Essential oils are obtained from plants. They are volatile liquids that have odor of their plant source. They are used in perfumes, flavoring essences, and in aromatherapy.Fixed oils are found in animals and in plants. They are used in mainly cooking. They are also used in the manufacture of soaps, lubricants, paints and varnishes. Mineral oils are composed of a mixture of hydrocarbons and are used as fuels and lubricants.

These days, man seeks oil under the seas and in places which were once a part of the seabed. Petroleum is called fossil fuel as it has organic origins. Ancient man knew of the existence of petroleum. The American Indians used it for its medicinal value. The actual exploitation of oil fields began with the first commercial well in Pennsylvania in 1859.

At first USA was the leading producer of petroleum. By the end of the 60’s the Middle East countries began to out produce USA and soon became the oil sultans. Their immense oil reserves practically led the whole world to depend on them for the supply of this fossil fuel for their transport and industrial purposes.

From crude oil, various products are made after the processes of distillation and other processes. Some of the products are fuel oil, gasoline, kerosene, diesel, lubricating oil, paraffin wax and petroleum jelly. Petroleum products and chemicals are used in large quantities in the manufacture of detergents, artificial fibres, plastics, insecticides, fertilizers, medicines, toiletries and synthetic rubber. Aviation fuel is a volatile form of gasoline.

Petroleum or crude oil is a natural mineral oil. It is a greenish brown flammable liquid found underground in the permeable rocks. This oil is the remains of marine plants and animals that died millions of years ago. They were covered by sand and mud at the bottom of the sea. Over the years they were buried deeper and deeper and gradually the mud and sand turned to rock due to the great pressure while the organic remains turned to oil and natural gas. Some seeped to the surface and escaped while some were trapped between the layers of solid rock that were impenetrable. In other places the earth movements twisted the layers of rocks and made natural traps for the petroleum.

These days the burning of petroleum is of great concern to mankind. Fossil fuel is one of the greatest contributors to the pollution of the air. Even worse are the oil spills that take place ever so often on the land and seas during drilling and transportation. These spills destroy plants and animal life resulting in the damage of the fragile environmental balance of our planet.