Poison? On MY Nails? - Show Your Working

Being the second post of my (hopefully) ongoing series Show Your Working, where I apply the lens of science and common sense to beauty products.

As a geeky, pedantic sort of girl, it really annoys me when I see things that aren't quite accurate. Honestly, it actually annoys me more than the totally, obviously untrue things that are sometimes said. For example, as someone who studied a great deal of ancient history, I literally twitch every time I see the Roman habit of deciding the life of a gladiator with the motion of a thumb either up or down portrayed the wrong way around. They can have modern fabrics on, and totally inaccurate hairstyles, and I'm fine. But if they do that one little thing that's not quite right....ugh, my jaw is tensing just thinking about it.

Bearing this is mind, I have been reading a lot of posts that reference the Big 3 - chemicals that were previously used in nail polishes and nail hardeners, and that are being more or less phased out currently. The Big 3 are formaldehyde, toulene, and dibutyl phthylate (DBP), which are all generally acknowleded to be "quite killy" as a friend of mine put it. A lot of retailers have declared themselves proudly 3 Free, meaning they don't use any of these ingredients.
I was curious as to whether this really mattered or not, so I went and buried my head in overly complicated diagnostic manuals, and toxicology reports as I am wont to do. Very quickly I came across several inaccuracies in the information being touted in the posts I had read that just made me twitch, so I've pulled all the information together here for you, dear reader, that I might get it out of my system, and also maybe help you make a more informed decision about this issue.

FORMALDEHYDE

I don't know about you, but when I think formaldehyde, I think school science classes. Memories of dead, pale eyes floating in a jar of yellow liquid swim to the front of my mind, and suddenly I'm 12 again, freaking the hell out because I could swear that frog just blinked at me and oh god oh GOD it's leg just fell off!!

...I'm okay.
The point is that the formaldehyde in your nail polish isn't the same as the stuff those poor frogs were floating in. Technically, chemically speaking, it's not really formaldehyde at all. The lovely and brilliant Lab Muffin has a wonderfully succinct explanation of the difference between formaldehyde and the liquid or resin compounds made from it that are used in nail hardeners. 
"When you dissolve formaldehyde in water, it's not just formaldehyde in water (unlike how sugar + water is just sugary water). It actually reacts to form methylene glycol, a different chemical:

The International Nomenclature of Cosmetic Ingredients (INCI), which tells cosmetic manufacturers what to write on their ingredient lists, used to require formalin was listed as formaldehyde, as it's made using formaldehyde. However, In 2008, the naming error was corrected.

HOWEVER: the reaction between formaldehyde and water to form methylene glycol is like the reaction between carbon dioxide and water to give carbonic acid. It's a special type of reaction known as a reversible reaction (you can tell from the double arrow). When a carbonated drink is in a bottle, it's not fizzy yet... but when you release the pressure by opening the lid, you get heaps of carbon dioxide gas bubbles. Just like that reverse reaction, under the right conditions, the methylene glycol will turn back into formaldehyde and water. So even if formaldehyde itself isn't in your nail hardening product, it's possible that chemicals which release formaldehyde are!"

So the long and short of it is that there IS something LIKE formaldehyde in your nail hardeners - but not nail polishes. (Also, Michelle from Lab Muffin writes a ton of fascinating posts like this, and you should really read her stuff.) These are the little inaccuracies that annoy the crap out of me, so let's get those sorted out right now. I also couldn't find any evidence that it's possible to absorb formaldehyde or any related substances through your nails, although it is fairly well absorbed when applied to your skin. So
maybe painting yourself all over with nail hardener is not a good plan.
HOWEVER, there does seem to be a pretty good indication that opening a bottle of nail hardener could release formaldehyde gas for you to suck into your pink, absorbent lung tissue. And that's probably bad.
But let's take a look at just HOW bad. Like zinc, formaldehyde does occur naturally in human bodies. But zinc is also extremely toxic in large doses. So how much formaldehyde is needed to take it from harmless to toxic?

According to the U.S based Agency for Toxic Substances and Disease Registry the 15 minute short term exposure limit (STEL) for formaldehyde is 2 parts per million (ppm) The STEL is the maximum recommended amount to which workers can be exposed continuously for a short period of time without suffering from irritation and/or chronic tissue damage. 
Unfortunately, I wasn't able to find any concrete information about how much formaldehyde gas is actually released from nail hardeners when you use them. I imagine it also varies pretty wildly depending on the actual product in question, because it would depend on how much formalin was used in the first place, and with what other chemicals. However, since I can smell the formalin in the average nail hardener, it seems safe to assume there is at least 0.5-1 part per million, since this is apparently the concentration at which you can start to smell it. In order to determine the upper estimated limit of how much toxic gas is released, it's useful to look at the effects of damaging levels of exposure to formaldehyde. seem to bring on headaches, dizziness, and difficulty breathing pretty quickly, and at relatively low levels. If you don't get any of these symptoms using a product (and why on earth are you using it if you do), then it seems pretty sensible to me to assume you're not being exposed to toxic levels.

TOLUENE

While formaldehyde makes me think of dissolving frogs legs, toluene just makes me think of Toulouse Lautrec - so much so I had to proof read this section a couple of extra times just to take out the typos where I put in Toulouse instead of toluene. Yeah, I am an ENORMOUS nerd.

Maybe she's grumpy because decent nail polish hasn't been invented yet

Toluene is a solvent, which means it's used to make sure all the ingredients in a nail polish don't clump up into chunky bits and instead make a nice smooth liquid. When it's not in your nail polish making sure all the pigment particles sit smoothly on your nail, it can also be found in fuel acting as an octane booster for Formula 1 racing teams. When looking for a bit less excitement, it can be used in model making instead of glue because if you brush it on carefully enough and place the pieces together quickly, it will dissolve the two edges so they reform as one piece. Sounds like pretty heavy duty stuff, and not exactly something you would want to put on your body. I mean, if it dissolves polystyrene, what the hell is it going to do to my nails?

But is it as bad as it sounds? While you certainly wouldn't want to be putting racing fuel on yourself, the amount of toluene in nail polish is a fraction of the amount used for that sort of purpose. While toluene can be absorbed through skin contact, like formaldehyde, the amount of skin that comes into contact with nail polish is pretty small, no matter how clumsy you are. The vapour released when it dries is however, like just about everything, can be really easily absorbed by the soft squishy parts in your lungs and nose.
So how much can you breathe in before you start bleeding from the nose? The STEL for toluene is 150 parts per million, but as with formaldehyde, I found information on just how much you are likely to ingest from using polish pretty hard to come by. This article features some concrete numbers, but as with almost all studies done by groups with an agenda one way or the other, the results vary enormously. The industry group that was seeking to prove toluene wasn't dangerous came up with quite acceptable numbers, but the group arguing that toluene should be banned came up with a figure nearly five times that of the other study. It's a perfect example actually of how questionable a lot of these "studies" can be. In this case, the two groups weren't even measuring the same action, let alone measuring exposure over the same period of time, so the results are totally incomparable, and their relevance to the debate pretty dubious.
However, the official EU Scientific Committee on Consumer Products (SCCP) found, as recently as October 2006, that toluene, as used in nail polish products, does not pose a risk to health. The California Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) requires the Governor of California to maintain a list of chemicals "known to the state" to cause cancer or reproductive toxicity, and Toluene is among the ingredients identified by this list. But it also currently categorised as No Significant Risk Level (NSRL) when used in nail products.
In this instance, I'm happy to defer to the organisations with more time and more brains on hand to tease out the details, and go with their suggestion that toulene is nothing to worry about unless you're huffing or drinking your polish. (in which case I think that maybe you have bigger problems)


DIBUTYL PHTHYLATE (DBP)

While formaldehyde and toluene aren't used that many places, and are being progressively used less and less, DBP on the other hand is absolutely EVERYWHERE. As the Australian Government National Pollutant Inventory points out, "Dibutyl phthalate is used extensively throughout society, it is now widespread in the environment. Most people are exposed to low levels in air, water, and food. In many cases the largest source of exposure is from food containing dibutyl phthalate. Some of the dibutyl phthalate in food is from plastics used to wrap and store the food and certain types of food (especially fish and shellfish) may absorb larger quantities of dibutyl phthalate (from 50 to 500 parts per billion). Air and water also contains small levels of dibutyl phthalate. Levels in city air are found to be 0.03 to 0.06 parts per billion. In drinking supplies it is found at 0.1 to 0.2 parts per billion."
Yikes, right? BUT the NPI also goes on to point out "At these low levels dibutyl phthalate is not expected to cause any harmful effects." In fact, the United States Consumer Product Safety Commission have "determined a tolerable daily intake value of 66 μg/kg body weight per day". That means that as someone who weighs 95kg, I could ingest 6270 micrograms of toluene per day without serious side effects.

These probably have DBP in them too

But that's just measuring how much of it we can eat - how much can we breathe in? Quite a bit apparently. Green Facts says "Repeated oral exposure to DBP mainly affects the blood, liver and kidney. No effects were seen at a dose of 152 mg/kg body weight/day" 152 mg, per kilo of body weight, per day. So doing some fast and loose maths again, I could breathe in 14,440mg a day. That seems like an awful lot.
But hey, we all know studies can be biased. Maybe these numbers are all made up by the big pharma companies to sell us nail polish. Putting that aside, the fact is that DBP IS in the air we breathe, the food we eat, in relatively large quantities. Considering we haven't all dropped dead yet, I'm going to go ahead and conclude this stuff isn't nearly as toxic as the other two.  Besides, unless you're going to put yourself in a little bubble and roll around, it seems a little...pedantic to insist on avoiding it in your nail polish. (Although putting yourself in a little bubble and rolling around DOES sound like enormous fun)

I will add though that there is some more recent research which has suggested that DBP might act as an endocrine disruptor - meaning it might stop your endocrine system working as well as it should. Preventing your endocrine system from doing it's thing can "cause cancerous tumors, birth defects, and other developmental disorders. Specifically, they are known to cause learning disabilities, severe attention deficit disorder, cognitive and brain development problems, deformations of the body (including limbs); sexual development problems, feminizing of males or masculine effects on females." However, I couldn't find any information to specifically link the amount of DBP in nail polish to anything like side effects this serious - not from pages that didn't also advocate homeopathy* anyway.  After the hoo-ha over aluminium and alzheimers that was later completely disproven, call me Scully when it comes to "suspected links."

CONCLUSION
None of these things are great. I wouldn't put them in my children's birthday cakes. You shouldn't drink them. You shouldn't hold a bottle of polish containing them to your nose and huff it. But are they worth specifically avoiding? I don't think so.

However, if you're still stressed and want to avoid them anyway, you can chill out, because most major brands are Big 3 free these days anyway. butter London, Calvin Klein, China Glaze, Color Club, Essie, Finger Paints, Hard Candy, Illamasqua, Maybelline Express Finish, Maybelline Salon Expert, Nicole, (some) OPI, MAC, Chanel, Dior, Estee Lauder, Givenchy, Lancome, Lippmann, L’oreal, Revlon, Rimmel London 60 Seconds, Sally Hansen Insta-Dri, Sante, Shades by Barielle, Shu Uemura, Sinful Colors and Zoya.....etc etc etc.

Personally, I really couldn't be bothered checking everything I like. From my reading I've come to the conclusion that a lot of the fear around the use of these chemicals is a hurricane in a handbasket. There is very little conclusive evidence it's going to do you any significant harm. By all means, support companies that are making the switch to less toxic formulas - less toxic is always nice. But if you find something you love, and you really really want to wear it, and it's NOT Big 3 free - just listen to Ben Folds and The Muppets, and do it anyway. 

*Just a little side note here - I know some people really believe in homeopathy, and I think that's lovely in the same way that I think religious faith is lovely. I don't have it, but if it makes you happy, knock yourself out. I just think it's appalling when people are conned into paying enormous amounts of money for what is essentially slightly impure water.