Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A Hazardous waste is waste that poses substantial or potential threats to public health or the environment. These wastes may be found in different physical states such as gaseous, liquids, or solids. A hazardous waste is a special type of waste because it cannot be disposed of by common means like other by-products of our everyday lives. Learn more about the many various types of hazardous waste in this book.