Toward an Objective Odor Characterization of Compounds Emitted in Industrial Zones: the “langage Des Nez®” as an Efficient Tool

Abstract

When studying odour nuisance, sensory analyses show many advantages making these approaches essential along with chemical analyses. However, sensory analyses face the problem of subjectivity related to the panel. This subjectivity, even if it may be cured when assessing the odour intensity, is still an obstacle when describing the odour profile. One method offers a solution: The Langage des Nez^®. This is an approach that uses definite chemical referents as odour descriptors. The aim of this work is to experiment the efficiency of this method when analysing the odour of incidentally emitted compounds in industrial zones.
The odour of 44 chemical compound that can be released incidentally in the industrial zone of the city of Le Havre, France, was described using the Langage des Nez^®. A trained panel was asked to describe the odour of each compound using one, two or three referents from the Langage des Nez^® and attributing a score over 9 for the chosen referents as a degree of representativity. Based on the frequency of citation of each referent and the attributed scores, one two or three referents were chosen as odour descriptors. The obtained results reveal that no correlation can be clearly established between the chemical structure of the compound and its odour descriptor(s). The difference between odour profiles obtained using conventional methods from the literature and the ones using Langage des Nez^® revealed that the later offers a more objective and precise lexicon. This work shows that the sensory approaches are indispensable when assessing odour nuisance. The use of Langage des Nez^® upgrades these analyses to an objective and reliable tool to anticipate potentially emitted odours during industrial incidents in any industrial city.