Editing Polystyrene (section)

==Safety==

===Health===
The [[American Chemistry Council]], formerly known as the Chemical Manufacturers' Association, wrote in 2011:
{{blockquote|Based on scientific tests over five decades, government safety agencies have determined that polystyrene is safe for use in foodservice products.  For example, polystyrene meets the stringent standards of the U.S. Food and Drug Administration and the European Commission/European Food Safety Authority for use in packaging to store and serve food.  The Hong Kong Food and Environmental Hygiene Department recently reviewed the safety of serving various foods in polystyrene foodservice products and reached the same conclusion as the U.S. FDA.<ref>{{cite web |title=Q & A on the Safety of Polystyrene Foodservice Products |date=2010–2011 |url=http://plasticfoodservicefacts.com/main/Safety/Californias-Proposition-65/Q-A-on-the-Safety-of-Polystyrene-Foodservice-Products.GMEditor.html |publisher=[[American Chemistry Council]] |access-date=2011-06-14 |url-status=dead |archive-url=https://web.archive.org/web/20110824143749/http://plasticfoodservicefacts.com/main/Safety/Californias-Proposition-65/Q-A-on-the-Safety-of-Polystyrene-Foodservice-Products.GMEditor.html |archive-date=24 August 2011 }}</ref>}}

From 1999 to 2002, a comprehensive review of the potential health risks associated with exposure to styrene was conducted by a 12-member international expert panel selected by the Harvard Center for Risk Assessment. The scientists had expertise in toxicology, epidemiology, medicine, risk analysis, pharmacokinetics, and exposure assessment. The Harvard study reported that styrene is naturally present in trace quantities in foods such as strawberries, beef, and spices, and is naturally produced in the processing of foods such as wine and cheese. The study also reviewed all the published data on the quantity of styrene contributing to the diet due to migration of food packaging and disposable food contact articles, and concluded that risk to the general public from exposure to styrene from foods or food-contact applications (such as polystyrene packaging and foodservice containers) was at levels too low to produce adverse effects.<ref>{{cite journal | author1 = Cohen JT |author2 = Carlson G |author3 = Charnley G | author4 = Coggon D | author5 = Delzell E | author6 = Graham JD | author7 = Greim H | author8 = Krewski D | author9 = Medinsky M | author10 = Monson R | author11 = Paustenbach D | author12 = Petersen B | author13 = Rappaport S | author14 = Rhomberg L | author15 = Ryan PB | author16 = Thompson K | title = A comprehensive evaluation of the potential health risks associated with occupational and environmental exposure to styrene | journal = Journal of Toxicology and Environmental Health Part B: Critical Reviews | volume = 5 | issue = 1–2 | pages = 1–265 | year = 2011 | doi = 10.1080/10937400252972162 |pmid = 12012775 |s2cid = 5547163}}
*{{cite web |title=A Comprehensive Evaluation of the Potential Health Risks Associated with Occupational and Environmental Exposure to Styrene |website=The McLaughlin Centre for Population Health Risk Assessment |url=http://www.mclaughlincentre.ca/publications/styrene.shtml}}</ref>

Polystyrene is commonly used in containers for food and drinks. The styrene monomer (from which polystyrene is made) is a cancer suspect agent.<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> Styrene is "generally found in such low levels in consumer products that risks aren't substantial".<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=11 June 2011 }}</ref> Polystyrene which is used for food contact may not contain more than 1% (0.5% for fatty foods) of styrene by weight.<ref>{{cite web|title=Sec. 177.1640 Polystyrene and rubber-modified polystyrene|url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=177.1640|archive-url=https://web.archive.org/web/20030915185751/http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=177.1640|url-status=dead|archive-date=15 September 2003|website=Code of Federal Regulations, Title 21—Food and Drugs, Subchapter B—Food for Human Consumption|publisher=U.S. Food and Drug Administration|access-date=4 April 2014}}</ref> Styrene oligomers in polystyrene containers used for food packaging have been found to migrate into the food.<ref>{{cite journal |doi=10.3358/shokueishi.41.200 |title=使い捨て弁当容器から溶出するスチレンダイマー及びトリマーの定量 |trans-title=Quantitative Analysis of Styrene Dimer and Trimers Migrated from Disposable Lunch Boxes |language=ja |journal=Journal of the Food Hygienic Society of Japan |volume=41 |issue=3 |pages=200–205 |year=2000 |last1=Sakamoto |first1=Hiromi |last2=Matsuzaka |first2=Ayako |last3=Itoh |first3=Rimiko |last4=Tohyama |first4=Yuko |doi-access=free }}</ref> Another Japanese study conducted on wild-type and [[Aryl hydrocarbon receptor|AhR]]-null mice found that the styrene trimer, which the authors detected in cooked polystyrene container-packed instant foods, may increase thyroid hormone levels.<ref>{{cite journal | vauthors = Yanagiba Y, Ito Y, Yamanoshita O, Zhang SY, Watanabe G, Taya K, Li CM, Inotsume Y, Kamijima M, Gonzalez FJ, Nakajima T | title = Styrene trimer may increase thyroid hormone levels via down-regulation of the aryl hydrocarbon receptor (AhR) target gene UDP-glucuronosyltransferase | journal = Environmental Health Perspectives | volume = 116 | issue = 6 | pages = 740–5 | date = June 2008 | pmid = 18560529 | pmc = 2430229 | doi = 10.1289/ehp.10724 | bibcode = 2008EnvHP.116..740Y }}</ref>

Whether polystyrene can be microwaved with food is controversial. Some containers may be safely used in a microwave, but only if labeled as such.<ref>{{cite web |url=https://www.health.harvard.edu/staying-healthy/microwaving-food-in-plastic-dangerous-or-not |title=Microwaving food in plastic: Dangerous or not? |date=20 September 2017 |publisher=Harvard Health }}</ref> Some sources suggest that foods containing carotene (vitamin A) or cooking oils must be avoided.<ref>{{cite web|title=Polystyrene & Health Homepage|url=http://www.ejnet.org/plastics/polystyrene/health.html|publisher=Energy Justice Network|access-date=9 December 2013}}</ref>

Because of the pervasive use of polystyrene, these serious health related issues remain topical.<ref>{{cite web |last=Entine |first=Jon |title=Styrene in the Crosshairs: Competing Standards Confuse Public, Regulators |url=http://www.aei.org/publication/styrene-in-the-crosshairs-competeing-standards-confuse-public-regulators/ |publisher=[[American Enterprise Institute]] |date=2011-09-14 }}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>{{unreliable source?|date=October 2018}}

===Fire hazards===
Like other [[organic compound]]s, polystyrene is flammable. Polystyrene is classified according to [[DIN4102 A1|DIN4102]] as a "B3" product, meaning highly flammable or "Easily Ignited". As a consequence, although it is an efficient insulator at low temperatures, its use is prohibited in any exposed installations in [[building construction]] if the material is not [[flame retardant|flame-retardant]].{{citation needed|date=June 2011}} It must be concealed behind [[drywall]], sheet metal, or concrete.<ref>{{cite book |oclc=166313665 |url=https://ir.canterbury.ac.nz/bitstream/handle/10092/14390/RNelligan06.pdf |type=MS Thesis |title=Guidelines for the use of expanded foam polystyrene panel systems in industrial buildings to minimize the risk of fire |first=R.J. |last=Nelligan |year=2006 }}</ref> Foamed polystyrene plastic materials have been accidentally ignited and caused huge fires and losses of life, for example at the [[Düsseldorf Airport fire|Düsseldorf International Airport]] and in the [[1996 Channel Tunnel fire|Channel Tunnel]] (where polystyrene was inside a railway carriage that caught fire).<ref>{{cite news|title=Foul Play Considered in Channel Tunnel Fire Inquiry |date=28 November 1996 |url=https://www.irishtimes.com/news/foul-play-considered-in-chunnel-fire-inquiry-1.110786 |newspaper=The Irish Times |access-date=14 January 2018}}</ref>