Editing Arsenic (section)

=== Wood preservation in the US ===
As of 2002, US-based industries consumed 19,600 metric tons of arsenic. Ninety percent of this was used for treatment of wood with [[chromated copper arsenate]] (CCA). In 2007, 50% of the 5,280 metric tons of consumption was still used for this purpose.<ref name="USGSYB2007">{{cite web|url = http://minerals.er.usgs.gov/minerals/pubs/commodity/arsenic/myb1-2007-arsen.pdf|first = William E.|last = Brooks|publisher = [[United States Geological Survey]]|access-date = 2008-11-08 |title = Minerals Yearbook 2007: Arsenic| archive-url= https://web.archive.org/web/20081217031509/http://minerals.er.usgs.gov/minerals/pubs/commodity/arsenic/myb1-2007-arsen.pdf| archive-date= 17 December 2008|url-status = live}}</ref><ref>{{cite web|url = http://minerals.er.usgs.gov/minerals/pubs/commodity/arsenic/160302.pdf|first = Robert G. Jr.|last = Reese|publisher = [[United States Geological Survey]]|access-date = 2008-11-08 |title = Commodity Summaries 2002: Arsenic| archive-url= https://web.archive.org/web/20081217031513/http://minerals.er.usgs.gov/minerals/pubs/commodity/arsenic/160302.pdf| archive-date= 17 December 2008|url-status = live}}</ref> In the United States, the voluntary phasing-out of arsenic in production of consumer products and residential and general consumer construction products began on 31 December 2003, and alternative chemicals are now used, such as [[Alkaline Copper Quaternary]], [[borate]]s, [[Wood preservation#Copper azole|copper azole]], [[cyproconazole]], and [[propiconazole]].<ref>{{cite web|url=https://www.epa.gov/ingredients-used-pesticide-products/chromated-arsenicals-cca|title=Chromated Copper Arsenate (CCA)|publisher=US Environmental Protection Agency|access-date = 2018-10-15 |date=16 January 2014}}</ref>

Although discontinued, this application is also one of the most concerning to the general public. The vast majority of older [[Timber treatment|pressure-treated]] wood was treated with CCA. CCA lumber is still in widespread use in many countries, and was heavily used during the latter half of the 20th century as a structural and outdoor [[building material]]. Although the use of CCA lumber was banned in many areas after studies showed that arsenic could leach out of the wood into the surrounding [[soil]] (from playground equipment, for instance), a risk is also presented by the burning of older CCA timber. The direct or indirect ingestion of wood ash from burnt CCA lumber has caused fatalities in animals and serious poisonings in humans; the lethal human dose is approximately 20&nbsp;grams of ash.<ref>{{Cite web|url=https://www.softwoods.com.au/blog/cca-treated-pine-safe/|title=Is CCA treated pine Safe? |website=www.softwoods.com.au|date=26 October 2010|language=en-AU|access-date=2017-02-24}}</ref> Scrap CCA lumber from construction and demolition sites may be inadvertently used in commercial and domestic fires. Protocols for safe disposal of CCA lumber are not consistent throughout the world. Widespread [[landfill]] disposal of such timber raises some concern,<ref>{{Cite book|url=https://books.google.com/books?id=3l_LBQAAQBAJ|title=Environmental Impacts of Treated Wood|last1=Townsend|first1=Timothy G.|last2=Solo-Gabriele|first2=Helena|year=2006|publisher=CRC Press|isbn=978-1-4200-0621-6}}</ref> but other studies have shown no arsenic contamination in the groundwater.<ref>{{Cite journal|last1=Saxe|first1=Jennifer K.|last2=Wannamaker|first2=Eric J.|last3=Conklin|first3=Scott W.|last4=Shupe|first4=Todd F.|last5=Beck|first5=Barbara D.|date=2007-01-01|title=Evaluating landfill disposal of chromated copper arsenate (CCA) treated wood and potential effects on groundwater: evidence from Florida|journal=Chemosphere|volume=66|issue=3|pages=496–504|doi=10.1016/j.chemosphere.2006.05.063|pmid=16870233|bibcode=2007Chmsp..66..496S}}</ref><ref>{{Cite web|url=http://www.woodpreservativescience.org/disposal.shtml|title=CCA Treated Wood Disposal {{!}} Wood Preservative Science Council {{!}} Objective, Sound, Scientific Analysis of CCA|last=BuildingOnline|website=www.woodpreservativescience.org|access-date=2016-06-16}}</ref>