It studies the transformation of crude oil (petroleum) and natural gas into useful products or raw materials. These petrochemicals have become an essential part of the chemical industry today.To many, this comes as a surprise. The word "chemistry" itself conjures up a world of mystery - what it really does is very much taken for granted. Yet it is a fascinating science and an inventive business sector, constantly adapting to new environments and meeting new challenges. Chemicals derived from petroleum or natural gas - petrochemicals - are an essential part of the chemical industry today. Petrochemistry is a fairly young industry; it only started to grow in the 1940s, more than 80 years after the drilling of the first commercial oil well in 1859. During World War II, the demand for synthetic materials to replace costly and sometimes less efficient products caused the petrochemical industry to develop into a major player in today's economy and society.