Editing Plaster (section)

==Safety issues==
The chemical reaction that occurs when plaster is mixed with water is [[exothermic]]. When plaster sets, it can reach temperatures of more than {{convert|60|°C|°F|abbr=on}} and, in large volumes, can burn the skin. In January 2007, a secondary school student in [[Lincolnshire]], [[England]] sustained [[third-degree burn]]s after encasing her hands in a bucket of plaster as part of a school art project.<!-- The burns were so severe she required [[amputation]] of both her thumbs and six of her fingers. << It might not be necessary to provide these details here. --><ref>{{cite news| url=http://news.bbc.co.uk/1/hi/education/6485481.stm | work=BBC News | title=Amputation after art class burns | date=23 March 2007 | access-date=22 May 2010}}</ref>

Plaster that contains powdered [[silica]] or [[asbestos]] presents health hazards if inhaled repeatedly. Asbestos is a known [[irritation|irritant]] when inhaled and can cause cancer, especially in people who smoke,<ref>{{cite journal|last1=Hammond|first1=EC|last2=Garfinkel|first2=L|last3=Seidman|first3=H|last4=Lew|first4=EA|title="Tar" and nicotine content of cigarette smoke in relation to death rates|journal=Environmental Research|date=December 1976|volume=12|issue=3|pages=263–74|pmid=1001298|doi=10.1016/0013-9351(76)90036-0|bibcode=1976ER.....12..263H}}</ref><ref>{{cite journal|last1=Saracci|first1=R|title=The interactions of tobacco smoking and other agents in cancer etiology|journal=Epidemiologic Reviews|date=1987|volume=9|pages=175–93|pmid=3315716|doi=10.1093/oxfordjournals.epirev.a036301}}</ref> and inhalation can also cause [[asbestosis]]. Inhaled silica can cause [[silicosis]] and (in very rare cases) can encourage the development of [[cancer]].<ref>{{cite journal|last1=Soutar|first1=CA|last2=Robertson|first2=A|last3=Miller|first3=BG|last4=Searl|first4=A|last5=Bignon|first5=J|title=Epidemiological evidence on the carcinogenicity of silica: factors in scientific judgement.|journal=The Annals of Occupational Hygiene|date=January 2000|volume=44|issue=1|pages=3–14|pmid=10689755|doi=10.1093/annhyg/44.1.3|doi-access=free}}</ref> Persons working regularly with plaster containing these additives should take precautions to avoid inhaling powdered plaster, cured or uncured.

People can be exposed to plaster of Paris in the workplace by breathing it in, swallowing it, skin contact, and eye contact. The [[Occupational Safety and Health Administration]] (OSHA) has set the legal limit ([[permissible exposure limit]]) for plaster of Paris exposure in the workplace as 15&nbsp;mg/m<sup>3</sup> total exposure and 5&nbsp;mg/m<sup>3</sup> respiratory exposure over an 8-hour workday. The [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[Recommended exposure limit]] (REL) of 10&nbsp;mg/m<sup>3</sup> total exposure and 5&nbsp;mg/m<sup>3</sup> respiratory exposure over an 8-hour workday.<ref>{{Cite web|title = CDC – NIOSH Pocket Guide to Chemical Hazards – Plaster of Paris|url = https://www.cdc.gov/niosh/npg/npgd0518.html|website = www.cdc.gov|access-date = 21 November 2015}}</ref>