Volatile organic compounds (VOCs) refers to organic chemical compounds which have significant vapour pressures. This book presents current research in volatile organic compounds, including the effect of transition metals on the reductive dechlorination of COCs by iron-bearing soil minerals; photocatalytic degradtion of VOC gases using a short wavelength UV light and water droplets; catalytic incineration of VOCs; transport of VOCs in polymers; sources and elimination of VOCs and in-vivo analysis of palm wine VOCs by proton transfer reaction-mass spectrometry.