The transition toward sustainable materials in the paint and coatings sector is advancing at remarkable speed, reshaping not only the chemistry of modern formulations but also the microbial landscape in which they exist. Few shifts have been as pivotal as the industry’s embrace of biobased raw materials and low-VOC systems, driven by regulatory pressure, corporate sustainability commitments and consumer demand for environmentally sound products. Yet as the sector moves into this greener future, an unexpected and complex challenge has emerged: the growing susceptibility of these very formulations to microbial spoilage. 

At first glance, the connection may seem counterintuitive. Biobased materials are often prized for their renewable origins and reduced environmental impact. However, these same characteristics can make them inherently more inviting to bacteria, yeast and fungi. Water-rich systems containing plant-derived or biodegradable materials create a microenvironment filled with nutrients that many microorganisms readily exploit. The natural preservative effects once offered by solvents or extreme pH have diminished, leaving formulations more vulnerable at a time when regulatory frameworks increasingly limit the preservatives available to protect them. 

This unfolding scenario has placed formulators in a paradoxical position. They must deliver high-performance, eco-aligned products while navigating one of the most challenging preservation landscapes the industry has ever encountered. The task is formidable, but it is also driving an era of innovation that promises to redefine how coatings are protected throughout their lifecycle. 

The increased susceptibility of biobased coatings begins with the simple reality of their composition. As renewable ingredients replace fossil-derived components, the resulting formulations tend to contain more carbohydrates, proteins, lipids and other organic structures that serve as nutrients for microorganisms. These nutrients were largely absent in older coatings systems, which relied more heavily on volatile solvents, chemically inert binders or synthetic additives that did not support microbial growth. Biobased additives, including thickeners, dispersants, stabilizers and binders, create a rich buffet for spoilage organisms, particularly when combined with reduced VOCs and a shift toward neutral pH. Waterborne systems based on these materials thus provide both the sustenance and the conditions microorganisms need to proliferate. 

Compounding this, the microbial populations themselves are evolving. The consolidation of permissible actives has created a selective pressure that favors organisms capable of tolerating or circumventing these preservatives. Across various industrial settings, including paint and coatings, raw materials and finished goods, researchers have observed an increase in hardy strains, especially within the Pseudomonas genus. Many of these strains are known for their metabolic adaptability and their ability to survive in environments previously thought inhospitable. As regulations remove or restrict actives with differing modes of action, the microbial ecology narrows, giving opportunistic species an advantage. This evolution mirrors patterns seen in healthcare and agriculture, where reliance on limited mechanisms of action has accelerated the development of tolerant populations. 

Even as microbial challenges grow more complex, formulators face a shrinking toolbox of permissible preservatives. Globally, regulatory bodies continue to reevaluate the safety, toxicity and environmental impact of biocidal active substances. In Europe, isothiazolinones have undergone particularly intense scrutiny, with tightened classification thresholds dramatically reducing their allowable use levels. Many are now classified as strong skin sensitizers at extremely low concentrations, affecting both formulation design and labeling requirements. Formaldehyde-releasing preservatives face broad restrictions and certain pyrithiones must navigate a shifting regulatory landscape. For formulators seeking global harmonization, the list becomes even shorter, as regional variations in approvals and thresholds limit the number of actives that can be used consistently across markets. The result is not just fewer options but fewer modes of action, which heightens the risk that tolerant microorganisms may flourish. 

These pressures have prompted the industry to search for alternatives that can maintain product integrity without depending solely on traditional biocides. What is emerging is a movement toward smarter, more holistic preservation strategies, approaches that rely on synergistic additives, controlled-release technologies and multifunctional components designed to enhance both the physical stability and microbial resilience of coatings. 

One of the most promising developments is the rise of active delivery systems, including encapsulated biocides that protect active molecules from premature degradation. By embedding the preservative in a protective matrix, these systems release actives more slowly and consistently over time. This not only extends the period of effectiveness but also reduces the total amount of biocide required to maintain adequate protection. Because the active substance is shielded from interacting unfavorably with other formulation components or environmental factors such as humidity or UV radiation, encapsulated systems can preserve efficacy even in demanding conditions. 

Alongside controlled-release technologies, the industry is investing in multifunctional additives that enhance both formulation performance and preservation. These materials help stabilize pH, maintain viscosity, improve pigment dispersion or deliver other benefits that indirectly support preservation. Increasing the resilience of the formulation matrix reduces susceptibility to microbial attack and makes it easier for lower levels of active substances to deliver meaningful protection. The concept draws inspiration from the cosmetics sector, where multifunctional additives have long played a role in mitigating the need for high preservative loads. 

Taken together, these advancements represent a philosophical shift, from treating preservation as a discrete additive to viewing it as an integrated part of formulation architecture. It is no longer sufficient to simply add a preservative at the end of the formulation process. Instead, preservation must be considered holistically, with attention to raw material selection, microenvironment control, delivery mechanisms and long-term durability. This reimagined approach allows formulators not only to meet regulatory requirements but also to create more robust and reliable products for end users. 

Across the industry, several suppliers and research organizations are contributing to this new wave of preservation science. Among them, Arxada has helped push forward technologies that expand what can be achieved with today’s regulatory-compliant actives. Work on multifunctional components for in-can stability, controlled-release platforms for dry-film protection and performance-amplifying additive systems reflects broader trends seen throughout the sector. While each supplier brings its own innovations, the common objective is clear: to enable a future in which sustainable coatings remain safe, durable and reliably protected. 

For formulators navigating the transition to biobased materials, these technologies arrive at an important moment. The rise of microbial susceptibility is not a temporary challenge but a structural one, inherent to the very materials that support the industry’s sustainability ambitions. By embracing the next generation of preservation science, the coatings sector can overcome this challenge and build systems that remain protected without compromising environmental goals. 

Looking ahead, the industry stands at the threshold of a new chapter, one defined not by the volume of active ingredients but by the intelligence of their deployment. Preservation is becoming smarter, more efficient and more aligned with the principles of sustainable chemistry. As biobased raw materials continue to influence the direction of formulation science, the solutions emerging today will play a central role in ensuring that the coatings of tomorrow are not only environmentally responsible but also reliably protected throughout their service life. 

All information in this article corresponds to Arxada’s knowledge on the subject at the date of publication, but Arxada makes no warranty as to its accuracy or completeness and Arxada assumes no obligation to update it. All information in this article is intended for use by recipients experienced and knowledgeable in the field, who are capable of and responsible for independently determining the suitability of ingredients for intended uses and to ensure their compliance with applicable law. Republication of this information or related statements is prohibited. Information provided in this article by Arxada is not intended and should not be construed as a license to operate under or a recommendation to infringe any patent or other intellectual property right. All trademarks belong to Arxada or its affiliates or to their respective third parties and are used here only for informational purposes. Copyrighted material has been produced with permissions or under license. All other materials © 2026 Arxada.
 

Read more coverage on sustainable coatings and the formulation strategies shaping the future of the paint and coatings industry.