The use of heavy metals in paint has raised concerns because of their toxicity at high levels of exposure and because they accumulate in the food chain.
Another harmful material that can be found in paint is lead. Lead is typically added to paint to speed drying, increase durability, maintain a fresh appearance, and resist moisture that causes corrosion. Paint with significant lead content is still used in industry and the military. For example, lead paint is sometimes used to paint roads and parking lines. Lead, a poisonous metal, can damage nerve connections (especially in young children) and cause blood and brain disorders. Due to the low reactivity and solubility of lead, lead poisoning generally only occurs in cases where it is dispersed, such as when lead-based paint is sanded before repainting.
Hexavalent chromium-containing primer paint is still widely used for aerospace and automotive refinish applications. Zinc chromate has been used as a pigment for artists’ paint, known as zinc yellow or yellow 36. It is very toxic and fortunately is now rarely used.
Antifouling paint (or bottom paint) is used to protect ship hulls from fouling by marine organisms. The antifouling paint protects the surface from corrosion and prevents any build-up of marine organisms from dragging onto the boat. These paints have contained organotin compounds such as tributyltin, which are considered toxic chemicals with negative effects on humans and the environment. Tributyltin compounds are moderate to high persistence organic pollutants that bioconcentrate in the food chain of marine predators. A common example is the leaching of marine paints into the aquatic environment, causing irreversible damage to aquatic life. Tributyltin has also been linked to obesity in humans, as it triggers genes that cause fat cells to grow.
The label on an oil-based paint will say “oil-based” or “alkyd,” or it will instruct you to clean brushes with mineral spirits or turpentine. Paints of this type are toxic and can cause great harm to the environment (including humans and animals) if not disposed of properly.
Latex or water-based paint, on the other hand, is not considered a hazardous waste and can enjoy many reincarnations after its initial use. Latex paints are those that clean with soap and water. They are very common for both interior and exterior painting. However, even this type of panit must be disposed of or recycled properly. Specifically, pouring latex paint down drains, onto the ground, or into streams, creeks, or rivers is not recommended. Disposing of paint in this way introduces contaminants into the air, soil, and groundwater that can eventually make their way up the food chain.
When considering how to dispose of large amounts of unused paint, always seek professional advice. Any reputable hazardous waste disposal service will be able to help you.
Here are some steps you can take to reduce the environmental impact of using paint.
1. Choose a low VOC paint if possible
Volatile Organic Compounds (VOCs) are gases emitted by various solids or liquids, many of which have short- and long-term adverse health effects. Solvents in traditional paints often contain large amounts of VOCs. Low VOC paints can improve indoor air quality and reduce urban smog. The beneficial characteristics of such paints include low odor, clean air, and safer technology, as well as excellent durability and a washable finish. Low VOC types of paint include latex (water-based), recycled latex (water-based), acrylic, and milk-based paint.
Labels on paint cans can be checked for the following information:
To be considered low VOC, the paint must contain <50 g / l VOC.
To be considered VOC free, paint must contain <5 g / l VOC.
Solids content typically ranges from 25-45%, higher solids percentages indicate less VOC
2. Avoid buying excess paint
Every year 10 per cent of the paint sold in the UK is thrown away simply because too much has been bought for each project. You can avoid that mistake by using a paint calculator or to help you determine how much paint your project actually needs.
3. Reuse your paint
If stored properly, the paint will last for years. To store it properly you must
– Cover the opening of the paint can with plastic wrap.
– Put the cap on securely and make sure it does not leak.
– Turn the can upside down to allow the paint to create its own stamp.
– Store the can upside down in a place safe from freezing and out of the reach of children and pets.
4. Recycle your unused paint
The best way to handle leftover paint (after avoiding overselling) is to find someone else who can reuse your leftovers. Try to be imaginative – local councils, schools, universities, and art academies may all be happy to use some of your old paint for their projects.
Unused paint can also be recycled to make low-quality paint. Latex sludge can be recovered and used as fillers in other industrial products. Waste solvents can be recovered and used as fuels for other industries. A clean paint container can be reused or sent to the local landfill.
If your large amount of paint cannot be reused or recycled, then it is a good idea to call in a professional chemical waste disposal service.