After Part 1, where I stained my nails (For Science!) to work out how best to prevent staining, the obvious next step was to figure out stain removal! I worked out in Part 1 that the teal colour is CI 77288, which is chromium(III) oxide. Here are my nails again – argh! I had to live with this for two weeks. TWO WEEKS.
I fielded a lot of suggestions, and gathered the most popular for the experiment:
Acids: Lemon juice – This contains citric acid, and has a pH of 2-3 (quite acidic). Bases: Baking soda – Aka sodium bicarbonate (or sodium hydrogencarbonate, if you want to be super correct), this forms a moderate alkaline/base with a pH of 9-10 when you mix it fresh with a bit of water. Cuticle remover – cuticle removers are also alkaline/basic, and usually contain sodium or potassium hydroxide, which are strong bases. I’m using Blue Cross Cuticle Remover, which has potassium hydroxide (“caustic potash”), pH 13-14 – very alkaline! The theory behind using acids and bases/alkalis is that they can help some chemicals wash out, or react with colourful molecules to make less colourful molecules (hopefully).
Oxidants: Hydrogen peroxide hair bleach – This is an oxidant, a type of chemical which causes an oxidation reaction (it’s complex, but basically it’s related to adding oxygen to things). These work best on big organic (carbon-based) molecules to remove colour (e.g. clothing dye), but sometimes they’ll change ionic compounds too, like the chromium(III) oxide that was on my nails. Denture tablets – These contain a mixture of potassium persulfate and sodium perborate, which are also oxidants. They work more slowly than hydrogen peroxide.
I was concerned when I found out that chromium(III) oxide was likely the stainer because an oxidised version of chromium, chromium(VI) (aka hexavalent chromium), is a carcinogen. After checking through the scientific literature, assisted by some chemist friends who handle chromium more than I do (including fellow Aussie nail blogger/scientist Shanee of Duck and Polish), I found that:
- Chromium(VI) is a known carcinogen by inhalation and ingestion (eating), after repeated exposure over a long period (think Erin Brokovich).
- It can irritate skin if it touches it, but doesn’t absorb much – there are a few reports of skin contact with chromium(VI) causing serious problems, but those involved large areas of the body.
- Hydrogen peroxide turns chromium(III) into chromium(VI) in basic (high pH) conditions.
- Persulfate is a stronger oxidant than peroxide, but acts slower (denture tablets work overnight).
- There are many antioxidants in the body which convert chromium(VI) back to chromium(III).
Given this info, I decided that oxidising the tiny amount of chromium on two nails on a single occasion was very unlikely to kill or harm me, even if my skin magically absorbed it all. I still took precautions – I didn’t let anything dry out (wet chromium won’t be inhaled but dry chromium dust could), washed my hands madly afterwards, and vowed that this would be a one-time deal! As far as I know, none of the other common nail stainers have issues with oxidants.There were a few other interesting suggestions that I didn’t have time to try, such as activated charcoal. OK, onto the experiments!
To minimise skin contact with the meaner ingredients (e.g. cuticle remover), I cut pieces of cotton pads that didn’t quite cover my nails:
I dipped these into the appropriate chemical using tweezers (here’s my baking soda slurry):
Then I placed each piece on a nail and pressed gently with tweezers for better contact with the nail surface.
Here are all my fingers! L = lemon juice, BC = bicarbonate (baking soda), CR = cuticle remover, HP = hydrogen peroxide, D = denture tablet, T = whitening toothpaste (I added this at the end out of curiosity, even though I had a strong suspicion it would be similar to hydrogen peroxide since the active ingredient is usually also a peroxide).
I took off the pads after 20 minutes and washed my hands thoroughly, then took photos of the cotton pads and my nails. At no point did I feel any tingling or pain – if I did, I would’ve washed it off quick!
Here are the pads (the denture tablets dissolve to make a blue solution):
And here are my nails:
Here’s the before pic for reference:
And we have our winner – cuticle remover! The teal on the other nails almost didn’t change at all. From the photo of the cotton pads, it seems like a little bit of teal dissolved in the baking soda and the toothpaste which makes sense – both of these are also quite alkaline, though not as strong as cuticle remover. The cuticle remover-treated nail was also the softest, plumpest and most fragile-feeling of the nails, although it went back to normal after half an hour. It also smelt a bit like burning hair.
Why did cuticle remover work so well?
My guess: hair and nails are made of keratin. Early hair relaxers used sodium hydroxide, which is very similar to the potassium hydroxide in cuticle remover. The high pH would make the keratin in hair swell. I’m guessing that the potassium hydroxide similarly made the nail swell and become more porous (easier to penetrate), which meant the teal pigment escaped more easily. The next thing I did was try removing the stains on all the nails of my left hand using cuticle remover (including a little patch left over on the middle finger). I only soaked for 10 minutes this time. Results:
As expected, almost all the teal was gone! The cotton pads were stained teal… except for the hydrogen peroxide one, which was pale yellow. Where did the teal go?? Well, remember the ominous safety note? Some of the hydrogen peroxide must have soaked into the nail… then when I added high pH cuticle remover, the peroxide oxidised the bright green chromium(III) to pale yellow chromium(VI). Eep! You can bet I scrubbed my hands violently! Don’t do this at home, kids. It’s possible that a similar thing might happen with the denture tablets and whitening toothpaste – lucky neither of these worked that well anyway!
What about buffing?
Buffing’s always treated as the last resort – this is physically removing the top layer of your nail with a fine-grit file, and as you might expect, this weakens the nail. I used a buffing block to remove the top layer from the thumb and forefinger of my right hand:
Whoa! Almost perfect removal! It turns out that the teal only stained the very top layer – this may be different for different people though, since my nails are quite hard and resilient. I buffed the rest of my fingers, and buffed a bit of the residue off my left hand:
PHEW!!!!! Normal nails again! Success!
The best teal stain removal method
So, what’s the best way to remove teal from your nails? Well, I’d recommend…
1. Start with gentle alkalines like baking soda and toothpaste. These didn’t work that well for me, but remember, my stains were two weeks old, and I was trying for maximum stainage! If these don’t do it, try either…
2a. Cuticle remover. This is hardcore and can soften and damage your nail, at least temporarily. Try to soak it for as little time as possible to reduce the chances of that – you can try soaking a cotton bud in remover and rubbing it on your nail instead of letting it soak like I did. If you feel any pain, stop!
2b. Alternatively, if your nails are thick enough, try gently buffing out the colour.
How far the colour has penetrated might depend on what your nails were like to begin with. Most importantly, if you have blue/green stains, avoid using hydrogen peroxide unless you’re sure the pigment isn’t chromium-based!! (Other stainers are fine to remove with hydrogen peroxide as far as I know.) It’s bad for you, and it doesn’t work that well on its own anyway. If you’re extra health-conscious, avoid other oxidants like denture tablets and whitening toothpaste for chromium stains too.
I hope you enjoyed this study! I’m considering doing the same thing with other stainer pigments, but first I need to get over the psychological trauma of thinking my nails were going to be teal for a year. I have never been so grateful to have naked nails! In the meantime, feel free to throw suggestions for stainy nail polishes I should try 🙂