Editing Xenon (section)

== Precautions ==
{{Chembox
| container_only = yes
| Section7={{Chembox Hazards
| NFPA-H = 0
| NFPA-F = 0
| NFPA-R = 0
| NFPA-S = SA
| NFPA_ref = <ref name="NFPA704Xe">{{cite report
| url       = https://www.airgas.com/msds/001050.pdf
| title     = Safety Data Sheet: Xenon
| date      = February 15, 2018
| publisher = [[Airgas]]
}}</ref>
 }}
}}

Xenon gas can be safely kept in normal sealed glass or metal containers at [[standard temperature and pressure]]. However, it readily dissolves in most plastics and rubber, and will gradually escape from a container sealed with such materials.<ref>{{
cite journal
 |last=LeBlanc|first=Adrian D.
 |author2=Johnson, Philip C.
 |title=The handling of xenon-133 in clinical studies
 |year=1971|journal=Physics in Medicine and Biology
 |volume=16|issue=1|pages=105–9
 |doi=10.1088/0031-9155/16/1/310
 |pmid=5579743|bibcode = 1971PMB....16..105L |s2cid=250787824
}}</ref> Xenon is non-[[toxic]], although it does dissolve in blood and belongs to a select group of substances that penetrate the [[blood–brain barrier]], causing mild to full surgical [[anesthesia]] when inhaled in high concentrations with oxygen.<ref name="finkel68" />

The [[speed of sound]] in xenon gas (169&nbsp;m/s) is less than that in air<ref>169.44&nbsp;m/s in xenon (at {{cvt|0|C}} and 107&nbsp;kPa), compared to 344&nbsp;m/s in air. See: {{cite journal
| last    = Vacek
| first   = V.
| author2 = Hallewell, G.
| author3 = Lindsay, S.
| title   = Velocity of sound measurements in gaseous per-fluorocarbons and their mixtures
| journal = Fluid Phase Equilibria
| year    = 2001
| volume  = 185
| issue   = 1–2
| pages   = 305–314
| doi     = 10.1016/S0378-3812(01)00479-4
| bibcode = 2001FlPEq.185..305V
}}</ref> because the average velocity of the heavy xenon atoms is less than that of nitrogen and oxygen molecules in air. Hence, xenon vibrates more slowly in the [[vocal tract|vocal cords]] when exhaled and produces lowered voice tones (low-frequency-enhanced sounds, but the [[fundamental frequency]] or [[Pitch (music)|pitch]] does not change), an effect opposite to the high-toned voice produced in [[helium]]. Specifically, when the [[vocal tract]] is filled with xenon gas, its natural resonant frequency becomes lower than when it is filled with air. Thus, the low frequencies of the sound wave produced by the same direct vibration of the [[vocal cords]] would be enhanced, resulting in a change of the [[timbre]] of the sound amplified by the vocal tract. Like helium, xenon does not satisfy the body's need for oxygen, and it is both a simple [[asphyxiant gas|asphyxiant]] and an anesthetic more powerful than nitrous oxide; consequently, and because xenon is expensive, many universities have prohibited the voice stunt as a general chemistry demonstration.<ref>{{Cite web
| title       = Helium Voice or other effects
| url         = https://www.bbc.co.uk/safety/resources/aztopics/bbc.com/safety/resources/aztopics/sfx-helium-voice-effects/
| access-date = May 6, 2024
| publisher   = BBC
| language    = en
}}</ref> The gas [[sulfur hexafluoride]] is similar to xenon in molecular weight (146 versus 131), less expensive, and though an asphyxiant, not toxic or anesthetic; it is often substituted in these demonstrations.<ref>{{cite web
| first        = Steve
| last         = Spangler
| date         = 2007
| url          = http://www.stevespanglerscience.com/experiment/from-donald-duck-to-barry-white-how-gases-change-your-voice
| title        = Anti-Helium – Sulfur Hexafluoride
| publisher    = Steve Spangler Science
| access-date  = October 4, 2007
| url-status   = dead
| archive-url  = https://web.archive.org/web/20070929003314/http://www.stevespanglerscience.com/experiment/from-donald-duck-to-barry-white-how-gases-change-your-voice
| archive-date = September 29, 2007
}}</ref>

Dense gases such as xenon and sulfur hexafluoride can be breathed safely when mixed with at least 20% oxygen. Xenon at 80% concentration along with 20% oxygen rapidly produces the unconsciousness of general anesthesia. Breathing mixes gases of different densities very effectively and rapidly so that heavier gases are purged along with the oxygen, and do not accumulate at the bottom of the lungs.<ref>{{cite journal
| last    = Yamaguchi
| first   = K.
| author2 = Soejima, K.
| author3 = Koda, E.
| author4 = Sugiyama, N
| title   = Inhaling Gas With Different CT Densities Allows Detection of Abnormalities in the Lung Periphery of Patients With Smoking-Induced COPD
| journal = [[Chest (journal)|Chest]]
| year    = 2001
| volume  = 120
| pages   = 1907–16
| doi     = 10.1378/chest.120.6.1907
| pmid    = 11742921
| issue   = 6
}}</ref> There is, however, a danger associated with any heavy gas in large quantities: it may sit invisibly in a container, and a person who enters an area filled with an odorless, colorless gas may be asphyxiated without warning. Xenon is rarely used in large enough quantities for this to be a concern, though the potential for danger exists any time a tank or container of xenon is kept in an unventilated space.<ref>{{cite web
| author       = Staff
| date         = August 1, 2007
| url          = http://www-group.slac.stanford.edu/esh/hazardous_substances/cryogenic/p_hazards.htm
| title        = Cryogenic and Oxygen Deficiency Hazard Safety
| publisher    = Stanford Linear Accelerator Center
| access-date  = October 10, 2007
| archive-url  = https://web.archive.org/web/20070609173316/http://www-group.slac.stanford.edu/esh/hazardous_substances/cryogenic/p_hazards.htm
| archive-date = June 9, 2007
}}</ref>

Water-soluble xenon compounds such as [[monosodium xenate]] are moderately toxic, but have a very short half-life of the body – [[intravenous]]ly injected xenate is reduced to elemental xenon in about a minute.<ref name="finkel68">{{cite web
| last        = Finkel
| first       = A. J.
| author2     = Katz, J. J.
| author3     = Miller, C. E.
| date        = April 1, 1968
| url         = https://ntrs.nasa.gov/citations/19680000076
| title       = Metabolic and toxicological effects of water-soluble xenon compounds are studied
| publisher   = NASA
| access-date = March 18, 2022
}}</ref>