What makes my makeup waterproof?

Waterproof makeup is great in theory: it lets you cry at weddings without looking like a goth, or jump in the pool without your face slipping off. Mascara, lip stick, foundation, and all the other cosmetics that come in waterproof form require similar ingredients, but in different concentrations. No single ingredient will make a formula waterproof, but companies will add in their patented combinations, so you can conquer moisture stress-free! But are the ingredients worth the convenience?


Enjoy this read and, as always, click the numbers in square brackets to check out all the references!


Most common waterproofing ingredients:


Dimethicone copolyol (a.k.a. polydimethylsiloxane)

Chemical structure of dimethicone copolyol


Dimethicone is in a lot of cosmetics because it creates a smooth product which often gives a matte look and can even have a filling effect in small lines and wrinkles[i]. Dimethicone copolyol is a very similar oil but it is made to adhere to skin and have water drip off of it. You can also find it in many other products like hair sprays, shampoos, and shaving products. Dimethicone is a silicone oil. What is that? Well basically a silicone is a synthetic (man-made) material made up of polymers (a polymer is just material which is made up of long, repeating chains of molecules)[ii]. Silicones are used in everything from cosmetics to cooking utensils.


Is it safe?

The majority of studies and review papers I found showed that dimethicone was a relatively non-toxic substance[iii,iv]. Some side effects I found were that it can cause eye and skin irritation[v] and that it can cause breakouts. Because it is a substance that sticks to your skin and doesn’t let anything pass through it can trap whatever is on your skin, like bacteria, sebum, etc. Although this can cause breakouts it can be dealt with by making sure you get your makeup off every night with a proper cleanser. There are some suggestions that it may also cause some digestive tract and respiratory tract issues but I could not find much on this[vi].


Wax

A very common ingredient since water rolls right off wax. Types of wax you’ll commonly find are beeswax, carnauba wax (comes from a type of Brazilian palm), and candelilla wax (comes from a North American shrub).


Is it safe?

I haven’t found any research showing that waxes are dangerous. Natural waxes might be a problem for some people if they are allergic to them so keep that in mind as a possibility if a wax-based product is bothering your skin. It also can clog your pores and cause breakouts if you aren’t cleansing your skin properly.


Teflon

Chemical structure of polytetrafluoroethylene


Yes, the same thing that’s in your pans. Teflon is a brand name of polytetrafluoroethylene (PTFE). PTFE is a polymer made up of carbon and fluorine atoms and falls under a larger group of similar chemicals called PFAS (polyfluoralkyl substances[vii]). PFAS go by a lot of names you might see on cosmetics[viii], some common ones are: polytetrafluoroethylene, Perfluorononyl Dimethicone, Perfluorodecalin, C9-15 and Fluoroalcohol Phosphate. It is used in waterproof makeup because it is hydrophobic, meaning water glides right off of it.


Is it safe?

This has been a complicated topic to research. A number of studies have shown that PTFEs and PFAS cause lots of issues in humans and animals. They suggest problems like disrupting child growth, decreasing the ability for women to get pregnant, disrupting hormone levels and cholesterol levels and increasing cancer risk[ix,x]. There have been water contamination crises[xi,xii] as well as research indicating that fumes from factories that produce PTFEs cause pulmonary edemas[xiii]. The catch though is all of these are in reference to industrial production and use of PTFEs and PFAS. Most of the cosmetic PTFE research implies that because so little is in each product you aren’t exposed to enough to be harmed by it[xiv]. All the research and reports I read agreed however, that more research has to be done because the safety isn’t quite clear[xv]. So is it safe? Only in small amounts. But remember that you use makeup every day...that can add up!


Acrylates Copolymer




Acrylates Copolymer chemical structure


This is a type of polymer made from acrylic and methacrylic acid[xvi]. Is hydrophobic so water rolls off of it, and is also used as a thickener in creams. It is popularly used in sunscreens as well as in waterproof makeup.


Is it safe?

It seems to be quite a safe ingredient. There were some suggestions that it can cause skin irritation but that can be managed with the right formula[xvii]. The molecules are pretty big so they cannot pass through the skin into your system[xviii]. Seems like a decent option as an ingredient!


Isododecane

Isododecane chemical structure


This polymer is made from petroleum derivatives[xix]. It is used in cosmetics because it gives them that ability to glide over your skin, it is pretty good at filling in lines in the skin, and is made of hydrocarbons so water doesn’t penetrate it[xx].


Is it safe?

The research on isododecane isn’t as thorough as I would like. It seems like it is safe but it is very difficult to be sure because there haven’t been enough tests done with it[xxi]. The big issue for me is the fact that it is made from petroleum derivatives. Petroleum is made from crude oil and the extraction of that has been proven time and time again to be detrimental to the environment, animals, and humans[xxii,xxiii,xxiv,xxv].


My two cents?

I tend to avoid anything waterproof. Your skin is your biggest organ and putting anything on it that stops it from exchanging gas and water with its environment just hits the wrong chord with me. I’d say go for water resistant formulas with higher concentrations of natural waxes and don’t use them every day, just when you really need them. Lastly, make sure you're always washing your makeup off thoroughly, waterproof or not, it'll ensure your skin can breather like it's meant to.