This white paper discusses the impact of odours on human health and well-being and details various methods for measuring odours.

• Odours are caused by volatile organic and inorganic compounds that stimulate olfactory receptors in the nose. Although odour sensitivity varies from person to person, odorous compounds can negatively impact human health and well-being at high concentrations. Some odours are pleasant, and others can be unpleasant and even cause health problems like headaches, nausea, and respiratory irritation.
• There are five factors that determine the development of odour nuisance, known as FIDOL factors: Frequency, Intensity, Duration, Offensiveness, and Location.
• Several methods for measuring odours include olfactory analysis, chemical analysis, and sensor technology. Olfactory analysis uses human assessors to smell and judge the intensity and character of an odour. Chemical analysis uses instruments to measure the composition of an odour. Sensor technology uses electronic sensors to detect and measure odour levels.
• Odour thresholds are the lowest concentration of an odorant in the air that a human being can detect. There are different types of odour thresholds, including odour detection threshold (ODT) and odour recognition threshold (ORT).
• Odour units are used to quantify odours. Three main odour units exist: the American and Australian Odour Unit (OU), the European Odour Unit (OUE/m3), and Oizom’s Odour Unit (OU). Each unit is determined using a slightly different method, but all serve the purpose of expressing odour strength in a measurable way.
• Odour monitoring systems are vital in maintaining air quality, ensuring compliance with regulations, and fostering positive relationships between industries and communities. As technology continues to advance, odour monitoring systems are becoming increasingly sophisticated, offering valuable data for industries around the world. 
• By implementing these systems, businesses can proactively manage odour emissions, stay ahead of regulatory requirements, and contribute to creating healthier and more enjoyable living environments.