The burning of fossil fuel can create another atmospheric pollution problem known as Photochemical Smog. Photochemical smog is a condition that develops when primary pollutants like oxides of nitrogen, Volatile organic compounds created from fossil fuel combustion interact under the influence of sunlight to produce secondary pollutants. The major chemical pollutants in Photochemical smog are NO and NO2,VOCs( volatile organic compounds), Ozone (O3) and PAN (Peroxyacetyl Nitrate). NO2 decreases visibility due to yellowish colour. It also contributes to heart and lung problem. Ozone( O3 ) contributes to bronchial constriction, coughing and wheezing. PAN causes eye irritation, high toxicity to plants.