Paints typically make up 80 per cent of a building’s surfaces, but the tins of pigment, resin, solvent and additives that help form the bare bones of design can have adverse environmental and health effects.
Possibly the most harmful chemical found in paints are Volatile Organic Compounds (VOCs) – carbon-containing solvents that vaporise into the air readily as paint dries.
These VOCs are emitted or ‘off-gassed’ into living spaces and the atmosphere up to five years after the paint has been applied, causing problems for indoor air quality and leading to health issues such as asthma, headaches, nausea and even cancer.
The rise in energy efficient, well-sealed buildings has compounded these problems, as VOCs are accumulated within buildings with no way of escape.
“There are studies that show that you get 70 per cent of the toxins that you absorb into your body through the air you breathe inside buildings,” says Stuart McPhee, ecolour’s national sales manager.
“Eight per cent comes from the food and water we eat and drink, but it is the air that we breathe inside buildings that is doing the most damage to us, and paint is the biggest contributor.”
Some VOCs also form ground level ozone by releasing odoriferous chemicals that lead to ‘urban smog’. This has negative impacts on the environment, with the paint industry responsible for up to 16 per cent of all VOC emissions in Australia.
Resene Zylone Sheen VOC Free paints were used at the GHD office fitout in Newcastle, NSW
So why are paints still being produced with high VOC levels?
According to Taubmans’ senior business development manager, Mark Lynch, there are two main types of VOCs in paint, utilised because they help paints to perform well. The first is coalescent, which is the ‘cross-linkage’ between the polymers that allows the paint to become a complete film. The second is propylene glycol.
“Generally speaking, propylene glycol is considered the bad VOC, but it is what helps the paint to maintain its wet edge. What this means is that when an applicator is putting paint on the wall, it prevents the paint from drying too quickly, which can result in an inferior finish,” explains Lynch.
Completely getting rid of propylene glycol is therefore easier said than done, especially in Australia where climatic conditions are a lot warmer than parts of Europe or North America. A paint product without these VOCs must be able to work in Melbourne in the winter, but also Darwin in the middle of summer, when paints with a wetter edge will be necessary to ensure desirable results.
VOC levels in Australia
There are numerous bodies in Australia that determine the usage of products by VOC levels, with the Australian Paint Manufacturer’s Federation (APMF) and the Green Building Council of Australia (GBCA) being two key organisations.
Working with the CSIRO, APMF developed the Australian Paint Approval Scheme (APAS), which uses a unique averaging and maximum system to set limits for VOC content in high volume architectural products. This system is expected to give paint manufacturers formulating flexibility whilst delivering reductions in the overall VOCs escaping to the atmosphere.
The $2 billion Fiona Stanley Hospital in WA by Hames Sharley, STH and Hassell utilised Taubmans’s low VOC Pure Performance Range
The GBCA also encourages the use of low or zero VOC paints via their Green Star credit rating system. Under this tool, credit points are awarded to projects that utilise low VOC certified products. For instance, under the Green Star – Office Interiors v1.1 benchmark, points are gained if 95 per cent of all painted surfaces in a project use low-VOC paints, or if no paint is used.
Driven by greater awareness of the need to reduce VOC emissions, these shifts have led low VOC paints to become the standard specification by architects in the last five years. These products contain less VOCs or VOC solvents than traditional coatings, but also offer faster drying times, low odour and non-yellowing properties.
The growing demand for low VOC paints is reflected in the increasing number of such products on the market. According to Lynch, solvent-based paints currently make up less than five per cent of Taubmans’ products – not a difficult decision to make for the company as sales for water-based paints increasingly outweigh solvent-based ones.
The APMF website also states that the volume of water-based retail architectural coatings produced in 2008 was approximately 12 times that of solvent-based finishes. The introduction of new products such as semi-gloss water-based enamels means that this gap would have since widened.
However, ecolour’s McPhee stresses that zero VOC is better than low VOC.
“Architects are looking for better options because they find that low VOC paints are a bit like menthol cigarettes,” he says. “Menthol cigarettes are better for you for sure, but now we look back at them and think what fools we were for thinking we could keep on smoking and everything will be fine. It’s the same situation with VOCs and paint.”
Australian eco-friendly commercial and residential painting company, Mr Green Stuff, agrees, stating on their website: “when you choose low VOC paint over no VOC paint (that offers the same job quality) you’re basically saying, ‘Hey, a few toxins won’t hurt me’.”
Conybeare Morrison specified Porter’s Mineral Paint for the exteriors of Aspinall House, Scots College, because of its low VOC properties, durability and flat colour, which looks good on heritage buildings
Do low/zero VOC paints have worse performance characteristics than solvent-based paints?
Of course, whether these low and zero VOC paints are as effective as traditional options is another question altogether. After all, removing VOC solvents does require a complete reformulation of the coating.
“When a low VOC product is produced, technology outside the solvents components need to ‘work harder’ to ensure that the application characteristics meet consumer needs,” Dulux trade’s marketing manager Steve Barnard explains.
“Typically if solvent is reduced in a paint product the application characteristics are impacted, making them harder to apply. Other characteristics such as hardness of finish and gloss level can also be impacted.”
He uses the example of a traditionally high VOC product which has been made available in lower VOC versions – the gloss or semi-gloss products frequently used on doors, windows and trims. Because they contain such high levels of VOC, approximately 450 grams per litre, they have great application characteristics with excellent flow, and leave little or no brush marks if applied correctly. They also dry to a very hard film.
Yet, as with most products today, new technology and innovation have allowed paint manufacturers to develop low and zero VOC paints that are comparable to their solvent-based counterparts, with many making great inroads in the last decade.
Taubmans’ head of trade marketing, Trevor Lowder, admits that the ‘Holy Grail’ is to achieve zero or low VOC content without sacrificing on paint performance or government and third-party regulations – a goal that is challenging but not impossible.