Nitrous oxide, commonly known as laughing gas, withtheformulaN2O. It is an oxide of nitrogen. At room temperature, it is a colorless, non-flammable gas, with a slightly sweet odour and taste. It is used in surgery and dentistry for its anaesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational useas a dissociative anaesthetic. It is also used as anoxidizer in the launching of rockets and in motor racing to increase the power output of engines. At elevated temperatures, nitrous oxide is a powerful oxidizer similar to molecular oxygen. Nitrous oxide gives rise to NO (nitric oxide) on reaction with oxygen atoms, and this NO in turn reacts with ozone. As a result, it is the main naturally occurring regulator Of stratospheric ozone. It is also a major greenhouse Gas and air pollutant. It is on the World Health Organization's List of Essential Medicines, a list of the most important medications needed in a health system.