This is guidance we give to specifiers and architects on how to choose environmentally sound performance paint. Read on to find out why:
NOTE The advice same would apply to stains, sealing/finishing oils and waxes.
- Read the ingredients, where ingredients are not published, it might be fair to assume that there is a reluctance by the manufacturer to disclose – in which case it might be wise to avoid that product altogether. Insist on a full declaration of ingredients.
- Buy waterborne, plant-based paints
- If that’s not possible buy plant-based paints with a plant-based (natural) solvent
- Specify water-based paint with low titanium oxide content together with low quantities of binder.
- Avoid paints with high levels of organic solvents – though this is becoming increasingly easy thanks to the effects of legislation.
- Further reduce health concerns by careful study of lists of ingredients, where available, and comparing of chemicals to databases of toxins.
It should go without saying that paint should at least do the job – but the sad fact is that there are some paints, particularly amongst the ‘eco’ paints, on the market that just don’t make the grade. Paint failures or inadequacies usually occur amongst outdoor paints. Common shortcomings include:
- Paint of poor durability, including fading, poor adhesion, chalking, yellowing, colour fading – all requiring early re-coating.
- Low levels of coverage, necessitating several coats – increasing the overall environmental impact.
- Performance that falls short in only moderately demanding environments.
First, a word about colour, many of us choose paint solely based on colour (which is not actually a problem) and second on target use such as exposed external or internal applications. Choosing paint can be an emotive design-driven purchase, well it is these days, and we no longer buy paint just to prolong the working life of a door or window.
We all understand that brands become deliberately associated with colours to gain market share this can mean brands become synonymous with entire areas of use, imagine what colour a “shaker kitchen” would be or how muted duck blues and moss greens have become almost ‘de rigueur’ for pretty cottages and mews houses, grey has made a huge comeback for windows and doors on modern buildings, all of this is an association between colour and emotion, so let’s keep the emotion and the ‘style a la mode’ but choose paints that are genuinely eco-friendly, try to choose paint that goes beyond its colour. But be warned choosing paint for low environmental impact and toxicity is not straightforward.
The greatest environmental impact will be from the manufacture of titanium oxide – a pigment so fundamental to the performance of any paint, that it is difficult to avoid – even amongst ‘eco’ paints. Alternatives exist, though careful consideration should be paid to embodied energy as well as performance – particularly coverage. See note below on ‘white pigment’
The most common toxic component of paint is from VOCs. Legislation is finally driving down levels, but many will consider that it still has some way to go. Other components such as additives are multifarious and difficult to recognise amongst other paint ingredients. Many additives are toxic, but there is very little legislative cover to accommodate all possible combinations. Standards have evolved both within and without the industry to try and control the more dangerous substances, but progress still needs to be made.
Great assistance could be provided by manufacturers if they would only volunteer to comprehensively list the ingredients of their paint, the only supplier we know that does this as a matter of principle is Livos (the world’s first industrial producer of natural pigments) who have listed a full declaration of ingredients on all products since 1984.
Watch out for Greenwash
The paint industry is rich in Greenwash. The prefix ‘Eco’ works overtime and features on just about every tin of paint that has fewer VOCs than the industry average of 20 years ago. So common is the use of the word that it is now virtually, in paint terms, meaningless.
Those who have a belief in ‘green’ products will be saddened by the fact that nearly every manufacturer, traditional or ‘green’, is guilty of misleading users about the levels of VOCs their paints contain. Particularly vexing is the use of the expression ‘Zero VOCs’ when an analysis of the contents will, with few exceptions, reveal their presence – however small in quantity.
Customers will be equally dismayed by misleading terminology. ‘Natural’ and “Nature” in particular are words with a myriad of interpretations. ‘Natural’ (or Nature) doesn’t always mean that a material has a low environmental impact or is non-toxic – for example, gum turpentine is often described as ‘natural’ but it is significantly toxic to people who use it. Nature doesn’t mean it was sourced from sustainable sources without harm to the environment.
Eco Labels for Paints
Non-toxic paints are often called Low-VOC, No-VOC, VOC-Free, odourless, odour-free and green, natural or organic paints. There are no set standards for defining these labels, and they are widely misused for marketing purposes. To help consumers make informed decisions on their paint purchases, various ecological labels have been developed by different countries to indicate that the paint has fulfilled certain environmental requirements, in accordance with respective government regulations. These eco-labels can be found as logos on paint cans, and include the European Eco-Label, Blue Angel in Germany, and Green Seal and Greenguard in the USA. In the UK, VOC labels are used, and indicate the content of VOCs using one of five classifications: Minimal (0-0.29%), Low, Medium, High and Very High (VOC content greater than 50%).
Low-VOC paints tend to use water as a carrier instead of petrochemical solvents, and so their emissions are minimal. Many conventional paints have achieved relatively low VOC levels. No-VOC or VOC-Free paints may still contain very low levels of VOCs in their pigments or additives. Although reducing VOC content is a move in the right direction, it is questionable whether either of these paint types can be considered non-toxic.
Natural paints are normally considered to be the only true non-toxic paint since they contain very low levels of naturally occurring VOCs, and are made from natural ingredients such as water, vegetable oils, plant dyes, and natural minerals. The main binders used in natural paints are linseed oil (from flax seeds), clay, lime, and milk protein. Lime and milk paints give an authentic period look and are often used in antique restoration projects. Chalk is used as an extender to thicken paint; turpentine (distilled from pine trees) is used as a solvent; essential oils from citrus fruits (d-limonene) are used as a solvent and fragrance, and natural mineral and earth pigments are used as colourants.
What is paint made from?
Most paint is made from three basic ingredients:
- Pigment – provides colour and opacity
- Binder – acts like a glue in holding the pigment to the surface
- Solvent – maintains the pigment and binder in liquid form
Other ingredients include those that prevent bacterial growth, economise the spreading of paint (fillers), thicken paint, prevent ‘skin’ from forming, enable paint to be easily applied, accelerate/retard drying and prevent foaming.
Paint works by its application to a surface followed by the evaporation of the solvent, thus leaving a film comprising of the pigment and binder.
Pigments are used to do different jobs in paint including helping to give the film the required properties (Extending pigment) and to increase the impermeability of the film (Barrier pigment), but the foremost is the one providing the permanent colour (Colouring pigment)
Titanium Dioxide or TiO2 is used almost universally throughout the paint industry – including both in conventional paints, but also in ‘eco’ paints. Titanium Dioxide replaced previously well-known white pigments such as Lead Oxide (‘Lead White’). Its near-universal appeal is derived from its high opacity (the ability to cover or hide). Less-used pigments include chalk and lime, which have very low opacity and therefore can require many coats applied to achieve acceptable opacity.
Although titanium oxide is considered inert and safe, it is used in foods, toothpaste, sunscreens etc and commonly in paint, its manufacture cannot be regarded as so benign. Titanium Dioxide is made in one of two ways, Sulphate or Chloride processing depending on the ore used for extraction, each of which has a significant environmental impact. The use of Titanium Oxide is ubiquitous largely because of its performance and because there are few economically viable alternatives. The key here is to use paints with as little Titanium Oxide as possible.
Pigments are either ‘organic’ or ‘inorganic’. Unless used in quantity, coloured pigments do not provide opacity so most paints rely on the inclusion of Titanium Dioxide.
‘Organic‘. Early organic pigments were based on dyestuffs derived from natural plants. Most contemporary organic pigments are synthesised from coal tar and petroleum distillates, but plant-based pigments continue to feature amongst ‘eco’ paint brands. Synthetic organic pigments are usually quite brilliant and have good colour strength. However, opacity tends to be low and many organics are not fully solvent resistant.
‘Inorganic‘. The earliest paints used pigments which were obtained by digging certain minerals out of the earth and grinding them to a fine powder. These ‘natural’ pigments are all inorganic compounds. Typical examples include ochre and Sienna. Other inorganic and more prolific pigments in the market are usually metallic oxides derived from iron and clay or synthetics produced from petrochemicals.
Over the past 2 decades, significant progress has been made in the manufacture of inorganic and organic pigments and now in addition to the more muted and softer colours, there is a wider choice than ever of darker colours to choose from.
In a paint mixture, the binder is responsible for providing adhesion, binding the pigment, and giving the paint resistance properties which make the final coating durable. There are two common types of binder: oil-based and latex-based plus mineral silicate (water glass).
Oil-based paint requires a binder that has similar properties to the paint-in this case, the binder oxidizes or dries when exposed to air, hardening along with the rest of the paint.
Binders in oil-based paints are either natural or synthetic. ‘Natural’ vegetable-based oils include linseed oil, tung oil and soya oil. Today, few paints are made with oil alone. Rather, they are based on modified oils called alkyds. Made from vegetable oils and synthetic resins, alkyds are chemical compounds that dry harder and faster than oils. Nearly all ‘oil-based’ paints (eg ‘gloss’) now have alkyds as binders. Exterior oil-based wood primers often are made with a combination of oil and alkyds.
Latex-based paints actually do not possess latex-rather, the polymer binder that is used creates a film in the paint that resembles natural latex rubber. Almost all water-based paints have a latex-based binder. When the coating is applied, water evaporates from the paint, leaving behind a film of pigment and latex-based binder, which bind together into one continuous coating.
Several polymer types are used as binders in latex paint. The two most common types are ‘acrylic’, most suitable for exterior use, and ‘vinyl acrylic’ which though also can be used externally, is mostly applied internally. Other latex binders include styrene-acrylic and terpolymer.
Most modern emulsions are water-based with the latex added to increase durability. The amount of latex determines the degree of sheen seen in matt, eggshell, silk and satin finishes.
Mineral silicate – water glass
Silicate paints are based upon mineral raw materials the binder is actually a potassium-based alkali silicate (water glass), also known as potassium silicate, mineral paints do not form a layer but instead works by soaking into the underlying material where the potassium silicate binder chemically reacts with the material to form a microcrystalline silicate bond which is insoluble. Secondary crystallisations also take place between the binder, the colour pigment and carbon dioxide in the atmosphere.
The result is a highly durable connection between the paint coat and substrate. Additionally, water glass is highly resistant against UV light as a result silicate paints offer an extraordinarily long life. Silicate paints require a siliceous substrate for setting. For this reason, they are best suited for mineral substrates such as mineral (lime or gypsum) plasters, lime and cementitious renders and concrete. Anecdotal evidence from Europe and Scandinavia claim that silicate paint systems can last in excess of 100 years. Pragmatically, though, maintenance should be programmed from 15 years onwards.
The permeability for water vapour of silicate paints is equivalent to that of the substrate which means that silicate paints do not inhibit the diffusion of water vapour. Moisture contained in parts of a structure or in the plaster may diffuse outward without resistance. The high alkalinity of the binding agent completely eliminates the need for additional preservatives.
Silicate paint is generally a very low toxic (limited to user exposure eyes and skin) paint with raw material, transport and energy as being the minimal environmental impacts.
The solvent is the liquid that suspends the other constituents to enable application. Once the paint is applied, the solvent evaporates, allowing the pigment and binder to produce a film of paint (a ‘coat’).
Solvents are either water or organic. The most common organic solvents, derived from petroleum, are ‘white spirit’, used in alkyds, and ‘mineral turpentine’ (‘turpentine substitute’) used as a paint thinner and for cleaning brushes. Other petroleum-based organic solvents include alkanes (isoparaffins), methyl ethyl ketone (MEK), methylated spirits (a mixture of methanol and ethanol), xylene, toluene and acetone. Solvents used in paint that are not petroleum-based include ‘gum turpentine and ‘citrus oil’.
It is important to note that most paints described as ‘water-based’ include small quantities of organic solvents to enhance workability.
The main benefits of natural paints are:
- Non-toxic – no hazardous fumes or harmful effects on health. This is significant for allergy sufferers and chemically sensitive people who are unable to tolerate chemical paints.
- Environmentally Friendly – use renewable resources; are biodegradable, can even be composted.
- Micro-Porous – allow walls and surfaces to breathe, preventing condensation and damp problems, and reducing associated indoor allergens. They are also less prone to paint flaking, peeling and blistering.
- Eco paint is an umbrella term for all sorts of products, including plant-based paints, lime & clay paints, chalk paints and milk paints (casein) and silicate mineral paints. Some brands make emulsions and gloss paints formulated with alternatives to toxic ingredients, such as solvents derived from citrus fruits and natural pigments and binders like clay, plant material and seed oils. Terms like ‘natural’ and ‘organic’ can be misleading – these words are borrowed from the food industry and can be used unregulated when it comes to paint.
It would be fair to say that it would be difficult to hold any single paint up as ‘the most eco-friendly’. Most manufacturers take a holistic approach by combining non-toxic ingredients and responsible production to make paints that are significantly less harmful than conventional ones, but remember none will have no environmental impact at all.
One final note on price, nowadays there is not much difference in price if any between a top-end branded paint and an eco paint. Eco paints do tend to be more expensive than mass-produced paints by big manufacturers. It is the difference in price that should help inform your decision, for example, if a standard paint cost for a room would be £100 and an eco version £130, the question is ‘can you see the value in the benefits of natural paint to a value of £30?’ these are emotive choices but most customers will tend towards health and environmental benefits and at £30 this comes pretty cheap after all what else does £30 buy and if the paint lasts for years and years then the choice of an eco paint becomes a no-brainer.
Please bear in mind that paint can have a huge impact on the environment during the manufacturing process and on health during its use phase equally unused liquid paint is also treated as ‘hazardous’ and requires appropriate disposal, try not to waste paint or dispose of inappropriately.
It’s worth singling out one manufacturer of natural paints to illustrate the difference between a committed manufacturer with core sustainability and human health principles and those who are less transparent about what their paints actually contain.
Livos have over 40 years’ experience in making natural and environmentally safe products. They were the first company in the world to manufacture natural pigments on an industrial scale and have a global reputation for the highest standards of research, sourcing, manufacture and quality all within the remit of environmentally friendly products. They publish a COMPLETE DECLARATION of ingredients for every product, unlike nearly all other paint manufacturers. Their core focus is on human health and they are committed to delivering the widest range of products for the allergy-prone and chemically sensitised that we have ever seen. Adopting a fully transparent approach to their formulations and testing is, in large part, the root of their success; customers don’t have to guess what’s in their products.
Livos’s long-running research and manufacturing base means their products are the ones that set industry standards and lead the way in delivering performance natural paints, stains and treatments.
After their wellbeing and sustainable credentials, the next most important attribute their products have is ‘they must work’ and they do, countless accreditations, awards and testing have created a wealth of genuine customer testimonials that not only confirm that the products work but often they work better and for longer than the synthetic products they replace.