From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Chemistry (Rated Start-class, High-importance)
WikiProject icon This article is within the scope of WikiProject Chemistry, a collaborative effort to improve the coverage of chemistry on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 High  This article has been rated as High-importance on the project's importance scale.


Rust 1. a : the reddish brittle coating formed on iron especially when chemically attacked by moist air and composed essentially of hydrated ferric oxide b : a comparable coating produced on a metal other than iron by corrosion

Rust is a generic term that most people use when they actually mean "Iron Rust". lets not confuse people by using the "common" word as law. i think the wording in certain areas should be more specific. — Preceding unsigned comment added by (talk) 18:54, 29 May 2012 (UTC)

rust removal[edit]

this section needs a redo. The aluminum foil method is junk science and real methods of removing rust (electrolysis,mechanical,ultrasonic,galvanic,phosphoric acid...)get no mention. There is no way a fast redox reaction could happen between aluminum and iron oxide by rubbing something with aluminum foil. A fast reaction is possible, and otherwise known as thermite, but it occurs well above the melting point of iron. I also highly doubt any substantial amount of foil is turned into aluminum oxide because the passivisation layer forms ridiculously quickly.

I agree. If no-one objects let's delete the junk science section. (talk) 08:36, 6 March 2010 (UTC)

Wow this edit conflict is confusing

The aluminum foil method works--I just took the rust off a knife this way. There are also a couple demonstration videos on the web. Based on these things, I think that excluding this method from the article, as well as labeling it "junk science," is inappropriate. Also, I notice that there is no section on rust removal, which I think should be reinstated. Plcfreeman (talk) 19:25, 2 February 2014 (UTC)

Fungus Disambiguation[edit]

Rust is understood by most English speakers as what scientists call iron oxide. Few people are familiar with the fungus (it is not a fungis but a precipitate).This is the dominant meaning of the term. Just because more than one thing share the same name doesn't mean that we disambiguate all the terms. --mav

as a gardener I disagree- if I'd clicked on the link from, say, comfrey expecting an article on rust the fungal disease but found an article about rust(iron oxide) I wouldn't be very pleased- they are two completely different things... quercus robur
Look at 'what links here'. And as a gardener you are in the unique position of being familiar with the fungus. Most English speakers don't know it exists and if they do most would probably expect what is commonly known as iron oxide to be at rust (given our naming convention for using common names). Do create a disambiguation block at the top of this article so that other gardeners can be directed to the correct place though. --mav
Disamb block created :-) mav's right on the relative frequencies. Rust, the fungus sounds familiar, but if I'd been asked to list meanings of the word rust I don't think I'd have remembered it -- Tarquin
OK Cheers tarquin. It would have been a hassle creating the disambig page then moving all the links anyway. quercus robur 21:15 Dec 17, 2002 (UTC)


I've heard that sometimes in shipyards, big iron things that can't be readily rustproofed will be temporarily electrified in order to prevent rust from forming. This usually involves leaking a small current into the surrounding water. I'm not a shipyard person though so I don't know. --dikaiopolis

Look up Cathodic_protection


i was under the impression that acids prevent rust, and alkalines accelerate it, but in the article, it says "Rusting is also accelerated in the presence of acids, but inhibited by alkali". Is this correct? Isn't rust itself an alkali, hence an acid will neutralize it? because I've heard vinegar (acid) will get rid of rust easily. --biggs

yes, rust coating found on undesired places is commonly washed off hydrochloric acid, via and acid-base reaction. look up the pickling of steel in the hydrochloric acid article. --xiankai

Rusting process speed[edit]

Can Someone help me? I am doing a science fair project about rust. I was wondering if anyone had any information on "do certain liquids cause rust to speed up or slowdown." I am testing 4 different substances, Bleach, H2O, Salt water, and vinegar. Does anyone know if any of these have an affect? Also any statistics would greatly help! ~ Ryan

Ryan- You may want to check different percentages of solutions also. For example, a 3% solution of sodium chloride (salt) and water is the most corrosive compared to ocean water that's at 5%. ~ LarryB

ryan- so far on my project vinegar was the fastest to increase the speed of rust... 34.67 seconds!!-brianna —Preceding unsigned comment added by (talk) 01:28, 19 January 2010 (UTC)


ryan- i just did a project on rust and when iron wool is put into vinegar, it completely disintegrates it. water reaction happens fastest though and salt water happens before the vinegar too. i dunno about bleach though. hope that helps! ~liz

sure i can help you rust is browny colour

i am also doing a science fiar project about rust and i need help!!!- brianna i am doing a science project on which one would rust a nail the fastest : vinger , water , orange juice, or soda and i need some resorces. please help me !- lauren —Preceding unsigned comment added by (talk) 18:44, 3 September 2010 (UTC)

Diagram request[edit]

My son is doing a class science project on Rust. Where can I find a molecular diagram of the chemical change that is taking place that is simple enough for elementary students to understand? Can someone explain why saltwater increases the speed that rusting takes place (in comparison to water alone). Thanks - Chris

it increases the speed due to the higher concentration of sodium chloride which makes the iron easier and quicker to transfer electrons!!!! i hope that helps your seawater question! donno bout the rest soz!

Wording confusing?[edit]

I'm very confused. cathodic protection is protecting rust, but it says that it protects water which obviously isn't subject to rust, it actually makes the process faster. Can anyone tell me about cathodic protection, as I don't understand it. Thanks - Oh P.S Ryan - H2O and salt will make it go faster , unsure bout others. Thanks - Leila

What you have written makes no sense. Why would anyone want to protect rust? Please read the article carefully, and then ask any questions here carefully. Please quote the sentence that you don't understand, and please start a new section. (And it is bad science to start with a presumption that something will happen, best to actually measure whether salt affects the speed of iron corrosion) --njh 08:19, 29 July 2006 (UTC)

Pencil can remove rust on certain items[edit]

I do not know if this is an original idea, but i find it puzzling that no one as far as i know have suggested that rubbing rusted surfaces with a pencil can actually remove some of the rust and make the item useful again.

I stumbled on this unique property of pencil to remove rust on a scissors that was rusted when i was conducting a seminar. I wanted to use the scissors but could not use it because it was stuck. Not only that the entire blades had rust all over them. Since the only thing i had was a pencil, i started rubbing it on the blade surfaces and lo and behold the rust started to disappear! I thought the pencil lead was just covering the rust, but when i wiped it with a tissue - the rust was really removed. Not only that, when i started rubbing the areas close to the rivet holding the two blades together, the blades started to slide easier.

Within 5 mins. of doing the rubbing or more of writing over the rust, the scissor become operational. Wow! that really felt good.

This is why i want to share this with the rest of the readers of Wiki. Find more useful ways and techniques for using pencils to remove rust or stains on other items.

Mario A. Diaz 06:30, 10 August 2006 (UTC)

There are at least two things happening here: the graphite is abrading away the loose rust flakes, and secondly providing a lubricant. I would find 'colouring' a rusting tool with a graphite pencil rather tiresome, so I just use a 'brill pad' (scotchbrite sort of thing) and a bit of machine oil. --njh 12:12, 10 August 2006 (UTC)

Someone on a bicycle blog said they used aluminum foil and water to clean the steel parts of their bicycle, and it seems to work quite well. I have also cleaned rust out of our steel wok, which my wife tends to leave soaking in water (grr!). The rust disappears quite rapidly, and the black oxidized aluminium polishes the steel as well. --Maxbox51 (talk) 17:44, 18 June 2008 (UTC)

They did some rust myths on Mythbusters, and one thing they did, reversed the rusting. IIRC, they put some powdered metal on the rust, then burned it. The burning reversed the rust by stealing ions or whatever from the powder. (talk) 23:42, 2 December 2010 (UTC)

Rust chemical makeup[edit]

1. Chemically, rust is not iron oxide Fe2O3. It is Fe2O3.xH2O, in other words a hydrated form of Fe2O3 with a variable amount of water and an unspecified crystal structure somewhere between amorphous and that of true Fe2O3.

2. Rusting is an electrochemical reaction, and for it to take place four conditions must be fulfilled simultaneously:


there must be present two phases in the rusting solid, such as ferrite (chemically, Fe) and cementite (chemically, Fe3C, Iron carbide. Iron with a very low carbon content (C<=0.02%) rarely ever does contain cementite and therefore is virtually rust-proof. Iron with higher carbon levels, and that includes all steels, has (with a few exceptions, such as martensitic steels), plenty of cementite and thus can rust freely. There is no need for non-rusting steel to contain the high percentages of chromium and nickel typical of stainless steel.


There must be liquid water in contact with the solid.


This water must contain an electrolyte (e.g. sodium chloride) at a sufficiently high concentration to enable a visible reaction rate.

Bold text[edit]

Headline text[edit]

CAN I EAT RUST?!!!!!!!!!!!!!?


In this water, there must be dissolved a sufficient level of oxygen to enable a visible amount of reaction.

The mechanism of rusting is thus: Since the concentration of iron atoms is different in cementite and ferrite, and because they are physically apart, a (electrochemical) battery is formed between the two (or any other two phases with different iron concentrations (for the purist, with different iron activities). The reaction at the cathode is Fe = Fe++ + 2e- (The iron metal is oxidised into an iron(II) ion and two electrons) This battery is shorted in the metallic solid, so that the current flowing is determined by the electrolyte concentration (for the purist, the electrolyte conductivity) in the water. At the anode, there are several reactions competing with each other: e- + H2O = H + OH- (each electron releases one proton. Since the proton is very small, it can penetrate into the metal, recombine at a porosity with another proton to form a hydrogen molecule H2, which is too big to be mobile, and thus lead to hydrogen embrittlement. 4 OH- + O2 = 2 H2O2 + 4 e- H2O2 + 2 Fe++ = 2 Fe+++ + 2 OH- Fe+++ + 3 OH- = Fe(OH)3 Since Fe(OH)3 has a low solubility, it precipitates in the form of a yellowish amorphous substance. Amorphous Fe(OH)3 can then shed some water and start to crystallise. When fully crystalline, red hematite (Fe2O3) will have formed. Since this requires substantial amounts of diffusion to have taken place, actual rust is somewhere in between, neither pure Fe(OH)3, nor pure Fe2O3.

3. If the rust does not flake off, the thicker the rust layer gets the more difficult it is for the Fe ions to move to the anode. Rust formation then slowly kills itself. This is the secret behind alloys such as CorTen (TM) which show substantial resistance against rusting through, but are not stainless. 20:43, 30 November 2006 (UTC)Wolf196.208.73.26 20:43, 30 November 2006 (UTC)

Is ingesting rust hazardous? There should be a section about eating rust.

This has to qualify as one of the most moronic statements in a supposedly "scientific" Wikipedia Page[edit]

"Rusting is a common term for corrosion, and usually is corrosion of steel."

No it is not "usually corrosion of steel". It is the oxidation of iron atoms. It might be seen more frequently in the material we call steel, assuming it is true that untreated steel is more common than untreated iron.

Well done Wikipedia. This is one of the most elementary of science topics and you guys have managed royally to screw it up in the first few lines. God only knows what you are doing with anything more complicated. 10:55, 18 February 2007 (UTC)

Good point, I reworded it a bit. It sounds like you have a lot of good suggestions. Please feel free to edit the article accordingly. —Ben FrantzDale 23:54, 26 February 2007 (UTC)

Boy Oh Boy - is this junk science[edit]

My primary school son needed to know about rusting so I suggested he look here. By the Lord, is this the biggest load of unscientific drivel I have ever seen. How can you people get away with writing this nonsense?

This is elementary physics and chemistry and you people cannot get it right.

Bye, bye. Wikipedia and science need to be taken with a very large pinch of salt (and if you dunderheads don't know what that is - look it up in a real encyclopedia or in a text book - here is a clue - it's called sodium chloride). 11:02, 18 February 2007 (UTC)

Seeing as you claim this is 'elementary physics and chemistry', I don't know why you looked it up. If the article _is_ nonsense, the reason Wikipedia people can get away with it is that those who know enough about science to contradict haven't done so. Perhaps someone more qualified than myself would care to revise this article. Unfortunately, I'm not able to do so.
[If someone can make my post sound less sarcastic, please feel free to edit] 20:51, 24 February 2007 (UTC)
Thanks for the feedback. If you could be more specific that would be helpful. —Ben FrantzDale 23:52, 26 February 2007 (UTC)
I love angry parents who criticize Wikipedia. It's publicly edited, which means that it is not infallible. And if it is so elementary, may i suggest you revise it yourself. Also, you may not be aware, but Wikipedia says you shouldn't use it as an academic source here. Impact--> No one is forcing you to use Wikipedia. —The preceding unsigned comment was added by (talk) 01:06, 3 April 2007 (UTC).
IANAE, but I actually liked the article. I found it very interesting and informative. Whoever has contributed you are amazing.Ben 21:46, 5 April 2007 (UTC)

This is NOT ALL junk science some of this is very good and if kids get a bad grade on something bc of it they blame wikipedia but i happen to have used wikipedia for rust and a lot of others and i ALWAYS got a hundred or higher I am in college too. this sight is very very good and u must be eduxated wrong and taught the wrong things. idk but this has always gotten me very VERY VERY VERY good grades.ALWAYS

Expert needed[edit]

In view of the comments here and in recent reversed edits to the article, I've asked for the help of an expert on chemistry. The main question seems to be which of these formulae is correct:

Fe3+ + 3 OH- = Fe(OH)3 - as in subhead 2.4 above by


Fe2+ + 2 OH- = Fe(OH)2 - as in the article.

Smalljim 11:48, 6 March 2007 (UTC)

Actually, it is simply 2 Fe + 1.5 O2 → Fe2O3. I have given the article a simple copy-edit to clear up the vague (or wrong) chemistry. Further improvements/enhancement, I gladly leave to others. Wim van Dorst (Talk) 23:48, 6 March 2007 (UTC).

That's the overall reaction. I don't know anything about the mechanism, but it doesn't sound implausible that Fe(II) is an intermediate. --Itub 09:20, 7 March 2007 (UTC)

Rust Prevention[edit]

One notable exception to the continuing process of rusting is a steel called 'Cor-Ten'. It forms a continuous, nonflaking surface of rust that strongly inhibits further degradation. LorenzoB 03:53, 14 March 2007 (UTC)

Chemical Theory[edit]

The Chemistry of rust was too concise and insufficient. I added a great deal more - however, if anyone disagrees with me they can simply revert to the older information. I'm just trying to help out, since for the past four years Wikipedia has been my number one source for research information (which really shows that i'm a very lazy person to look anywhere else.) Dhabih | talk | fictionwikia 14:44, 10 May 2007 (UTC)

Rusting products[edit]

I have a product that is rusting due to high dewpoint and temperature. The rust occurs during the May/June timeframe when dewpoint is 20 to 25 deg C and goes away in July when the low temp in this area gets high enough to stay above the dew point.

So my question is- Does temperature increase the speed of rust formation, particularly when the temp and dew point are between 20 and 25 deg C?


Hey, this page was blanked. I reverted it so I could read it. If that's wrong, oh well. —Preceding unsigned comment added by (talk) 16:33, 31 October 2007 (UTC)


Not really important but just wondering about the current arrangement for the sections. I'm just thinking: shouldn't Chemical reactions be the first subtitle, followed by Economic impact, then only Rust preventions? Any comments will be appreciated, thanks. — Yurei-eggtart 16:36, 2 January 2008 (UTC)


Question: how come there is no mention of impurities like copper that results in the cathode being inert? Isn't that an important topic to talk about? Impurities affect the rusting of iron, does it not? (talk) 05:30, 28 May 2008 (UTC) bewildered researcher

I am doing a science project on rust and if anyone can help me find some info on it please tell me the site or the fact i will put you on the acknoledgements of the prject -- (talk) 02:22, 2 February 2009 (UTC)Mari-- (talk) 02:22, 2 February 2009 (UTC)


Nothing about rust and health. Is it OK to drink water with rust in it? --Henri de Solages (talk) 10:21, 2 April 2009 (UTC)

Agree and maybe a word about Tetanus? — Preceding unsigned comment added by (talk) 09:25, 10 December 2011 (UTC)
There is absolutely no connection between rust and tetanus - another old wives' tale hits the dust.Rust is an oxide or iron, Tetanus is a suite of symptoms experienced following an infection with Clostridium tetani.  Velella  Velella Talk   18:16, 16 January 2012 (UTC)

Tidy up needed[edit]

I think some redistribution of text between Rust, Rustproofing and Rust removal is needed. Biscuittin (talk) 16:23, 22 May 2009 (UTC)

I suggest that Rustproofing be re-named Rust prevention and removal and that "Rust removal" (which is currently part of the phosphoric acid article) be merged with it. Biscuittin (talk) 22:19, 23 May 2009 (UTC)

Perhaps a knowledgeable or thoughtful person should take over this page?[edit]

I worked as a chemist for an industrial testing laboratory. Part of our job was determining cause of failure and precise legal description for the subsequent lawsuit.

Rust [1] 1 a : the reddish brittle coating formed on iron especially when chemically attacked by moist air and composed essentially of hydrated ferric oxide b : a comparable coating produced on a metal other than iron by corrosion c : something resembling rust : accretion 2 : corrosive or injurious influence or effect

1.) Corrosion occurs to almost all metals. Rusting is a peculiar type of corrosion specific to Iron and its Alloys. Although Aluminum can corrode in this same manner, it is not called Rust.

2.) In acidic (pH < 4) solution, Iron (and Steel of course) dissolves, like other other metals with Electronegative E.M F., giving 2 electrons to H+ (protons) to form H2 (Hydrogen gas) and dissolving a Ferrous ion (Fe+2)(actually in solution this is (Fe(H2O)6)+2. At the start, the entire exposed Metal surface dissolves at the same rate.

3a.) Ferrous Hydroxide (kSP ~~ 10-15 is slightly soluble in water about 1.5 grams per Liter (same as Calcium Carbonate) which is similar to the solubility of Magnesium Hydroxide (Ferrous and Magnesium ions can trade places in many minerals).

3b.) "Ferric Hydroxide" (kSP ~~ 10-39 is nearly insoluble and removes itself from the thermodynamic equilibrium and driving the reaction. From about pH 3 through pH 5.5 hydrated Ferric ions deprotonate and then polymerize by sharing bridging hydroxide anions. Starting from (Fe(H2O)6)+3 to (Fe(H2O)5(OH)1)+2 then (Fe(H2O)4(OH)2)+1 then neutral species and polymerization by bridging Oxo anions like {(Fe(H2O)2(OH)2)(OH)2(Fe(H2O)2(OH)2)}

4.) In neutral (or pH > 6) or alkaline solutions the corrosion proceeds by 1.) Iron going into solution as Ferrous (+2) ions in pits where Oxygen is not present (Ferrous Hydroxide is oxidized to Ferric Hydroxide outide of the pit) and 2.) electrons donated by the Iron dissolution are donated to Oxygen molecules (O2 + 4 H2O + 4 e- = 4 OH-) at the large external surface, an electrochemical corrosion. The electromotive force (voltage) generated by the Oxygen is equivalent to the Iron being in contact with a metal higher on the EMF scale.

Shjacks45 (talk) 00:24, 12 April 2010 (UTC)

THE SOLUBILITY OF FERROUS HYDROXIDE AND ITS EFFECT UPON CORROSION First PageHi-Res PDF[550 KB]W. G. Whitman, R. P. Russell, G. H. B. Davis J. Am. Chem. Soc., 1925, 47 (1), pp 70–79

Chemical reactions[edit]

The two sub-sections 'Oxidation of iron metal' and 'Associated reactions' seem to be duplicating information. They both mention that salts can increase the rate of corrosion. Also, some of the statements in 'Oxidation of iron metal' seem to be contradictory. For example: "As with other metals, like aluminium, a tightly adhering oxide coating, a passivation layer, protects the bulk iron from further oxidation" and "Unlike iron oxides, iron oxides are not passivating because these materials do not adhere to the bulk metal".

Iron doesn't behave like aluminium and and is not protected from further oxidation, so I think that statement needs to go. I'm not sure what was meant by the second statement, it may be a typo.

I think 'Oxidation of iron metal' is probably superfluous, but I don't want to wade in and start re-editing without discussion, since I may have misunderstood the original editor's intended meaning. However, if there are no comments or objections I will revise it. I don't have the referenced source to check it, does anyone else? I have other corrosion texts I can refer to if not. Apau98 (talk) 06:09, 12 January 2011 (UTC)


The very last link ("How do you remove and prevent flash rust on stainless steel") appears to be link spam stuffed into a whole bunch of pages related to corrosion. I haven't time to actually make fixes, but I hope this brings it to someone's attention -- search finds them easily.. — Preceding unsigned comment added by (talk) 00:20, 30 May 2011 (UTC)

oxides in oxygen busters ?[edit]

Hi, I found out from the technical sales guy at Dessicare that the oxygen busters that they use in food products have iron in them which oxidises over time and then becomes Iron Oxide II and Iron Oxide III - I would like to know if this can be added to soil in my garden (and everyone's gardens) and if it is fine to do so. The main purpose is to promote some reuse of the oxygen busters (but cutting them open to get the iron out) as the are so prolific now and I hate that they cannot be recycled at all. Any help appreciated. Plmoknqwerty (talk) 09:55, 24 September 2012 (UTC)

The desert[edit]

Back when I was touring egypt in 2006 on camel-back there was a sandstorm and we (me and my camel 'driver' ) were separated from the group and for 3 weeks we wondered lonely in the desert. On the 4 day in the evening I noticed rust like substance on the camels foot. I thought nothing of it and went to sleep but I was awoken in the wee hours of the morning by the 'driver' hurriedly sanding the camel using a rock. It turns out that the silica composition of the sand and the highly alkali blood of the camel caused its skin to rust. Aparently all animals can rust, given the right conditions. — Preceding unsigned comment added by (talk) 15:47, 30 November 2013 (UTC)

Replacing the rusted bolt image[edit]

Rusted struts of the 70-year-old Nandu River Iron Bridge

Could we use this? It really shows what rust can do because there's no dirt on it. Anna Frodesiak (talk) 00:53, 13 May 2013 (UTC)

Okay, now that I think about it, rust didn't do it. Rust is just there, right? Anna Frodesiak (talk) 00:55, 13 May 2013 (UTC)

Opening sentence[edit]

Can anyone change the first sentence so it actually explains what rust is? (I would do this myself but I'm not too clear.) George8211what did I do wrong now? 19:09, 6 November 2013 (UTC)

  1. ^