Indoor air is a complex and dynamic mixture of a huge variety of volatiles and particulate matter. Some of the constituents are odorous and originate from various sources such as construction materials, furniture, cleaning products, inhabitants and many more. Therefore, every indoor environment has a unique chemical composition in its air space. Volatile organic compounds and odorants in indoor air may cause psychological and/or physiological discomfort in humans. To reduce unwanted indoor air pollutants, it is of great interest to evaluate their sources and chemical structures. This chapter will provide an overview of methods used to evaluate indoor air and material emissions as well as current knowledge of odorants emitted by selected and common sources of indoor odors and in addition human bio-effluents. Measures to avoid and reduce odors as well as health concerns associated with indoor odorants will be discussed. Importantly, this chapter focuses on odorous organic volatiles present in indoor environments - non-odorous volatile organic compounds that can also affect indoor air quality will be mentioned only in passing.
