The Science Behind Cleaner Facades: AMME® Reduces Biocide Runoff

A Year in the Elements. Real Coatings. Real Results.

A full year of rain, wind, and weather. That’s what it took for the Fraunhofer Institute for Building Physics (IBP) to run one of the most telling studies on facade coatings in recent memory. Their goal was simple: to understand how much biocide leaches out of coatings once exposed to the real world, not a lab, not a simulation.

The breakthrough? Coatings made with THOR’s AMME^® microencapsulation technology released up to 85% less biocide than conventional systems. And that’s not speculation. That’s field data.

The Problem Facades Can’t Ignore

Exterior coatings use biocides to keep walls clear of algae and fungi. But when it rains, those actives often wash off, entering stormwater systems and, eventually, the environment. It’s a quiet problem, out of sight, but not out of consequence.

What Fraunhofer found is that encapsulation isn’t just a formulation upgrade. It’s a shift in how we think about environmental performance. Less leaching means cleaner water, better regulatory alignment, and coatings that work smarter, longer.

Inside the Study

• Five active ingredients tested: Terbutryn, Diuron, IPBC, OIT, and DCOIT

• Coating types: Conventional vs. AMME^®-encapsulated

• Conditions: One year of real-world exposure to driving rain and daylight

• Measured outcome: Runoff water analysed for active content

The standout: Diuron, a commonly used algicide, showed the greatest improvement—an 85% reduction in leaching when encapsulated.

That matters. Because Diuron is effective, but under scrutiny. AMME^® gives it a longer, cleaner runway.

What Makes AMME^® Work

AMME^® encapsulates each biocidal active inside a polymer shell, suspending it in the coating. That shell slows down release, protecting the active from weathering and minimising loss during rain. Think of it like time-release medicine for your building.

The result? Controlled delivery. Longer performance. Lower environmental load.

Proof, Not Promise

Plenty of technologies promise sustainability. Few get tested like this. With independent data from a world-leading research institute, AMME^® steps out of the lab and into real-world credibility.

This is not just about a better coating. It’s about building materials that respect the surfaces they protect and the systems they drain into.

Read the study (PDF, German):

Download from Fraunhofer IBP

Explore AMME^® technology:

How AMME Enhances Dry-Film Antimicrobial Performance