More and more people ask their painter, before finalising a quote, whether the chosen paint is "eco-friendly" or "low-VOC". The question is legitimate, but the answer is not always straightforward, because not every paint advertised as sustainable meets the same criteria. Understanding what lies behind these terms helps make a more informed choice, especially in enclosed or poorly ventilated rooms, where indoor air quality matters more day to day.
What VOC really is and why it matters
Volatile Organic Compounds: the definition that counts
VOC stands for Volatile Organic Compounds, substances present in many conventional paints that are released into the air during and after application. When talking about eco-friendly or low-VOC paints, what is at stake is the concentration of these compounds, and in Portugal some brands already offer products with values equal to or below 0.3 grams per litre, a level well below the limit allowed by European legislation.
This exposure has real consequences inside the home. Studies on indoor air quality in Portugal show that exposure to indoor pollutants such as tobacco smoke, formaldehyde, biological agents, volatile organic compounds and radon significantly contribute to respiratory and cardiovascular diseases. This is why, in baby rooms, dining areas or spaces with poor ventilation, the VOC value of paint stops being a technical detail and becomes a practical criterion.
Why water-based alone is not enough
A paint is not eco-friendly just because it is water-based: for a product to be truly sustainable, it should also avoid heavy metal-based pigments, synthetic fungicides and petroleum derivatives. Many common plastic paints are already water-based and can still have other components that weigh on the environmental assessment. So, before comparing prices, it is worth understanding what type of information appears on the product's technical data sheet.
How to read labels and certifications without getting lost
The European Ecolabel (Ecolabel)
Among the most credible seals is the European Union Ecolabel, created in 1993 and recognised in dozens of product categories, including paints and varnishes. The European Ecolabel is a European Union certificate that guarantees that the product or service has high environmental performance, due to the demanding requirements that manufacturers must meet to obtain that label. In the case of paints specifically, this seal guarantees that the product has reduced environmental impact throughout its life cycle, meets strict emission limits and does not contain certain substances classified as hazardous.
Interestingly, a recent Eurobarometer showed that 57% of respondents in Portugal admit they do not know the flower-shaped label created by the European Union, the highest rate across the entire bloc. This means many Portuguese consumers overlook this seal even when it is on the packaging, reinforcing the importance of learning to identify it before buying paint.
The criteria for paints and varnishes were recently updated: Commission Decision (EU) 2025/2607 establishes the criteria for awarding the EU Ecolabel to paints, varnishes and related decorative products, making the award dependent also on durability requirements and resource use efficiency.
Brands and ranges available in Portugal
On the Portuguese market there are already several alternatives with very low VOC values. Brands such as Neuce, Biofa, Auro and Robbialac offer specific ranges for those looking for more sustainable products, with Neuce launching the NeuceNature line, which uses biologically-based resins and has a VOC content equal to or below 0.3 grams per litre. Biofa, meanwhile, offers natural paints based on lime, silicate and plant pigments, with no toxic emissions, especially suitable for surfaces that need to breathe, helping to regulate humidity and prevent condensation and fungal problems.
For those seeking more in-depth guidance on brands and where to buy, this topic has already been covered in detail in the article on eco-friendly paints in Portugal.
Where it makes most sense to invest in low-VOC paint
Interiors: bedrooms, living rooms and kitchens
In enclosed spaces, especially bedrooms and living rooms, the impact of VOC on indoor air quality is greater, because there is less air renewal than outdoors. In these cases, choosing low-VOC or Ecolabel paint usually makes sense, especially in:
- Children's or baby rooms, where occupancy is prolonged;
- Kitchens and bathrooms, where humidity and odours accumulate more easily;
- Apartments with poor cross-ventilation, common in older buildings in Lisbon and Porto.
A well-planned interior paint combines the right product with proper surface preparation, something that professional interior painting already takes into account from the start of the project.
Exteriors and facades: other priorities
Outside, exposure to open air quickly dilutes volatile compounds, so the main criterion becomes resistance to weather, UV radiation and humidity typical of the Portuguese coast. Even so, silicate and lime paints, mineral-based, remain an interesting eco-friendly option for facades, as they are breathable and help regulate the humidity of walls. Anyone planning work on their facade can consult the page on facade painting to understand which solutions suit their region's climate.
Compare options before deciding
The following table summarises the main differences between the most common types of paint on the Portuguese market, to make comparison easier:
| Paint type | Typical VOC | Best use | Main feature |
|---|---|---|---|
| Conventional plastic | Medium to high | Interior, dry walls | More affordable price |
| Low-VOC (water-based) | Up to 50 g/L | Interior, bedrooms and living rooms | Less odour, faster drying |
| With European Ecolabel | Generally below 30 g/L | Interior, sensitive spaces | Certification verified by independent body |
| Lime or silicate (mineral) | Very low or none | Facades, walls with moisture | Breathable, regulates humidity |
Before finalising any quote, it is worth asking the professional for the technical data sheet of the proposed paint and confirming the VOC value in g/L, rather than relying solely on the word "eco-friendly" on the packaging. When a quote is calculated per m², it is important to remember that this value is always indicative, because two walls of the same area can be in very different conditions (cracks, moisture, degraded plaster). The final price can only be confirmed after assessing the real condition of the surfaces, whether by photos and videos or through a visit to the site, both of which work in the same way. This is why our platform always requests photos and videos of surfaces before finalising any quote, precisely to avoid surprises during the work.
Frequently Asked Questions
Not always. Some low-VOC ranges have a price similar to mid-range plastic paints, especially in brands already established on the Portuguese market. The cost difference tends to be greater in mineral paints (lime or silicate), as they require more specific raw materials and manufacturing processes.
The exact value in grams per litre (g/L) should be stated on the technical data sheet or on the packaging. A value below 50 g/L is usually considered low-VOC, and below 5 g/L approaches zero-VOC. Trusting only the word "eco-friendly" on the label, without checking the number, can be misleading.
Not necessarily. Many water-based formulations with low-VOC dry as fast or faster than conventional paints, which also allows the room to be reoccupied sooner after painting.
Yes, especially mineral paints made from lime or silicate, which in addition to having very low emissions, help regulate the humidity of walls and are suitable for the humid climate of various regions in Portugal. The choice also depends on sun exposure and the type of facade substrate.
Before presenting any professional as an option, our platform confirms they are properly registered as self-employed or have an incorporated company, so the client has that guarantee before proceeding with the work.
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