As The Toast searches for its one true Gal Scientist, we will be running a ton of wonderful one-off pieces by female scientists of all shapes and sizes and fields and education levels, which we are sure you will enjoy. They’ll live here, so you can always find them. Most recently: Why Are There So Few Female Scientists?
There’s soap in your mayonnaise!
As a scientist with a degree in chemistry, the surge in chemophobia over the last five years has been both baffling and frustrating.
While there are plenty of toxic substances that we should be well frightened of, there are also many safeguards against their use – by and large, the chemicals you encounter in your day-to-day life are benign, even the ones with the scary unpronounceable names and the ones made from substances that can literally chew your face off (sodium chloride, I’m looking at you). But it’s incredibly easy to fall into the trap of common-sense-based marketing. Scientific literature is not exactly reader-friendly, and scientists have a long history of alienating themselves from Normal People.
“Just kicking back with a brewski in my favourite fuck-off flask. What’s with the side-eye?”
There’s one particularly painful tactic which anti-chemical lobbyists love to use, and that is the faulty generalization. You’ve no doubt seen it enough times already…
“I had the flu vaccine and still got the flu, therefore vaccines don’t work.”
“This chemical gave rats cancer in a study, we need to take it out of our shampoo/food/clothing!” (Despite the fact that the rats used in these sorts of studies are specifically bred to grow tumors like they’re going out of style, and to receive the amount the rats did, you’d have to mainline a swimming pool’s worth of shampoo/food/clothing every week.)
“Mineral oil comes from crude oil, therefore you’re rubbing petrol on your face! Use our natural, organic face cream instead, because you know exactly what’s in it.” (Which is ironic, since natural products are notoriously variable in composition.)
“It contains chemicals! Chemicals are bad.” (Except for the million or so chemicals that you unwittingly use every day to stay alive, like oxygen and water and neurotransmitters, one of which is pretty much MSG dissolved in water.)
To demonstrate how easy it is to make these grand leaps from benign facts to chemophobic, scaremongering argumentum ad Natural News, let me introduce you to my lovely assistant, surfactants, one of my favourite categories of chemicals (yes, chemists all have their favourite chemicals, it’s a disease.)
Chemicals can be roughly divided into two broad categories. On one side are the hydrophiles, which dissolve readily in water, and are highly charged, which lets them interact favourably with other highly charged things – common examples are water, salt, and ethanol (drinking alcohol.) On the other side there are lipophiles, which are oily, and tend to be weakly charged or neutral. The two don’t interact favourably enough to hang out together in a happy stable mix, and despite any amount of violent shaking, they invariably separate and go to their respective sides.
The line between oil and water here is called a phase boundary – a term you might want to casually whip out at your next dinner party. Or not.
Surfactants are magic because they’re essentially the double agents of the chemistry world – a hydrophile and a lipophile chemically bonded into one neat package:
There’s the charged end which dissolves nicely in water and other hydrophilic chemicals, and a long fatty tail, which mingles with oily lipophilic substances. Since the hydrophiles and lipophiles repel each other, there’s a natural drive towards minimal contact. Adding surfactants reduces the repulsion (aka surface tension), which means it actually allows water to dissolve oil, or vice versa (depending on which one you have more of). The surfactant molecules surround the droplets of oil, kind of like a microscopic pin-cushion:
Since they’re such handy molecules, you can find surfactants everywhere. And now for my magic marketing trick! (I mean, illusion.) By simply conflating surfactants and their main use, soap, I will now proceed to warn you that soap is in absolutely everything, and we should all freak the hell out, NOW.
There’s soap in your soap (and detergents)
Soaps and detergents are almost all surfactant – they help lift oil from your skin (or clothes, or dishes) so it washes off into water.
There’s soap in your soap-free foaming cleanser
Believe it or not. Technically, soap is made from a strong alkali reacting with a fat, so as long as one of those components is missing, it can be labelled “soap-free,” regardless of whether it’s harsher or not. (Those “micellar cleaning solutions” contain surfactant too – they’re mild enough to be left on the skin without washing off.)
There’s soap in your mayonnaise…and your ice cream
To mix hydrophilic vinegar and lipophilic oil, the two undergo a frenzied tussle with the surfactant lecithin to form the stable goop that is mayonnaise. It’s the same deal with the dairy fats and water in ice cream – the lecithin stops your ice cream from becoming a field of ice crystals floating on syrupy cream (though that actually sounds like a Blumenthal recipe.) Lecithin occurs naturally in egg yolks. Which brings us to…