Since Polling Day, social media has been flooded with stained and gangrene-looking fingers. While we’re all super proud of playing our part in this historic event, I’m sure you’re also a little curious as to why your finger has turned from a light violet to an almost black/dark brown colour. So here’s a little chemistry knowledge for all of you.
Warning: It’s about to get real scientific!
Indelible ink contains about 10-20% of silver nitrate mixed with violet ink dye. Silver nitrate on its own is clear like water when pure, so the light violet colour that you saw when you first dipped your finger is actually just the dye.
This solution of silver nitrate + ink dye reacts with the sodium chloride (salt) from your skin to form silver chloride.
When silver chloride is exposed to ultraviolet light – or in other words, the sun – it breaks down the silver chloride into metallic silver which is the brown that you see now! This chemical reaction is similar to that used in photographic film.
If the solution did not contain any dye, it might take minutes to hours for a reaction to take place.
The greater the concentration of silver nitrate in the solution, the faster the stain darkens, the darker it becomes, and the longer it lasts.
Good thing the solution is dyed, otherwise you might accidentally get some on your ballot papers! Phew!
Since metallic silver is insoluble in water and organic solvents, attempting to remove the ink with nail polish won’t work. Silver is also not reactive towards acid, so washing your finger in vinegar won’t work either!
How many of you have tried these methods?
However, one of the ways that could prevent the ink from staining is keeping your finger in the dark.
Since silver chloride reacts to the sun to turn the ink brown, covering your finger by clenching your fist or hiding it under your shirt would keep it from further exposure to the UV rays. After that, all you have to do is wash your finger under low-light conditions with soap and hot water for 20 seconds and voila! Clean fingers and minimal staining!
Fun fact: silver nitrate is very soluble in water even after it dries
But since we all want to show off that we voted, it might be a bit too late now lah!
Still, there are some who have successfully removed the ink with chlorox + lemon, and some even used Veet which almost completely got rid of the ink.
Wow, Malaysians are quite the scientists!
But if you want to leave it on because you’re just too proud of yourself for contributing to this momentous occasion (like me), not to worry! The stain will fade when new skin cells replace the old ones (within 96 hours more or less). Just be patient and you’ll have normal-looking fingers in no time!
Also read: Here Are The Coalitions and Parties Fighting To Be Malaysia’s Next Government