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Aalto University and XAMK researchers have developed bio-based fire retardants that can provide a safe alternative to today’s widely used harmful chemicals. Materials are already close to commercialisation. The aim of the project is to develop fire retardant coating with bio-based raw materials, including wood-based raw materials, which do not contain harmful chemicals. The overall goal of the project is to create the industry with an entirely new bio-based concept for fire retardants and related raw materials.

Test results exceeded expectations

When a public building is built, the materials used must meet certain fire class requirements. As the wood itself does not meet the strictest standards, it often has to be treated with fire retardants. However, many of the leading fire retardants on the market are harmful to the environment and human health. In recent years, the EU has tightened their regulation. 

Many fire-retarding products on the market contain ‘Substances of Very High Concern’ (SVHC), which will also be banned in the EU in the near future. Therefore, the industry is forced to abandon many of the fire retardants currently used, for which the project is developing bio-based and harmless alternatives. 

Intumescent coating in fire protection

The project develops a so-called intumescent coating, which expands into an insulating carbon layer in the heat of a fire and thus slows down the progress of the fire. Instead of harmful and fossil raw materials, this coating is made from biomaterials. 

“A year ago, we carried out laboratory tests and found that our substance slows down the burning of wood considerably more efficiently than commercial fire retardants. We immediately got excited and continued our development work,” says Professor of Practice Juha Lipponen from Aalto University.

Chemical engineering student Niklas Roth has completed his bachelor's thesis on the project. Roth’s role in the project has been to familiarise himself with the first indicative classification SBI (Single Burning Item) results of bio-based fire retardants and analyse the need and quality of further research.

“The preliminary results have been highly promising. More testing is needed for final classifications, but the preliminary results have been promising, and the future looks bright at the moment. Productisation must also consider additional factors, such as water and attrition resistance, which have not yet been examined,” says Roth.

Promising results from fire class tests

The development work progressed rapidly, and at the end of the project, it was time to test the performance of the substances in a full-scale fire class test. The indicative classification incineration was carried out at the premises of the Eurofins classifier in Otaniemi, in January 2025, and the results were very promising:
“We tested seven different bio-based coating combinations, and nearly all of them met the criteria for B fire class, which was a complete surprise to us. Our goal was for our substances to reach near the required limits so that we would know what to develop in the future,” says Lipponen.

In connection with the fire tests, Eurofins representative Taru Huokuniemi said that they had not seen such low Fire Growth Rate Index figures (FIGRA) in the fire test of wood products in the past, including the harmful chemicals leading the market. “We were totally astonished to achieve these results on the first try,” Juha Lipponen commented.

The Eurofins test is only indicative. The official fire classification is carried out using the same test, but it contains more co-incinerations to ensure a more reliable result. Although the official classification has not yet been obtained, the test indicates that the active substances developed by Aalto University and XAMK researchers seem to work even better than the commercial and often harmful solutions available on the market.

Next steps: Towards commercialisation

The project is about to enter the commercialisation phase. “We are currently applying for Research to Business funding from Business Finland, which will help the research progress towards commercialisation. Our goal is to bring these bio-based fire retardants to the market as commercial products, for example as harmless fire-retarding components for fire protection products, either through our own start-up or a chemical industry partner,” says Lipponen. "Hopefully, we will get the funding, we believe we will."

Next, the researchers intend to optimise the recipes for their fire retardants and develop them to be more efficient, as well as suitable for paint product formulations. The key findings of the project have been patented. Lipponen believes that the solutions are near commercialisation, and that this innovation can significantly change the way construction materials are treated in the future.

“The most rewarding aspect of this development work is the fact that these solutions developed by the researchers and students help save lives,” says Lipponen.

This is a joint project by Aalto University and XAMK, which has received funding from the Regional Council of South Savo.

The BIOSUOJA project was conducted in cooperation with the South-Eastern Finland University of Applied Sciences (XAMK), as well as multiple company collaborators (Carbon Reuse Finland Oy, Andritz Oy, Aisti Corporation Oy, European Cellulose Insulation Association, Kumart Oy, Nordic Bioproducts Group Oy, Tikkurila Oyj/PPG Finland Oy, the City of Savonlinna). The European Regional Development Fund project is co-funded by the European Union. 

Background reading

• Biosuoja project – Bio-humectants based flame retardants for impregnation and coatings treatment of wood substrates
• Aalto.fi article on the results of the Biosuoja project