Difference in the odor concentrations measured by the triangle odor bag method and dynamic olfactometry
1Tokyo Metropolitan Research Institute for Environmental Protection, 1-7-5 Shinsuna, Koto-ku, Tokyo 136-0075, Japan. ueno-h@tokyokankyo.jp
Summary
The triangle odor bag method often overestimates odor concentration compared to dynamic olfactometry. Applying European standards for panel selection minimizes this difference, improving odor measurement accuracy.
Area of Science:
- Environmental Science
- Analytical Chemistry
- Sensory Science
Background:
- Odor pollution is a significant environmental concern, necessitating accurate measurement techniques.
- Japan's offensive odor control law utilizes the triangle odor bag method for odor assessment.
- European standard EN 13725 defines dynamic olfactometry, a widely recognized method for odor measurement.
Purpose of the Study:
- To compare the odor concentration measurements obtained by the triangle odor bag method and dynamic olfactometry.
- To identify discrepancies between the two methods and explore factors influencing them.
- To evaluate the applicability of European panel selection criteria to the triangle odor bag method.
Main Methods:
- Odor samples were analyzed using both the triangle odor bag method and dynamic olfactometry (EN 13725).
- Odor concentration was measured using both forced choice and Yes/No response modes.
- Panel selection criteria from EN 13725 were applied to the triangle odor bag method.
- Individual odor threshold data for n-butanol were considered.
Main Results:
- The triangle odor bag method generally yielded higher odor concentration values than dynamic olfactometry in forced choice mode.
- Measurements from both methods showed good agreement in Yes/No mode when using the same sensory panel.
- Implementing EN 13725 panel selection criteria reduced the differences between the two measurement techniques.
- The European panel selection criteria were effective in mitigating equipment-related measurement variations.
Conclusions:
- The triangle odor bag method may overestimate odor concentrations, particularly in forced choice settings.
- Standardized panel selection, as defined by EN 13725, is crucial for harmonizing odor measurement results.
- While effective, the strictness of European panel selection criteria warrants consideration in relation to individual sensory thresholds.
