nitrous oxide
Colourless, nonflammable gas that, used in conjunction with oxygen, reduces sensitivity to pain. In higher doses it is an anaesthetic. Well tolerated, it is often combined with other anaesthetic gases to enable them to be used in lower doses. It may be self-administered; for example, in childbirth. It is a greenhouse gas; about 10% of nitrous oxide released into the atmosphere comes from the manufacture of nylon. It used to be known as ‘laughing gas’.
| According to the US Environmental Protection Agency (EPA) in 1998, nitrous oxide is responsible for more than 7% of the warming effect of US greenhouse gas emissions. Nitrous oxide emissions increased in the USA by 23% 1990–96. |
