Editing Vacuum pump (section)

== Hazards ==
Old vacuum-pump oils that were produced before circa 1980 often contain a mixture of several different dangerous [[polychlorinated biphenyl|polychlorinated biphenyls (PCBs)]], which are highly [[toxic]], [[carcinogenic]], [[persistent organic pollutant]]s.<ref>{{cite journal | author=Martin G Broadhurst | title=Use and replaceability of polychlorinated biphenyls | journal=Environmental Health Perspectives | volume=2 |date=October 1972 | pages=81–102 | doi=10.2307/3428101 | pmid=4628855 | pmc=1474898 | jstor=3428101}}</ref><ref>{{cite book | author=C J McDonald | author2=R E Tourangeau | name-list-style=amp | title=PCBs: Question and Answer Guide Concerning Polychlorinated Biphenyls | publisher=Government of Canada: Environment Canada Department | date=1986 | isbn=978-0-662-14595-0 | url=http://www.ec.gc.ca/wmd-dgd/default.asp?lang=En&n=AD2C1530-1&offset=3&toc=show | access-date=2007-11-07 }}{{cbignore|bot=medic}}</ref>