Talk:Chromium/Archive 1

glass ware
Is anybody still using this stuff or was it only substituted here in Europe by sulfuric acid hydrogen peroxide mixtures?--Stone 10:54, 4 April 2006 (UTC)

Yes, in the U.S. they are still currently using Chromium for all sorts of jobs.--DK 1:02, 14 Febuary 2008 (UTC) —Preceding unsigned comment added by 164.58.63.14 (talk)

Question about units of measurement?
I'm not sure what a "µg" is. If I'm not sure, I'm guessing some others aren't either. Maybe someone could clear this up here and in the article if it needs it? 11:51, 5 April 2007 (UTC)


 * You're from the US, right? Don't worry, they'll catch up sooner or later. :) It's micrograms, micro (µ) is a common prefix in the International System of Units. I've added a link in the article. Femto 14:41, 5 April 2007 (UTC)

Chromium Nicotinate
What is "Chromium Nicotinate"? It is on the ingrediant list for Spava Coffee's "Metabolism Coffee". Is it a a mix of Chromium and Nicotine? Chromuim and Nickel? Is there any research on it? Thanks Antmusic 15:10, 7 August 2007 (UTC)

chemical
What are some chemical properties of chromium?Potterfa11 (talk) 22:05, 14 January 2008 (UTC)

Reflectance
Chromium is often used because it's 'shiny' so some hard values on the material's reflectance would be nice. would help in computer graphics as well Dan Frederiksen (talk) 05:34, 14 April 2008 (UTC)

discovery
It says it was discovered in 1974...that seems like a mistake. —Preceding unsigned comment added by 128.197.189.152 (talk) 19:55, 8 July 2008 (UTC)
 * It wasn't actually a mistake. The 1974 date was referencing when the artifacts were found. However, it was poorly worded to easily confuse. I changed it to be less confusing. Wizard191 (talk) 02:48, 9 July 2008 (UTC)

Disambiguation for Chromium/Google Chrome
Because of the Chromium open source project (highly in the news lately along with its flagship implementation, Google Chrome) I added a disambiguation for "Chromium (web browser)". Because the main article is named "Google Chrome" this was unfortunately changed to a link to "Google Chrome", then deleted because it was not similar enough (which is obviously true). However many users may search for Chromium, and should be redirected to the main article which describes both Chromium and Google Chrome. Please provide any input you may have here before removing this again. sHARD (talk) 14:31, 4 September 2008 (UTC)
 * I switched to linking to a disambig page to handle additional meanings of chromium as well. This should handle the situation well. -- Ed (Edgar181) 15:21, 4 September 2008 (UTC)
 * Looks good to me sHARD (talk) 15:55, 4 September 2008 (UTC)

Electron configuration
We all know that even though the expected electron configuration of Chromium would be [Ar]4s23d4...it is shown to actually be [Ar]4s13d5

My chemistry textbook says this exception to the sequence in which orbitals are filled is still largely unknown and the reason for the anomaly is still disputed amongst chemists

I'm not too well researched in the dispute or the possible explanations, but wouldn't it be a key part of this article? Shouldn't it be brought up, maybe given it's own section?

Does anyone know where I can learn more about the research being done on chromium's and copper's anomalies?-Aspiring chemist (talk) 21:51, 16 November 2008 (UTC)

Chinese atomic theory?
In the history section the wording is such that the chinese discovered this element, which is misleading, unless they had an atomic theory and categorized the material they discovered as a chemical element. It is also misleading becauser there is no indiciation that the knowledge was transfered to the westerners, but rather that later archeological discoveries have revealed this chrome plating or similar to be a hidden knowledge, much later to be independently discovered by westeners. This is not like iron, which was discovered before antiquity, and the generally known knowledge of iron was transfered to the "western civilization", later to be classified as a chemical element. Chromium was rediscovered in West, and needs a (re)discoverer. The element was classified as a chemical element in the west, and if that was by Vaquelin, then he is a discoverer. Chinese allegations aside (unless they can provide a similar Chinese record). ... said: Rursus (bork²) 10:45, 9 January 2009 (UTC)

Chromium and oral health
Hodges SJ, Spencer RJ, Watkins SJ. Unusual indelible enamel staining following fixed appliance treatment. J Orthod. 2000 Dec;27(4):303-6

Ç. Türksel Dülgergil, Ebru Olgun Erdemir, Erturul Ercan, and Ali Erdemir An Industrial Dental-Erosion by Chromic Acid: A Case Report Eur J Dent. 2007 April; 1(2): 119–122.

Gomes ER. Incidence of chromium-induced lesions among electroplating workers in Brazil. IMS Ind Med Surg. 1972 Dec;41(12):21-5.

http://coseinteressanti.altervista.org/Chromium.pdf —Preceding unsigned comment added by 82.50.165.9 (talk) 20:39, 2 April 2009 (UTC)

Biology: Chromium, Bioavailability and Cancer
Certainly, there are no studies on cancer and uptake of hexavalent chromium thru skin or GI tract. But hexavalent chromium is carcinogenic, and is penetrating easily the skin. It is not correct to conclude only from the fact that no clinical / environmental studies on cancer other than lung are available that it would not have an carcinogenic effect. To make it clear, the dosage is important for the generating of cancer. However from the nutritial point of view one would not expect to exceed this dosage.

National Institute for Occupational Safety and Health, USA NIOSH Safety and Health Topic: Chromium (Chromium IV, Chromic (VI) Acid, Chromates (VI)) http://www.cdc.gov/niosh/topics/chromium/

Baranowska-Dutkiewicz B.(1981) Absorption of hexavalent chromium by skin in man. Arch Toxicol. Mar;47(1):47-50. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=7283739&query_hl=7&itool=pubmed_docsum

Kerger BD, Paustenbach DJ, Corbett GE, Finley BL, (1996) Absorption and elimination of trivalent and hexavalent chromium in humans following ingestion of a bolus dose in drinking water. Toxicol Appl Pharmacol. Nov;141(1):145-58. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=8917687

Dutkiewicz T, Baranowska-Dutkiewicz B, Konczalik J. (2000) Percutaneous absorption studies after forty years. Int J Occup Environ Health. Apr-Jun;6(2):111-3. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=10828139&query_hl=7&itool=pubmed_docsum Robi123 21:32, 6 May 2007 (UTC)

According to UC Berkeley Professor Nancy Amy, Chromium is carcinogenic. Source: 16:30 in class "19: Trace Minerals" in online course "NS 10: Introduction to Human Nutrition", available on iTunes via [].Robi123 19:44, 11 May 2007 (UTC)

Shouldn't Chromium also be in Category:Biology and pharmacology of chemical elements ? Eldin raigmore (talk) 18:49, 16 May 2009 (UTC)

Acidic oxide?
This page says that Cr has a solely acidic oxide whereas Chromium(III) oxide claims to be amphoteric. Which is correct? Alecjw (talk) 09:15, 16 June 2009 (UTC)
 * acidic means that if you put it into water the pH is between 1 and 7, while amphoteric means the molecule is able to act as base in acidic medium while it reacts as a acid in basic medium. For example HSO4- is a relative strong acid, but in acidic conditions you can reprotonate it to become H2SO4 sulfuric acid or deprotonate it to become a SO42- sulfate ion.--Stone (talk) 13:03, 16 June 2009 (UTC)

Abundance in groundwaters
The last paragraph of the 'Occurance' section states:

"..although in some areas the ground water can contain up to 39 µg of total chromium of which 30 µg is present as Cr(VI)"

µg per what? µg/mL is a lot, wheras µg/m³ is tiny. Or is that µg in total, everywhere? I'd alter this myself, but am uncertain about my wiki-editing skills and have no desire to muck up a Good Article. I note that the claim is cited, so there's an assumption that the true units are in there someplace.

Cheers

PS... it's litres (LEE-ters), not liters (LIE-ters) ;-) 81.144.241.196 (talk) 10:57, 1 February 2011 (UTC)
 * Done! its µg/L --Stone (talk) 22:25, 1 February 2011 (UTC)

Questions?
1. Occurence; see Peridotite: "Minor minerals and mineral groups in peridotite include plagioclase, spinel (commonly the mineral chromite)"; I was thinking of Chromium mines in the San Juan Is. and Olympic Penninsula (used in WWII). Aside: the City of Seattle Arborist (Marv Black dec.) noted that the high Chromium content of some forest soils in the Bellingham/Lake Chelan led to stunted tree growth and excellent Bonsai.
 * What I could find: Olympic Penninsula was mostly manganese mining;

2. or K3[Cr(CN)5NO] as +1 : the German reference doesn't Google except for references to your wiki page. Metal nitrosyl complex information doesn't match +1 designation if only because it seems to violates the section on bonding and symmetry. I've got a text on advanced inorganic chemistry for a post grad course I took but ...
 * This is real, the structure shows linear CrNO, which indicates NO+ and therefore Cr+, 17e-.
 * The book gives that structure.

3. Natural Cr(VI)??? I did environmental water testing for several years. EPA Chromium in water is usually tested by AA or ICP, Standard Methods described Hexavalent chromium test using diphenylcarbazide, not usually done due to expense/time consuming. Cr is then reported as Cr(VI) leading to this erroneous statement. Subsoil is usually acidic and anaerobic, and does not spontaneously generate Cr(VI). It accelerates corrosion of stainless steel and our lab did a fair number of gas station remediation testing (30 year SS Tanks only last about 15 years underground.)(Put a cast iron bolt and a stainless steel fork in separate pickle jars: the bolt will be rusty and the SS fork will dissolve.) EPA Region X library in Seattle had studies of reports of "natural" Cr(VI) and it could not be recreated under identical conditions. This included air oxidation of sea water (pH=8.4). In freshman lab we add peroxide to Chromite solution to make Chromate but (like Aluminate) the Chromite solution is pH=12 or higher. I don't think caustic soda lakes in the desert get that high, above 10 and you absorb carbon dioxide from the air.
 * I agree that natural Cr(VI) seems unlikely in nature, but the statement is backed with a ref to a published study. It would be helpful to find a publication that states that Cr(VI) is highly unlikely to be of concern.
 * would this be an acceptable ref?

4. Dermatitis to Stainless Steel is usually attributed to Nickel allergy which affects women disproportionately (e.g. earrings with SS posts, SS flatware).
 * A ref would help, but we need to examine such comments.

5. I appreciate Cr(VI) toxicity however I remember that Potassium Dichromate "mouthwash" was sold OTC for dental diseases at Bartell's and Rexall drug stores. Found some obscure Formularies on Google books from 1907 and 1921, but I remember seeing it in the drug store as late as the 90's.
 * Amusing. Again a ref would help.  The section starting "In 2010, the Environmental Working Group studied..." is preachy in a way.
 * sodium dichromate mouthwash

6. Chromium doesn't actually "replace" Aluminum in Ruby as the Al occupies tetrahedral space and Cr occupies an octahedral position. (Similar to Iron colorant; same Fe+3 in Amethyst and Citrine, difference is octahedral to tetrahedral).
 * Al is not typically tetrahedral in its oxides, which one can barely figure out reading our unclear article aluminium oxide.

Amythyst is quartz (SiO2) wherein Fe(III) occupies Si sites, I am pretty sure. Not sure how change balance is maintained, maybe OH for O.
 * ruby

7. Tried to add Hexavalent chromium in "see also" but doesn't connect? Redirected?

8. Glass is commercially colored green by iron (ferrous). Refractory Chromium oxide is an opaque green glaze.
 * Cr(III) is indeed used as a glaze component as well as a colourant for glass, according to my source.

9. Copper Chromite is an important hydrogenation catalyst. http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0142
 * yes, an oversight. I started a section on catalysis.
 * Really helpful comments BTW. Do other elements...
 * Nice work! Hope for more!

Shjacks45 (talk) 06:45, 26 August 2011 (UTC)
 * --Smokefoot (talk) 13:01, 26 August 2011 (UTC)
 * --Stone (talk) 20:40, 26 August 2011 (UTC)

File:Chromium crystals and 1cm3 cube.jpg to appear as POTD soon
Hello! This is a note to let the editors of this article know that File:Chromium crystals and 1cm3 cube.jpg will be appearing as picture of the day on December 14, 2011. You can view and edit the POTD blurb at Template:POTD/2011-12-14. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks!  howcheng  {chat} 17:12, 13 December 2011 (UTC)

Vandalism
Under the section Passivation, it says that oxygen forms an oxide layer a few turds thick. I am unaware of any unit of measure called a turd, and wiki brings up feces when I search for the word turd. I would guess its vandalism, but that's just me. — Preceding unsigned comment added by 174.254.86.145 (talk) 16:04, 5 January 2012 (UTC)


 * Fixed, thanks. Vsmith (talk) 16:11, 5 January 2012 (UTC)

Is it Chromium(III) or Chromium(VI) that's used in stainless steel?
Subject says it all really. The article doesn't make this clear, and I was wondering if someone could clarify. Thanks. --Rebroad (talk) 00:44, 20 January 2012 (UTC)


 * It isn't both used in stainless steel. You have metalic chromium (= Chromium(0)) used in stainless steel. --Alchemist-hp (talk) 01:43, 20 January 2012 (UTC)

electron configuration in the table
Why is it [Ar]3d54s1 in the table?Asoer (talk) 01:30, 21 November 2008 (UTC)

I don't know, it should be [Ar]4s3d^5. Landfieldjc (talk) 16:54, 25 January 2012 (UTC)

typical charge on a single atom of chromium
this is useful information that is too hard to find- I just looked elsewhere. the typical ion configuration is more important that in being used in electroplating on bumpers... duh — Preceding unsigned comment added by 24.17.154.154 (talk) 04:33, 13 March 2012 (UTC)

Wrong confugration description
Isn't it the other way around? It says now on the table on the side: 4s^1,3d^5 It is the wrong order. First write the lower level and then the higher one. It should be, I think: 3d^5 then 4s^1, giving 3d^5, 4s^1 — Preceding unsigned comment added by 31.210.186.117 (talk) 07:52, 20 April 2012 (UTC)

biology
The 1st sentence of the last paragraph in the intro section (to wit: "Trivalent chromium (Cr(III)) is required in trace amounts for sugar and lipid metabolism. ") seems to contradict the "Biological Role" section.

Most evidence in refs 46-50 seems to indicate possible roles for Cr III in lipid and carbohydrate metabolism, as well as a potentiation effect on insulin action. Some of these conclusions seem to be undergoing review, however it seems premature to flatly state "Chromium has no verified biological role and has been classified as not essential for mammals.", even if there is one reference, contradicting others, that supports at least the last part of that statement. — Preceding unsigned comment added by Ggpauly (talk • contribs) 01:18, 6 September 2012 (UTC)

"Came to attention"?
The text seem to allege that the early Chinese usage of chromium indirectly led westerners on the track of a more systematical use of chromium – the key phrase is "came to attention". I don't believe so. I believe westerners "rediscovered" the metal independently. Or the westerners "discovered" it as a chemical element, unless the Chinese had a theory of chemical elements too. Not being too West-centric is a good thing, but a discovery includes full knowledge about the inner workings of ones own findings. Rursus dixit. ( m bork3 !) 03:45, 4 January 2012 (UTC)
 * The history reads as though the Terracotta warriors had chromium-plated uncorroded weapons, which is nonsense. This isn't in the lede, but the lede is still rather too detailed on this issue for a lede. Yes, it needs fixing. See discussion. S  B Harris 03:55, 3 October 2012 (UTC)
 * A documentary TV program i saw, (may have been Nova), claimed the chinese had chromium stainless steel circa 950 AD Song dynasty; i'll try finding a reference. -- 174.137.243.141 (talk) 16:53, 19 July 2013 (UTC)

Electronic Configuration:
Reasons for Chromium's electronic configuration of 3d5 4s1: 1. Hund's rule of maximum multiplicity states that half filled orbitals have maximum spin and hence lower the energy level, making the atom more stable. 2. in carbon in that case it should be 2s1 2p3. but the energy required for carbon to excite( in the sense shift) an electron from 2s to 2p is more than the energy lowered by the p3 half filling stability. 3. 3d and 4d have only a little more energy than 4s and 5s respectively. hence, the shifting is possible. Even in Cu (Cooper) the configuration is 3d10 4s1 not 3d9 4s2 because of the same reason.

117.192.93.55 (talk) 14:01, 11 October 2010 (UTC)RohanShankar


 * For lack of a better word, this is BS that just happens to work for the 4th period. There is a lot more going on than that and you are not going to be able to predict the electron configuration without a lot of calculation. Since the 4th period of transition metals is usually the first one covered in schools it is taught as a kludge that works, just like sloppy Aufbau. How does this explain Ru's configuration of [Kr] 4d7 5s1, or (even more funnily) W's configuration of [Xe] 4f14 5d4 6s2? Double sharp (talk) 14:13, 12 November 2013 (UTC)

Talk
- What does "lucious" in Notable characteristics mean?--Warut 11:50, 10 November 2006 (UTC)


 * Lustrous, I presume, referring to its luster - or else it's just lusty stuff :-) Vsmith 12:28, 10 November 2006 (UTC)

- What does Chromium look like when it reacts to a different element?--DK 12:52, 14 February 2008 (UTC)

- I believe there is a problem with the electronic configuration, it is shown as 3d5, 4s1: i believe it is 3d4 4s2
 * Then you might have to consider reëxamining your beliefs, because it is actually [Ar] 3d5 4s1. Not all elements obey the Aufbau principle. Double sharp (talk) 14:14, 12 November 2013 (UTC)

Chromium(III)

 * File:Cut Ruby.jpg, caption: "The red colour of rubies is from a small amount of chromium(III)"
 * I changed the caption, chromium(III) is green. A citation is needed.
 * File:Muscovite-150242.jpg, caption: "Fuchsite, a chromium(III) bearing muscovite var."
 * File:Chlorid chromitý.JPG, caption: "Chromium(III) chloride hexahydrate ([CrCl2(H2O)4]Cl·2H2O)."
 * File:Spodumene-21687.jpg, caption: "Hiddenite (a chromium bearing spodumene var.)*
 * Although anhydrous chromium(III) is violet.
 * File:Chromium(III)-chloride-purple-anhydrous-sunlight.jpg, caption: "Anhydrous chromium(III) chloride (CrCl3)."
 * --Chris.urs-o (talk) 03:06, 6 April 2013 (UTC)

chromium is a element that is used for jhfekjwafneruy2wqdxnolmrbe qiupnsiuy43qfdr gbeuywq[xfmepiuwqdkyr431isl.dwoq — Preceding unsigned comment added by 65.51.227.33 (talk) 17:38, 17 March 2014 (UTC)

Picture of proprietary patented product sold as supplement, moved from main page
There has been a persistent effort by patent holders and sellers of the unproven and possibly dangerous product to push it on these pages with insertions like this touting a proprietary product by "NUTRITION 21," and to remove or marginalize any mention of glucose tolerance factor.

— Preceding unsigned comment added by Ocdcntx (talk • contribs) 23:23, 19 April 2015 (UTC)

Wrong Mohs hardness values probably taken on the net
I just saw that Chromium was listed on this article as 8.5 on Mohs scale. Something is wrong on wikipedia: look at Osmium's Brinell hardness value listed on the dedicated article, 3900 MPa. Molybdenum's Brinell hardness is at 1500 MPa. Tungsten's Brinell hardness is listed on wikipedia as being 2570 Mpa. Now look at the value for chromium: 1120 Mpa. It is impossible that tungsten is a "7" on Mohs scale and chromium a "8.5" given their respective Brinell hardness. Strangely here on wikipedia we have odd Moh values taken who knows where and Vickers & Brinell values whose sources are unidentified yet. I highly suspect the source for the erroneous Mohs hardness values for metals seen here, comes from webelements.com, values that probably were then spread out in the wild through various blogs and websites especially in articles entitled "what is the hardest metal" which list even ceramics and composites as "metals" in their poorly written pages.82.240.163.245 (talk) 05:23, 30 September 2014 (UTC)
 * OK, thanks for posting this explanation. I'm sorry for reverting you: I checked the talk page before doing so, but your comment didn't show up for some reason (did you forget to save? the timestamp shows a later time than my revert). Looks like we need to check these Mohs values and get rid of the spurious ones. I have some doubts that they should be listed at all, BTW – Mohs is a nonlinear scale, so it's not clear what fractional values mean, and I gather it is not in much use in metallurgy (isn't it a mineralogical thing?). Double sharp (talk) 08:36, 30 September 2014 (UTC)
 * Mohs scale not being linear doesn't mean that an inferior Brinell value will give a higher Mohs value than for a material with a higher Brinell hardness value (such as tungsten for example) . Mohs scale is -not- a scale with values that are inversely related to either Brinell or Vickers! Not being "linear" is just a laymans term translating the fact that Mohs follows an exponential law, nothing else. Now to find the correct values, the real problem...82.240.163.245 (talk) 12:45, 30 September 2014 (UTC)
 * I didn't mean that: I agree with you that Mohs goes in the same direction in Brinell or Vickers. What I meant is that since Mohs isn't linear, it's not clear what a value like "8.5" even means. Double sharp (talk) 13:23, 30 September 2014 (UTC)
 * Seems like almost all the studies that mention chromium's hardness only do so in a context of microhardness of various types of chromium platings . If you read this 1993 government research paper ( http://hal.inria.fr/docs/00/25/17/66/PDF/ajp-jp4199303C7144.pdf ) hard chromium platings between 0.5 and 500μm thickness reach 1120 HV (Vickers) microhardness ( pages 933 934). Interestingly, electroless nickel platings reached even higher hardness values such as 1300HV (compare with actual value proposed on wikipedia ...) . Concerning research a bit more recent, a 2011 study ( http://www.mtf.stuba.sk/docs/internetovy_casopis/2011/2/martinkovic_a_kol1.pdf ) shows that the highest hardness value for hard chromium plating is the same value again of .. 1120 HV 0.025 . To have a clue how to translate more or less precise vickers, brinell, rockwell, knoop hardness values to an approximate mineral hardness value in Mohs scale, you need to check charts in engineering books or online such as on page 721 of the document available on the official website of the Mineralogical Society of Great Britain and Ireland pertaining to the correlation between Mohs (very imprecise scale) and Vickers values and what they really represent in terms of material testing http://www.minersoc.org/pages/Archive-MM/Volume_28/28-206-718.pdf . Note that for a mineral rated with a given Mohs value, the actual Vickers hardness depends on the angle at which the sample is tested which is evident. For metals this problem is not as much of an issue and exposing metal to various angles will not yield dramatically different values. Look at this modern industrial reference chart comparing Mohs scale and Vickers hardness values http://www.cidraprecisionservices.com/mohs-conversion.html . A quick estimation would place a 1120 HV Vickers hardness value in the 7-7.5 hardness range, and that is only for an extremely thin section of material in form of a plating, not bulk material. Being in the 8.5 Mohs range would mean to have a Vickers hardness circa 1900 HV which is far from being the case for chromium either in plating or bulk anyways. Hope this helps.  — Preceding unsigned comment added by 89.82.152.110 (talk) 00:22, 4 October 2014 (UTC)
 * Vickers and Brinell hardness tests are both indentation tests, while the Mohs scale is a scratch test. The two are not directly comparable, although there is some correlation (for reference, corundum, which is 9 on the Mohs scale, averages about 677 HB; or 930 HV). The basic explanation behind its hardness is that it forms a passivation layer; a thin layer of chromium (III) oxide that itself has a Mohs hardness of 8-8.5; it is also the same reason for the high hardness of chrome microstructures as well. Since chromium is one of the few metals that can be found in native form (albeit in very small amounts), the Mohs scale number is still a useful piece of information. I would recommend adding the information back into the article. Xander T. (talk) 14:01, 24 February 2016 (UTC)

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Table of isotopes
The table is showing the isotopes of Vanadium rather than Chromium. — Preceding unsigned comment added by Lars.Jorgensen (talk • contribs) 16:42, 13 April 2017 (UTC)
 * Fixed. Double sharp (talk) 05:14, 14 April 2017 (UTC)

Hexavalent not toxic???
What the heck are we doing with this statement? Can someone please confirm with the source: "Cr(VI) has not been established as a carcinogen when in solution, although it may cause allergic contact dermatitis (ACD).[1]"

It is in direct contradiction of this statement, a few paragraphs later:

"The acute oral toxicity for chromium(VI) ranges between 50 and 150 µg/kg.[1]" Grammar's Li'l Helper Discourse 23:22, 17 May 2016 (UTC)

These statements do not contradict each other. Carcinogens are chronic toxins. The toxicity data given is for acute oral toxicity, not for chronic toxicity. --Acewolf359 (talk) 16:17, 17 May 2017 (UTC)

DELETE - current ref CONTRADICTS statement
In the section: Biological role, the statement is made that: Cr(VI) has not been established as a carcinogen when in solution However the (authorative: the Agency for Toxic Substances and Disease Registry) reference given (https://web.archive.org/web/20140708162618/http://www.atsdr.cdc.gov/toxfaqs/TF.asp?id=61&tid=17) states: Exposure to chromium occurs from ingesting contaminated food or drinking water or breathing contaminated workplace air. Chromium(VI) at high levels can damage the nose and cause cancer. Ingesting high levels of chromium(VI) may result in anemia or damage to the stomach or intestines. Unless I am mistaken the statement in the ariticle is incorrect to say the least. However, I have tagged it as simply needing some suitable corroborating reference (that trumps the ATSDR. IMO though it should be deleted. LookingGlass (talk) 14:58, 10 May 2017 (UTC)
 * I have edited the article based on your link to point to the link between CrVI solutions and stomach tumours. Double sharp (talk) 05:17, 7 June 2017 (UTC)

Not essential
Hello. I am sorry to edit your lead because this is a Good Article. We can't have a lead saying that chromium is an essential micronutrient when we have a food authority in disagreement. You can debate all you like in the article, but I do not believe in all fairness that Wikipedia can say in the lead that this is a fact open for debate. -SusanLesch (talk) 18:32, 20 March 2018 (UTC)
 * This article passed GA on April 29, 2009. I have cited the lead for EFSA from September 2014. -SusanLesch (talk) 18:41, 20 March 2018 (UTC)
 * No need to be sorry! You found a piece of out-of-date content, updated/corrected it with a recent and reliable-source citation, and explained clearly what and why you did. That's exactly how things should work around here. DMacks (talk) 19:01, 20 March 2018 (UTC)
 * Well I wish it were that simple. Here are two U.S. sources in the interest of fairness. Both still think it's essential, one of them quite recently. My professor says no to that. US NAS (National Center for Biotechnology Information, U.S. National Library of Medicine) 2001 and US Office of Dietary Supplements March 2, 2018 -SusanLesch (talk) 21:49, 20 March 2018 (UTC)
 * (coming over from WT:MED)


 * Following are the first two paragraphs from the "Chromium" Chapter (pages 352-356) in the Encyclopedia of Human Nutrition (Third Edition), 2013, published by Elsevier (the chapter author is R.A. Anderson, from the Diet, Genomics and Immunology Laboratory, Beltsville Human Nutrition Research Center, ARS, Beltsville, MD, USA): "Chromium in the trivalent form is an essential nutrient that functions primarily in sugar and fat metabolism. Dietary intake of Cr by humans and farm animals is often suboptimal. Insufficient dietary intake of Cr is associated with increased risk factors associated with type 2 diabetes mellitus (type 2 DM) and cardiovascular and related diseases. Chromium functions in glucose and insulin metabolism primarily via its role in the improvement of insulin activity. Improved insulin function is also associated with an improved lipid profile. People with type 2 DM have a more than twofold increase in the incidence of cardiovascular diseases (CVDs) compared with control subjects. Improved insulin function also leads to a decrease in diseases associated with inflammation, antioxidants, and even some forms of cancer and brain function including Alzheimer disease. / Chromium in foods and dietary supplements is trivalent, whereas Cr often found in paints, welding fumes, and other industrial settings is hexavalent and is severalfold more toxic than the trivalent nutritional Cr. Trivalent Cr is one of the safest nutrient supplements based on the ratio of the amount that is needed relative to the amount that can be consumed over a lifetime with no adverse effects. An expert panel of the US Food and Nutrition Board was unable to set an upper level of safe intake because none of the levels of intake tested showed any signs of toxicity. Toxicity is alleviated by the low levels of absorption, usually less than 2%. This review will be focused on the effects of trivalent Cr on human subjects." Hope this helps. &mdash; soupvector (talk) 01:34, 21 March 2018 (UTC)
 * I'm finding that MEDRS consistently support chromium as an essential micronutrient. Clinical Nutrition (Wiley, 2008) indicates that IV nutrition should include chromium (10-15 micrograms of chromium daily according to chapter 1, 10-20 micrograms daily according to chapter 9).
 * Here's a nice passage from Diet and Nutrition in Critical Care (Springer, 2015), chapter titled "Micronutrient Function, Status and Disposition in Critical Illness": "Chromium exists in several oxidation states with the stable trivalent form biologically active. Its bioactivity comes from incorporation into a low-molecular-weight organic molecule (chromodulin) which improves tissue insulin sensitivity through amplification of protein tyrosine kinase activity. Chromium is transported bound to transferrin (and albumin) in the plasma and competes with iron for binding sites. The main excretory route is through the urine; however, some chromium is excreted in the feces through bile and small intestinal losses. Urinary losses increase with metabolic stress, trauma, and ascorbic acid deficits. Chromium deficits induce glucose intolerance, and glucose intolerance can further drive urinary chromium losses. Chromium supplementation is not beneficial to glucose tolerance in nutrient-replete patients. Administration is best reduced or discontinued in patients with renal dysfunction."


 * I do see the recent controversy you've highlighted, stemming from the concerns expressed by the EFSA in 2014. Since it's been a few years, it should not be hard to find a more recent MEDRS that acknowledges that statement and provides additional context; absent that, I think you may be right about removing claims that this is an essential micronutrient. &mdash; soupvector (talk) 02:08, 21 March 2018 (UTC)
 * suggests against considering chromium essential, and a very recent European review (available free) strikes a nice balance, saying that the EFSA 2014 statement suggested that there is insufficient evidence to support chromium as an essential nutrient, but still suggested chromium supplementation at a low level in people receiving parenteral nutrition. &mdash; soupvector (talk) 02:23, 21 March 2018 (UTC)
 * Wow, soupvector, thank you for the detailed reply. I agree with your approach. However I have a problem with "striking a nice balance" by basing our decision on that one review. Here's why:
 * This recent review of parenteral trace element provision has two paragraphs on chromium. First the authors say, "A reliable biomarker of chromium status in patients receiving PN is lacking, and the early detection of chromium deficiency remains problematic in patients receiving PN." And then without citing a reference they end the discussion with, "On the basis of serum concentrations as a reliable biomarker, 10μg/day of chromium should be sufficient in PN therapy." How in the world did they arrive at that conclusion?
 * * My lecture says, "The benefits of chromium supplementation in total parenteral nutrition are due to a pharmacological effect as opposed to the correction of a chromium deficiency." (copyright 2018 Mathieu Lalonde, PhD)
 * Mineral (nutrient) should be updated along with this article. If needed I can cite other studies from lecture but I think the point is clear enough. -SusanLesch (talk) 22:40, 21 March 2018 (UTC)
 * I suspect you'll agree that what your lecturer says has no consequence for this encyclopedia (it's all about MEDRS), unless it leads to better sourcing. While it might be hard for us to understand how the author(s) of a MEDRS arrived at their conclusion, I cannot say that the conclusion is clearly invalid (and it seems to be in line with other MEDRS). It is exceedingly hard to design an ethical study of critically-ill (or other parenteral nutrition-dependent people) that would determine the benefits of a tiny dose (versus none at all) of trivalent chromium when it's thought to be safe. So, eliminating the description of "essential" while also saying that MEDRS suggest supplementation seems like "striking a nice balance" to me. &mdash; soupvector (talk) 23:07, 21 March 2018 (UTC)


 * I agree the study you describe would likely be unethical.
 * I am sorry to reject . The authors aren't known for work on chromium, so I have to take their conclusion as coming from the ASPEN, ESPEN and AuSPEN figures in table 2, all of which precede the EFSA opinion. The context of their review is 1) there is no good way to gauge chromium nutritional status — but we'll take a stab at it, and 2) ESFA found chromium inappropriate for all patients — but it's okay because we're only recommending a teensy dose.
 * To resolve this, I suggest that if the next "ESPEN Guidelines on Parenteral Nutrition" recommends chromium, then Wikipedia should add a note on parenteral nutrition.


 * I am not arguing that chromium is useless to humans but I struck my lecture above because you are correct it doesn't advance our cause.
 * I agree that removing "essential" from the lead would help.
 * Supplementation is an early 20th century idea. We used to think that isolating and manufacturing nutrients would save humans from disease conditions. I would prefer not to have to "balance" an outdated premise. -SusanLesch (talk) 15:07, 22 March 2018 (UTC)
 * Here's a trend. The Australasian group (AuSPEN) doesn't seem to mention chromium in 2016 but they did in 2014  when they noted that the 2014 upper recommendation was reduced from 1999. -SusanLesch (talk) 19:22, 22 March 2018 (UTC)
 * I'm intrigued by your criterion "authors aren't known for work on chromium" (in rejecting a MEDRS); is this a widely accepted criterion for MEDRS (a link to such guidance would be welcomed) and if so how it is estimated? WP is not the place to right great wrongs - you seem to be choosing references in a non-NPOV way. &mdash; soupvector (talk) 20:26, 22 March 2018 (UTC)
 * It is disappointing that only 2.5 sentences of my reply appear to have been read. It is a statement of fact. I chose to assess the authors' involvement because I asked here how they reached their conclusion. You replied, "it might be hard for us to understand how the author(s) of a MEDRS arrived at their conclusion", so I looked! Who knows, they might be the world's most experienced experts. One of the three authors co-wrote one other study about several supplements including chromium, and that's it. I have in the past found members of WikiProject:Medicine willing to reject acceptable MEDRS as low quality. I don't make that assessment. You or anyone else are welcome to use this source per WP:MEDASSESS. -SusanLesch (talk) 23:32, 22 March 2018 (UTC)
 * I read your entire reply. Good luck with your mission. &mdash; soupvector (talk) 01:15, 23 March 2018 (UTC)
 * Thank you. I was about to call it quits, too. Follow up will be at Talk:Mineral (nutrient). I was looking in the wrong place for ESPEN guidelines. 2017 doesn't mention chromium. If anyone comes across this discussion and would like to trace their history it's all here.
 * ESPEN is http://www.espen.org -SusanLesch (talk) 16:22, 23 March 2018 (UTC)

Supplementation
Content on chromium supplementation was created for the Chromium deficiency article. Slightly shorter version now copied into this article. The Chromium article gets close to 2,000 views per day versus ~50 for Chromium deficiency, so decided it was appropriate to have the topic covered here in the Chromium article. A suggestion - changes to the Supplement section in this article should also be made to the Chromium deficiency article. David notMD (talk) 15:15, 24 April 2018 (UTC)

Ref checking
Went through all refs. Many cannot be checked, as are books with ISBN numbers. Did some fixing. Removed one duplicate. Refs 56 and 66 attempt to go to a specific page in a book, but access denied. Ref 23 does not work. Ref 28 has two Wikilinks. That last ref is to a template which gives "", so I am guessing that it should be left alone, even though I see no benefit in linking in a ref to an author or a publisher. David notMD (talk) 11:35, 17 October 2018 (UTC)

Have we reached a consensus on what out WP:CITESTYLE should be? I started to change some dates to the standard YYYY-MM-DD, but many of the author listings are completely unorganized. I believe that most of these citations used {first1|last1|first2|last2|etc}, but David changed some of these to {vauthors} when he went through with citation checking, but he did not change them all. I propose we stick with the {first1|last1|first2|last2|etc} option when applicable, as most of the citations as far as I've seen have followed this format. (And David was right: if two initials are given, we should just combine them the way he had them. But to Stone's point, first names should be left whenever available.) UtopianPoyzin (talk) 03:14, 18 October 2018 (UTC)
 * I concur there should be a consistent format for references. I prefer vauthors, but will stop making changes in that direction. Ditto on initials versus first names, and date as year only versus more detail. A note on Good Article and Featured Article statistics. From a check on numbers, in English language Wikipedia there are 5.7 million articles of which 38,707 are GA and 5,398 are FA. David notMD (talk) 08:52, 18 October 2018 (UTC)

FAC Preparation

 * missing pages -- The reference Rieuwerts in the Occurrence section about background concentrations of chromium. --Stone (talk) 19:27, 9 October 2018 (UTC)
 * factual discrepancy section biological role: leaving in question whether chromium is essential for healthy people while supplementation states : because deficiency can occur if it is not essential how is deficiency possible? --Stone (talk) 20:00, 9 October 2018 (UTC)
 * Exactly. Researchers on this topic (and governments) disagree on whether chromium is essential or not. Even when governments decide it is essential, an Adequate Intake (AI) is stipulated rather than an Estimated Average Requirement (EAR) and a Recommended Dietary Allowance (RDA). AIs are typically set at what people consume in a normal diet, versus EARs and RDAs, which are set to avoid the known consequences of deficiency. In effect - AIs are what people eat and they seem to be healthy - so those amounts are enough. David notMD (talk) 03:30, 10 October 2018 (UTC)
 * My point is not that there is an Adequate Intake for non essential elements, but that we state that it is in question if it is essential but in a second sentence we state that you show signs of deficiency if your intake is to low. If there is deficiency it is essential. If it is not essential there should be no detectable defieciency.--Stone (talk) 05:41, 10 October 2018 (UTC)
 * This will need revised wording for Biological role, Supplementation and Dietary recommendations to convey that there is not a scientific consensus, and governments disagree on essentially. As late as 1989 the U.S. tentatively recommended an intake between 50 and 200 micrograms, and a 100% Daily Value (for dietary supplement labeling purposes) was set at 120 micrograms. It was in 2001 that the AIs were set, and only recently was the label 100% DV revised to match the AI. David notMD (talk) 11:39, 10 October 2018 (UTC)


 * non information in food sources Why do we include a sentence about a database which do not contain information on the chromium content --Stone (talk) 20:02, 9 October 2018 (UTC)


 * The sentence is "Food composition databases such as the those maintained by the U.S. Department of Agriculture do not contain information on the chromium content of foods." For many nutrient minerals the USDA database includes mineral content per serving, allowing for the identification of good sources of minerals and calculations of mineral content from diet. Chromium is not included in the database, so determining average chromium intake or percent of people not consuming what has been identified as an Adequate Intake of chromium is not possible. David notMD (talk) 03:18, 10 October 2018 (UTC)


 * References


 * Fawcett, Eric (1988). missing page number
 * Weast, Robert (1984). missing end page number
 * John Rieuwerts (14 July 2017) page numbers
 * Chromium (with location data), Mindat is missing accesdate and author ......
 * Chromium from Udachnaya-Vostochnaya pipe missing all info necessary
 * Cotton, F. A.; Walton, R. A. (1993). is missing page numbers
 * Chemistry Blog. WPZOOM is this a credible source?
 * Meyer, R. J. (1962). Chrom missing page numbers
 * Papp, John F. & Lipin, Bruce R. (2006) missing page numbers
 * Davis, JR (2000). is that really in Afrikaans?
 * Gerd Anger et al. is missing page numbers
 * Twigg, M. V. E. (1989). is missing page numbers
 * Garverick, Linda (1994) is missing page numbers

--Stone (talk) 10:44, 17 October 2018 (UTC)
 * I'll give these a look. UtopianPoyzin (talk) 00:46, 19 October 2018 (UTC)
 * For one, I can verify that the "Chemistry Blog" citation is credible. The author, Mark Lorch, says this in his personal biography, "Mark Lorch has PhD in biochemistry and is a Professor of Chemistry and Science Communication at the University of Hull, UK. As well as research, teaching and blogging, he can sometimes be found 'science busking' on the streets of Yorkshire." This could mean nothing, as it is only words and not a certificate; I also don't know if blogs written by people with doctorates are considered credible sources. After checking out the references you provided, most of these I was unable to view, for I lacked privileges to do so.UtopianPoyzin (talk) 01:24, 19 October 2018 (UTC)

Featured article candidate?
Hello everyone, I have been fixing up this article with a goal of boosting it up to the prestigious class of featured article, and was just checking in to see what I must do. I have looked over the criteria, and the article looks pretty spot on to me, but I wanted to get some outside input to see exactly where my next steps of working would need to be. Any suggestions? Help to get this article to FA would also be appreciated. This is a big undertaking, and I have a few going on at the moment. (unsigned, was by UtopianPoyzin)
 * Looks like this could be fun. --Stone (talk) 07:38, 2 October 2018 (UTC)
 * To consider: for some of the minerals which are also essential nutrients, there is a section within the article "Biological Role," but also a link to an article "____ in biology." For example, Magnesium links to Magnesium in biology. Chromium does a "See also" to Chromium deficiency and Chromium in glucose metabolism but not Chromium in biology. I am not suggesting you do that - especially as from your track record, more interested in the mineral-as-mineral than mineral-as-nutrient - but if in the future someone else creates that article, some of what is in Chromium now could be moved, leaving a short version behind. I had worked on the nutrition-related content back in 2017 and April 2018 and am fairly comfortable with the content and referencing currently there. David notMD (talk) 15:14, 2 October 2018 (UTC)
 * P.S. You should be aware that Stone has contributed mightily to FA and GA efforts on many minerals. David notMD (talk) 15:21, 2 October 2018 (UTC)
 * P.P.S. Be careful about your Edit summary wording. Here in Talk you moved older content into an archive, but what you wrote was "Deleted archived content." David notMD (talk) 15:25, 2 October 2018 (UTC)
 * Well thank you for your blessing Stone! I'd love to have you join me on this adventure! And David notMD, I didn't have the time today to check the talk page; I wish I would have read this earlier. You are correct, I do typically tend to focus more on the physical / chemical aspects of these types of articles rather than the biological side. My knowledge in chemistry far surpasses that in biology, but I could try to make by if you need me to. What I'm trying to get at is that I probably am not the resource needed to write "Chromium in biology", but if you know somebody who could sufficiently compose an article along those lines, that would be excellent and very beneficial. I personally believe that the content that is currently available could probably make do for FA, and I'm a bit late on the ballgame to introduce relevant information here without it carrying for too long when an entirely new article could be made on the matter (i.e. "Chromium in biology") The writing currently is rather unprofessional, and occasionally covers the same topics twice in the article and / or repeats itself. I'll also be adding in plenty of citations, and maybe a table or graph or two to make this article more visually representable and appealing. (and what I meant was "deleting the already archived content from the main talk page, but my lazy three word edit summary was insufficient looking back on it...) UtopianPoyzin (talk) 01:59, 3 October 2018 (UTC)

FAC to-do list:
UtopianPoyzin (talk) 14:45, 3 October 2018 (UTC)...... UtopianPoyzin (talk) 02:13, 4 October 2018 (UTC)... UtopianPoyzin (talk) 01:59, 9 October 2018 (UTC)
 * The lead mentions chromium's use in the creation of stainless steel twice... UtopianPoyzin (talk) 04:28, 19 October 2018 (UTC)
 * "Characteristics/#Physical" fixing. What is available in the section is fine information, but it needs to be reworded along with new content along those lines.
 * Still needs work. UtopianPoyzin (talk) 14:12, 16 October 2018 (UTC)
 * "Chemistry and compounds" needs to either have new content added to each of the oxidation states listed, or undergo some serious content merging.
 * Hey, I saw that you were adding some hidden refs for these sections. It could just be a lack of my time here, but why would we hide the references? Is it because they were in Google Book format? I still don't know why we wouldn't make them public, but you know what you're doing. UtopianPoyzin (talk) 01:57, 14 October 2018 (UTC)
 * If not Stone, then anybody else? UtopianPoyzin (talk) 00:56, 16 October 2018 (UTC)
 * I put the references in to use them when necessary. I had no time to formate them apropriatly. --Stone (talk) 05:34, 16 October 2018 (UTC)
 * Section completed. UtopianPoyzin (talk) 14:05, 16 October 2018 (UTC)
 * "Dietary recommendations" needs some total reworking. Never looked at it too much up until now, but the information given needs to be standardized, especially in the last two paragraphs.
 * After a review of the section, I sadly cannot take dietary recommendations off of the list. The beginning sentences of both the current second and third paragraphs on October 4, 2018 need thorough work, which I will be attending to within the next couple days. User:David notMD made significant changes here for the recommendations for AU/NZ/IN/JP, yet the US section is nowhere near complete.
 * This might be the largest field of work in the article. I remember the Germanium article withe the fight about the germanium supplements.  --Stone (talk) 09:25, 6 October 2018 (UTC)
 * Is this about the Dietary recommendations text, or what comes after that for Food sources and Supplementation? The Dietary recommendations content generally follows the format and content that exists for all vitamins and nutritionally essential minerals. One improvement could be creating a table to show the U.S. recommendations, as was done for Vitamin C, a Good Article. David notMD (talk) 10:51, 6 October 2018 (UTC)
 * Section was completed a few days ago, never removed until now. UtopianPoyzin (talk) 14:11, 16 October 2018 (UTC)
 * Fix the margins on the wikitable for the oxidation states of chromium. The paragraph is getting to close for comfort, and I personally am not great with article formatting.
 * This was a silly nitpick that isn't as bad looking back at it. UtopianPoyzin (talk) 14:08, 16 October 2018 (UTC)
 * Many of the later headings simply seem lacking in content. I am unsure how to fix this, and I'm positive that it'll be fine in the long run, but topics such as tanning should probably remain on the article about tanning.
 * Still needs work. This article has a large amount of sections. Is it too much? UtopianPoyzin (talk) 14:12, 16 October 2018 (UTC)
 * More sections when the time is seen fit.
 * Peer Review!
 * FAC?


 * Ref repairs for the Dietary recommendations section. Includes adding more country-by-country examples, per as was done when Vitamin C elevated to Good Article. David notMD (talk) 16:35, 3 October 2018 (UTC)
 * Thanks for your help David! I do appreciate the work you put into the dietary recommendations, but I would still stand by my belief that there is still a lot more work needed to be done in that section. UtopianPoyzin (talk) 02:18, 4 October 2018 (UTC)
 * Added Food sources section David notMD (talk) 12:30, 4 October 2018 (UTC)


 * Vancouver citation style is used (I count 13 vautyhor in 116 references). Per WP:CITESTYLE, we should use a single citation style throughout. I propose to use the default style (see Cite web for example). - DePiep (talk) 10:46, 6 October 2018 (UTC)
 * Slogging through ref repair was one of the tasks I least liked in bringing articles to GA. David notMD (talk) 11:42, 6 October 2018 (UTC)