THOMAS WITTERSEH from the Danish Technological Institute shares what needs to be taken into consideration to ensure fitouts do not negatively affect building occupants’ health.
Buildings with a healthy indoor environment are important to the well-being of people. Our facilities must provide an indoor environment in which we do not get ill. Schools must provide safe and inspiring frames for teaching and learning. In the same way, indoor environment in offices and other workplaces should not set limits for our work performance. Several investigations have shown that a poor indoor environment negatively affects work and school performance. Typically, a reduction of five to 10 percent in performance may be observed.
In the Western part of the world, people spend on average up to 90 percent of their time in indoor environments – at home, at work and during transportation, for instance. The effect of the indoor environment has a great impact on our health, with a large number of health symptoms being related to air quality. It is, therefore, important that indoor air is of a high quality and free from harmful chemical substances.
Previously, ventilation was considered the only way to establish good indoor air quality (IAQ). It was not until the early 1990s that a new method was seriously considered: source control. It was recognised that people may not be the only sources of indoor air pollution. A ventilation rate solely based on the carbon dioxide production of buildings’ occupants may not be adequate in buildings where human beings are not the major source of pollution.
INDOOR AIR POLLUTION FROM VOCs
Indoor air may be polluted by several hundred different volatile organic compounds (VOCs). In addition to the emissions from human beings, construction products, furniture and other indoor articles contribute to air pollution. Some of these substances may cause irritation of skin and mucous membranes. Others can have carcinogenic or mutagenic effects.
Formaldehyde, which is a known carcinogen, is the most regulated substance worldwide when it comes to indoor air. The most widely occurring sources are wood-based panels, such as particle boards, which are glued with formaldehyde-releasing glue. But, varnishes for furniture and other materials can also emit formaldehyde in significant amounts.
Formaldehyde and other VOCs may be emitted from indoor materials over weeks or even years and, thereby, contribute to a deterioration of IAQ. There are large variations in room air concentration for the different substances to cause irritation or odour problems.
It is not uncommon that the installation of new materials in a building may cause problems in the indoor environment – sometimes in combination with well-known materials. A combination of products applied in a wet form like paint, filler or glue may cause unforeseen chemical reactions that affect emissions to the indoor air – not only during the installation phase, but also at a later stage. Sometimes the only way to stop the unwanted emissions is to remove the products and substitute them (partly) with other products.
NEED FOR VENTILATION DECREASED, OCCUPANTS HEALTH INCREASED
Both when erecting new and renovating existing buildings it is important to select low-emitting materials to minimise the pollution load on a facility’s indoor air, and, thereby, reduce the need for ventilation. For this purpose, a number of material emission labelling schemes have been established.
A large number of products are labelled with an eco-label. However, many eco-labels focus primarily on environmental properties during the production and recycling phase of the product, and to a lesser extent on the environmental properties during the in-use phase. It is difficult to be against the use of environmentally friendly products, but it is important to pay attention to the fact that materials that are harmless to the outdoor environment are not necessarily harmless to the indoor environment.
By selecting products labelled according to their indoor environmental properties, it’s possible to create a sound starting point for healthy IAQ – even in cases where, from an energy efficiency point of view, you want to limit the air change rate.
ECO-FRIENDLY PRODUCTS NOT ALWAYS IAQ FRIENDLY
Increased environmental awareness, which is positive in many ways, has unfortunately in some cases had a negative effect on the indoor environment. For example, in Germany and the US there have been reports of new products based on recycled materials causing problems indoors. Products partly based on recycled rubber material have been shown to emit substances that cause skin irritation and are known to be carcinogen to humans. This proves that there is still a need to document new materials’ possible effects on indoor air.
Most labelling schemes are best recognised and most widely used in their national markets. This limits manufacturers’ willingness to label their products according to these schemes, which, in turn, limits the number of labelled products available to end users. To combat this, the largest labelling schemes in Europe have now joined with the EU Joint Research Centre to develop an EU common voluntary labelling scheme for low-emitting products. It is expected that a common scheme that is well-known and recognised in all European markets (and possibly even beyond) will result in a larger variety and number of products with documentation of their effects on the indoor environment.
Thomas Witterseh is team manager at the Danish Technological Institute.