Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) is chromium in any chemical compound that contains the element in the +6 oxidation state (thus hexavalent). Virtually all chromium ore is processed via hexavalent chromium, specifically the salt sodium dichromate.HexavalentchromiumFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchAnexampleofachromium(VI)compound:chromiumtrioxideHexavalentchromium(chromium(VI),Cr(VI),chromium6)ischromiuminanychemicalcompoundthatcontainstheelementinthe+6oxidationstate(thushexavalent).Virtuallyallchromiumoreisprocessedviahexavalentchromium,specificallythesaltsodiumdichromate.Hexavalentchromiumiskeytoallmaterialsmadefromchromium.Approximately136,000tonnesofhexavalentchromiumwereproducedin1985.[1]Additionalhexavalentchromiumcompoundsincludechromiumtrioxideandvarioussaltsofchromateanddichromate,amongothers.Hexavalentchromiumisusedintextiledyes,woodpreservation,anti-corrosionproducts,chromateconversioncoatings,andavarietyofnicheuses.Industrialusesofhexavalentchromiumcompoundsincludechromatepigmentsindyes,paints,inks,andplastics;chromatesaddedasanticorrosiveagentstopaints,primers,andothersurfacecoatings;andchromicacidelectroplatedontometalpartstoprovideadecorativeorprotectivecoating.Hexavalentchromiumcanbeformedwhenperforming"hotwork"suchasweldingonstainlesssteelormeltingchromiummetal.Inthesesituationsthechromiumisnotoriginallyhexavalent,butthehightemperaturesinvolvedintheprocessresultinoxidationthatconvertsthechromiumtoahexavalentstate.[2]Hexavalentchromiumcanalsobefoundindrinkingwaterandpublicwatersystems.[3][4]Allhexavalentchromiumcompoundsaretoxic(duetotheiroxidizingpower)aswellascarcinogenic(IARCGroup1),especiallyifairborneandinhaledwheretheycauselungcancer.Positiveassociationshavealsobeenobservedbetweenexposuretochromium(VI)compoundsandcancerofthenoseandnasalsinuses.[5]Workersinmanyoccupationsareexposedtohexavalentchromium.Problematicexposureisknowntooccuramongworkerswhohandlechromate-containingproductsandthosewhogrinda