8 Things Everyone Gets Wrong About ‘Scary’ Chemicals

scaryChemicals. The word sounds a little bit scary, doesn’t it? For some it probably conjures up memories of school, and that time little Joey heated something up to “see what would happen” and you all had to evacuate the building. Which was actually good fun – what’s not to love about an unplanned fire drill during lesson time?

But for others the word has more worrying associations. What about all those lists of additives in foods, for starters? You know, the stuff that makes it all processed and bad for us. Don’t we need to get rid of all of that? And shouldn’t we be buying organic food, so we can avoid ….

….Read the rest of this article at WhatCulture Science.


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Do you really need to worry about baby wipes?

Never mind ingredients, just give me a packet that's not empty!

Never mind ingredients, just give me a packet that’s not empty!

A little while back I wrote a post about shampoo ingredients, and in passing I mentioned baby wipes. Now, these are one of those products which you’ve probably never bought if you’re not a parent, but as soon as you are you find yourself increasingly interested in them. Yes, I know, reusable ‘wipes’ are a thing. But after dealing with a nappy explosion at 2am in the morning, I’m willing to bet that more than one parent’s environmental conscience has gone in the rubbish bin along with a bag of horror they never want to see again, at least for a little while.

But which wipes to buy? The cheapest ones? The nicest-smelling ones? The fragrance-free ones? The ones with the plastic dispenser on the top that allow you to easily grab one wipe at a time? Or not, because those bulky dispensers produce yet more plastic waste? Or just whichever brand you grabbed first at the all-night supermarket at some unpleasant hour that’s too late to be night yet too early to be morning?

All of the above at one time or another, probably. However, I’m going to suggest that one thing you can stop worrying about right now is whether or not your wipes are labelled ‘chemical-free’.

As I’ve explained before, everything is made up of chemicals. By any sensible definition, water is a chemical, and thus the claim that Water Wipes® (“the world’s purest baby wipe”) are “chemical free” is simply incorrect.

These wipes are not, actually, chemical-free.

These wipes are not, actually, chemical-free.

In fact, Water Wipes® aren’t even, as you might imagine, made of some sort of non-woven fabric impregnated with plain water. No, they contain something else: grapefruit seed extract.

Well, that sounds natural, I hear you say. It does, doesn’t it? Grapefruit, that sounds fresh. Seed, well seeds are healthy, aren’t they? And the word ‘extract’ is very natural-sounding. What’s the problem?

Let’s start with what grapefruit seed extract, also called GSE, actually is. It’s made from the seeds, pulp and white membranes of grapefruit. These ingredients are ground up and a drop of glycerin is added. Glycerin, by the way, is otherwise known as glycerol, or propane-1,2,3-triol. It’s naturally-occurring – it’s one of the molecules you get when you break up fats – and it’s usually made from plants such as soybeans or palm (uh oh…), or sometimes from tallow (oh dear…) or as a byproduct of the petroleum industry (yikes! – I wonder if the manufacturers of Water Wipes® enquired about the nature of the glycerin being added to their product…?)

But anyway, back to GSE. Like all plant extracts, grapefruit seed extract is stuffed full of other chemicals that occur naturally. In particular, flavonoids, ascorbic acid (vitamin C), tocopherols, citric acid, limonoids and sterols.

citric acid synthetic vs natural

Can you tell the difference?

So… in short, not chemical-free at all. Not even a bit. The problem here is that, in marketing, the term ‘chemical-free’ is used to mean something that only contains ingredients from ‘natural’ sources. But this is meaningless. Take citric acid, for example. (E330 by the way – E numbers don’t mean something’s deadly, either. In fact, quite the opposite.) There’s no difference between citric acid extracted from a grapefruit and citric acid prepared in a laboratory. They both have exactly the same atoms and the same molecular formula and structure. They both react in the same way.

They’d both be classified as corrosive in high concentrations, and irritant in low concentrations. This isn’t even “might” cause irritation. This is absolutely, definitely, positively WILL cause irritation.

Wait, hang on a minute! There’s a potentially corrosive chemical in the ‘chemical-free’ baby wipes, and unsuspecting parents are putting it on their baby’s skin?!

Yep.

But before anyone runs off to write the next Daily Mail headline, let’s be clear. It’s really not going to burn, alien acid-style, through a new baby’s skin. It’s not even going to slightly redden a baby’s skin, because the quantity is so miniscule that it quite literally has no corrosive properties at all. It’s the same logic as in the old adage that “the dose makes the poison“.

This is where we, as consumers, ought to stop and think. If a fraction of a drop of citric acid is harmless then…. perhaps that small quantity of PEG 40 hydrogenated castor oil or sodium benzoate in most (considerably less expensive, I’m just saying) other brands of baby wipes isn’t as awful as we thought, either…

Indeed, it’s not. But what sodium benzoate in particular IS, is a very effective preservative.

Grapefruit seed extract is marketed as a natural preservative, but studies haven't backed up this claim.

Grapefruit seed extract is allegedly a natural preservative, but studies haven’t backed up this claim.

Why does this matter? Well, without some sort of preservative baby wipes, which sit in a moist environment for weeks or months or even years, might start to grow mould and other nasties. You simply can’t risk selling packets of water-soaked fabric, at a premium price, without any preservative at all, because one day someone might open one of those packets and find it full of mould. At which point they would, naturally, take a photo and post it all over social media. Dis-as-ter.

This is why Water Wipes® include grapefruit seed extract, because it’s a natural preservative. Except…

When researchers studied GSE and its antimicrobial properties they found that most of their samples were contaminated with benzethonium chloride, a synthetic preservative, and some were contaminated with other preservatives, some of which really weren’t very safe at all. And here’s the kicker, the samples that weren’t contaminated had no antimicrobial properties.

In other words, either your ‘natural’ grapefruit seed extract is a preservative because it’s contaminated with synthetic preservatives, or it’s not a preservative at all.

If you're worried, just use cotton wool pads and water.

You can always use cotton wool pads and water.

If you’re worried that baby wipes may be irritating your baby’s skin – I’m not claiming this never happens – then the best, and cheapest, thing to do would be to simply follow the NHS guidelines and use cotton wool and water. It’s actually easier and less messy than you might imagine – packets of flat, cosmetic cotton wool pads are readily available (and pretty cheap). Simply dip one in some clean water, wipe and throw it away. It’s really no more difficult or messy than wipes.

But if you’re choosing a particular brand of wipes on the basis that they’re “chemical-free”, despite the fact that other types have never actually caused irritation, you can stop. Really. Buy the cheap ones. Or the nicest-smelling ones, or the ones that come out of the packet most easily. Because NONE of them are chemical-free, and it’s really not a problem.


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Are you (still) a chemist and you didn’t know it?

I recently wrote a post listing five bits of chemistry you (probably) do every day.  It was surprisingly popular and so, just like the big movie companies, here’s the sequel!

Picture 0151.  Make fresh coffee (or at least drink one someone else made)
Espresso (the basis of most coffee drinks) is made by forcing a small amount of very-nearly boiling water through ground coffee beans.  This handily extracts a number of chemicals including all the ones that produce the lovely coffee flavours and aromas but also, crucially, our friend caffeine, without which many of us simply wouldn’t function on a daily basis.  What you (or your favourite barista) have done here is a form of chemical extraction.  Extraction techniques are extremely important in chemistry, because nature has an annoying habit of stirring up the stuff we want with lots of other things.  Chemists, especially the organic ones (produced with all-natural fertilisers) spend most of their lives carefully and painstakingly extracting things from other things. Some of them probably earn less than baristas, too.

2.  Make toast
You know when you make the perfect slice, and it goes that lovely brown colour, just before black?  That’s the Maillard reaction in action.  It’s the same thing that happens when you brown meat, chips, onions or, well, anything else that goes brown when you cook it.  It’s a reaction between amino acids (the stuff proteins are made of) and sugars.  It’s also responsible for those lovely toasted-biscuity smells and favours.  The surface of the food has to be in contact with dry heat for this reaction to happen, which is why boiled and microwaved food doesn’t brown.  And alkaline conditions help it along, which is the main reason lye is traditionally used on the surface of pretzels and other German breads (that’s always made me a bit nervous).

Haemoglobin3.  Breathe
I mentioned respiration in my previous post but as any 13 year-old pupil will tell you, and most adults have long since forgotten, respiration is not the same as breathing.  Here I’m actually thinking of oxygen exchange (which is also not, technically, the breathing bit but bear with me).  You’re probably aware that you blood has iron in it: in fact that iron is tied up in rather beautifully complicated haemoglobin molecules.  Oxygen molecules bond to four iron atoms in the haemoglobin with something called coordinate, or dative covalent, bonds.  If it weren’t for this nifty bit of chemical bonding, there’s no way our blood could carry enough oxygen around our bodies, delivering it safely to our cells, to keep us going from one minute to the next.

251840969_6404.  Neutralised some excess acid
Taken an indigestion tablet recently?  Did you realise you were doing a chemistry experiment in your very own stomach?  Well you were!  Indigestion tablets contain a variety of substances, but some of the most common ingredients are magnesium hydroxide (also known, when suspended in water, as ‘milk of magnesia’), calcium carbonate, sodium bicarbonate and magnesium carbonate.  These are all bases: they react with acids to form a salt and water and, in the case of the carbonates, carbon dioxide as well.  The acid in your stomach is hydrochloric acid, so for example:

sodium bicarbonate + hydrochloric acid –> sodium chloride + water + carbon dioxide

Now, is that Rennie advert that claims to “turn acid into water and other natural substances” starting to make sense?  They don’t want to use the word salt for some reason…

5.  Used drain cleaner
This is one of my favouritist little bits of chemistry.  Really.  It’s lovely.  Well apart from the horribly caustic chemicals involved obviously.  Drain cleaner is dangerous concoction nasty stuff but it’s main ingredient is often a strong alkali, like sodium hydroxide (there are also acidic drain cleaners; it’s quite important that you don’t mix them).  The stuff that blocks up your plughole is, largely, protein (hair, skin cells, yuck) and and oily dirt.  The strong alkali reacts with these things in a reaction called hydrolysis.  Now this is clever, because soap is made by (virtually) the exact same reaction.  Soap is produced by saponification, where fats are mixed with a strong alkali.  So what are you doing when you put drain cleaner in your stuffed-up plug hole?  You’re not only breaking down the gunk, you’re also effectively making soap in situ, which helps to wash away the remaining dirt.  How brilliant is that?

With thanks to Andrew (@_byronmiller) for his suggestions.