Veterinary facilities use paint mainly for "architectural coating," i.e., painting interior and exterior walls, floors, trim, etc. to prevent corrosion, improve wearability and scrubability, and enhance appearance. This section identifies environmental and safety issues related to painting, and explains the regulations affecting architectural paints. You will also find information on selecting "environmentally friendly" paints, on best management practices for paint use and cleanup, on paint recycling, and on issues involving lead paint and aerosol spray paint.
Health and Environmental Issues
Paint is composed of four basic types of materials:
- solvent -- The liquid that carries the solid components of paint. It must be present to allow the paint to be of 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 is one of the most important components of paint. It is the basic solid film former that remains after the solvent has evaporated and which binds the pigment particles together into a cohesive paint film.
- pigment -- This is the component that gives paint its other most important properties of color and opacity. The pigments used in paint are normally present as fine solid particles that are dispersed, but not soluble, in the binder and solvent.
- additives -- Additives are the specialist components of paint. They are used in small quantities to improve production and storage properties of the liquid paint product as well as application and other performance properties of the paint film (e.g., anti-marring agents, anti-mold agents).
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, alcohols, ketones, esters, glycol ethers) 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, sometimes referred to as latex paints, are an alternative to solvent-based paints. The volatile organic compound (VOC) content of water-based paints is significantly lower than conventional solvent-based paints, thereby reducing VOC emissions.
Architectural paint is a product that is used in and on buildings everywhere. Paint serves important functional and aesthetic purposes, but it also 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 of the elements in paint, 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 paint, 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 participate in the formation of ozone. In the presence of nitrogen oxides (NOx) and sunlight, VOCs react with oxygen in the air to produce ozone, the most toxic component of the form of pollution commonly known as smog. Ozone attacks lung tissue, and is very injurious, even in very low concentrations. To prevent the formation 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.
VOCs. With millions gallons of architectural paint being applied at millions of locations each year, it would be impossible for EPA or state environmental agencies to permit or monitor each one. Therefore, the approach taken by EPA to limit VOC emissions from architectural painting operations is to control what goes into the product, rather than to try to control the user. The resulting rules effectively force paint makers to minimize the use of volatile organic compounds (VOCs) in their products. The rules also limit the use of certain particularly hazardous materials, designated "hazardous air pollutants", or HAPs. In addition, certain kinds of solvents known as "ozone depleting substances", or (ODSs) are also strictly regulated. (Ironically, the problem with ODSs is that they destroy ozone, as opposed to VOCs, which create it. However, 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.
In the regulations, EPA has defined VOC very broadly. In effect, any volatile compound of carbon is classified as a VOC for regulatory purposes, unless specifically "exempted". EPA uses is 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.
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 but it 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 and these include acetone, methyl acetate, PCBTF (Oxsol 100), and volatile methyl siloxanes.
The federal rules do not regulate the users of architectural paints, such as healthcare facilities, 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.
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
All paints need to perform well, both during and after application. The paint should flow and level well, cover in one coat, and dry in a reasonable amount of time. When the job is complete, the coating should be easy to maintain and able to withstand the elements. If the paint selected does not perform well, and fails to meet performance expectations, then the area will likely need to be repainted sooner than otherwise. In addition to the obvious financial costs, this rework creates excess environmental and health impacts because of the additional resource use and chemical releases into the environment.
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 actually to determine whether it is 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 needed to cover the areas to be painted, and purchase only the amount you will use for the project. Excess paint can become unusable if it is not stored properly or if the color is not acceptable for subsequent painting needs. Paints are often sold by the gallon. Most paints cover about 400 square feet per gallon, depending upon the product and application method. So use these factors to determine how much paint you will need for the area being painted.
- 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 very volatile solvents as carriers, in order to impart suitable application and drying characteristics to the products. Furthermore, alkyd paints require additional harmful solvents for cleaning up after the job is complete. Note that 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. According to the Green Seal standard for paints, there are various compounds used in paint that should be restricted from the paint you select. These substances 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, improved matching systems for 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
The BMPs listed below will help reduce or eliminate pollution that could otherwise be generated from painting operations.
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. The wastewater must be collected, and may be discharged to the sanitary sewer if the building exterior paint does not contain lead or mercury (after 1978, lead was phased out of most architectural paints). If paint containing lead or mercury was used, contact your state environmental agency for information about the appropriate disposal options before beginning work.
- If grinding or blasting is used 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 a hazardous waste.
- 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.
- Paintbrushes and containers may never be cleaned or rinsed into a street, gutter, creek, 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" towards the street, gutter, or catch basin.
Recycling/Disposal of Residuals
- Properly store leftover paint. Even when you attempt to estimate your needs, there may be paint remaining. If there is enough paint for a smaller job or to save for future touch-ups, close the can tightly to prevent it from drying out. To indicate the color inside, write the location that the color was used or put a dot of paint on the lid of the can. In colder regions, another storage consideration is that latex paints may freeze below a certain temperature.
- 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.
There are two types of recycled paint available in the marketplace:
- reblended (also known as consolidated)
Each of these originates 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.
Over 15 states have paint reblending programs, which are often initiated by environment 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 whereby the collected paint is re-mixed, screened and packaged for distribution. Reblended paint contains 100 percent post consumer 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), light and dark colors, 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 has been banned since 1978, but many older structures still have this paint on walls, woodwork, siding, windows, and doors. Construction and demolition (C&D) workers can be exposed to lead contamination by cutting, scraping, sanding, heating, burning, or blasting lead-based paint from building components, metal bridges and metal storage tanks. In addition to exposure to workers, lead-based paint debris or dust can also make its way into soil, potentially contaminating surface waters. Lead poisoning is a serious health threat for adults and is especially damaging to young children.
Lead-based paint waste (e.g., paint chips, dust, and sludges) from removal or remediation activities and C&D debris from commercial sites that is 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, veterinary 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. There are 12 states (AL, AK, FL, ID, MT, NM, NY, NV, SC, SD, WA, and WY) that are not operating 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 gasses (CFCs) were originally used as propellants, but were banned from use in 1978 when it was discovered that they deplete the ozone layer. Other gasses like butane and propane were used as replacements for CFCs. These hydrocarbons propellants were used as primary propellants until the 1980's when it was determined that these chemicals contribute to smog. Subsequently, regulations were passed that limited the amount that could be used in spray paint. To solve these problems, a new class of propellants known as hydrofluorocarbons (HFCs) where developed for use in aerosols. 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 all the health and environmental risks and impacts previously discussed. In addition, empty aerosol paint cans with residual amounts of material are typically classified as "hazardous waste" by virtue of their flammable contents and therefore will add to the quantity of hazardous waste disposed of by your facility. Unfortunately, the only way to remove the material causing the aerosol can to be hazardous is to relieve the residual pressure they contain by puncturing them. 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.
Recycled-Content Latex Paint (GS-43). This environmental standard contains the basic requirements for Recycled-Content Latex Paint (as defined in the Scope section) to be certified by Green Seal. Green Seal is a non-profit 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.