Editing Group 5 element (section)

== Toxicity and precautions ==

Pure vanadium is not known to be toxic. However, [[vanadium pentoxide]] causes severe irritation of the eyes, nose, and throat.<ref name = "Emsley"/> Tetravalent [[vanadyl sulfate|VOSO<sub>4</sub>]] has been reported to be at least 5 times more toxic than trivalent V<sub>2</sub>O<sub>3</sub>.<ref>{{cite journal|last= Roschin|first= A. V.|date= 1967|title= Toxicology of vanadium compounds used in modern industry|journal= Gig Sanit. (Water Res.)|volume= 32|issue= 6|pages= 26–32|pmid= 5605589}}</ref> The [[Occupational Safety and Health Administration]] has set an exposure limit of 0.05&nbsp;mg/m<sup>3</sup> for vanadium pentoxide dust and 0.1&nbsp;mg/m<sup>3</sup> for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.<ref name="OSHA">{{cite web|url= http://www.osha.gov/SLTC/healthguidelines/vanadiumpentoxidedust/recognition.html|title= Occupational Safety and Health Guidelines for Vanadium Pentoxide|publisher= Occupational Safety and Health Administration|access-date= 29 January 2009|url-status= dead|archive-url= https://web.archive.org/web/20090106063227/http://www.osha.gov/SLTC/healthguidelines/vanadiumpentoxidedust/recognition.html|archive-date= 6 January 2009}}</ref> The [[National Institute for Occupational Safety and Health]] has recommended that 35&nbsp;mg/m<sup>3</sup> of vanadium be considered immediately dangerous to life and health, that is, likely to cause permanent health problems or death.<ref name="OSHA" /> Vanadium compounds are poorly absorbed through the gastrointestinal system. Inhalation of vanadium and vanadium compounds results primarily in adverse effects on the respiratory system.<ref>{{cite book|last= Sax|first= N. I.|date= 1984|title= Dangerous Properties of Industrial Materials|edition= 6th|publisher= Van Nostrand Reinhold Company|pages= 2717–2720}}</ref><ref name="ress" /><ref>{{cite journal|title= Nanoparticulate Vanadium Oxide Potentiated Vanadium Toxicity in Human Lung Cells|author= Wörle-Knirsch, Jörg M. |author2= Kern, Katrin |author3= Schleh, Carsten |author4= Adelhelm, Christel |author5= Feldmann, Claus |author6= Krug, Harald F. |name-list-style= amp|journal= Environ. Sci. Technol. |date= 2007|volume= 41|pages= 331–336|doi= 10.1021/es061140x|pmid= 17265967|issue= 1|bibcode= 2007EnST...41..331W}}</ref> Quantitative data are, however, insufficient to derive a subchronic or chronic inhalation reference dose. Other effects have been reported after oral or inhalation exposures on blood parameters,<ref>{{cite journal |last=Ścibior |first=A. |author2=Zaporowska, H. |author3=Ostrowski, J. |date=2006 |title=Selected haematological and biochemical parameters of blood in rats after subchronic administration of vanadium and/or magnesium in drinking water |journal=Archives of Environmental Contamination and Toxicology |volume=51 |issue=2 |pages=287–295 |doi=10.1007/s00244-005-0126-4 |pmid=16783625|bibcode=2006ArECT..51..287S |s2cid=43805930 }}</ref><ref>{{cite journal |last=Gonzalez-Villalva |first=A. |display-authors=etal |date= 2006|title=Thrombocytosis induced in mice after subacute and subchronic V2O5 inhalation |journal=Toxicology and Industrial Health |volume=22 |issue=3 |pages=113–116 |doi=10.1191/0748233706th250oa |pmid=16716040|bibcode=2006ToxIH..22..113G |s2cid=9986509 }}</ref> liver,<ref>{{cite journal|journal= Toxicology|volume= 228|date= 2006|pages= 162–170|doi= 10.1016/j.tox.2006.08.022|title= Pentavalent vanadium induces hepatic metallothionein through interleukin-6-dependent and -independent mechanisms|author= Kobayashi, Kazuo|pmid= 16987576|issue= 2–3|last2= Himeno|first2= Seiichiro|last3= Satoh|first3= Masahiko|last4= Kuroda|first4= Junji|last5= Shibata|first5= Nobuo|last6= Seko|first6= Yoshiyuki|last7= Hasegawa|first7= Tatsuya|bibcode= 2006Toxgy.228..162K}}</ref> neurological development,<ref>{{cite journal |last=Soazo |first=Marina |author2=Garcia, Graciela Beatriz |date=2007 |title=Vanadium exposure through lactation produces behavioral alterations and CNS myelin deficit in neonatal rats |journal=Neurotoxicology and Teratology |volume=29 |issue=4 |pages=503–510 |doi=10.1016/j.ntt.2007.03.001 |pmid=17493788|bibcode=2007NTxT...29..503S }}</ref> and other organs<ref>{{cite journal|last= Barceloux|first= Donald G.|author2=Barceloux, Donald |date= 1999|title= Vanadium|journal= Clinical Toxicology|volume= 37|issue= 2|pages= 265–278|doi= 10.1081/CLT-100102425|pmid= 10382561}}</ref> in rats.

There is little evidence that vanadium or vanadium compounds are reproductive toxins or [[teratogen]]s. Vanadium pentoxide was reported to be carcinogenic in male rats and in male and female mice by inhalation in an NTP study,<ref name="ress">{{cite journal |last=Ress |first=N. B. |display-authors=etal |date=2003 |title=Carcinogenicity of inhaled vanadium pentoxide in F344/N rats and B6C3F1 mice |journal=Toxicological Sciences |volume=74 |issue=2 |pages=287–296 |doi=10.1093/toxsci/kfg136 |pmid=12773761|doi-access=free }}</ref> although the interpretation of the results has recently been disputed.<ref>{{cite journal |last=Duffus |first=J. H. |date=2007 |title=Carcinogenicity classification of vanadium pentoxide and inorganic vanadium compounds, the NTP study of carcinogenicity of inhaled vanadium pentoxide, and vanadium chemistry |journal=[[Regulatory Toxicology and Pharmacology]] |volume=47 |issue=1 |pages=110–114 |doi=10.1016/j.yrtph.2006.08.006 |pmid=17030368}}</ref> The carcinogenicity of vanadium has not been determined by the [[United States Environmental Protection Agency]].<ref>{{cite web|url= https://rais.ornl.gov/tox/profiles/vanadium_f_V1.html|title= Toxicity Summary for Vanadium|date= 1991|first= Dennis M.|last= Opreskos |access-date=8 November 2008 |publisher= Oak Ridge National Laboratory}}</ref> Vanadium traces in [[diesel fuel]]s are the main fuel component in [[high temperature corrosion]]. During combustion, vanadium oxidizes and reacts with sodium and sulfur, yielding [[vanadate]] compounds with melting points as low as 530&nbsp;°C, which attack the [[passivation (chemistry)|passivation layer]] on steel and render it susceptible to corrosion. The solid vanadium compounds also abrade engine components.<ref>{{cite book |page= 92 |url= https://books.google.com/books?id=RC_k4q6y-JIC&pg=PA92 |title= Pounder's Marine Diesel Engines and Gas Turbines |isbn= 9780080943619 |last1= Woodyard |first1= Doug |date= 2009-08-18| publisher=Butterworth-Heinemann }}</ref><ref>{{cite book |page= 152 |url= https://books.google.com/books?id=J_AkNu-Y1wQC&pg=PA152 |title= Fuels and Lubricants Handbook: Technology, Properties, Performance, and Testing |isbn= 9780803120969 |last1= Totten |first1= George E. |last2= Westbrook |first2= Steven R. |last3= Shah |first3= Rajesh J. |date= 2003-06-01}}</ref>

Niobium has no known biological role. While niobium dust is an eye and skin irritant<ref name = "Emsley"/> and a potential fire hazard, elemental niobium on a larger scale is physiologically inert (and thus hypoallergenic) and harmless. It is often used in jewelry and has been tested for use in some medical implants.<ref>{{cite journal|title = New trends in the use of metals in jewellery|author=Vilaplana, J.|author2=Romaguera, C.|author3=Grimalt, F.|author4=Cornellana, F.|journal = Contact Dermatitis|volume = 25|issue = 3 |pages = 145–148|date = 1990|doi = 10.1111/j.1600-0536.1991.tb01819.x|pmid = 1782765|s2cid=30201028|doi-access = }}</ref><ref>{{cite journal|title = New developments in jewellery and dental materials|first = J.|last = Vilaplana|author2=Romaguera, C. | journal = Contact Dermatitis|volume = 39|issue = 2| pages = 55–57|date = 1998|doi = 10.1111/j.1600-0536.1998.tb05832.x|pmid = 9746182|s2cid = 34271011}}</ref> Niobium and its compounds thought to be slightly toxic. Short- and long-term exposure to niobates and niobium chloride, two water-soluble chemicals, have been tested in rats. Rats treated with a single injection of niobium pentachloride or niobates show a [[median lethal dose]] (LD{{sub|50}}) between 10 and 100&nbsp;mg/kg.<ref name="Haley">{{cite journal|title = Pharmacology and toxicology of niobium chloride|author=Haley, Thomas J.|author2=Komesu, N.|author3=Raymond, K.|journal = [[Toxicology and Applied Pharmacology]]|volume = 4|issue = 3|pages = 385–392|date = 1962|doi = 10.1016/0041-008X(62)90048-0|pmid=13903824|bibcode=1962ToxAP...4..385H }}</ref><ref>{{cite journal|title = The Toxicity of Niobium Salts |author=Downs, William L. |display-authors=4 |author2=Scott, James K. |author3=Yuile, Charles L. |author4=Caruso, Frank S. |author5=Wong, Lawrence C. K.|journal = American Industrial Hygiene Association Journal|volume = 26|issue = 4|pages = 337–346|date = 1965|doi = 10.1080/00028896509342740|pmid = 5854670}}</ref><ref>{{cite journal|title = Zirconium, Niobium, Antimony, Vanadium and Lead in Rats: Life term studies|author=Schroeder, Henry A.|author2=Mitchener, Marian|author3=Nason, Alexis P.|journal = Journal of Nutrition|volume = 100|issue = 1|pages = 59–68|date=1970|pmid =5412131|doi=10.1093/jn/100.1.59|s2cid=4444415|url = https://pdfs.semanticscholar.org/7730/157588b8312d9076f95fcfb78d404a893033.pdf|archive-url = https://web.archive.org/web/20200219052439/https://pdfs.semanticscholar.org/7730/157588b8312d9076f95fcfb78d404a893033.pdf|url-status = dead|archive-date = 2020-02-19}}</ref> For oral administration the toxicity is lower; a study with rats yielded a LD{{sub|50}} after seven days of 940&nbsp;mg/kg.<ref name="Haley" />

Compounds containing tantalum are rarely encountered in the laboratory, and it and its compounds rarely cause injury, and when they do, the injuries are normally rashes.<ref name = "Emsley"/> The metal is highly [[biocompatible]]<ref name="Gerald L. Burke 1940">{{cite journal|journal = Canadian Medical Association Journal |first = Gerald L. |last = Burke |date = 1940 |title =The Corrosion of Metals in Tissues; and An Introduction to Tantalum |volume = 43|issue = 2 |pages = 125–128 |pmid = 20321780 |pmc = 538079 }}</ref> and is used for body [[implant (medicine)|implants]] and [[coating]]s, therefore attention may be focused on other elements or the physical nature of the [[chemical compound]].<ref>{{cite journal|journal = Biomaterials|author = Matsuno H|author2 = Yokoyama A|author3 = Watari F|author4 = Uo M|author5 = Kawasaki T.|date = 2001|volume = 22|title = Biocompatibility and osteogenesis of refractory metal implants, titanium, hafnium, niobium, tantalum and rhenium. Biocompatibility of tantalum.|doi = 10.1016/S0142-9612(00)00275-1|pmid=11336297|issue = 11|pages = 1253–62}}</ref> People can be exposed to tantalum in the workplace by breathing it in, skin contact, or eye contact. The [[Occupational Safety and Health Administration]] (OSHA) has set the legal limit ([[permissible exposure limit]]) for tantalum exposure in the workplace as 5&nbsp;mg/m<sup>3</sup> over an 8-hour workday. The [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[recommended exposure limit]] of 5&nbsp;mg/m<sup>3</sup> over an 8-hour workday and a short-term limit of 10&nbsp;mg/m<sup>3</sup>. At levels of 2500&nbsp;mg/m<sup>3</sup>, tantalum is [[IDLH|immediately dangerous to life and health]].<ref>{{Cite web|title = CDC – NIOSH Pocket Guide to Chemical Hazards – Tantalum (metal and oxide dust, as Ta)|url = https://www.cdc.gov/niosh/npg/npgd0585.html|website = www.cdc.gov|access-date = 2015-11-24}}</ref>