会议时间：2019年3月21-23日
会议地点：奥地利·格拉茨
演讲嘉宾：Martin Weigl
Holzforschung Austria, Austria

摘要：
Altered architecture andbuilding physics constantly lead to changes in indoor air quality (IAQ).Whereas prevention of the sick building syndrome is covered by a variety ofregulations, and the development of low or non-formaldehyde emitting woodproducts is promoted, things are different for VOC emissions (volatile organiccompounds). Typical VOCs from soft- or hardwood originate from substance groupssuch as terpenes, aldehydes, or organic acids and might be primary (thesubstance is immanent in wood) or secondary (the substance is formed e.g. dueto oxidation processes). Though sum values (e.g. TVOC) don’t allowscientifically based statements concerning the impact on health and humanwell-being, they are often used for rating IAQ. However, just singlesubstances, where the toxicological effect is known should be of interest. Thedevelopment and application of the EU-LCI-values (lowest concentration ofinterest) in evaluation schemes is therefore very much appreciated.

Different emission dynamics canbe observed following all stages from cradle to grave. Building products suchas CLT or OSB are usually tested under controlled conditions within the firstfour weeks (28 days) after production, and most often do not reach a steadystate in this time span. During the construction phase of wooden buildings, aheterogeneous mixture of building products (also including non-wooden products)and uncontrolled conditions usually lead to unstable and unrepresentativeindoor air conditions. At the time of move-in, stabilization might begin, butadditional emissions from sources such as furniture get introduced, once againgiving an unrepresentative picture of IAQ. Thereafter, IAQ depends mainly onthe air exchange rate, in addition it is also influenced by human activities.Measurements under real-life conditions in a variety of different settingsindicate that a reliable assessment of IAQ should not be made prior to threemonths after move-in, ideally half a year later. In many cases wooden buildingsin use show good or even excellent IAQ, with no toxicological peculiarities atthat time. On the other hand, building industry most commonly can´t wait thatlong, if IAQ measurements are required, e.g. with respect to buildingcertification. In this respect, wood processing industry is constantly forcedto reduce emissions of their products, although the measured emission profilesdon´t reflect the real indoor air conditions.

Therefore, decision makers andrelevant stakeholders should put the focus on research on the above describedmissing link between product emission and IAQ, to slow down the overregulationof product emissions.                                                                                                                                                                      

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