Editing Halocarbon (section)

== History and context ==
A few halocarbons are produced in massive amounts by microorganisms. For example, several million tons of [[methyl bromide]] are estimated to be produced by marine organisms annually. Most of the halocarbons encountered in everyday life – solvents, medicines, plastics – are man-made. The first synthesis of halocarbons was achieved in the early 1800s. Production began accelerating when their useful properties as solvents and anesthetics were discovered. Development of plastics and synthetic elastomers has led to greatly expanded scale of production. A substantial percentage of drugs are halocarbons.

=== Natural halocarbons ===
A large amount of the naturally occurring halocarbons, such as [[Dioxins and dioxin-like compounds|dioxins]], are created by wood fire and [[Volcanism|volcanic activity]]. A third major source is marine algae, which produce several chlorinated [[methane]] and [[ethane]] containing compounds. Several thousand complex halocarbons are known to be produced mainly by marine species. Although chlorine compounds are the majority of the discovered compounds, bromides, iodides and fluorides have also been found in nature. [[Tyrian purple]] is a bromide and is produced by certain sea snails. [[Thyroxine]] is secreted by the [[thyroid gland]] and is an iodide. The highly toxic [[Fluoroacetic acid|fluoroacetate]] is one of the rare natural organofluorides and is produced by certain plants.<ref name="Gribble98">{{Citation
 | title = Naturally Occurring Organohalogen Compounds
 | author = Gordon W. Gribble
 | journal = [[Acc. Chem. Res.]]
 | volume = 31 | issue = 3 | pages = 141–152
 | year = 1998 | doi = 10.1021/ar9701777
}}.</ref><ref name="Gribble99">{{Citation
 | title = The diversity of naturally occurring organobromine compounds
 | author = Gordon W. Gribble
 | journal = [[Chemical Society Reviews]]
 | volume = 28 | issue = 5 | pages = 335–346
 | year = 1999 | doi = 10.1039/a900201d
}}.</ref><ref name="Gribble02">{{Citation
 | title = Naturally Occurring Organofluorines
 | editor1-first = A. H. | editor1-last = Neilson
 | author = Gordon W. Gribble
 | journal = Organofluorines
 | series = The Handbook of Environmental Chemistry | volume = 3n | pages = 121–136
 | year = 2002 | doi = 10.1007/10721878
| isbn = 3-540-42064-9 }}.</ref>