The Chronicles of the Chronicle Flask: 2016

2016 is limping to its painful conclusion, still tossing out last-minute nasty surprises like upturned thumb tacks in the last few metres of a marathon. But the year hasn’t been ALL bad. Some fun, and certainly interesting, things happened too. No, really, they did, honestly.

So with that in mind, let’s have a look back at 2016 for the Chronicle Flask….

January kicked off with a particularly egregious news headline in a well-known broadsheet newspaper: Sugar found in ketchup and Coke linked to breast cancer. Turns out that the sugar in question was fructose. Yes, the sugar that’s in practically everything, and certainly everything that’s come from a plant. So why did the newspaper in question choose ketchup and Coke for their headline instead of, oh, say, fruit juice or honey? Surely not just in an effort to sell a few more newspapers after the overindulgent New Year celebrations. Surely.

octarineThere was something more lighthearted to follow when IUPAC  verified the discoveries of elements 113, 115, 117 and 118. This kicked off lots of speculation about the elements’ eventual names, and the Chronicle Flask suggested that one of them should be named Octarine in honour of the late Sir Terry Pratchett. Amazingly, this suggestion really caught everyone’s imagination. It was picked up in the national press, and the associated petition got over 51 thousand signatures!

In February I wrote a post about the science of statues, following the news that a statue to commemorate Sir Terry Pratchett and his work had been approved by Salisbury City Council. Did you know that there was science in statues? Well there is, lots. Fun fact: the God of metalworking was called Hephaestus, and the Greeks placed dwarf-like statues of him near their Hearths – could this be where the fantasy trope of dwarves as blacksmiths originates?

MCl and MI are common preservatives in cosmetic products

MCl and MI are common preservatives in cosmetic products

My skeptical side returned with a vengeance in March after I read some online reviews criticising a particular shampoo for containing a substance known as methylchloroisothiazolinone. So should you be scared of your shampoo? In short, no. Not unless you have a known allergy or particularly sensitive skin. Otherwise, feel free to the pick your shampoo based on the nicest bottle, the best smell, or the forlorn hope that it will actually thicken/straighten/brighten your hair as promised, even though they never, ever, ever do.

Nature Chemistry published Another Four Bricks in the Wall in April – a piece all about the potential names of new elements, partly written by yours truly. The month also brought a sinus infection. I made the most of this opportunity by writing about the cold cure that’s 5000 years old. See how I suffer for my lovely readers? You’re welcome.

In May I weighed in on all the nonsense out there about glyphosate (and, consequently, learned how to spell and pronounce glyphosate – turns out I’d been getting it wrong for ages). Is it dangerous? Nope, not really. The evidence suggests it’s pretty harmless and certainly a lot safer than most of its alternatives.

may-facebook-postSomething else happened in May: the Chronicle Flask’s Facebook page received this message in which one of my followers told me that my post on apricot kernels had deterred his mother from consuming them. This sort of thing makes it all worthwhile.

In June the names of the new elements were announced. Sadly, but not really very surprisingly, octarine was not among them. But element 118 was named oganesson and given the symbol Og. Now, officially, this was in recognition of the work of Professor Yuri Oganessian, but I for one couldn’t help but see a different reference. Mere coincidence? Surely not.

July brought another return to skepticism. This time, baby wipes, and in particular a brand that promise to be “chemical-free”. They’re not chemical-free. Nothing is chemical-free. This is a ridiculous label which shouldn’t be allowed (and yet, inexplicably, is still in use). It’s all made worse by the fact that Water Wipes contain a ‘natural preservative’ called grapefruit seed extract which, experiments have shown, only actually acts as a preservative when it’s contaminated with synthetic substances. Yep. Turns out some of Water Wipes claims are as stinky as the stuff they’re designed to clean up.

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

Maria Lenk Aquatic Enter, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

August brought the Olympics, and speculation was rife about what, exactly, was causing the swimming pools to turn such strange shades of green. Of course, the Chronicle Flask knew the correct solution…

August also saw MMS and CD reared their ugly heads on social media again. CD (chlorine dioxide) is, lest we forget, a type of bleach solution which certain individuals believe autistic children should be made to drink to ‘cure’ them. Worse, they believe such children should be forced to undergo daily enemas using CD solutions. I wrote a summary page on MMS (master mineral solution) and CD, as straight-up science companion to the commentary piece I wrote in 2015.

mugsSeptember took us back to pesticides, but this time with a more lighthearted feel. Did you know that 99.99% of all the pesticides you consume are naturally-occurring? Well, you do if you regularly read this blog. The Chronicle Flask, along with MugWow, also produced a lovely mug. It’s still for sale here, if you need a late Christmas present… (and if you use the code flask15 you’ll even get a discount!)

In October, fed up with endless arguments about the definition of the word ‘chemical’ I decided to settle the matter once and for all. Kind of. And following that theme I also wrote 8 Things Everyone Gets Wong About ‘Scary’ Chemicals for WhatCulture Science.

Just in case that wasn’t enough, I also wrote a chapter of a book on the missing science of superheroes in October. Hopefully we should see it in print in 2017.

Sparklers are most dangerous once they've gone out.

Sparklers are most dangerous once they’ve gone out.

I decided to mark Fireworks Night in November by writing about glow sticks and sparklers. Which is riskier? The question may not be as straightforward as you’d imagine. This was followed by another WhatCulture Science piece, featuring some genuinely frightening substances: 10 Chemicals You Really Should Be Scared Of.

And that brings us to December, and this little summary. I hope you’ve enjoyed the blog this year – do tell your friends about it! Remember to follow @ChronicleFlask on Twitter and like on Facebook – both get updated more or less daily.

Here’s wishing all my lovely readers a very Happy New Year – enjoy a drop of bubbly ethanol solution and be careful with the Armstrong’s mixture…. 

See you on the other side!


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?!


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.

Follow The Chronical Flask on Facebook at and Twitter as @chronicleflask for regular updates.




Should you be scared of your shampoo?

I was doing some grocery shopping online recently (I have small children, I’ve started to view traditional supermarket shopping in the same way as beating my carpets with a stick and washing clothes in a stream) when I came across some reviews for a particular brand of shampoo.

Most of the reviews were positive, but some were not. In particular, there were a few one star ones complaining about ingredients called methylchloroisothiazolinone and methylisothiazolinone.



What, you may be wondering, are these monstrosities? Surely with names that long they must be huge great big molecules? Actually no, they’re quite small. Methylchloroisothiazolinone (shown in the graphic) has a mere four carbon atoms and an interesting assortment of other elements. They’re part of a group of compounds called isothiazolinones, which are heterocyclic molecules that include a five-membered ring which contains nitrogen, sulfur and a C=O group.

Not surprisingly considering the unwieldy name, methylchloroisothiazolinone is often shortened to MCI. Likewise, the chemically-similar methylisothiazolinone (imagine the molecule above without the -Cl bit) goes by the moniker MI, or sometimes MIT.

MCl and MI are common preservatives in cosmetic products

MCl and MI are common preservatives in cosmetic products.

Why are these things in shampoo? Well, they are very effective preservatives. They’re antibacterial and antifungal, and work against both gram-positive and gram-negative bacteria, as well as yeast and fungi. This is a good thing, because some of these microbes are pretty nasty. The bacteria, for example, include such lovelies as Nocardia (associated with a particular type of respiratory disease), Staphylococcus (associated with various infections) and Listeria (most famous for causing gastrointestinal distress). It may be a small risk, but showers are warm, moist environments – basically the perfect breeding ground for these sorts of things. If these microbes start growing in your shampoo, shower gel and so on, they would then end up on your hair and skin, possibly be inhaled, and might even make their way into your bloodstream if you had a small cut somewhere.


So, that’s why these chemicals are there. That all sounds good, right? Why are people complaining?

The dose makes the poison is an important principle in toxicology (image credit: Lindsay Labahn, click for link)

The dose makes the poison is an important principle in toxicology (image credit: Lindsay Labahn, click for link)

Well, because they also have their hazards. Now, before I go any further, we should remember a very important principle of toxicology, which is that “the dose makes the poison“. Everything, I really mean EVERYTHING, is dangerous if you’re exposed to too much of it. Oxygen is quite crucial if you want to carry on living, for example, but breathe in too much of it for too long and you’re at risk of developing visual disturbances, tinnitus, nausea and muscle spasms. Too much could even be lethal. Similarly, a pinch of salt is quite nice on chips, but try and drink say, seawater, and you’ll soon regret it. Even plain water can be dangerous if you consume too much in too short a time, particularly if you’re also exercising hard.

Many chemicals that are used industrially have scary lists of associated hazards, but it’s important to remember that these warnings are usually aimed at people who use said chemical in an industrial setting. In other words, they might be handling kilograms or even tonnes of the stuff, all day every day, as opposed to the teeny tiny quantity you’re likely to meet a few times a week.

I could pick literally any ingredient in that shampoo bottle and proclaim that it’s dangerous. This would be perfectly true, but also meaningless. A more pertinent question is: is it dangerous in the quantity that you usually use?

Are methylchloroisothiazolinone and methylisothiazolinone in shampoo dangerous? There’s no evidence that they bioaccumulate (build up in the body) or that they’re linked to any kind of cancer (phew). In 2002, there was an in vitro (i.e. outside of living organisms) study of the neurotoxicity of MI which showed that mature neurons in tissue culture could be killed by 4-12 ppm solutions of the chemical. But these experiments were performed on rat brain cells in culture. Lots of things will damage cells in a petri dish: it doesn’t mean that we necessarily have to worry about them in every day life. A shampoo solution pouring straight into your brain might well be harmful, but I suggest that if that’s happening in the shower you have bigger problems. Namely, major head trauma.

However, in high concentrations, MI and MCl are definitely skin and membrane irritants, which can cause chemical burns. They’re known chemical ‘sensitisers‘. This means that exposure to them, even at fairly low levels, might cause an allergic reaction.


A patient who presented to a medical centre following a severe reaction to methylisothiazolinone in a wipe (SA Government – click image for source).

This is where we get into difficult territory, because exactly how a particular individual is going to respond to something like this can be hard to predict. For example, I’ve never had a nasty reaction to methylchloroisothiazolinone. Give me an aspirin, on the other hand, and I’m likely to be in trouble. Allergies are specific to individuals. But there is no doubt that some people do have nasty reactions to MCI and MI; some sources have suggested it might be as many as 15% of the population (and that this number might, worryingly, have increased in recent years).

These chemicals are, or at least have been, also used as preservatives in other products such as sunscreens, moisturisers and wipes (baby wipes, facial wipes and moist toilet tissue, for example), which is a particular concern because you don’t wash off the the residue from these products – that generally being the point of using them – so it lingers on the skin.

A 2014 report from the International Journal of Toxicology concluded that although MI and MCI are sensitisers at concentrations of 50 ppm and above, they weren’t at concentrations of 15 ppm (and below). And therefore they, “may be safely used in ‘rinse-off’ products at a concentration not to exceed 15 ppm and in ‘leave-on’ cosmetic products at a concentration not to exceed 7.5 ppm”.

However, also in 2014, the European Commission Scientific Committee on Consumer Safety argued that: “For leave-on cosmetic products (including ‘wet wipes’), no safe concentrations of MI for induction of contact allergy or elicitation have been adequately demonstrated.”

People have been particularly worried about children, especially with respect to baby wipes. This is not unreasonable, since not only is the contact dermatitis that can occur painful and unpleasant, but once sensitisation has occurred it can’t be reversed: anyone affected will have to read labels extremely carefully for ever after. As a result, consumer groups have campaigned to have MI and MCI removed from any product that’s left on the skin over the last few years.

I happen to have three different brands of baby wipes in my house at the moment (small children you see), and a quick glance at the ingredients tells me that MI and MCI aren’t in any of them, and nor are they ingredients in the packet of flushable moist toilet tissue in the bathroom. This is hardly a comprehensive survey of course, but it suggests that these substances might be falling out of favour. Big companies aren’t really out to get us: pictures of people with nasty skin lesions after using their products doesn’t do them any favours.

Some consumers have complained about the use of MI and MCl in products.

Some consumers have complained about the inclusion of MI and MCl in products.

Do you really need to worry? Were these consumers right to highlight the fact that the shampoo contains MI and MCI in their reviews? Well, if you know you have sensitive skin then these substances probably are best avoided. But is shampoo likely to cause sensitisation if you’re fortunate enough to be blessed with the sort of skin that generally doesn’t erupt into a rash if the wind so much as changes? No one can say for certain, but it seems unlikely because you wash it off: these substances are only in contact with your skin for a few seconds.

So, whilst it doesn’t hurt to be aware of such things, there’s probably no need to panic and throw out all your shampoo just in case. On the other hand, if you’ve been wondering why your skin seems to be permanently irritated, it might be worth checking a few ingredients labels.

Follow The Chronicle Flask on Facebook and @chronicleflask on Twitter for regular updates.

Is oxygen really that good for you?

dove oxygen shampoo officialI don’t find time for huge amounts of television these days, and certainly not adverts. But I recently caught an advert for Dove Oxygen Shampoo out of the corner of my eye, and it brought me up short. Of course, beauty products are full of nonsense generally. Think, for example, of L’Oreal’s famous ingredient, ‘Boswelox’. (A word which, thanks to the wonderful Karl Pilkington, has since acquired a whole new meaning.) A little while ago I wrote a post about a toothpaste that was claiming to contain ‘liquid calcium’ (if it were true, cleaning your teeth would be much more exciting, trust me). It’s just par for the course. Really, is there any point wasting valuable energy continuing to be annoyed by these things?

Well yes, actually. Because this kind of silly hogwash just reinforces the ridiculous ‘science is so terribly hard, oooh aren’t all the complicated words impressive?’ attitude that is so frustratingly prevalent in the world today.

Besides which, picking apart this kind of thing is practically the reason for the existence of this blog. So here goes.

Firstly, a few snippets from Dove’s website:

“Oxygen & Moisture shampoo, conditioner and finishing products are pumped with Oxyfusion Technology, a new generation of moisture. This system moisturises fine, flat hair, giving you hair volume.”

And clicking through a bit further:

“[the shampoo] provides conditioning ingredients fused with oxygen as it instantly dissolves on your hair and breathes life into it.”


Let’s start with that last sentence. Firstly: it dissolves on your hair? What does that mean? I’m just going to mention here that the meaning of the word dissolve is taught in year 7 (first year, in old money) science in all secondary schools in this country, and has been for many, many years. So everyone should know it, even the employees of the media company that came up with this tosh. (If you don’t, and you’ve ever muttered anything whatsoever about slipping standards and/or grade inflation, shame on you.)

‘Dissolve’ usually refers to solids. Salt dissolves in water. Sugar dissolves in tea (yes all right, also mostly water). It means that the solid becomes incorporated into the liquid, forming a solution. I haven’t checked, but I’m assuming Dove’s shampoo is not solid, as that would make it rather difficult to get out of the bottle.

Ok, oils and fats dissolve in certain solvents (not water mind you), and they could feasibly be liquid and yet the word still applies. True enough. It’s possible that the original text was ‘dissolves the grease on your hair’ (more or less accurate enough), and some marketing guy said, ‘I like really love it, I really reaaaahhhly do, but can we just lose two words from the middle?’

And yes, I think it’s safe to assume their shampoo mixes with water, because that is quite an important feature of shampoo, but they haven’t said ‘dissolves in the water’, they’ve said ‘dissolves on the hair’, which does sort of give the impression that it’s your hair that’s somehow dissolving the shampoo. Which is just weird.

But misuse of the world dissolve is only a minor irritation. No, my bigger problem is ‘ingredients fused with oxygen’. What the Dove does that mean?

For years and years we’ve been told that oxidants are bad. Or at least, that antioxidants are good (although this hasn’t really been backed up by scientific studies).

Is it difficult to work out that oxygen is an oxidant? It’s the granddaddy of oxidants. It’s the oxidant that all the other oxidants were named after. Oxy/oxi – see?

Chemists have two definitions of oxidation, but they’re broadly equivalent. Oxidation can be thought of as gaining oxygen, or it can be thought of as loss of electrons. Electrons are the negatively-charged particles that surround atoms. I mention them because the phrase ‘free radicals’ often turns up in the same breath as ‘antioxidants’. Free radicals are atoms or molecules which have an unpaired electron. Electrons like to be paired up. They REALLY like to be paired up. When they’re not, they’ll do pretty much anything they can to get paired up. Unpaired electrons are, if you like, the desperate guy at the nightclub at the end of the night. This makes them incredibly reactive, which means they can cause cell damage.

Worse, this happens in a chain reaction – meaning that a single free radical can do an awful lot of harm. So where to antioxidants come in? Well, antioxidants react with free radicals and essentially stop them in their tracks.

oxygen cylinder

Don’t suck on this.

Jolly good. But you see where I’m going here? Oxygen is the complete opposite of this. Yes, we breathe oxygen. It’s quite important stuff. Certainly, if you run out of it you’re in trouble. But it’s far from harmless. The air we breathe is only about twenty-one percent oxygen. Too much oxygen is flat-out dangerous. Breathe air with something like 50% oxygen for any length of time and you risk damaging your lungs, eyes and central nervous system. Really. Hospitals control oxygen use very carefully, and scuba divers who use it have to undergo rigorous training. The fad for oxygen bars has caused real concern in some quarters.

What does ‘ingredients fused with oxygen’ mean? Does it mean Dove have somehow dissolved oxygen in their shampoo? I’m certain that it doesn’t, because this wouldn’t be stable, and it would likely cause your shampoo to ‘go off’ in some way very quickly. Does it mean that their shampoo contains an ingredient that releases oxygen somehow? Hydrogen peroxide famously does this, when it breaks down into oxygen and water. Of course hydrogen peroxide is used to bleach hair, so… probably not (and anyway, again, not stable).

I looked up the ingredients in Dove Oxygen Moisture shampoo (and I’ve reproduced them below). To be honest, looking at the list I’m drawing a blank. My suspicion is that they’re using ‘oxygen’ simply because it’s the latest trendy thing. Oxygen is common enough – water contains one atom of oxygen in every molecule for starters, so they’re safe with the idea that the shampoo contains oxygen in some form – just not elemental oxygen.

But, ok, if I had to pick something… there is an interesting ingredient called ‘guar hydroxypropyltrimonium chloride‘ in there. If that is the one that inspired them, I can see why they went with Oxyfusion Technology – guar hydroxypropyltrimonium chloride hardly trips off the tongue.


Table sugar (sucrose) – perhaps we should wash our hair with this?


Guar gum – check your salad dressing. Another conditioning alternative perhaps?

I’ve picked that one out of the list partly because it has ‘hydroxy’ in its name. Now in reality, that just means it contains an -OH group or several. This isn’t anything particularly special, table sugar has eight of ’em. Guar hydroxypropyltrimonium chloride comes from guar gum, which in turn is made from guar beans. Guar gum is a food additive that’s used to thicken foods, and it turns up all over the place (check your salad dressing or ice cream).

Guar hydroxypropyltrimonium chloride has been shown to have conditioning properties, which explains its inclusion in shampoo (this is my other reason for picking it out). It probably does leave your hair feeling nice and soft. And it does have several -OH groups, so it arguably sort of works with the ‘conditioning ingredients fused with oxygen’ claim. In the sense that it has oxygen atoms chemically bonded to it. As does, you know, water.

There’s no way that it releases oxygen though. Now in fairness to Dove, that claim isn’t actually made explicitly anywhere, although the lovely bubbly imagery does its damnedest to imply it.


Bad hair day?

And here’s the thing: even if you could, would you want to routinely use a product that releases oxygen directly onto your skin or hair? Given that oxygen is an oxidising agent, and is likely to cause cell damage in high concentrations? Just bear in mind what happens to hair that’s exposed to too much hydrogen peroxide.

And don’t even get me started on the dozens and dozens of moisturisers that claim to do the same. Really? Straight into your skin? There are even some products that claim to do both at once, which frankly is jolly clever. In the Doctor Who sense of clever. I.e. fictional.

But what I want to know is this: after years of anti-oxidant this, and anti-oxidant that, how have we managed to go in exactly the opposite direction without consumers saying ‘er, hang on a minute, surely this has to be a load of old boswelox?’

Ingredients in Dove Oxygen & Moisture Shampoo:
Aqua, Sodium Laureth Sulfate, Sodium Chloride, Cocamidopropyl Betaine, Glycerin, Citric Acid, Dimethiconol, Disodium EDTA, Guar Hydroxypropyltrimonium Chloride, Laureth-23, Parfum, PPG-12, TEA-Dodecylbenzenesulfonate, TES-Sulfate, DMDM Hydantoin, Sodium Benzoate, Amyl Cinnamal, Benzyl Alcohol, Benzyl Salicylate, Butylphenyl Methylpropional, Hexyl Cinnamal, Limonene, Linalool, CI 17200, CI 42090.

Liquid calcium? Why words really matter in chemistry

dl-265_1zI happened to see an advert for Arm & Hammer toothpaste on TV a couple of days ago, in which they cheerfully proclaimed that it contained “liquid calcium”.


Calcium, on the left. With the metals.

This brought me up short.  First thing: calcium is a metal.  Now, as a famous British movie star might say (or perhaps might not say), “not many people know that”.  Ask a roomful of people if calcium is a metal and most of them will tell you it’s not.   I’ve even heard students who know what the periodic table is and what the position of elements within it means, and who can see calcium right there on the left hand side, express their doubts.  Everyone associates calcium with bones and teeth, possibly rocks at a push.  No one (other than chemists of course) hears ‘calcium’ and thinks of a silvery-grey metal.

But that is indeed what it is.  It is a metal, and although its melting point isn’t huge in the grand scheme of metals, it’s still a fairly substantial 842 oC.  The temperature in your bathroom is probably in the region of 20 oC.  In fact your kitchen oven probably only goes up to about 240 oC, so the melting point of calcium is some 600 oC hotter than the hottest setting on your oven.


Calcium and water: what you can’t see is how hot this sucker is going to get.

Temperature problems aside, pure calcium is also highly reactive.  Drop some in water and you’ll see a lot of violent bubbling followed by the solution turning white as a corrosive calcium hydroxide solution forms.  The bubbling is due to flammable, potentially explosive, hydrogen gas.  Oh, and it will get really, really hot too – this is what chemists call an exothermic reaction.  I for one will confess to once (many, many years ago, of course) dropping a red-hot boiling tube into which I’d popped just a little too much calcium metal.  After it had also bubbled up and covered my hand with the aforementioned calcium hydroxide.  Ooopsie.  (Fear not, my hand survived unscathed, after the application of copious amounts of cold water – the go-to cure for most chemical exposures).

So, at the risk of stating the obvious, there’s no liquid calcium in Arm & Hammer toothpaste.  And a jolly good thing too.

What is there?  At this point I should probably point out that Arm & Hammer are quite careful, in their literature and on their packaging, to always put a little ™ by “Liquid Calcium”.  A quick glance at their website clarifies that they’re talking something called “Liquid Calcium ™ Technology” which refers to an ingredient that contains “up to 8 times more calcium and phosphate ions than the amount found in saliva so it is able to replenish ion content in your mouth and subsequently re-mineralise and protect your teeth more efficiently.”

Ah, now we get to the truth of the matter.  It’s not liquid calcium, but calcium ions in solution.

Does this matter?  Am I being unnecessarily pedantic?  Liquid/solution, calcium metal/calcium ions, what’s the difference?


When an extra O really matters.

Well, the thing is, chemists are pedantic.  See, in chemistry, it genuinely could be a matter of life and death.  Ethanol, for example, is ‘drinking’ alcohol.  It’s the stuff in beer, and wine, and strawberry daiquiris.  It may not be exactly healthy, but most adults can consume some fairly safely.  Ethanal, on the other hand, is a toxic and probably carcinogenic substance that’s mainly used industrially as a starting point to make other chemicals.

To pick another example, chlorine is a highly toxic gas that’s been used in chemical warfare; chloride ions are found in salt and are consumed perfectly safely every day.  The difference between ions (atoms or molecules which have become charged due to the gain, or loss, of electrons) and atoms is really quite critical in chemistry, and in life in general.

potassium and water

Potassium reacting with water – pretty!

‘Everybody’ knows that bananas contain lots of potassium.  But potassium is another highly-reactive metal.  In fact it’s even more reactive than calcium.  Potassium explodes with a rather beautiful lilac flame in contact with water.  It’s pretty to watch, but you wouldn’t want it in your mouth.  Actually bananas contain potassium ions (and just to really mess with everything you thought you knew, not even that much compared to lots of other foods).

Back to the dubious labelling again, It’s interesting that Arm & Hammer have chosen to say “fluoride” – which specifically, and correctly, refers to fluoride ions – and not “liquid fluorine”.  I mean surely, in the spirit of consistency, it should be liquid fluorine and liquid calcium (argh!), or fluoride ions and calcium ions.

The word liquid has a specific meaning in chemistry.  It means a pure element or compound in its molten state.  Pure water at room temperature is a liquid.  So is ethanol, and mercury, and bromine (interestingly these last two are the only chemical elements which are liquids at room temperature).  Ethanol dissolved in water, as it is in strawberry daiquiris (more or less), isn’t a liquid.  It’s a solution.  This matters.  Liquid ethanol is pure ethanol.  Drink that and you’re looking serious alcohol poisoning in the face, and it’s about to wallop you for looking at it funny.


An Arm & Hammer chemist?

Saying, or even implying, that calcium ions in solution is ‘liquid calcium’ is like saying that seawater is liquid sodium (sodium is another highly reactive metal – orange flame this time).  It’s just nonsense.  Ok, it’s probably not going to cause anyone any actual harm, but that’s not the point.  It’s completely factually inaccurate.  I am absolutely certain that the chemists working for Arm & Hammer wanted to tear their hair out when the advertising company came up with this name for the formulation they’d spent (probably) years slaving over.  And I expect they were essentially told to shut up about it, the vast majority of our customers won’t know the difference.

And sadly this may be true.  But it shouldn’t be.  Would Arm & Hammer care if their boxes were labelled ‘tothpast’ instead of toothpaste?  I bet they’d be bothered if the boxes were priced at £250 instead of £2.50.  Why fuss over spelling and numbers but be careless over scientific literacy?  Either precision matters or it doesn’t.

Perhaps it’s time scientists starting making as much noise about this kind of thing as people who complain about stray apostrophes or the misuse of the word disinterest.  You never know, it might help levels of scientific understanding.

Mind you, perhaps the author of a blog called The Chronicle Flask shouldn’t throw stones…


After I wrote this post I tweeted something referring to “liquid phosphorous”.  It was pointed out to me, quite rightly, that I meant “liquid phosphorus”.  Phosphorus is the noun – the name of the chemical element – and phosphorous is an adjective.  As in, “phosphorous fertiliser”.  I confess I was a bit hazy on that one until made to check, which is ironic really. Consider me sent to the back of the class 😉

Yesterday’s 18 minutes of infuriating nonsense

Oooh my blood fairly boiled yesterday, it really did.  Well ok, not really.  At least not in the sense that my blood reached 100 degrees Celsius, more in the sense that I was shouting pointlessly at the radio.  Why?  Because the Jeremy Vine radio show on BBC Radio 2 had a piece about the Royal College of Obstetricians and Gynaecologists’ (RCOG) paper that suggested that pregnant women should avoid exposure to certain everyday chemicals.  Now, I will get to that issue in a minute, but first let’s talk about the item on the radio programme.

It started with lots of talk of avoiding ‘chemicals’, and Jeremy asking if listeners made a habit of avoiding them.  Now as I discussed in a previous post, chemicals are all around us.  Because everything is a chemical.  Water is a chemical, so is oxygen, so is baking soda, so is vitamin C.  Frankly, anyone who thinks they avoid chemicals doesn’t understand what they are.  Now, this was BBC Radio 2.  If someone had mixed up the words less and fewer there would be hell to pay, but apparently no such rigour applies to use of scientific terms.

hazelThe next irritation was the choice of guests. Hazel Courteney was pitched against Adam Hart-Davis.  Courteney is a journalist specialising in alternative health (alternative treatments being, by definition, the ones which have not been proven effective using scientific methods; the ones which have been proven effective are, you know, medicine).  She was described on the show as a ‘health journalist’ but as far as I can tell, she has no scientific or medical qualifications.  article_adamhartdavisw2Hart-Davis, on the other hand, has a PhD in organometallic chemistry.  Is this balanced?  Just because two people appear to have opposing viewpoints, should they necessarily be given equal weight?  It happens all too often with scientific and medical issues, presumably because it’s perceived as being more entertaining, but it’s worrisome because it gives the impression to the listener that the two people are equally qualified and knowledgeable.

So were they?  Let’s get on to some of the things Courteney said.  I have forced myself to listen again on iPlayer to make absolutely sure I’m not misquoting.  I hope everyone appreciates the sacrifice.  My blood pressure may never be the same again.

“The average person absorbs into their bloodstream alone about 14 kg of toxins annually through their skin.”

I can find no evidence for this claim, and have no idea where it comes from (update: I later went on to write a blog post for the Ask for Evidence campaign on this question).  Skin is actually pretty impermeable stuff.  If it weren’t we’d all be in a whole heap of trouble every time we had a bath.  Never mind chemicals, you’d turn into a water-filled balloon.  There are some chemicals that can be absorbed through skin, but not many in the grand scheme of things.  Nicotine is one, that’s how nicotine patches work, but that’s fairly easily avoided.  There are herbicides and pesticides that can be absorbed this way, but unless you’re spraying with them and utterly failing to follow health and safety protocols (there’s a reason people wear gloves and masks), you’re not going to come into contact with anything at all significant.  Even if you’re spraying without the proper safety gear, you’re not going to absorb 14 kg unless you take a bath in the stuff.  Stop press: pregnant women shouldn’t bathe in herbicide.

“[ammonia] is in toilet cleaners, window cleaners.  It’s also in hair dyes.”

One of her less outlandish claims, but I include it because first of all, not really.  Most bleaches sold in this country are based on hypochlorite, not ammonia.  And the majority of window cleaners on sale are little more than some detergent and vinegar.  Ammonia might once have been in hair dye, but a lot of them are marketed as ‘no ammonia’ these days, mainly because consumers hate the smell.  Ammonia really stinks.  Secondly, it’s pretty irrelevant.  Yes ammonia is toxic, but it’s also extremely volatile.  In a well-ventilated area it will quickly disperse and you’ll barely notice it.  The small quantities you might inhale aren’t harmful because the body actually has a mechanism to prevent ammonia build up (because it’s a by-product of breaking down protein, which we all do whether we know it or not).  Yes if you lock yourself in an enclosed space with a large quantity of ammonia gas, it will irritate your eyes and lungs.  But, you know, don’t do that.

“Oestrogen is a builder, and therefore the more hormone-disrupting toxins you have in your body, the more oestrogen-like compounds you will make, and they can migrate to fatty tissues such as your breasts, and that’s one of the major contributing factors to breast cancer today.”

Oestrogen is a builder?  What, like Bob?  I’m not even sure what she means by that.  Oestrogens promote the development of female secondary sexual characteristics, such as breasts, and there are legitimate concerns about certain substances in the environment causing fertility problems particularly for men, who under normal circumstances wouldn’t be exposed to oestrogen.  But a major contributing factor to breast cancer?  Well, according to the NHS choices website, the major contributing factors are age and family history.  Way down the list is: “Your risk of developing breast cancer may rise slightly with the amount of oestrogen your body is exposed to.”  Note the word ‘slightly’.  Not ‘significantly’.  And using combined contraceptives, hormone replacement therapy or just being a woman will expose you to a lot more oestrogen than you’ll ever seen from your environment.  In fact, being pregnant actually reduces your exposure to this hormone, because its production is disrupted during pregnancy.  So in this respect by being pregnant you’re doing yourself a big health favour.  That’s something comforting to remember when you’re throwing up and nursing your swollen ankles.

“Clingfilms (that) contain PCBs”

PCB stands for polychlorinated biphenyl.  They were once used as plasticisers, but mostly in paints and cements.  They’re definitely toxic and they’ve been linked to cancer.  But PCB production was banned by the United States Congress in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001.  If you have clingfilm that contains PCBs, I’m curious to know where you bought it.

“If you have a takeaway meal, and you microwave it in a plastic container, that releases large amounts of oestrogen-altering chemicals.”

Now, there is ongoing debate about a substance used in plastics called bisphenol A (BPA).  It does exhibit hormone-like properties, it might be released when certain plastics are heated, and the European Union, Canada, and the United States have consequently banned BPA use in baby bottles.  Baby bottles are a specific case though; you have to bear in mind that a lot of people sterilise them by heating to high temperatures for extended periods of time.  The Food Standard Agency’s position is that “current level of consumer exposure to BPA from food contact materials does not represent a food safety risk for consumers”, that the science shows that it only has “weak oestrogenic effects” and that “effects [are] generally seen at high doses”.  Genuine concern aside, I still take issue with Courteney’s use of the words “large amounts”.  The Plastic Materials and Articles in Contact with Food (England) Regulations 2009 (snappy title) permit the use of BPA provided that no more than 6 mg per kg migrates into food.  Let’s say we have a plastic container that weighs 100 g (that would be quite a large tub), that means that at the very top end we’re talking about 0.0006 g of BPA getting into your food.  And it’s highly likely to be far less than that in reality.  That’s not a ‘large amount’.  Still I will grudgingly admit that she may have a bit of a point here: if all this worries you, put your food into a glass container before you heat it.

“If your shampoo or body lotion has sodium laureth sulfate or sodium lauryl sulfate these are detergents and emulsifiers used in thousands of cosmetics, um, when you ingest them they can have a really negative effect” followed a little later by, “it’s heavily linked to cancers.  There’s plenty of research to show that it does accumulate.  SLS does accumulate in the eyes, the heart, the liver, the brain.  It can be come quite toxic to the liver.  And the more toxins you have in your liver the angrier you become.”

Mmm.  So, better not eat your shampoo or shower gel then.  Why is she talking about ‘ingesting’ substances which aren’t generally eaten?  Sodium lauryl sulfate and sodium laureth sulfate are detergents, that bit’s true, but they’ve been used for an awfully long time and there really is no evidence either is horribly harmful.  Both have been tested extremely rigorously, and have been consistently shown have no causal link with cancer.  It’s just possible they might cause skin irritation in sensitive individuals, that’s about it.  Although you know, perhaps it is better to be safe than sorry.  Wouldn’t want to risk an angry liver.

“When you ingest chemicals, say in food, your saliva and stomach acid help break them down and you excrete them.  But when you’re absorbing all these toxins through your skin they’re absorbed straight into your bloodstream and therefore, you know, can have a very negative impact over time.”

Er, what?  Just, what?  This makes no sense.  She’s saying that it’s safer to eat these substances than put them on your skin?  But didn’t she just say that sodium laurel sulfate was particularly harmful if ingested?  Make your mind up.

All this nonsense in 18 minutes.  Impressive, no?  Poor Adam Hart-Davis did try and argue against some of it, but I fear he lost the battle.  I’m not sure he was expecting quite such an onslaught.  Poor man.

I should make brief mention of the thing that started all this in the first place.  The Royal College of Obstetricians and Gynaecologists (RCOG) released a Scientific Impact Paper titled “Chemical Exposure During Pregnancy: Dealing with Potential, but Unproven, Risks to Child Health” (I have linked to the actual, original, paper, not a news report).  Now, the clue is in the title.  Unproven risks.  Essentially they are commenting on the, very small, possibility that a pregnant woman’s exposure to a variety of environmental toxins might combine to create a harmful effect to the baby.  They suggest using fresh food rather than processed (shock), as well as some less practical tactics such as reducing the use of foods/beverages in cans/plastic containers (perhaps women should carry their water supplies in a traditional oilskin bag?) and minimising the use of personal care products such as moisturisers and shower gels (presumably it would be much healthier to just stop washing).

In fairness, the original document does include statements that balance things a bit.  It comments that: “Under normal lifestyle and dietary conditions, the level of exposure of most women to individual environmental chemicals will probably pose minimal risk to the developing fetus/baby.”  And, “it is unlikely that any of these exposures are truly harmful for most babies”.

Unfortunately the media didn’t initially present that side of it.  We had multiple headlines such as: “Pregnant women warned over household product chemicals” and at the more alarmist end of the spectrum: “Pregnant women told to avoid painting the nursery, buying new furniture or going near non-stick FRYING PANS” (sic).  Fortunately lots of other, more sensible, people immediately started writing about the issue and now a search for this particular news item brings up lots of articles putting the other side, for example: “New advice to pregnant women is unhelpful and confusing, say critics“.  I don’t think there’s any need for me to say it all again.  But if you are pregnant right now, my advice (as someone who’s recently been through it) would be to try not to worry about it, put your feet up and have a biscuit.  Pregnancy is difficult enough as it is.

Chemical paranoia: are they really going to get you?

chemicals1There are many warnings about nasty chemicals on the internet. “Ooh, chemicals are really BAD for you!!” type these paranoid types, on their computer made largely of polymers, with a screen containing liquid crystals, running on a lithium ion battery. “We’re being POISONED by all this stuff They’re putting into our food and water!!!” They cry, whilst drinking coffee that (naturally) contains caffeine, chlorogenic acids and umpteen other chemicals, having earlier swallowed some diphenhydramine for their many allergies and popping paracetamol pills for their terrible stress headache caused by all those capital letters and exclamation marks.

A quick glance at Snopes’ wonderful ‘Toxin du jour‘ page reveals a long list of stories which Snopes, the original home of internet urban legends, has cheerfully debunked, from the notion that aspartame is responsible for a cancer epidemic (it’s not), that microwaving plastic containers leaches dangerous chemicals into the food (it doesn’t) and the bizarre story of a mixture of certain type of baby formula and dog food causing a todler’s stomach to explode (do I need to state the obvious?)

Of course in writing this I fear I’m preaching to the converted, since people that forward on emails warning of the risk of deadly poisoning from re-using plastic drinking water bottles and the like never seem to be the sort of people to actually check their facts by, say, taking three seconds to type anything at all into a well-known search engine. And I therefore suspect they wouldn’t be reading this blog, it being dangerously factual and all. But for the sake of thoroughness, chemicals are all around us. The dictionary definition is “something with a distinct chemical composition that is produced by, or used in, a chemical process”. Most things are used in a chemical process somewhere, including such mundanities as water, oxygen and nitrogen. The only way anyone could avoid chemicals all together would be to lock themselves into a hermetically sealed chamber and pump all the air out. And that’s far from being a route to a long and healthy life.

“Ah, but,” the fearful cry, “we don’t mean NATURAL chemicals. We mean ARTIFICIAL ones. The ones chemists cook up in laboratories. Not nice natural things!”

Ah yes. Lovely, naturally-occurring chemicals. Like nicotine (the deadly nerve poison found in tobacco), lily of the valley (contains a high enough concentration of cardiac glycosides that even the water the flowers are placed in could be dangerously toxic), carbon monoxide (deadly by-product of the incomplete combustion of any carbon-based fuel, including all the ones you might be using in your house, such as wood, or coal, or gas) and botulinum toxin (the most acutely toxic substance known, naturally produced by the bacterium clostridium botulinum).

In fact, sometimes the synthetically produced is safer: for example salicylic acid (naturally-occurring in willow tree bark), while not particularly deadly is certainly a lot less friendly to the human digestive system than its chemically-modified cousin acetylsalicylic acid, otherwise known as aspirin.

And then there are food additives. They’re bad for you, right? They cause cancer, irritable bowl syndrome, hyperactivity, asthma, headaches, obesity, bad skin, bloating, unmanageable hair, purple rashes, gymphobia and notlikeingmondayitis, amongst other things. All of them*. You should definitely always buy foods that don’t have additives in. Everyone knows that.

Actually, no. In fact a lot of food additives keep us safe. Remember that botulinum toxin I mentioned up there? The most acutely toxic substance known? The bacterium that produces it grows in meat products. In fact, the German medical writer Justinus Kerner called it a “sausage poison” for that very reason. Why don’t people die from botulism more often? Because sodium nitrite (E250) is regularly added to meat products, and it does a great job of preventing clostridium botulinum from growing. It’s true that nitrites aren’t entirely controversy-free (in particular they’ve been linked to bowel cancer) but, and it’s a big but, the risk from botulism is much, much bigger than the small, theoretical, increase in your chances of developing cancer. Eating a botulism-laden sausage will kill you. Quickly. If you’re going to eat sausages at all, E250 is a good thing.

Many, many food additives are from entirely natural sources. Take the emulsifier lecithin (E322). It’s usually extracted from eggs or soy beans. Entirely homemade mayonnaise makes use of this chemical (whether knowingly or not) to keep the fat and water in the recipe from separating into layers. Ascorbic acid (E300) is used as an acidity-regulator and anti-oxidant, and its other name is good old vitamin C. Beeswax (E901) is routinely used as a glazing agent, espeically on apples, and there are a whole raft of colourings that are totally natural in origin, including caramel (E150a), Riboflavin (vitamin B2, E101) and beetroot red (E162). And by the way, those scary E numbers? The E just means they’re substances which have been approved for use within the European Union. In other words, they’ve been tested and shown to be safe. You could argue that those E’s are actually a very good thing. Who knew?

Then of course there’s E621, monosodium glutamate, used as a flavour enhancer (it produces the meaty flavour, umami). I feel sorry for poor old MSG, it gets a bad press. Blamed for everything from migraines to obesity to asthma (really this time). It’s been used for more than 100 years to season food, and is just the sodium salt of glutamic acid, one of the most abundant naturally-occurring amino acids. The MSG that’s added to food these days is mostly made by bacterial fermentation, not unlike yoghurt or vinegar. But glutamic acid turns up everywhere, or at least everywhere there’s protein, and therefore so do its salts. Lots of foods are naturally high in glutamate, including cheese, tomatoes, mushrooms and walnuts. It’s the same stuff, just with less sodium. So it’s safe to say that you can cheerfully ignore anyone who tells you that MSG is horribly bad for you, especially if they’re munching on a mushroom. Not to suggest that you should live off processed foods, of course, but you may do better to worry about the salt, sugar and fat content first.

In fact a lot of synthetic chemicals make our lives easier. Where would we be without medicines for example? (Not to be too blunt, probably dead.) Without the concoction that is toothpaste, most of us wouldn’t have our own teeth. Without chlorine in water we’d probably have died of typhoid or cholera (people arguing against it usually conveniently forget about those two, which used to kill by the tens of thousands). Just have a look around at all the plastic you use, and imagine for a second what life would be like without it: no soft contact lenses, no mobile phones, computers or TVs, no waterproof jacket or shoes, no biros, no packaging to keep food fresh and protected, no nylon or other synthetic fabrics… the list goes on.

So next time someone talks disparagingly about all those ‘chemicals’, ask them about all the ones they’re using right now. Or send them to Snopes. Or order that hermetically sealed, vacuum-pumped chamber. At least it’d be quiet.


After I published this post, I came across this absolutely brilliant pic on Twitter:

*Given that I earlier claimed to be factual, I should admit that I may have made some of those up.