Kyoto Protocol European Union-15, made up of 15 states at the time of the Kyoto negotiations) commit themselves to binding targets for GHG emissions. The targets apply to the four greenhouse gases carbon dioxide (), methane (), nitrous oxide (), sulphur hexafluoride (), and two groups of gases, hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). The six GHG are translated into CO equivalents in determining reductions in emissions. These reduction targets are in addition to the industrial gases, chlorofluorocarbons, or CFCs, which are dealt with under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. Under the Protocol, only the Annex I
Nitrous oxide B levels should be checked in people with risk factors for vitamin B deficiency prior to using nitrous oxide anaesthesia. Several experimental studies in rats indicate that chronic exposure of pregnant females to nitrous oxide may have adverse effects on the developing fetus. At room temperature (20 °C (68 °F)) the saturated vapour pressure is 50.525 bar, rising up to 72.45 bar at —the critical temperature. The pressure curve is thus unusually sensitive to temperature. Liquid nitrous oxide acts as a good solvent for many organic compounds; liquid mixtures may form shock sensitive explosives. As with many strong oxidisers, contamination