Ammonia gas is a combination of Nitrogen and Hydrogen with the formula NH3. It is normally encountered as a gas with a characteristic pungent odour. Ammonia gas contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers.
It is used to control plant pests such as aphids, thrips, whiteflies and scales. Ammonia gas can be used in a wide range of refrigeration applications including : thermal storage systems, HVAC chillers, process cooling and air-conditioning, food processing and supermarkets.