Editing Cyanide (section)

===Niche uses===
[[Potassium ferrocyanide]] is used to achieve a blue color on cast [[bronze sculpture]]s during the final finishing stage of the sculpture. On its own, it will produce a very dark shade of blue and is often mixed with other chemicals to achieve the desired tint and hue. It is applied using a torch and paint brush while wearing the standard safety equipment used for any patina application: rubber gloves, safety glasses, and a respirator. The actual amount of cyanide in the mixture varies according to the recipes used by each foundry.

Cyanide is also used in [[jewelry]]-making and certain kinds of [[photography]] such as [[sepia toning]].

Although usually thought to be toxic, cyanide and cyanohydrins increase germination in various plant species.<ref>{{Cite journal|doi=10.1104/pp.52.1.23 |last1=Taylorson |first1=R. |last2=Hendricks |year=1973 |first2=SB |title=Promotion of Seed Germination by Cyanide |journal=Plant Physiol. |volume=52 |issue=1 |pages=23–27 |pmid=16658492 |pmc=366431}}</ref><ref>{{Cite journal|last1=Mullick |first1=P. |year=1967 |last2=Chatterji |first2=U. N. |title=Effect of sodium cyanide on germination of two leguminous seeds |journal=Plant Systematics and Evolution |volume=114 |issue=1 |pages=88–91|doi=10.1007/BF01373937|bibcode=1967PSyEv.114...88M |s2cid=2533762}}</ref>

====Human poisoning====
{{main|Cyanide poisoning}}
Deliberate cyanide poisoning of humans has occurred many times throughout history.<ref>{{Cite book
|title=Medical Management of Chemical Casualties Handbook
|edition=4th
|last1=Bernan
|publisher=Government Printing Off
|year=2008
|isbn=978-0-16-081320-7
|page=41
|url=https://books.google.com/books?id=oiw2ZzsBvsoC}}, [https://books.google.com/books?id=oiw2ZzsBvsoC&pg=PA41 Extract p. 41]
</ref>
Common salts such as [[sodium cyanide]] are involatile but water-soluble, so are poisonous by ingestion. [[Hydrogen cyanide]] is a gas, making it more indiscriminately dangerous, however it is lighter than air and rapidly disperses up into the atmosphere, which makes it ineffective as a [[chemical weapon]].

====Food additive====
Because of the high stability of their complexation with [[iron]], ferrocyanides ([[Sodium ferrocyanide]] E535, [[Potassium ferrocyanide]] E536, and Calcium ferrocyanide E538<ref>{{cite book
|title=Benders' dictionary of nutrition and food technology
|edition=7th
|first1=David A.
|last1=Bender
|first2=Arnold Eric
|last2=Bender
|publisher=Woodhead Publishing
|year=1997
|isbn=978-1-85573-475-3
|page=459
|url=https://books.google.com/books?id=IrYfDEl7XPYC}} [https://books.google.com/books?id=IrYfDEl7XPYC&pg=PA459 Extract of page 459]
</ref>) do not decompose to lethal levels in the human body and are used in the food industry as, e.g., an [[anticaking agent]] in [[table salt]].<ref>{{cite book
|title=Geochemical processes in soil and groundwater: measurement – modelling – upscaling
|first1=Horst D.
|last1=Schulz
|first2=Astrid
|last2=Hadeler
|author3=Deutsche Forschungsgemeinschaft
|publisher=Wiley-VCH
|year=2003
|isbn=978-3-527-27766-7
|page=67
|doi=10.1002/9783527609703
|url=http://onlinelibrary.wiley.com/doi/10.1002/9783527609703}}
</ref>