Typically, this unused paint is either stored indefinitely, or ends up being poured down the drain and into waterways.
It is currently illegal for paint or wastewater attributed to painting – washing paintbrushes – to be disposed of directly into a stormwater drain or stormwater drainage network which could pollute a natural waterway.
Some companies have come up with innovative solutions to this problem.
Dulux's Waste Paint Hardener turns water-based paints and timber coatings into solid waste for easy disposal.
The product comes as a powder, which is added to the unused paint, and left for two hours. During that time, it turns into a solid, hardened product, which can be wrapped in newspaper and disposed of.
"It facilitates the opportunity for consumers to separate the paint from the container, allowing the paint to be disposed of, and the container to be put out for curbside recycling," said Steve Barnard of the Dulux Group.
There are currently no other products like this on the market.
Washing paintbrushes is another industry problem, as paintbrushes are commonly washed with a hose on-site, with contaminated water ending up in waterways. To address this, Dulux developed the EnviroWash System – a water-based paint wash and treatment system which turns dirty paint water from cleaning brushes into clean wash water.
"We are striving to increase the usage and advocacy of the system amongst all professional painters in our efforts to drive industry sustainability," Barnard said.
The WashBox also provides an environmentally friendly way of washing paintbrushes and was one of one of the first commercial products to gain Smart WaterMark approval.
Created by Sydney-based company, GeoSentinel, the product can be used on construction and industry sites where wet trades need to clean up.
Andrew Crimston, of GeoSentinel, said a WashBox can save up to 3,000 litres of water a week, as water from washing paintbrushes and other tools does not get flushed into sewers or discharged elsewhere.
How does it work? Trades people clean their tools and brushes in the WashBox. Dirty water is retained within the basin-type box and reduces fresh water use by up to 90%.
The product recycles 100% of waste, with all solid and liquid waste being removed for use as raw materials for the building industry.
The product was developed around four years ago, and has since been used on projects such as Bovis Lend Lease's Rouse Hill Town Centre, Sydney airport, and the Royal North Shore Hospital.
"We estimate that a team of ten trades people use and pollute around 150,000 litres of drinking quality water in a year, which is poorly handled and either ends up in the sewer or on the ground," Crimston said.
"It contains approximately two tonnes of paint, render and plaster solids destined for the environment. The WashBox directly solves this environmental problem."
As the property industry continues to advance in its aim of zero emission projects, products such as these will slowly but surely have a positive impact on reaching that target.
