Who would think that a freshly painted wall, so smooth and glossy, could hide such a serious problem? Paint is one of the finishing touches that brings beauty and protection to both indoor and outdoor spaces. But beneath this layer of color, there’s an invisible coat that, silently, accumulates in our ecosystems and even in our bodies. Recent research from Switzerland identifies construction paint as one of the largest sources of microplastic pollution in oceans, rivers, and other environments. These microplastics, less than 5 mm in size, enter ecosystems through weathering, accumulating in marine and terrestrial animal bodies — and ultimately, in humans. Although the long-term effects on human health are still under study, evidence so far indicates that continuous exposure may contribute to various physical and metabolic health issues. Yet, sustainable alternatives are emerging, offering a way to create healthier spaces while minimizing environmental impact.
Latex paint is composed of water and plastic polymers (such as acrylic and vinyl) that form a durable film on surfaces. Over time, this film wears down due to exposure to sunlight, rain, and abrasion, releasing small plastic particles into the environment. Traditional construction paint contains about 37% microplastics, highlighting the urgency for more sustainable materials in this area. According to the European Commission, an estimated 231,000 to 863,000 tons of microplastics enter European environments each year from paint waste. With a target to reduce microplastics by 30% by 2030, researchers stress the importance of designing materials with this concern in mind from the outset to avoid the high costs and complexities of later remediation.
To combat the growing problem of microplastic pollution, BC Materials, a Brussels-based startup, offers a sustainable alternative: a mineral paint made from excavated soil, free of microplastics and VOCs (volatile organic compounds). BC Materials has been developing clay-based products under its Léém brand, including clay plaster, clay mortar, and, more recently, a clay paint.
This paint is crafted with approximately 65% secondary resources, incorporating sustainably extracted, locally sourced, pollution-free soil. By significantly reducing the reliance on virgin raw materials, it supports a production cycle with a lower environmental footprint. Its clay-based formula provides a palette of natural, earthy tones, including red, brown, cream, and gray, offering a rustic and inviting aesthetic. These colors not only reflect the material’s natural origins but also underscore its commitment to circularity and environmental responsibility.
The product was recently showcased at MABO Primary School, where children and teachers painted a classroom wall together, replacing old, microplastic-laden paint. Sofie De Clercq, principal of MABO Brussels, expressed relief after replacing the old, peeling paint, emphasizing the risks children face with toxic products loaded with microplastics.
Complementing BC Materials' efforts, another study led by the Danish architecture firm Henning Larsen and conducted by the Danish Consumer Council Forbrugerrådet Tænk offers insights into the environmental impact of various types of paint for indoor environments. The results of their climate assessment reveal that mineral-based paints have a significantly lower global warming potential than conventional acrylic (latex) paints. Moreover, the study encourages manufacturers to publish Environmental Product Declarations (EPDs) for better data quality, especially for plant-based options. The Danish study also suggests that not all surfaces necessarily require painting, a perspective aligned with the broader mantra of sustainable design: "the most sustainable building is the one that isn’t built." Where painting is essential, choosing mineral-based paints or other low-impact alternatives can contribute to a reduced environmental footprint.
The growing emphasis on eco-friendly, microplastic-free building materials represents a vital shift toward sustainability, with significant benefits for both human health and the planet. By prioritizing materials designed with long-term impact in mind, the construction and design industries can help pave the way for a future where buildings — and paints — are safe, circular, and aligned with natural systems. As Marilys Tran The Thri, materials designer at BC Materials, states: “Instead of having to clean up our landscapes, rivers, and oceans afterward, it’s better to design materials that are inherently safe and made from abundant, healthy resources.”
