Editing Nitrogen (section)

===Gas===
Although nitrogen is non-toxic, when released into an enclosed space it can displace oxygen, and therefore presents an [[Nitrogen asphyxiation|asphyxiation]] hazard. This may happen with few warning symptoms, since the human [[carotid body]] is a relatively poor and slow low-oxygen (hypoxia) sensing system.<ref>{{cite web|url=http://www.bath.ac.uk/internal/bio-sci/bbsafe/asphyx.htm |title=Biology Safety&nbsp;– Cryogenic materials. The risks posed by them |publisher=University of Bath |access-date=2007-01-03 |url-status=dead |archive-url=https://web.archive.org/web/20070206095504/http://www.bath.ac.uk/internal/bio-sci/bbsafe/asphyx.htm |archive-date=February 6, 2007 }}</ref> An example occurred shortly before the launch of the [[STS-1|first Space Shuttle mission]] on March 19, 1981, when two technicians died from asphyxiation after they walked into a space located in the [[Mobile launcher platform#Saturn V and Space Shuttle|Space Shuttle's mobile launcher platform]] that was pressurised with pure nitrogen as a precaution against fire.<ref>{{cite news| title = Space Shuttle Columbia Fast Facts| url = http://www.cnn.com/2013/09/30/us/space-shuttle-columbia-fast-facts| date = September 30, 2013| publisher = CNN| access-date = January 20, 2016| archive-date = February 2, 2016| archive-url = https://web.archive.org/web/20160202181327/http://www.cnn.com/2013/09/30/us/space-shuttle-columbia-fast-facts| url-status = live}}</ref>

When inhaled at high [[partial pressure]]s (more than about 4 bar, encountered at depths below about 30&nbsp;m in [[scuba diving]]), nitrogen is an anaesthetic agent, causing [[nitrogen narcosis]], a temporary state of mental impairment similar to [[nitrous oxide]] intoxication.<ref>{{Cite journal|last1=Fowler|first1=B.|last2=Ackles|first2=K. N.|last3=Porlier|first3=G.|title=Effects of inert gas narcosis on behavior – a critical review|journal=Undersea Biomed. Res.|volume=12|issue=4|pages=369–402|year=1985|pmid=4082343|url=http://archive.rubicon-foundation.org/3019|access-date=2008-09-21|archive-url=https://web.archive.org/web/20101225052236/http://archive.rubicon-foundation.org/3019|archive-date=2010-12-25|url-status=usurped}}</ref><ref>{{Cite journal|author=Rogers, W. H.|author2=Moeller, G.|title=Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis|journal=Undersea Biomed. Res.|volume=16|issue=3|pages=227–32|year=1989|oclc=2068005|pmid=2741255|url=http://archive.rubicon-foundation.org/2522|access-date=2008-09-21|archive-url=https://web.archive.org/web/20090901020853/http://archive.rubicon-foundation.org/2522|archive-date=2009-09-01|url-status=usurped}}</ref>

Nitrogen dissolves in the [[blood]] and body fats. Rapid decompression (as when divers ascend too quickly or astronauts decompress too quickly from cabin pressure to spacesuit pressure) can lead to a potentially fatal condition called [[decompression sickness]] (formerly known as caisson sickness or ''the bends''), when nitrogen bubbles form in the bloodstream, nerves, joints, and other sensitive or vital areas.<ref name="DCShx">{{Cite journal|last=Acott|first=C.|title=A brief history of diving and decompression illness|journal=South Pacific Underwater Medicine Society Journal|volume=29|issue=2|year=1999|oclc=16986801|url=http://archive.rubicon-foundation.org/6004|access-date=2008-09-21|archive-date=2011-09-05|archive-url=https://web.archive.org/web/20110905152645/http://archive.rubicon-foundation.org/6004|url-status=usurped}}</ref><ref name="Kindwall">{{Cite journal|last1=Kindwall|first1=E. P.|last2=Baz|first2=A.|last3=Lightfoot|first3=E. N.|last4=Lanphier|first4=E. H.|last5=Seireg|first5=A.|title=Nitrogen elimination in man during decompression|journal=Undersea Biomed. Res.|volume=2|issue=4|pages=285–97|year=1975|oclc=2068005|pmid=1226586|url=http://archive.rubicon-foundation.org/2741|access-date=2008-09-21|archive-url=https://web.archive.org/web/20110727224419/http://archive.rubicon-foundation.org/2741|archive-date=2011-07-27|url-status=usurped}}</ref> Bubbles from other "inert" gases (gases other than carbon dioxide and oxygen) cause the same effects, so replacement of nitrogen in [[breathing gas]]es may prevent nitrogen narcosis, but does not prevent decompression sickness.<ref name="usn1">{{Cite book|title=US Navy Diving Manual, 6th revision|date=2006|publisher=US Naval Sea Systems Command|location=United States|url=http://www.supsalv.org/00c3_publications.asp?destPage=00c3&pageID=3.9|access-date=2008-04-24|archive-date=2008-05-02|archive-url=https://web.archive.org/web/20080502023541/http://www.supsalv.org/00c3_publications.asp?destPage=00c3&pageId=3.9|url-status=live}}</ref>