Volatile Organic Compounds (VOCs) have anthropogenic and biogenic origins. At the Earth's scale, the natural sources represent a great part of the total VOCs present in the atmosphere but in industrialised regions, anthropogenic ones become the majority due to the various human activities related mainly to chemical industries (liquid fuels, solvents, thinners, detergents, degreasers, cleaners and lubricants). Almost all VOCs have effects on human health and many of them are even carcinogenic. It is also known that the VOCs can affect the central nervous system and may have mutagenic effects. Apart from human health, they also play an important role towards the environment, especially in the atmospheric pollution processes. Indeed, VOCs emissions lead to the promotion of photochemical reactions in the atmosphere (ozone formation, depletion of the stratospheric ozone layer and formation of photochemical smog). The present book gathers and presents some current research from across the world conducted by scientific experts in their fields. In seven valuable contributions, it deals with the emission and the environmental impact as well as the control of the Volatile Organic Compounds.