Editing Styrene (section)

==Hazards==
=== Autopolymerisation ===
As a liquid or a gas, pure styrene will polymerise spontaneously to polystyrene, without the need of external [[Radical initiator|initiators]].<ref>{{cite journal |last1=Miller |first1=A.A. |last2=Mayo |first2=F.R. |title=Oxidation of Unsaturated Compounds. I. The Oxidation of Styrene |journal=Journal of the American Chemical Society |date=March 1956 |volume=78 |issue=5 |pages=1017–1023 |doi=10.1021/ja01586a042|bibcode=1956JAChS..78.1017M }}</ref> This is known as ''autopolymerisation''. At 100&nbsp;°C it will autopolymerise at a rate of ~2% per hour, and more rapidly than this at higher temperatures.<ref name=autopoly1 /> As the autopolymerisation reaction is [[exothermic]] it can be self-accelerating, with a real risk of a [[thermal runaway]], potentially leading to an explosion. Examples include the 2019 explosion of the tanker ''Stolt Groenland'',<ref>{{cite web |title=Report on the investigation of the cargo tank explosion and fire on board the chemical tanker Stolt Groenland |url=https://assets.publishing.service.gov.uk/media/60f93e2cd3bf7f044c51590b/2021-09-StoltGroenland-Report.pdf |publisher=e UK Marine Accident Investigation Branch}}</ref> explosions at the [[Phillips Petroleum Company]] in [[Phillips explosion of 1999|1999]] and [[2000 Phillips explosion|2000]] and overheating styrene tanks leading to the 2020 [[Visakhapatnam gas leak]], which killed several people.<ref>{{cite web |url=https://economictimes.indiatimes.com/news/politics-and-nation/live-updates-eight-dead-several-fall-sick-after-gas-leak-at-lg-poymers-plant-in-visakhapatnam/articleshow/75592838.cms |title=Vizag Gas Leak Live News: Eleven dead, several hospitalised after toxic gas leak from LG Polymers plant |access-date=2020-05-07 |date=2020-05-07 |work=The Economic Times}}</ref><ref>{{cite web |url=https://www.theguardian.com/world/2020/may/07/gas-leak-at-chemical-factory-in-india-kills-hospitalises-lg-polymers |title=Hundreds in hospital after leak at Indian chemical factory closed by lockdown |access-date=2020-05-07 |date=2020-05-07 |newspaper=The Guardian}}</ref> The autopolymerisation reaction can only be kept in check by the continuous addition of [[polymerisation inhibitor]]s.

=== Health effects ===
Styrene is regarded as a "known [[carcinogen]]", especially in case of eye contact, but also in case of skin contact, of ingestion and of inhalation, according to several sources.<ref name="ullstyrene" /><ref>{{cite web |author=MSDS |date=1 November 2010 |title=Material Safety Data Sheet Styrene (monomer) MSDS |url=http://www.sciencelab.com/msds.php?msdsId=9925112 |publisher=[[MSDS]] |access-date=2011-06-11 |url-status=live |archive-url=https://web.archive.org/web/20110807203703/http://www.sciencelab.com/msds.php?msdsId=9925112 |archive-date=7 August 2011|author-link=MSDS }}</ref><ref>{{cite web |title=OPPT Chemical Fact Sheets (Styrene) Fact Sheet: Support Document (CAS No. 100-42-5) |date=December 1994 |url=http://www.epa.gov/chemfact/styre-sd.pdf |publisher=[[US EPA]] |access-date=2011-06-11 |url-status=live |archive-url=https://web.archive.org/web/20101224191345/http://www.epa.gov/chemfact/styre-sd.pdf |archive-date=24 December 2010}}</ref><ref>{{cite web |url=http://www.atsdr.cdc.gov/tfacts53.pdf |title=Archived copy |access-date=2008-04-06 |url-status=live |archive-url=https://web.archive.org/web/20080602233207/http://www.atsdr.cdc.gov/tfacts53.pdf |archive-date=2 June 2008}}</ref> Styrene is largely metabolized into [[styrene oxide]] in humans, resulting from oxidation by [[cytochrome P450]]. [[Styrene oxide]] is considered [[toxic]], [[mutagenic]], and possibly [[carcinogenic]]. Styrene oxide is subsequently hydrolyzed ''in vivo'' to styrene glycol by the enzyme [[epoxide hydrolase]].<ref>{{cite journal | doi = 10.2307/3428333 | first = Kenneth C. | last = Liebman | journal = [[Environmental Health Perspectives]] | volume = 11 | pages = 115–119 | year = 1975 | url = http://ehis.niehs.nih.gov/members/1975/011/11018.PDF | title = Metabolism and toxicity of styrene | jstor = 3428333 | pmid = 809262 | pmc = 1475194}}{{Dead link|date=June 2018 |bot=InternetArchiveBot |fix-attempted=no }}</ref> The [[US Environmental Protection Agency]] (EPA) has described styrene to be "a suspected toxin to the gastrointestinal tract, kidney, and respiratory system, among others".<ref name="epa2004">{{cite web | title=EPA settles case against Phoenix company for toxic chemical reporting violations | publisher=US Environmental Protection Agency | url=http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/09b1cf3cd5813928852570d8005e1603!OpenDocument | access-date=2008-02-11 | url-status=live | archive-url=https://web.archive.org/web/20080925222611/http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/09b1cf3cd5813928852570d8005e1603!OpenDocument | archive-date=25 September 2008}}</ref><ref name="epa2003">{{cite web | title=EPA Fines California Hot Tub Manufacturer for Toxic Chemical Release Reporting Violations | publisher=US Environmental Protection Agency | url=http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/b3249e555c0ed02c852570d8005e1576!OpenDocument | access-date=2008-02-11 | url-status=live | archive-url=https://web.archive.org/web/20080925224819/http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/b3249e555c0ed02c852570d8005e1576!OpenDocument | archive-date=25 September 2008}}</ref> 

On 10 June 2011, the [[National Toxicology Program|US National Toxicology Program]] has described styrene as "reasonably anticipated to be a human carcinogen".<ref name="Harris">{{cite news |last1=Harris |first1=Gardiner |title=Government Says 2 Common Materials Pose Risk of Cancer |date=10 June 2011 |url=https://www.nytimes.com/2011/06/11/health/11cancer.html |newspaper=[[The New York Times]]|access-date=2011-06-11 |url-status=live |archive-url=https://web.archive.org/web/20110613153643/http://www.nytimes.com/2011/06/11/health/11cancer.html |archive-date=13 June 2011}}</ref><ref name="12Report2011">{{cite web |author=National Toxicology Program |title=12th Report on Carcinogens |date=10 June 2011 |publisher=[[National Toxicology Program]] |url=https://ntp.niehs.nih.gov/go/roc12 |access-date=2011-06-11 |url-status=dead |archive-url=https://web.archive.org/web/20110612024850/http://ntp.niehs.nih.gov/index.cfm?objectid=72016262-BDB7-CEBA-FA60E922B18C2540 |archive-date=12 June 2011|author-link=National Toxicology Program}}</ref> However, a [[Statistical Assessment Service|STATS]] author describes<ref>{{cite web |url=http://stats.org/stories/2011/styrene_crosshairs_sept14_11.html |title=STATS: Styrene in the Crosshairs: Competing Standards Confuse Public, Regulators |access-date=2012-09-24 |url-status=dead |archive-url=https://web.archive.org/web/20120609233948/http://www.stats.org/stories/2011/styrene_crosshairs_sept14_11.html |archive-date=9 June 2012}}</ref> a review that was done on scientific literature and concluded that "The available epidemiologic evidence does not support a causal relationship between styrene exposure and any type of human cancer".<ref>Boffetta, P., et al., [http://journals.lww.com/joem/Abstract/2009/11000/Epidemiologic_Studies_of_Styrene_and_Cancer__A.5.aspx Epidemiologic Studies of Styrene and Cancer: A Review of the Literature] {{webarchive |url=https://web.archive.org/web/20121009081133/http://journals.lww.com/joem/Abstract/2009/11000/Epidemiologic_Studies_of_Styrene_and_Cancer__A.5.aspx |date=9 October 2012}}, ''J. Occupational and Environmental Medicine'', Nov.2009, V.51, N.11.</ref> Despite this claim, work has been done by Danish researchers to investigate the relationship between occupational exposure to styrene and cancer. They concluded, "The findings have to be interpreted with caution, due to the company based exposure assessment, but the possible association between exposures in the reinforced [[plastics industry]], mainly styrene, and degenerative disorders of the nervous system and pancreatic cancer, deserves attention".<ref>{{cite journal |last1=Kolstad |first1=HA |last2=Juel |first2=K |last3=Olsen |first3=J |last4=Lynge |first4=E. |title=Exposure to styrene and chronic health effects: mortality and incidence of solid cancers in the Danish reinforced plastics industry. |journal=Occupational and Environmental Medicine |date=May 1995 |volume=52 |pages=320–7 |pmc=1128224 |pmid=7795754 |issue=5 |doi=10.1136/oem.52.5.320}}</ref> In 2012, the [[EPA Network|Danish EPA]] concluded that the styrene data do not support a cancer concern for styrene.<ref>Danish EPA 2011 review {{cite web |url=http://www.compositesworld.com/cdn/cms/uploadedFiles/danish_epa_styrene_review(2).pdf |title=Archived copy |access-date=2012-02-15 |url-status=live |archive-url=https://web.archive.org/web/20140714125424/http://www.compositesworld.com/cdn/cms/uploadedFiles/danish_epa_styrene_review(2).pdf |archive-date=14 July 2014}}</ref> The US EPA does not have a cancer classification for styrene,<ref>{{cite web |url=http://www.epa.gov/iris/subst/0104.htm |title=Styrene (CASRN 100-42-5) &#124; Region &#124; US EPA |access-date=2009-10-18 |url-status=live |archive-url=https://web.archive.org/web/20090512191949/http://www.epa.gov/iris/subst/0104.htm |archive-date=12 May 2009}} US environmental protection agency. Section I.B.4 relates to neurotoxicology.</ref> but it has been the subject of their Integrated Risk Information System (IRIS) program.<ref>{{cite web |url=http://cfpub.epa.gov/ncea/iristrac/index.cfm?fuseaction=viewChemical.showChemical&sw_id=1051 |title=EPA IRIS track styrene page |website=epa.gov |access-date=1 May 2018 |url-status=live |archive-url=https://web.archive.org/web/20111222014519/http://cfpub.epa.gov/ncea/iristrac/index.cfm?fuseaction=viewChemical.showChemical&sw_id=1051 |archive-date=22 December 2011}}</ref> 

The [[National Toxicology Program]] of the [[US Department of Health and Human Services]] has determined that styrene is "reasonably anticipated to be a human carcinogen".<ref>{{cite web |url=http://ntp.niehs.nih.gov/ntp/roc/content/profiles/styrene.pdf |title=Styrene entry in National Toxicology Program's Thirteenth Report on Carcinogens |website=nih.gov |access-date=1 May 2018 |url-status=dead |archive-url=https://web.archive.org/web/20171022090346/https://ntp.niehs.nih.gov/ntp/roc/content/profiles/styrene.pdf |archive-date=22 October 2017}}</ref> Various regulatory bodies refer to styrene, in various contexts, as a possible or potential human carcinogen. The [[International Agency for Research on Cancer]] considers styrene to be "probably carcinogenic to humans".<ref>{{cite journal |last1=Kogevinas |first1=Manolis |last2=Gwinn |first2=William M. |last3=Kriebel |first3=David |last4=Phillips |first4=David H. |last5=Sim |first5=Malcolm |last6=Bertke |first6=Stephen J. |last7=Calaf |first7=Gloria M. |last8=Colosio |first8=Claudio |last9=Fritz |first9=Jason M. |last10=Fukushima |first10=Shoji |last11=Hemminki |first11=Kari |date=2018 |title=Carcinogenicity of quinoline, styrene, and styrene-7,8-oxide |journal=The Lancet Oncology |volume=19 |issue=6 |pages=728–729 |doi=10.1016/s1470-2045(18)30316-4 |pmid=29680246 |s2cid=48357020 |issn=1470-2045 }}</ref><ref>{{cite web |url=https://www.sciencedaily.com/releases/2018/05/180530113105.htm |title=After 40 years in limbo: Styrene is probably carcinogenic |website=ScienceDaily |access-date=2020-03-31}}</ref>

The neurotoxic<ref>{{Cite journal|last1=Cherry|first1=N.|last2=Gautrin|first2=D.|date=January 1990|title=Neurotoxic effects of styrene: further evidence|journal=British Journal of Industrial Medicine|volume=47|issue=1|pages=29–37|issn=0007-1072|pmc=1035091|pmid=2155647|doi=10.1136/oem.47.1.29}}</ref> properties of styrene have also been studied and reported effects include effects on vision<ref>{{Cite journal|last1=Murata|first1=K.|last2=Araki|first2=S.|last3=Yokoyama|first3=K.|date=1991|title=Assessment of the peripheral, central, and autonomic nervous system function in styrene workers|journal=American Journal of Industrial Medicine|volume=20|issue=6|pages=775–784|issn=0271-3586|pmid=1666820|doi=10.1002/ajim.4700200609}}</ref> (although unable to reproduce in a subsequent study<ref>{{cite journal |last1=Seeber |first1=Andreas |last2=Bruckner |first2=Thomas |last3=Triebig |first3=Gerhard |date=2009-03-29 |title=Occupational styrene exposure, colour vision and contrast sensitivity: a cohort study with repeated measurements |journal=International Archives of Occupational and Environmental Health |volume=82 |issue=6 |pages=757–770 |doi=10.1007/s00420-009-0416-7|pmid=19330514|bibcode=2009IAOEH..82..757S |s2cid=7463900 |issn=0340-0131}}</ref>) and on hearing functions.<ref>{{cite journal |last1=Campo |first1=Pierre |last2=Venet |first2=Thomas |last3=Rumeau |first3=Cécile |last4=Thomas |first4=Aurélie |last5=Rieger |first5=Benoît |last6=Cour |first6=Chantal |last7=Cosnier |first7=Frédéric |last8=Parietti-Winkler |first8=Cécile |date=October 2011 |title=Impact of noise or styrene exposure on the kinetics of presbycusis |journal=Hearing Research |volume=280 |issue=1–2 |pages=122–132 |doi=10.1016/j.heares.2011.04.016 |issn=1878-5891 |pmid=21616132|s2cid=34799773 }}</ref><ref name=":0">{{cite journal |last1=Lataye |first1=R. |last2=Campo |first2=P. |last3=Loquet |first3=G. |last4=Morel |first4=G. |date=April 2005 |title=Combined effects of noise and styrene on hearing: comparison between active and sedentary rats |journal=Noise & Health |volume=7 |issue=27 |pages=49–64 |issn=1463-1741 |pmid=16105249 |doi=10.4103/1463-1741.31633 |doi-access= free}}</ref><ref name=":1">{{cite journal |last1=Campo |first1=Pierre |last2=Venet |first2=Thomas |last3=Thomas |first3=Aurélie |last4=Cour |first4=Chantal |last5=Brochard |first5=Céline |last6=Cosnier |first6=Frédéric |date=July 2014 |title=Neuropharmacological and cochleotoxic effects of styrene. Consequences on noise exposures |journal=Neurotoxicology and Teratology |volume=44 |pages=113–120 |doi=10.1016/j.ntt.2014.05.009 |issn=1872-9738 |pmid=24929234|bibcode=2014NTxT...44..113C }}</ref><ref>{{cite book |title=Occupational exposure to chemicals and hearing impairment |last=Johnson |first=Ann-Christin |date=2010 |orig-year=2009 |publisher=[[University of Gothenburg]] |others=Morata, Thais C., Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals., Sahlgrenska akademin (Göteborgs universitet), Göteborgs universitet., Arbetsmiljöverket. |isbn=9789185971213 |location=Gotenburg |oclc=792746283}}</ref> Studies on rats have yielded contradictory results,<ref name=":0" /><ref name=":1" /> but epidemiologic studies have observed a [[synergistic]] interaction with noise in causing hearing difficulties.<ref>{{cite journal |last1=Sliwińska-Kowalska |first1=Mariola |last2=Zamyslowska-Szmytke |first2=Ewa |last3=Szymczak |first3=Wieslaw |last4=Kotylo |first4=Piotr |last5=Fiszer |first5=Marta |last6=Wesolowski |first6=Wiktor |last7=Pawlaczyk-Luszczynska |first7=Malgorzata |date=January 2003 |title=Ototoxic effects of occupational exposure to styrene and co-exposure to styrene and noise |journal=Journal of Occupational and Environmental Medicine |volume=45 |issue=1 |pages=15–24 |issn=1076-2752 |pmid=12553175 |doi=10.1097/00043764-200301000-00008|s2cid=7030810 }}</ref><ref>{{cite journal |last1=Morata |first1=Thais C. |last2=Sliwinska-Kowalska |first2=Mariola |last3=Johnson |first3=Ann-Christin |last4=Starck |first4=Jukka |last5=Pawlas |first5=Krystyna |last6=Zamyslowska-Szmytke |first6=Ewa |last7=Nylen |first7=Per |last8=Toppila |first8=Esko |last9=Krieg |first9=Edward |date=October 2011 |title=A multicenter study on the audiometric findings of styrene-exposed workers |journal=International Journal of Audiology |volume=50 |issue=10 |pages=652–660 |doi=10.3109/14992027.2011.588965 |issn=1708-8186 |pmid=21812635|s2cid=207571026 }}</ref><ref>{{cite journal |last1=Sisto |first1=R. |last2=Cerini |first2=L. |last3=Gatto |first3=M.P. |last4=Gherardi |first4=M. |last5=Gordiani |first5=A. |last6=Sanjust |first6=F. |last7=Paci |first7=E. |last8=Tranfo |first8=G. |last9=Moleti |first9=A. |date=November 2013 |title=Otoacoustic emission sensitivity to exposure to styrene and noise |journal=The Journal of the Acoustical Society of America |volume=134 |issue=5 |pages=3739–3748 |doi=10.1121/1.4824618 |issn=1520-8524 |pmid=24180784 |bibcode=2013ASAJ..134.3739S}}</ref><ref>{{Cite web |title=Preventing hearing loss caused by chemical (ototoxicity) and noise exposure. SHIB 03-08-2018: DHHS (NIOSH) Publication No. 2018-124 |url=https://www.cdc.gov/niosh/docs/2018-124/default.html |language=en-us |doi=10.26616/NIOSHPUB2018124|doi-access=free |publisher= Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health |year= 2018}}</ref>