Relation between emission and olfactory tests

At present, sensory evaluation is not yet integrated in all labels and standards. After comparison and interpretation of the weaknesses and the strengths of the several existing methods, a methodology has been elaborated. Previous experience in off-odour measurements for environmental field investigations help us to propose a methodology based on the assessment of odour intensity and hedonic tone. Various floor covering materials were tested in the lab with a self-made instrument. The sampling procedure is based on a "Field and Laboratory Emission Cell" (FLEC). The odour of the material is compared to a 8-level butanol intensity scale generated through a vaporization chamber and 8 stainless steel capillaries distributing the diluted n-butanol to 8 sniffing ports. First results shows generally a correlation between bad hedonic tone and odour intensity. On the contrary, there are no systematic relations between VOC levels and odour perception. The less odorous materials (PVC) are also the ones with the higher level of total VOC and the linoleum had a strong odour with a low level of total VOC.
The explanation lies in the chemical family composition of the emission.
The PVC emission contains mainly alkanes compounds (non odorous family) whereas the linoleum contains also odorous chemical families like carboxylic acids and aldehydes.