Katepal NOxOFF
Katepal NOxOFF is a new product that neutralises air pollution and reduces environmental load
Katepal introduces new NOxOFF roofing products that neutralise air pollution invisibly and efficiently.
Much of the pollution in urban air originates from traffic and industry. A large share of these impurities are nitrogen oxides (NOx), which drift in the air with the wind before eventually settling on surfaces such as roofs. But when they land on a Katepal roofing membrane treated with NOxOFF, they can no longer cause harm – because NOxOFF begins neutralising them immediately.
NOxOFF roofing membrane helps nature purify the air
NOxOFF roofing membranes are similar to traditional SBS bitumen membranes, but with the addition of an innovative photocatalytic coating developed by Photocat A/S.
Under UV light, a chemical reaction on the coating breaks down nitrogen oxides.
The photocatalytic coating is sprayed onto the surface granules of the membrane during production. Like every Katepal product, NOxOFF roofing membranes are durable, long-lasting and easy to install.
During the photocatalytic reaction, nitrogen oxides that have settled on the NOxOFF membrane are neutralised into harmless particles such as nitrites. These particles dissolve in rainwater and flow off the roof via the gutters into the sewage system and back to nature. There, they serve as a natural source of nutrients for plants and microorganisms.
With NOxOFF membranes, the surface area capable of capturing and neutralising harmful air pollutants can be increased. The vegetation in our environment already helps to purify the air by absorbing impurities through its roots and breaking them down with microbes into nutrients suitable for plants and microorganisms. Now roofs can also play their part in this process.
A silent and invisible danger in the air we breathe
Unlike the visible smog clouds in many large cities around the world, air pollution in Finland is an invisible threat.
Fine particles rise with air currents before settling on surfaces like roofs, harming both people and the environment. Although pollutants are not the sole cause of disease, they are known to increase the risk of illness and raise the overall load of emissions that are harmful to human health.
The most common air pollutants are nitrogen oxides (NOx particles), mainly emitted from traffic and industry. These pollutants cause respiratory symptoms, especially in children, the elderly and people with heart or lung diseases. Nitrogen oxides enter the lungs and bloodstream when we breathe, damaging tissues and contributing to heart attacks.
A 2018 study by Jena University Hospital in Germany found that even short-term increases in nitrogen oxide concentrations in the air led to a higher number of heart attacks in the study area.
NOxOFF – a colourless and remarkably efficient air purifier
Katepal’s new NOxOFF coating is sprayed onto the surface granules of the roofing membrane during production. This allows larger amounts of the purifying agent to be applied, significantly increasing the air-purifying efficiency.
Tests show that NOxOFF is up to ten times more effective than our previous-generation air-purifying product, LessNox.
LessNox had a titanium-dioxide coating that was light in colour, which limited its use to light-coloured roofing membranes. The new NOxOFF coating only slightly darkens the untreated granule surface. Thanks to its colourless nature, even black and other dark-coloured roofing membranes that are popular in Finland can now help to purify the air.
Certified purifying performance
Katepal NOxOFF roofing membranes have been developed in cooperation with the Danish company Photocat A/S, which has granted Katepal the exclusive right to use its innovative coating agent in Finland.
Katepal NOxOFF products have been tested and certified in accordance with the ISO 22197-1 international standard. Test results indicate that a 1000 m² roof covered with Katepal NOxOFF bitumen membrane has the same air-purifying capacity as a 10×10 m lawn or approximately 120 trees.
With one simple decision, your roof can start purifying the air in your neighbourhood.
Choose an environmentally friendly building material
Katepal has already invested heavily in the ecological development of its roofing materials. The Katepal range includes the popular Green product family, which uses renewable bio-based and recycled raw materials. The coating used in NOxOFF roofing membranes can also be applied to products from the Green family, making it possible to construct a roof that is both environmentally friendly to produce and able to purify the air throughout its lifetime.
Katepal hopes that in the future, all roofs will be able to help purify the air, as the difference in total cost compared to traditional roofing membrane solutions is very small. A roof lasts for decades – so your choice should be one that benefits the next generation.
“By making a small additional investment in a NOxOFF product, you are making a responsible choice that will improve the quality of your living environment for years to come,” says Henri Pirttilahti, Development Manager at Katepal.
Together with other environmentally friendly solutions such as the Green product family, Katepal NOxOFF is helping to make Finland’s building stock healthier and more sustainable.
