OdourICH is an abbreviation for ODOUR Intensity, Character and Hedonic tone.
Odourich measurement technique has been developed from sensory measurement technique. The procedure follows both Australian and ISO standards AS/NZS 2542.2.3 - 2014, Sensory analysis - Specific methods - Guidelines for the use of quantitative response scales (rating) and ISO 4121, 2003, Sensory analysis -- Guidelines for the use of quantitative response scales. Both the International Organization for Standardization and Standards Australia have broadened the scope of the sensory analysis standards to industries other than food, such as the environment.
Odour concentration measurement uses dilution-to-threshold technique. In contrast, odourich measurement presents the air sample “as it is”, normally in a controlled environment, to the same group of panellists used in the odour concentration measurement. The trained and screened panellists, follow the selection procedures in the odour measurement, which has already been checked against the standard odour reference (n-butanol). They are also trained for the assessment of odour intensity, character and hedonic tone. This improvement will significantly improve the reliability of the testing results.
Odourich measurement is used to determine the odour level at the ambient environment where odour concentration measurement cannot be applied. It studies the ambient odour level where odour is perceived or where the odour impact takes place. It answers questions such as whether the environment has an odour, how strong the odour is, what the odour is and how bad the odour is. Three attributes, known as odour ICH (intensity, character, hedonic tone), are assessed:
- an intensity scale (7 levels) is used to rate the odour intensity
- an odour wheel (8 level-one categories and 60 level-two categories) is specifically developed for categorising the environmental odour
- a hedonic scale (9 levels) is used to rate hedonic tone
Odourich measurement allows the ambient air, collected in the special bag, to be evaluated for their sensory attributes. The DynaScent digital olfactometer presents the samples without dilution to a group of trained panellists, collects their responses and calculates the results.