Chemical substances have a specific chemical composition. The concept of chemicals has firmly been established in the late eighteenth century. These have been widely used for decades. They have made a drastic change in our life style, life quality and expectancy. There are various kinds of chemicals which can be used for different purposes like research, industrial & household settings, agriculture, medicines, explosives etc. Despite the virtues, chemicals also have risks. These could be proved hazardous for human health and environment. In spite of this, chemicals have widely been used for all good purposes mentioned above.