Various kinds of raw materials from crude oil are produced in petrochemical plants, these include gasoline and other fuels, lubricants or asphalt. Oil undergoes complex chemical processes in specialized factories. Usually refinery chimneys are visible from afar and they do not add any charm to the landscapes of cities where petrochemical plants are located. They also pose a threat to the environment, which is why more and more factories are forced to take measures to reduce emissions of harmful gases.