Oil is divided into the categories of oils based on the risk and the possibility of employing them, namely:
The first category: light oils, so characterized their transparency and quick ignition and float above the water as well as the usability of evaporation and features toxicity include types of oil is high quality.
Category II: heavy oils have Alaltsaq property, the color brown or black as it is unsinkable and the danger they may stick to fish, animals and birds, which may cause poisoning.
Category III: oils non-adhesion, where the float on the surface of the water and be in the form of wax and hard to attach to the soil or birds and animals, and the degree of toxicity less and can be disposed of by washing with water.
The fourth category: liquid oils and are non-toxic color with dark brown or black and thermoplastic melt, leading to difficulty cleaned and include heavy oil types.
