Odorous substances can be formed from industrial sources include both inorganic and organic gases and particulate. Many odorous compounds result from emissions from chemical processes in industries. Hydrogen Sulphide (H2S), mercaptan, organic sulphide, ammonia, amines, Sulfur, nitrogen and many VOCs generated in industrial process and in municipal waste treatment are the main content in various odorous substances. Though foul odor may not cause direct damage to health, toxic stimulants of odor may cause ill health or respiratory symptoms.