H2SO4 Posted May 2, 2005 Posted May 2, 2005 I was wondering what causes KMnO4 to stain skin so horribly. I was making saturated solutions of oxidizers to dip cotton string into to see how strong each oxidizers where (and just for the hell of it) to make fuses. Although nothing faces up to black powder rolled in tissue paper. I always get lightly stained by potassium permanganate and try to avoid it, but this saturated solution was so crazy, the second it hits skin it leaves brown marks, even if contact is for even a second, its very quick. I dipped a bit of steal wool in the solution to see how fast it would burn when dry. I put the steal wool on a firebrick and set it on the ground in the sun to dry. About 10 minutes later i came walking to my garage BAREFOOTED and stepped on the steal wool. All my toes are dark brown and alittle in the area underneath my toes. The stains dissipate after about three showers so i dont realy care, but i was wondering what causes this? Why is it purple then goes brown? Is it some kind of oxididation reaction. Also, when you get conc. H2O2 on your skin, it seems to bleach the local area, and sometimes slightly blisters, but i dont understand it because it reverts to normal within 1/2 hour. I know i shouldnt be getting chemicals on my hands, but it just happens sometimes. The only thing thats actualy ever caused pain was the conc. H2O2, but even the it was very little. I once had a wet knuckle and some NaOH pelets got on it and started to sting, but never auctual even caused a red mark. Ive put tiny amounts (i mean like half drop) of conc. H2SO4 on my skin and let it remail for quit some time, and nothing happened at all. My only explanation is that chemicals are only "skin damaging" if the area is large. I do think that people over-exhaderate on how dangerous chemicals are on skin contact, now eyes is a whole different thing. There delicate. All in all, this post was originaly intended to fimd out what causes KMnO4 to stain skin and turn brown.
H2SO4 Posted May 2, 2005 Author Posted May 2, 2005 I just remembered when you heat KMnO4 it turns brown after it gives up its oxygen. SO it must be an oxidation reaction. Oxidation of skin, creepy.
YT2095 Posted May 2, 2005 Posted May 2, 2005 make up a soln of Iron II Sulphate, it`ll remove the stain if you catch it quickly
raivo Posted May 2, 2005 Posted May 2, 2005 Brown color is at least partially due of MnO2. Its true that chemicals on the skin do not cause always burns. I have similar experience with conc H2SO4. No burn but fingers got nastily oily and started to itch. It took lot of washing with soda and water to reach the point where my finger did not change water ph any more Saing that its still very important to be cautious with chemicals because contact with skin turns painfull even in case of such friendly stuff as NaCl or KNO3 if you have small cuts on your skin (i have experienced this) - and you will get permanent damage if you happen to touch your eyes with hands in such condition!
akcapr Posted May 2, 2005 Posted May 2, 2005 after about 20 min conc. h2so4 will dissolve a small cube of steak
budullewraagh Posted May 2, 2005 Posted May 2, 2005 i've handled KOH. it's not so bad at all. the powder smells somewhat ammoniacal. it dries the skin and is irritating. wet conc KOH on the other hand is very, very caustic. i got a drop on my arm, didnt notice, then suddenly i felt a crescendo of searing pain. the fact that your KMnO4 was wet and conc plays quite a role in its oxidizing powers when it is placed on something dry
H2SO4 Posted May 2, 2005 Author Posted May 2, 2005 Saing that its still very important to be cautious with chemicals because contact with skin turns painfull even in case of such friendly stuff as NaCl or KNO3 if you have small cuts on your skin (i have experienced this) - and you will get permanent damage if you happen to touch your eyes with hands in such condition! Ya, KNO3 gives a strange sting on little cuts and abrasions. I work with black powder alot and it always gets in my cuts.
H2SO4 Posted May 3, 2005 Author Posted May 3, 2005 Has anyone here ever been severely burned by chemicals? I know there was a thing on the news about some women who got a thing of acid dropped on her head and it "severely maimed" her. I dont know what to think becasue i cant believe a thing of acid can screw someone up that bad pretty quickly. The only thing i can think of is like if it was peroxymonosulfuric acid (conc.?).
akcapr Posted May 3, 2005 Posted May 3, 2005 like u h2so4, i have kind of been amazed at how i have never been hurt by acid- even when hydroxides and acids have gotten directly on my skin. THe worst i ever got was when i put my 20% or 30% or so h202 on my hand and it turned a bitr red and itched. But normally when handling something "dangerous' i wear rubber gloves. My mom gets em really chea pand a box lasts me alot. ANd it makes me feel a bit more comfortable while doing experiments and such. Plus it completes my chemist uniform =)
YT2095 Posted May 3, 2005 Posted May 3, 2005 KMnO4 soln is quite harmless to the skin, infact it`s often used as an antiseptic/antifungal treatment, THAT is why it`s sold in pharmacies
raivo Posted May 3, 2005 Posted May 3, 2005 I suppose we do not get acid ( or alkali ) burns because we are rather quick to remove acid from skin. Minute or two are just not enough do decompose skin. Half on hour may be completely different story.
H2SO4 Posted May 3, 2005 Author Posted May 3, 2005 KMnO4 soln is quite harmless to the skin, infact it`s often used as an antiseptic/antifungal treatment, THAT is why it`s sold in pharmacies I was wondering why it was sold in pharmecies. Why is KNO3 sold in pharmecys. Is it another antiseptic?
YT2095 Posted May 3, 2005 Posted May 3, 2005 re: post #14 you even QUOTED me, and then you ask what I just said ??????
jdurg Posted May 3, 2005 Posted May 3, 2005 I believe he stated 'I was wondering why it was sold in pharmarcies' with the emphasis on the 'wondering', as in 'I was WONDERING why they sold it in pharmacies, and now I know.'
H2SO4 Posted May 3, 2005 Author Posted May 3, 2005 Bleached skin from H2O2 has lasted days for me. Realy, it goes away quick for me. Akcapr, your mom you'sed to give you a bath with KMnO4!!?? Wouldnt that terribly stain your skin and/or the tub brown?
H2SO4 Posted May 3, 2005 Author Posted May 3, 2005 I believe he stated 'I was wondering why it was sold in pharmarcies' with the emphasis on the 'wondering', as in 'I was WONDERING why they sold it in pharmacies, and now I know.' exactly.
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