Thorough testing spotlights VOCs
When we stay indoors, the body absorbs chemicals from the air. Yet building materials with a recognised indoor climate label provide assurance of a low degree of degassing of hazardous volatile organic compounds (VOCs).
Helene Klinke, Business Manager, Danish Technological Institute, explains why it is important to test building materials – even when they enter the lifecycle of new buildings.
We saw the nightmare scenarios in the 1970s. Back then it was not uncommon to use building products such as chipboard, which preferably were coated with an extra layer of formaldehyde glue to provide strength. This meant that the panels were emitting large volumes of harmful formaldehyde directly into indoor spaces.
This resulted in bringing focus to bear on limit values for formaldehyde degassing as a requirement for the CE marking of building products. Since then, the development of advanced measurement methods has made it possible to chart several other volatile substances. They are also known as Volatile Organic Compounds – or VOC for short.
Helene Klinke is head of the Danish Technological Institute’s indoor climate laboratory. She points out that cancer, asthma and allergies are some of the diseases that can be affected by VOCs.
“Every day, all of us breathe in many litres of air from the indoor climate, and researchers have defined the health risk whenever these harmful substances are present in this air. Babies and toddlers are particularly at risk because they breathe in lots of air in proportion to their body weight. Older people are also at risk, because they have a thinner layer of skin which absorbs the substances more easily,” she says.
Voluntary mark of quality
Together with her colleagues, Helene Klinke conducts the tests which form the basis of the Danish Indoor Climate Label – and which are also found in several international schemes such as The Blue Angel, Germany’s Ecolabel. One of the criteria for qualifying for the recognised labels is low VOC degassing.
Labelling is voluntary and measurements are based on the list of substances for which the EU has set recommended limit values – but which manufacturers in the vast majority of countries are not required by law to follow.
“Some EU countries, such as France, Belgium, Italy and Poland, have introduced national legislation in this area, but in others, such as Denmark, having products tested for volatile substances that go beyond the requirements of the CE marking is still voluntary. The indoor climate schemes are a mark of quality that assures both builders and building users that the indoor climate is healthy,” says Helene Klinke.
Schemes may complement one another
Whenever the Technological Institute tests a product, this is done in a climatic chamber that simulates the conditions in a typical indoor space. Over 28 days of testing, the Danish Technological Institute takes air samples showing the concentrations of the various VOCs. The first test is taken already after three days.
In addition, tests are carried out to detect noxious odours which may not be hazardous, but nevertheless have an adverse impact on air quality and, thus, the indoor climate. A test panel of at least 15 people assesses whether a product emits an odour that is acceptable in a building.
“The degassing of many volatile substances flattens out over the 28 days. But materials that gradually decompose will over time also emit secondary substances that we do not test for with this method,” Helene Klinke says.
She stresses that VOCs are also not the only parameter that determines the health of a building material. Because there are also problematic ingredients that ‘reside’ in the product that can be harmful to humans and the environment without necessarily showing up in a degassing measurement.
“This is why it can be beneficial for manufacturers to qualify for different labels and certifications which complement one another,” she adds.
Remembering indoor climate in a circular economy
In a circular economy, old materials are recycled into new buildings – either directly or as a raw material in new products. A couple of examples of this are cleansed bricks or melted plastic bottles that are turned into carpets. Once materials enter into circulation, it is crucial to be aware of the indoor climate, Helene Klinke points out.
“Circular economy is good for the environment because we minimise waste. But this is not always good for the indoor climate, as the recycled materials may have been exposed to chemicals during their service life or have been damaged by moisture during storage. They may have been painted or new harmful substances may emerge during upcycling processes due to heating. This is why it is important to continuously measure the indoor climate in one’s building, even in new buildings made old recycled materials,” she says.
Testing methods at the Danish Technological Institute
- The indoor climate laboratory at the Danish Technological Institute conducts independent tests for companies and individuals on the degassing of chemical substances from materials to the indoor climate. They do this on the basis of voluntary labelling schemes and current legislation.
- The ISO 17025 accredited test for the degassing of VOCs from products is done in climatic chambers using chemical analyses of air samples and air quality assessments.
- The testing methods cut across several international labelling schemes, including the Danish Indoor Climate Label and Germany’s EcoLabel, The Blue Angel.
Business Manager, Danish Technological Institute