Odors from building products and in interiors

Unpleasant odors impair people’s sense of well-being and are often responsible for complaints. Odor pollution is caused by substances that have a low odor threshold. The perception of an odor by the human nose depends on its concentration and varies according to age and genetic disposition. The characteristics of an odor can be described in words.

An odor in itself is not harmful. However, an odor is perceived as bad if:

• it is extremely unpleasant (e.g. fecal, burnt) or
• if it is emitted from a source and smells different than expected.

Various standards describe methods for evaluating the potential for odor complaints:

• DIN ISO 16000-28 (Indoor air – Part 28: Determination of odour emissions from building products using test chambers)
• DIN ISO 16000-30 (Indoor air – Part 30: Sensory testing of indoor air)
• VDI 4302-1 (Sensory testing of indoor air and determination of emissions from building products)
   

Odor testing

Odor testing starts with an evaluation of the odor by a sensory panel. A panel of test persons assesses the properties of odors from materials or in interiors according to national and international standards as well as industrial guidelines. Odor intensity, hedonics and acceptance can be determined by a trained or untrained panel. Therefore, we regularly train a panel of about 30 test persons (“test smellers”) who can classify odor intensity on the basis of defined scales and describe odors using a recognized vocabulary.

Fraunhofer IBP is accredited by the German Accreditation Body DAkkS for the method of odor testing using a trained sensory panel under certificate number D-PL-11140-11-05.
 

On-site inspection of rooms with noticeable odors

Building occupants expect the air in indoor areas to be healthy and of good quality. Unpleasant odors, like chlorinated aromatics, formaldehyde, nitrogen- or sulfur containing organic compounds, can affect a user’s sense of well-being. Frequently, odor pollution occurs after old building stock has been renovated. In pollutant inspections, sources are identified, odor-active substances are analyzed, and measures are devised to minimize the odors. Inspections are carried out according to DIN EN ISO 16000-32.

Odor analysis

To clarify which materials are the cause of odors, the conventional analysis of volatile organic compounds (VOC) and a special sensory analysis are used. This method combines instrumental analysis (GC-MS) with human olfactory perception (GC-MS/Olf).
 

Odor testing in the automotive industry

Different materials are installed in the vehicle cabin, and their emissions contribute to the general smell in the interior. If unpleasant odors arise, the source can be identified by evaluating the odors emanating from each part. The affected part is then subjected to an odor analysis.