Editing Propylene oxide (section)

==Safety==
Propylene oxide is both acutely toxic and [[carcinogen]]ic. Acute exposure causes [[respiratory tract]] [[irritation]], eventually leading to death.<ref name="NAC/AEGL">{{cite book|author=National Research Council (US) Committee on Acute Exposure Guideline Levels|title=Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 9|chapter=Propylene Oxide Acute Exposure Guideline Levels |year=2010|publisher=National Academies Press|url=https://www.ncbi.nlm.nih.gov/books/NBK208161/}}</ref> Signs of toxicity after acute exposure include [[salivation]], [[lacrimation]], nasal discharge, gasping, lethargy and [[hypoactivity]], weakness, and incoordination. Propylene oxide is also [[Neurotoxicity|neurotoxic]] in rats, and presumably in humans.<ref>{{cite journal | vauthors = Ohnishi A, Murai Y | title = Polyneuropathy due to ethylene oxide, propylene oxide, and butylene oxide | journal = Environmental Research | volume = 60 | issue = 2 | pages = 242–247 | date = February 1993 | pmid = 8472653 | doi = 10.1006/enrs.1993.1032 | bibcode = 1993ER.....60..242O }}</ref> Propylene oxide [[Alkylation|alkylates]] [[DNA]] and is considered a mutagen for both animals and humans.<ref>{{cite journal | vauthors = Lawley PD, Jarman M | title = Alkylation by propylene oxide of deoxyribonucleic acid, adenine, guanosine and deoxyguanylic acid | journal = The Biochemical Journal | volume = 126 | issue = 4 | pages = 893–900 | date = February 1972 | pmid = 5073240 | pmc = 1178497 | doi = 10.1042/bj1260893 }}</ref><ref>{{Cite journal |last=Albertini |first=Richard J. |date=April 2003 |title=Correspondence re: Czene et al., Analysis of DNA and hemoglobin adducts and sister chromatid exchanges in a human population occupationally exposed to propylene oxide: a pilot study. Cancer Epidemiol. Biomark. Prev., 11: 315-318, 2002 |url=https://pubmed.ncbi.nlm.nih.gov/12692119/ |journal=Cancer Epidemiology, Biomarkers & Prevention |volume=12 |issue=4 |pages=388; author reply 388–389 |issn=1055-9965 |pmid=12692119}}</ref><ref>{{Cite journal |last1=Thiess |first1=A. M. |last2=Schwegler |first2=H. |last3=Fleig |first3=I. |last4=Stocker |first4=W. G. |date=1981 |title=Mutagenicity Study of Workers Exposed to Alkylene Oxides (Ethylene Oxide/Propylene Oxide) and Derivatives |url=https://www.jstor.org/stable/45005617 |journal=Journal of Occupational Medicine |volume=23 |issue=5 |pages=343–347 |jstor=45005617 |pmid=7241247 |issn=0096-1736}}</ref> Pregnant rats exposed to 500ppm of propylene oxide for less than 8 hours gave birth to litters with significant deformities and weight deficiencies. Similar exposure has also shown to reduce animal fertility.<ref name=":0">{{Cite web |last=Fishersci |date=1 July 1999 |title=Material Safety Data Sheet Propylene Oxide |url=https://fscimage.fishersci.com/msds/19910.htm |access-date=September 27, 2024 |website=Fisher Scientific}}</ref> As such, it is a known animal carcinogen<ref name="Ringo_1982" /> and potential human carcinogen, and is included into the [[List of IARC Group 2B carcinogens]].<ref name="Grana2014">{{cite journal | vauthors = Grana R, Benowitz N, Glantz SA | title = E-cigarettes: a scientific review | journal = Circulation | volume = 129 | issue = 19 | pages = 1972–1986 | date = May 2014 | pmid = 24821826 | pmc = 4018182 | doi = 10.1161/circulationaha.114.007667 }}</ref>

Propylene oxide is an extremely flammable liquid, and its vapors can form explosive mixtures with air at concentrations as low as 2.3% ([[Flammability limit|Lower Explosive Limit]]).<ref name=":0" /> Propylene oxide vapor is twice as [[Relative density|dense as air]]. When exposed to an open atmosphere, the vapor can accumulate in low-lying areas while spreading out over long distances and reach ignition source, causing [[Flash fire|flashback]] or an explosion.<ref name=":0" /><ref>{{Cite journal |last1=Wan |first1=Hangwei |last2=Wen |first2=Yuquan |last3=Zhang |first3=Qi |date=2023-01-01 |title=Explosion behaviors of vapor–liquid propylene oxide/air mixture under high-temperature source ignition |url=https://www.sciencedirect.com/science/article/abs/pii/S0016236122026424 |journal=Fuel |volume=331 |pages=125815 |doi=10.1016/j.fuel.2022.125815 |bibcode=2023Fuel..33125815W |issn=0016-2361}}</ref> When heated, propylene oxide can [[Autoacceleration|rapidly self-polymerize]] and decompose producing other toxic gases such as [[carbon monoxide]] and various [[Radical (chemistry)|free radicals]].<ref>{{Cite journal |last=HARDWICK |first=T |date=March 8, 1968 |title=Thermal decomposition of propylene oxide |url=https://cdnsciencepub.com/doi/pdf/10.1139/v68-398 |journal=Canadian Journal of Chemistry |volume=46 |issue=14 |pages=2454–2456 |doi=10.1139/v68-398 |via=Canadian Science Publishing}}</ref><ref name=":0" /> Propylene oxide fires are especially dangerous and difficult for firefighters to extinguish. In a fire, sealed tanks of propylene oxide should be cooled with fire hoses to prevent explosion from self-polymerization.<ref name=":0" /> When burning in open air however, water can transport propylene oxide outside of the fire zone which can reignite upon floating to the surface. Additional firefighting measures should be taken to prevent propylene oxide from washing out to nearby drains and sewers contaminating the surrounding environment.<ref>{{Cite web |title=Emergency Response Guide No. 127P for FLAMMABLE LIQUIDS (Water-Miscible) – HazMat Tool |url=https://www.hazmattool.com/emergencyguide.php?i=127P |access-date=2024-09-27 |website=www.hazmattool.com}}</ref><ref name=":0" />