It’s Saturday night, and you’re getting ready to go out. As you’re finishing up your hair and your make-up that your mother finally let you wear, you notice that something is missing. Looking down at your fingernails, you notice that you’ve neglected the finishing touch to your look.
Rummaging through a drawer, you find a bottle of nail polish, give it a good shake and start applying. As you’re blowing on your nails, you wonder, what is in nail polish anyway, why do I need to mix it up each time I use it, and most importantly with the clock ticking away, how can I make it dry faster!!
Nail Polish: Ancient Origins
Nail polish (or nail lacquer or enamel) has come a long way since its origins, around 3000 BC. Although quite different from today’s product, adding colour to one’s nails was practiced in China as well as in Egypt. In both civilizations, colour wasn’t just a matter of matching your nails to your outfit; it was representative of social rank. In China, black and red were considered royal colours and in Egypt dark rust red was worn by Cleopatra herself. Lower class women were restricted to paler hues and being caught wearing a royal colour was even punishable by death! While the Chinese used gum arabic, egg whites, gelatin, and bees wax to create their nail polish, today’s producers use a combination of various long-named chemicals to create the perfect polish.
Did you know? Revlon is credited with being the first manufacturer of coloured nail polish.
The Break Down…Chemically Speaking
Nail polish is essentially a combination of three different types of ingredients: hardening or thickening agents, liquid solvents to hold these agents until you apply them to your nails and colouring agents to give the polish its colour.
The main hardening agent in nail polish is nitrocellulose. Nitrocellulose (or cellulose nitrate) is a polymer made by treating cotton with nitric acids. A polymer is a chain of molecules made up of many similar smaller molecules.
Did you know? Nitrocellulose is the major component in smokeless gunpowder.
In addition to nitrocellulose, makers often add various other hardening agents such as acrylate, polyester or polyurethane co-polymers that are essentially plastics that are soluble in organic (carbon-based) solvents.
Solvents are the liquids that other substances are dissolved in. The most common solvents in nail polishes are ethyl acetate, butyl acetate, formaldehyde and isopropyl alcohol (rubbing alcohol).
Did you know? The shelf life of nail polish is about 1-2 years, to help keep your nail polish for a long time keep it in a cool place like a closet or even the fridge.
The solvents retain the pigments and other components of the nail polish until it is applied to your nails. This is the stuff that evaporates once you’ve coated your nails. It’s this step that you’re patiently waiting for (or trying to speed up if you blow on your nails).
Did you know? Nail polish remover is an organic solvent (usually acetone) that simply reverses the application process by redissolving the colour so you can wipe it away.
Manufacturers are constantly trying to come up with different formulas to make the drying time shorter. For example, nail polishes containing solvents with lower boiling points (temperature when a liquid turns to a gas) evaporate and therefore dry faster than ones with higher boiling points.
Finally, companies use different types of mineral or synthetic pigments, tiny particles that add colour, such as titanium oxide to give the nail polish its unique shade.
Unlike a dye, pigments are insoluble and don’t completely dissolve in the solvents. In fact, many of the components of nail polish come out of suspension with time which is why it’s necessary to shake the bottle before you use it. Some nail polishes also add mica or pearl additives to create a ‘shimmer’ effect.
Did you know? Different pigments are different colours because they reflect and absorb different wavelengths of light.
So until the chemists find the perfect combination of solvents to make a super, ultra fast-drying nail polish, we’ll just have to keep patiently blowing on our nails.
enotes.com, how things are made: nail polish
The History of Beauty: Nail polish and the history of nail polish
emedicine: nail cosmetics
ivillage beauty and style: what’s in a nail and how fast do they grow?
Christine is a native Vancouverite with a B.Sc. in Biophysics from UBC. She is currently working towards a PhD in biochemistry at McGill, in a lab that focuses on cancer research. Christine is also learning what ‘wind chill factor’ and 'humidity' is since moving out east. When she’s not slaving away in the lab, she can usually be found spiking volleyballs into opponents’ courts.