Odour is a perception of smell, it may range from an unpleasant odour (like the rotten smell of garbage) to a pleasant one (fragrance). The effect of odour varies from person to person, but at significantly higher concentrations, harmful odours may have a direct effect on human health. It generally leads to vomiting, headaches, nausea, stress, anxiety, frustration, restriction in outdoor activities.

As per official estimates, around 62 million tonnes of solid waste is generated every year, and by 2030, it is expected to reach 165 million tonnes. Of the 62 million tonnes, 43 million tonnes are collected, and only 12 million tonnes are treated. This means the rest 31 million tonnes go untreated and are dumped in landfill sites, and this number is expected to grow as the total amount of waste increases.

Degradation of waste at landfills and dumpyards generates gases like Ammonia (NH3), Hydrogen Sulfide (H2S), SOx, NOx, Total Volatile Organic Compounds (TVOCs), Methane (CH4), Methyl Mercaptan, etc. therefore, it becomes mandatory for some odour management system to be in place for landfills and dumpyards.

The mismanagement of waste in these landfills gives rise to harmful and odourful gaseous contaminants. The World Health Organization recognizes these odours as pollution and says it affects the quality of life and social well-being of individuals.