WOOD-BASED MATERIALS FOR HEALTHY INTERIORS
We spend around 90 percent of our time indoors. And the quality of the air we breathe has a major influence on our wellbeing and health. Ideally, we should breathe oxygen-rich, odourless air with low pollutant levels.
SWISS KRONO OSB products bonded without formaldehyde are amongst the healthiest building materials available. This counts all the more considering that emissions are a frequently debated issue.
The principal criteria for deciding whether indoor air is good include the following:
- How is the room used?
- How is the building insulated?
- How is a supply of fresh air ensured?
- Which materials have been used to construct the building?
How a room is used is, of course, a very personal decision. It goes without saying that there are differences between rooms that are generally used by many people, including smokers, and, for example, workrooms that are only occasionally utilised.
Hermetic Building Shells Rob Us of Air to Breathe
Modern insulation definitely has benefits: it reduces energy consumption, the associated costs for heating and environmental burdens. On the other hand, it allows only about a tenth as much air to circulate between the inside of a building and outdoors, and the air indoors becomes more contaminated as a result. Ventilation is very important for creating a healthy indoor climate and thus also for the wellbeing of a building’s occupants. We inhale and exhale several thousand litres of air each day. Every one of us needs some 30 cubic metres of fresh air an hour in order to feel well and fit. If we are unable to get them, symptoms including difficulty in concentrating, headaches, irritated mucous membranes, stinging eyes, sleep disorders, and even muscle and joint pain can develop. Insufficient ventilation also causes the relative humidity to increase, which attracts mites and mildew.
This actually means that we should open the windows wide for at least five minutes every two hours. Unfortunately, that is rarely practicable in everyday living, and in any event it would cause the loss of much of the painstakingly accumulated indoor heat.
Modern Ventilation Concepts Ensure Fresh Air
When installing high-quality contemporary insulation, a modern ventilation system is essential. Currently, systems involving heat exchangers are the most efficient, eco-friendly approach. These systems extract used warm air from living areas and channel it outside. At the same time, fresh cold outdoor air is warmed up via a heat exchanger and then conveyed inside the building. Up to 85 percent of the heat is removed from the used air and transferred to the fresh air that is flowing inside. This automatically ensures an adequate supply of fresh air, without creating any draughts or annoying noise. Some systems also monitor and automatically regulate the relative humidity and/or are equipped with an activated charcoal filter to keep out unwanted pollen and dust.
Emission-Free Building Materials for a Healthy Indoor Climate
The materials used for a building play a crucial role in whether it has a good indoor climate. Many engineered wood materials are guilty of being produced with formaldehyde-containing binders, which is bad for the health. SWISS KRONO therefore makes a point of only using formaldehyde-free binders to make its OSB products. As a result, the boards only contain the formaldehyde that naturally occurs in wood, resulting in emissions of a mere 0.01 ppm, which is far below the maximum level of 0.10 ppm prescribed by the European E1 regulation. These “natural” emissions from wood are even less than the formaldehyde concentrations that are found in the ambient air of some cities and considered normal.
They are also below the stricter ceiling of 0.03 ppm that various German timber construction associations are calling for (including the Association of German Premanufactured Building Manufacturers – BDF, the Working Group for Ecological Timber Construction – AköH, and the Association for Quality in Timber Construction, Interior Finishing and Roofing – GHAD). The test report of the Fraunhofer Institute for Wood Research (WKI) on SWISS KRONO OSB/F**** and the environmental product declaration (EPD) for SWISS KRONO OSB, with details on their composition and emission levels, can be viewed in the download section under Certificates.
The polyurethane (PU) adhesive used instead is food-safe and has the added advantage of reducing the amount of binder in materials made with it. We constantly encounter PU these days: it is used in car dashboards, the insulating foam in refrigerators, shoe soles, and many other applications. The German Federal Environment Agency (UBA), in its “Guideline for Indoor Hygiene in School Buildings”, concludes that di-isocyanates (the chemical term for PU adhesives) are chemically so thoroughly altered by the production of engineered wood products that no hazards in the form of indoor emissions can be detected. In contrast to formaldehyde-containing binders, institutes engaged in scientific studies (including the German Federal Environment Agency, the Fraunhofer Institute for Wood Research (WKI) in Brunswick, and Empa in Zurich) have found no evidence at all that OSB products containing PU binders pose health hazards of any kind. SWISS KRONO OSB was tested by ECO-INSTITUT to determine its methylene diphenyl di-isocyanate (MDI) emissions for its product declaration, with this finding: “The three-day emissions study failed to detect any di-isocyanate monomers.“
A large-scale study of the VOC emissions (VOC = volatile organic compounds) of wood and wood-based materials conducted by Prof. Dr. Volker Mersch-Sundermann (director of the Department of Environmental Health Sciences of the Freiburg University Medical Center) and Prof. Dr. Rainer Marutzky (former director of the Fraunhofer Institute for Wood Research (WKI) in Brunswick) delivered substantiated data. In an open letter published in 2010, the two experts stated that “in respect of the VOCs specific to wood and wood-based materials that occur in actual rooms […] there are no indications of health hazards for their occupants, especially considering that when these materials are properly installed the concentrations of specific VOCs are significantly lower than those measured in the study and also typically subside quickly. […] Although this does not prove that wood is healthy or is conducive to good health, it has been possible to show that no health hazards within buildings are to be expected from wood or wood-based products when they are properly installed.”
Detailed information on all SWISS KRONO OSB products is available on the product pages and in the OSB full-line catalogue “Wood-Based Materials – Innovation & Respect for Nature“ in the download section.