Carbon dioxide equivalent of carbon dioxide. Equivalent (e) is the concentration of that would cause the same level of radiative forcing as a given type and concentration of greenhouse gas. Examples of such greenhouse gases are methane, perfluorocarbons, and nitrous oxide. e is expressed as parts per million by volume, ppmv. Carbon dioxide equivalent Carbon dioxide equivalent (CDE) and equivalent carbon dioxide (e and eq) are two related but distinct measures for describing how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of carbon dioxide () as the reference. Carbon dioxide
Nitrous oxide because has a very short duration under normal circumstances, it is less likely to be neurotoxic than other NMDA antagonists. Indeed, in rodents, short-term exposure results in only mild injury that is rapidly reversible, and neuronal death occurs only after constant and sustained exposure. Nitrous oxide also may cause neurotoxicity after extended exposure because of hypoxia. This is especially true of non-medical formulations such as whipped-cream chargers (also known as "whippets" or "nangs"), which never contain oxygen, since oxygen makes cream rancid. Additionally, nitrous oxide depletes vitamin B levels. This can cause serious neurotoxicity if the user has preexisting vitamin