-based paints, such as formaldehyde and benzene, are carcinogenic, while others, such as heavy metals and phthalates, are human and ecosystem toxins.

By far, the most important environmental impact from paints is the release of volatile organic compounds (VOCs) during the drying process after the coating is applied. Virtually everything but the solids in a typical paint formulation is released to the air.

Once in the atmosphere, VOCs react with oxygen to produce ozone, the most toxic component of smog. Ozone attacks lung tissue and is injurious even in very low concentrations. To prevent the formation of excessive levels of ozone, the VOC content of paint and its conditions of use are subject to regulation by federal, state, and local environmental agencies.

Regulations

Federal rules do not regulate the users of architectural paints, but some states have taken up that role. For example, New York regulations extend to painting and thinning practices:

• Any person who applies architectural coatings shall ensure that all containers used to apply the contents therein to a surface directly from the container by pouring, siphoning brushing or rolling, padding, ragging or other means, shall be closed when not in use. Containers of any VOC-containing materials used for thinning and cleanup shall also be closed when not in use.
• No person who applies or solicits the application of any architectural coating shall apply a coating that is thinned to exceed the applicable VOC limit specified in subdivision (a) of this section.

Check with your state air regulatory agency for additional state rules that may apply.

VOCs

To comply with EPA regulations, paint makers minimize the use of VOCs, cetain “hazardous air pollutants” (HAPs) and certain solvents known as “ozone depleting substances,” or ODSs. (ODSs destroy ozone, as opposed to VOCs, which create it. The difference is that ODSs are long-lived compounds that gradually diffuse into the stratosphere, many miles above the earth, where most of their ozone-destroying action occurs. While it is a health hazard at ground level, ozone in the stratosphere serves a function essential to human health, by blocking out the most harmful ultraviolet rays in sunlight. The use of ODSs is limited in order to protect stratospheric ozone.)

The National Volatile Organic Compound Emission Standards for Architectural Coatings Rules were finalized in 1998. The requirements established a VOC content limit for each of 61 categories of architectural coatings. These limits apply to the VOC content that would result after thinning a coating according to the manufacturer’s maximum thinning recommendations. The requirements were based on demonstrated technologies; many coatings on the market already met the limits in the rule. All states have adopted regulations at least as stringent as the federal rules. Some states, such as California, have enacted even more stringent standards.

EPA regulations define VOC very broadly. In effect, any volatile compound of carbon is classified as a VOC, unless specifically “exempted”. EPA uses a specific test method, known as Test Method 24, which determines what is to be treated as a VOC. Individual states may have their own VOC definitions, including their own list of exemptions. Although state definitions (including exemptions) are generally the same as the EPA definition, a solvent user should be aware of the precise definition that applies in his or her state.

Exempt Solvents

An exempt solvent is a volatile organic compound that does not participate in an atmospheric photochemical reaction to form smog. It can be an organic solvent that takes so long to react with nitrogen oxides (NOx) in the presence of sunlight that the EPA considers its reactivity to be negligible. Only a handful of exempt solvents are approved for use in paints and coatings; these include acetone, methyl acetate, PCBTF (Oxsol 100), and volatile methyl siloxanes.

Hazardous Materials and Wastes

Waste from solvent-based coatings is typically hazardous, and its management is regulated by the Resource Conservation and Recovery Act (RCRA), 40 CFR 260-265. In addition, storage requirements from OSHA may apply if coatings are flammable liquids (29 CFR 1910).

Selecting a Paint

There are many products on the market that can meet both environmental and performance goals, so you can often select one that has less environmental impact without sacrificing quality or price. Depending upon the type of paint you select, you can improve the appearance of your building while protecting human and ecological health. Here are some guidelines to help you do that:

• Does it really need painting? The first step is to determine whether it is actually necessary to paint the area. If the repainting job is specified as part of a periodic maintenance schedule, make sure that the area is truly in need of paint before proceeding. It may be possible to postpone the project if the existing coating is intact and the area simply needs to be cleaned rather than repainted.
• Purchase only what you need for the job at hand. Once you have decided that the area needs to be painted, calculate the quantity of paint required and purchase only the amount you will use for the project. Most paints cover about 400 square feet per gallon, depending upon the product and application method. Excess paint can become unusable if it is not stored properly or if the color is not acceptable for subsequent painting needs.
• Work with water. Latex paints are environmentally preferable to alkyd paints because they use a benign solvent, water, as a carrier. Alkyd paints, on the other hand, generally utilize volatile solvents, and require additional harmful solvents for cleaning up after the job is complete. Technological advances have enabled latex paints to meet or exceed the performance of oil-based paints for most applications.
• Choose paints without heavy metals or toxic ingredients. The label on the outside of the can may indicate the presence of harmful constituents inside. A low VOC level is not the only criterion to use in paint selection. The Green Seal standard for paints prohibits various compounds that can be replaced by less harmful ingredients without a loss of desired attributes or quality. Specific ingredients may not appear on the label, but you could review the product’s material-safety data sheets for the Green Seal-prohibited ingredients.
• Consider using reblended paint. Originally available only in beige or brown, reblended paints are now found in a much wider selection of colors. Even a limited color palette may offer shades that are suitable for areas where bright colors are not desired. For example, reblended paints are well-suited to use in low-traffic areas, where color is less important.

Best Management Practices

Removing Old Paint

• Cover or berm nearby storm drain inlets when stripping or cleaning building exteriors with high-pressure water prior to painting. The wastewater must not be discharged to the storm drain system. It must be collected, and may be discharged to the sanitary sewer if the building exterior paint does not contain lead or mercury. (Lead was eliminated from most architectural paints after 1978.) If paint containing lead or mercury was used, contact your state environmental agency for information about the appropriate disposal options before beginning work.
• When grinding or blasting to remove old paint, protect nearby storm drain inlets with a protective cover such as a heavy rubber mat. Paint dust, particles, and other debris must be completely cleaned up, preferably by sweeping, after the job is done.
• Non-hazardous paint chips and dust from dry stripping and sand blasting may be swept up or collected and disposed of as trash. Chemical paint stripping residue, and chips and dust containing lead or tributyl tin, must be disposed of as hazardous waste.

Painting

• Paint and paint thinner may never be discharged into the storm drain system. In addition, wastewater or runoff containing paint or paint thinner may never be discharged into a storm drain. When there is a risk of a spill reaching the storm drain, nearby storm drain inlets must be protected prior to starting painting.
• Clean up spills immediately.
• Keep paint containers closed when not in use.

Cleanup

• Paintbrushes and containers may never be cleaned or rinsed into a street, gutter, stream, body of water, or storm drain.
• When cleaning brushes and rollers after painting, brush out excess paint onto newspaper or cardboard. If using latex paints, the brush or roller may then be rinsed in a sink that is plumbed to the sanitary sewer. If using oil-based paints, the brush or roller needs to be cleaned with paint thinner which cannot be discharged to the sanitary sewer. Paint thinners must be disposed of as hazardous waste.
• Leftover paint in the roller pan should be drained back into the paint can. If using paint hoses and guns, spray out the paint residue into the paint can.
• When the job is completed, collect all unused or waste materials and dispose of properly. Never leave or abandon materials onsite, and ensure that nothing has “drifted” toward the street, gutter, or catch basin.

Recycling/Disposal

• Properly store leftover paint. If there is enough paint left for a smaller job or to save for future touch-ups, close the can tightly to prevent drying out. To indicate the color inside, write the location where the color was used, or put a dot of paint on the lid of the can. In colder regions, remember that latex paints may freeze.
• Recycle, return to supplier, or donate unwanted water-based (latex) paint. Dried latex paint and empty paint cans may be disposed of in the garbage.
• Leftover oil-based paint may be recycled or disposed of as hazardous waste. Paint thinners must be disposed of as hazardous waste.

Recycled Paint

There are two types of recycled paint available in the marketplace:

• reblended (also known as consolidated)
• reprocessed

Each of these originate from post-consumer latex paint collected through public and private paint programs. As the volume of leftover paint collected by public and private sectors increases, more government programs and paint manufacturers are becoming involved in paint recycling. Also, Federal procurement guidelines under the Resource Conservation and Recovery Act require the purchase of recycled-content latex paint where possible, which may provide impetus for increased entry into this market.

Reblended or consolidated paint consists of postconsumer latex paint with similar characteristics (e.g., type, color family, and finish) that is consolidated at the point of collection. Consolidated paint is typically used for exterior applications or as an undercoat.

More than 15 states have paint reblending programs, often initiated by environmental or waste management departments. Paint collected in these programs is combined and sold, often at lower prices than non-recycled paints. Some of these programs collaborate with paint manufacturers to process and package paint. Reblended paint contains 100 percent postconsumer content with no virgin materials such as resins and colorants added, and paints are not tested to specifications.

Reprocessed paint is postconsumer latex paint that has been sorted by a variety of characteristics including type (i.e., interior or exterior), color and finish (e.g., high-gloss versus flat). Reprocessed paint is available in various colors and is suitable for both interior and exterior applications.

Lead-Based Paint

Lead poisoning is a serious health threat for adults and is especially damaging to young children. Lead-based paint has been banned since 1978, but persists in many older structures. Construction and demolition (C&D) workers can be exposed to lead contamination by cutting, scraping, sanding, heating, burning, or blasting lead-based paint from buildings, bridges, and storage tanks. Lead-based paint debris or dust can make its way into soil, potentially contaminating surface waters.

Lead-based paint waste from removal or remediation activities (e.g., paint chips, dust, and sludges) and C&D debris contaminated with lead-based paint must be managed as RCRA hazardous waste if a representative sample meets the toxicity characteristic (D008). When encountering lead-based paint waste or C&D debris that is contaminated with lead-based paint, health care facilities and/or their contractors are urged to contact their state authority to determine which rules apply.

Most states operate training and certification programs for lead-based paint activities in target housing and child-occupied facilities. Only 12 states (AL, AK, FL, ID, MT, NM, NY, NV, SC, SD, WA, and WY) do not operate their own authorized lead training program for target housing and child-occupied facilities. For these states, EPA operates a Federal training and certification program. In many states, the rules for training and certification extend to certain construction activities, such as those associated with commercial buildings or residential housing. Check out the rules in your state before engaging in lead-based paint activities.

Aerosol Paint Cans

Aerosol-can spray paint is often used for small jobs and touch-up painting. In addition to the four basic paint ingredients, aerosol sprays also contain propellants. Propellants are gasses that force the paint out of the can by expanding rapidly when the valve is opened. Chlorofluorocarbon gases (CFCs) were originally used as propellants, but were banned from use in 1978 when it was discovered that they deplete the ozone layer. Hydrocarbon propellants replaced CFCs and were in use until the 1980s, when it was determined that they contribute to smog. Subsequent regulations limited the amount of hydrocarbon propellant that could be used in spray paint. A new class of propellants known as hydrofluorocarbons (HFCs) weere developed for aerosol use. These include and 1,1,-difluoroethane (Propellant 152A) and 1, 1, 1, 2,-tetrafluoromethane (Propellant 134A).

Aerosol spray paint is solvent-based, and therefore comes with health and environmental risks. Used aerosol paint cans containing residual amounts of material are typically classified as hazardous waste. Unfortunately, the only way to remove the flammable materials that cause aerosol cans to be hazardous is to relieve residual pressure by puncturing the cans. This violates the safety precautions on most cans, and will add to air emissions. Unless you have a puncturing device and personnel trained to use it, do not puncture aerosol containers.

More Resources

Recycled-Content Latex Paint (GS-43). This details the requirements recycled-content latex paint must meet to be certified by Green Seal, the nonprofit organization devoted to environmental standard setting, product certification, and public education. Green Seal’s mission is to work towards environmental sustainability by identifying and promoting environmentally responsible products, purchasing, and production.

Green Seal Certified Paints and Coatings. This list includes manufacturers and product names of certified Green Seal Paints and Coatings.

Choose Green Report. Choosing architectural paint is no longer simply a matter of functionality and aesthetics. Increasingly, managers and procurement professionals must consider the environmental impact and health effects of the paint they select. This report presents criteria for environmentally preferable brands of interior and exterior paint, and lists 96 products from 17 manufacturers. It offers a concise breakdown of paint components and details how each affects overall performance. This information is followed by helpful tips for selecting the appropriate paint. Also includes a discussion of recycled paint.