“eco” paints (?)

A good example of the problem we have in trusting in “eco” materials are paints. There are hardly any industrially produced exterior paints that really consist of purely natural ingredients. For interior painting, it is worth taking the choice seriously.
Paints in general are made up of water, mineral powder as filler, pigments and binders.
The critical part of “eco” quality, in many cases, are the binders and the water.

It is not without reason that plastic-based binders are criticised. The reason is their production and waste problems for the environment and the possible health hazards. Everyone may decide for themselves where to set priorities, but unfortunately the information necessary for a free decision is purposely hidden. In order not to have to mention the delicate component plastic by name, there is suddenly only talk of water-based, mineral or dispersion paints. Every paint contains water. Every paint contains minerals in the form of stone powder, called “filler”. Dispersion means the mixing of components that normally cannot be mixed such as water and plastic. But: what makes the difference are the binders. Their designation characterises the properties of the respective type of paint. If paints are not called by the names of their binders, this is reason enough for mistrust.

But even then. Example silicate paints: The first generation of silicate paints always consisted of two components that were mixed on site shortly before painting: liquid water glass and quartz sand with pigments. In this way, the plaster was dyed/silicified in a relatively tedious way, the silicate paint was so thin that no superficial coating was formed. The result was an exceptionally long durability, no mould, non-fading strong colour tones. To the delight of the applicators, the product, which until then had been difficult to process, was “further developed”. The paint became single component and easier to apply. This was the second generation of silicate paints, the so-called “dispersion silicate paints” according to DIN 18363 with 5% plastic binder. The third generation, the so-called sol-silicate paints, are also advertised on the basis of DIN 18383 without addressing the plastic content. What remains are only good memories of what silicate paints once were.

Clay and lime paints: Clay paints from responsible manufacturers are often powder paints supplemented with vegetable-based binders, caseins. In the upper hand, however, are liquid clay paints that swim along on the eco-wave with plenty of chemicals as additional binding agents and preservatives. Also lime paints may contain plastics; it is best to read up on the composition in the product data sheet. Those who have nothing to hide express themselves clearly. For me, a high-priced, ecologically award-winning (!) lime paint with nano-technology took the cake. After opening the paint, an intensive plastic odour escaped like hardly any other officially declared high-quality plastic paints, the smell left no doubt…

Water in paint is a problem because it cannot do without additives. In all ready-mixed, water-based paints, various chemical additives are normally used to conserve water and to maintain good application: additives to reduce water evaporation, binders, emulsifying agents, anti-foaming agents, fungicides, anti-skinning agents, etc.

Truly ecological paints are supplied as powder paints to avoid these additives. In addition, transport and storage costs are reduced and the shelf life is considerably extended.

Speaking of nano-technology: Nano-technology for many years has been part of the production of paints in general. In the ecological world, nanotechnology is not welcome because it carries health risks. Nanotechnology is defined by the size of the particles used.
We are talking about a maximum particle size of 0.0001 mm. At this size particles can easily enter our bodies through the skin, respiratory or tear ducts. There are particles that are naturally nano-sized, such as sand on the beach, and there are others that are produced by micronisation. Without knowing the nano-sized material used and its risk to our bodies, nanotechnology is not reliable. From the point of view of sustainability and bio-construction, the use of products containing nano particles, including sol-silicate paints, is not reliable.
Science is still a long way from being able to analyse the impact of nanoparticles on the environment and on the human organism.
Unfortunately, for the customer it is very difficult to find out which products are made with
nanotechnology if the manufacturer does not make its “innovation” public.

Primers also belong to almost every paint job. I know of only one truly ecological primer, the casein primer from Kreidezeit, for example. The vast majority of all suppliers of ecological paints work with primers containing polymers.

VOC content of interior paints: the maximum content of matt interior paints certified according to the EU Eco Directive is 10gr/l. If you are in good shape, you can read page 38 with the VOC limits and some of the other 156 pages of the current directive from April 2020. A paint with less than 1gr/l is considered to have no VOC content. And: monitoring of the limit values is virtually non-existent.

Moral of the story: just because a paint is marketed as silicate, lime or clay paint does not mean that the paint is really ecological in the sense of what we expect. Do not trust advertising and read the product description. The more difficult the product composition is to find, the more diffuse its presentation, the more there is to disguise. The last instance is smell, trust your nose.

There are paint manufacturers who are members of the International Association of Natural
Building Materials Manufacturers. In.Ve.Na. is a voluntary association of companies that fully declare the ingredients of their product range.