Release of organic compounds and particulate matter from products, materials, and electrical devices in the indoor environment

In the indoor environment, the need for the reliable assessment of human exposure to indoor pollutants is still attracting increasing attention. This, however, requires a detailed understanding of the relevant compounds; their sources, physical and chemical properties, dynamics, and reactions; and their distribution among the gas phase, airborne particles, and settled dust as well as the availability of modern measurement techniques. With respect to a healthy indoor environment, only low-emitting products, which do not influence the indoor air quality in a negative way, should be used in a building. Therefore, materials and products for indoor use need to be evaluated for their chemical emissions. The demand for standardized test methods under laboratory conditions has resulted in several guidelines for determination of emission rates by use of test chambers and cells. Many studies have shown that the types of sources in occupational and residential indoor environments, the spectrum of emitting compounds, and duration of emission cover a wide range. Furthermore, it has now been recognized that both primary and secondary emissions may affect indoor air quality. The problem might become dominant when components of different materials can react with each other or when catalytic materials are applied. As a consequence, modern product development should also consider secondary products, which seem to be of importance for long-term emissions. In order to characterize the release of compounds and particles from materials under realistic conditions, it is important to study the influence of processing, substrate, and climatic parameters on emitting species and emission rates.