Development of Odour Intensity Reference Solutions for Environmental Odour Evaluation

For the appropriate evaluation of environmental odours, it is necessary to develop a reliable odour measurement scale. Odour intensity is one of the main odour characterisation parameters and a remarkably common and important sensory indicator of environmental odours. In this study, the odour intensity level between two and four of the six-point odour intensity scale was focused on, and odour intensity reference solutions of representative odorants for environmental odour evaluation were developed. As a result, propionic acid, propylamine, ethyl acetate, and isobutyraldehyde were selected as representative odorants, and three concentration steps of each odorant were determined to cover the odour intensity of two, three, and four of the six-point odour intensity scale. These reference odour solutions will be applicable to the training of inexperienced panel members and reliable on-site investigations of environmental odours.