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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Words of woo: what does ‘alkalise’ mean?

220px-Marketvegetables

‘alkaline’ diets usually revolve around eating lots of fruit and vegetables – no bad thing, but it won’t change your body’s pH

If you hang around in the unscientific chunks of the internet for any length of time, as I find myself doing from time to time, you start to come across certain words that get used over and over. They are usually words that sound very sciency, and they’re being used to make things sound legitimate when, if we’re honest, they’re really not.

One such word is ‘alkalise’ (or ‘alkalize’). I’ve met it often ever since I wrote my post ‘Amazing alkaline lemons?‘. So, what does this word mean?

Good question. Google it, and at least the first three pages of links are about diets and how to ‘alkalise your body’ featuring such pithy lines as:

“It’s not really a diet… it’s a way of eating” (is there a difference?)
“Alkalise or live a life of misery” (gosh)
“Alkalise or die” (blimey)
“Alkaline water” (apparently this is a thing)
“Why it’s important to alkalise your water” (using our overpriced products)

In fact, I had to click through several pages of Google links before I even got to something that was simply a definition. (I’m aware that Google personalises its search results, so if you try this yourself you might have a different experience.) Certainly, there are no legitimate chemistry, biochemistry – or anything else like that – articles in sight.

Hunt specifically for a definition and you get turn basic and less acidic; “the solution alkalized”‘ (The Free Dictionary), to make or become alkaline. (Dictionary.com) and, simply, ‘to make alkaline’ (Collins).

Universal_indicator_paper

pH 7 is neutral, more than 7 is basic

The first of these is interesting, because it refers to ‘basic’. Now, as I’ve explained in another post, bases and alkalis are not quite the same thing. In chemistry a base is, in simple terms, anything that can neutralise an acid. Alkalis, on the other hand, are a small subset of this group of compounds: specifically the soluble, basic, ionic salts of alkali metals or alkaline earth metals.

Since there are only six alkali metals (only five that are stable) and only six alkaline earth metals (the last of which is radium – probably best you steer clear of radium compounds) there are a rather limited number of alkalis, namely: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, caesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide and radium hydroxide. There you go. That’s it. That’s all of them. (Okay, yes, under the ‘soluble in water’ definition we could also include ammonium hydroxide, formed by dissolving the base, ammonia, in water – that opens up a few more.)

This, you see, is why real chemists tend not to use the term ‘alkalise’ very often. Because, unless the thing you’re starting with does actually form one of these hydroxides (there are some examples, mostly involving construction materials), it’s a little bit lead-into-gold-y, and chemists hate that. The whole not changing one element into another thing (barring nuclear reactions, obviously) is quite fundamental to chemistry. That’s why your chemistry teacher spent hours forcing you to balance equations at school.

No, the relevant chemistry word is ‘basify‘. This is such a little-known word that even my spell checker complains, but it’s just the opposite of the slightly better-known ‘acidify’ – in other words, basify means to raise the pH of something by adding something basic to it. Google ‘basify’ and you get a very different result to that from ‘alkalise’. The first several links are dictionary definitions and grammar references, and after that it quickly gets into proper chemistry (although I did spot one that said ‘how to basify your urine’ – sigh).

What does all this mean? Well, if you see someone using the word “alkalising” it should raise red flags. I’d suggest that unless they’re about to go on to discuss cement (calcium hydroxide is an important ingredient in construction materials) cocoa production or, possibly, certain paint pigments, then you can probably write off the next few things they say as total nonsense. If they’re not discussing one of the above topics, the chances are good that what they actually know about chemistry could safely fit on the back of a postage stamp, with space to spare, so nod, smile and make your escape.

For the record, you absolutely don’t need to alkalise your diet. Or your urine*. Really. You don’t.

And please don’t waste your money on alkaline water.

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Lemon

There’s no good evidence that drinking lemon juice has a significant impact on urine pH.

* In the event that you actually have problematically acidic urine, perhaps due to some medical condition, there are proven treatments that will neutralise it (i.e. take it to around pH 7, which is the pH urine ought to be, roughly). In particular, sodium citrate powder can be dissolved in water to form a drinkable solution. Of course, if this is due to an infection you should see a doctor: you might need antibiotics – urinary tract infections can turn nasty. Yes, I am aware that the salt of the (citric) acid in lemons is sodium citrate, however there is no good evidence that drinking lemon juice actually raises urine pH by a significant amount. And yes, I’m also aware that dietary intake of citrate is known to inhibit the formation of calcium oxalate and calcium phosphate kidney stones, but that’s a whole other thing. If you have kidney stones there are a number of dietary considerations to make, not least of which might be to cut down on your consumption of certain fruits and vegetables such as strawberries and spinach (and ironically, if you look at some of the – entirely unscientific – lists of acid-forming and alkali-forming foods these are almost always on the alkaline side).

Amazing alkaline lemons?

Tonight on How Not to Get Old (I really shouldn’t have been watching it) I heard the following gem:

Lemon

Can lemons neutralise acids? (Spoiler: no)

“Lemons neutralise acidity.”

In fact, not only did I hear it, it even flashed up on the screen in a helpful little box. The speaker was Elizabeth Peyton-Jones, who says on the Channel 4 website that she is a “herbalist, naturopath and food and health consultant” and that she has “run a highly successful alternative health clinic in Central London for over a decade.”

Hm.

256px-Zitronensäure_-_Citric_acid.svg

A molecule of citric acid. Definitely not an alkali.

Let’s start here: lemons are acidic. Why are they acidic? They contain citric acid, about 5% by weight. Citric acid has the chemical formula C6H8O7, and the catchy systematic name of 2-hydroxypropane-1,2,3-tricarboxylic acid. If you look at the molecule you can see why it’s an acid. See those OH’s that are sitting next to =O’s? Those are acid groups. There are three of them. This is most definitely an acid.

Why do they make it an acid? Or rather, what is an acid? Well there is a bit more to this than I’m about to explain (interested parties could read about Lewis acids) but essentially acids are substances that can release H+ ions (‘hydrogen ions’) when they’re dissolved in water. Those three acid groups in citric acid can, in theory, release three H+ ions per molecule. So you might expect that citric acid is a pretty strong acid.

In fact, it’s not.  It’s actually what chemists call a weak acid, because although it can release three hydrogen ions per molecule it doesn’t really want to that much. It’s a stingy old Scrooge and likes to keep hold of them. But that doesn’t make it somehow not an acid, it still is one. The pH of lemon juice is about 2.

Which brings me to pH. It’s possibly the most abused and misunderstood scale ever. (There are two wonderful blog posts on that very subject, written by Marc Leger, which you really should read, obviously after you’ve finished here.) I’ve even found a school text book, yes honestly a school text book, that said “no one really knows what pH stands for”. Er. What?

Chemists know what it stands for thank you very much (I suspect, or at least hope, that the author of that book was not a chemist). The H stands for, guess what? Yes, the amount of hydrogen ions. The p is a symbol chemists use as shorthand for ‘negative log10‘ (it’s p because it comes from the German word for potency or power, potenz, and this might be why some books claim that pH stands for ‘potential hydrogen’, which it doesn’t really).

Log refers to logarithms. I’m not going to explain those in depth here – if you want to know more, this page has a clear explanation – but you will have come across other log scales. Probably the best-known is the one used to describe earthquakes: the Richter scale. Basically when you go up by a factor of 1 on the scale, it’s actually a power of 10. A major would-seriously-damage-buildings earthquake that measures 7 on the Richter scale is 1000 times more powerful than a light crockery-rattling quake that only measures 4. The pH scale is like this: every point on the scale represents ten times more (or fewer, depending on which way you’re going) hydrogen ions.

Slightly counter-intuitively (but the maths works out, honest) a lower pH means more hydrogen ions. An acidic solution with a pH of 2 has 1000 times more free hydrogen ions than one with a pH of 5. The pH scale goes from 14 down to 0, and actually negative pH values are possible as well. Values above 7 are described as alkaline (or basic), 7 itself is neutral and those below 7 are acidic.

Saying that this or that acid has a pH of a specific number (like I sort of did back up there when talking about lemons, remember I started with lemons?) is a bit of a nonsense, although many authors do it. pH refers to the concentration of hydrogen ions. You could get some hydrochloric acid (the stuff in your stomach) and dilute it, and its pH would actually go up. Really. If you drop a bit of lemon juice in a big glass of water its pH would be closer to neutral (pH 7) than 2. If you think about it you know this: drink neat lemon juice and you’re puckering up your lips in a classic ‘sour’ face. Drink some water with a bit of lemon in and you barely notice it.

Phew. Ok. Back to the frankly silly statement that lemons neutralise acid. We’ve established that lemons contain citric acid, and although citric acid is a weak acid, it still is an acid. It produces hydrogen ions when you put it in water, and for that reason the pH of lemon juice – as it comes out of the lemon – is about 2.

If you want to neutralise an acid, you need an alkali (or, more generally, a base). Alkalis contain OH ions (hydroxide ions) which can react with hydrogen ions and actually remove them from a solution, like this:

H+  +  OH  –>  H2O

Look, that’s water on the right hand side of that slightly-wonky arrow. Pure water has a neutral pH of 7. If you add exactly enough hydroxide ions to join up with all the hydrogen ions, you get water (and a salt, because there will have been some other stuff in there as well).

Once you get this far, it becomes fairly obvious that adding more hydrogen ions to hydrogen ions isn’t going to neutralise anything. It’s like trying to turn your blue paint purple by adding more blue paint.

If anything, adding more acid will make your solution even more acidic (although with a weak acid it may not be quite that simple, is it ever?) Again, experience bears this out. Your stomach contains hydrochloric acid, along with some other stuff, and has a pH of between 1.5 and 3.5. Fortunately your stomach is lined with special cells that protect you from this powerful stuff. Acid indigestion, something many of us have experienced at one time or another, happens (usually) when that stomach acid gets where it shouldn’t be, i.e. into your esophagus, where it burns.

If you have indigestion, do you drink lemon juice? No you do not. Not unless you actively like pain, that is. No, you take an indigestion remedy. Guess what they’re made of? Yes, alkalis, or bases (and sometimes other clever ingredients as well). They really do neutralise the excess acid by way of the equation I wrote up there.

And unless you have indigestion, why would you want to ‘neutralise acidity’ anyway? Stomach acid evolved for a reason. It helps to break down your food, proteins in particular, and it also keeps you safe from lots of bacteria and other nasties which usually don’t like acidic conditions. Once your stomach has done its thing the partially-digested food passes into your small intestine where it gets squirted with bile, which actually does neutralise it so it can pass through your intestines without doing any damage.

Your body has this covered. There really is no need to mess with it, and in any case, you can’t really. At least, not beyond your stomach (and urine, possibly – see my comment at the end). Homeostasis insures that everything stays remarkably consistent, and good thing too. There are lots of chemical reactions going on in your body that keep you alive, whether you realise it or not. If you could actually mess with the pH of your blood (pH 7.35-7.45) you’d be in a whole heap of trouble.

So can lemons neutralise acid? No. Can what you eat ‘alkalize’ your blood? (It’s terrifying just how many websites there are about this.) No. Absolutely not. Under no circumstances. If you were to eat a lot of indigestion tablets they would neutralise the acid in your stomach, but that would have no effect on your blood. Literally no effect.

By all means eat a healthy diet. Fruit and vegetables are definitely good for you. Lemons contain vitamin C (yet another acid: ascorbic acid) which is a vital nutrient. Eating them will certainly do you no harm and might well do you some good. But don’t let anyone tell you they’re anything more than a healthy citrus fruit.

Note: 
As you can see, this post has generated a lot of comments. Some more scientific than others.  In particular, a lot of them have focused on urine, and the effect lemon juice might or might not have on urine pH. My original post was not about urine, but clearly a lot of people are fascinated by the subject. Who knew?

So here’s a little extra on that topic to save me repeating myself in comments.

It’s well-known that chemical makeup of urine can be affected by what we eat. We’ve probably all experienced the odd effects of asparagus, or beetroot, or even sugar puffs, so the idea that certain dietary substances make their way into urine is nothing particularly new or surprising.

And following from this it IS possible to affect urine pH by eating or drinking certain substances. For example, if you’re a cystitis sufferer, you might have used a sodium citrate-containing product such as Cymalon. During a cystitis attack the urine becomes more acidic. These products work by creating a buffer effect in the bladder, which means they raise the pH slightly towards neutral and, crucially, stabilise it so that it doesn’t drop again (or, indeed, rise).

Lemons contain citric acid, the salt of which is citrate. So it’s possible eating a lot of lemons (or drinking a lot of lemon juice) could have a similar effect. I found a paper on this very topic. The researchers found that drinking lemon juice produced a small increase in urinary pH from about 6.7 to 6.9. So, ok, it went up a tiny bit (remember that pH 7 is neutral) but given that the error in their measurements was +/- 0.1, that’s virtually no change at all.

That said, the main focus of their interest was actually treatment of kidney stones, which are, in some cases, caused by a build-up of calcium oxalate which then forms crystals. The researchers found that the lemon juice helped the body to get rid of oxalate, and they’re not the only ones to draw this conclusion. Magnesium can also help prevent kidney stone formation (magnesium-rich foods include leafy greens, nuts and seeds, oily fish and whole grains – basically all that ‘healthy diet’ stuff, funnily enough).

So in summary (and I stress, I am not a medical doctor and you should take your GP’s advice over that of some blogger on the internet), if you suffer from kidney stones, lemon juice might be helpful. It certainly won’t do you any harm (well, except possibly to your tooth enamel). A generally healthy diet will also, not surprisingly, be beneficial. Lemon juice might have a very tiny effect on urine pH. However if it does, the result is only to raise the pH a tiny bit closer to pH 7 (i.e. neutral). It does not make your urine alkaline.

The topic of gout has also come up. Vitamin C is known to help with gout. Lemons contain a lot of vitamin C (ascorbic acid, not to be confused with citric acid). If you’re a gout sufferer, drinking lemon juice might help. Although taking a vitamin C supplement might be even better.

None of this in any way relates to the blood, or ‘the body’ in general. You cannot, absolutely cannot, affect your blood pH with your diet, and nor would you want to.

Oh, and buffers seem to come up a lot too. To save time I put all of that in a separate blog post: buffers for bluffers.

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Note: comments have been closed on this post because I found myself repeatedly refuting the same arguments over and over again. One in particular is the notion that lemon juice somehow becomes alkaline once in the body, and that this is why lemons are considered ‘alkaline’. Lemon juice will certainly be neutralised during the digestive process but there is no mechanism by which it could possibly “become alkaline”. Please don’t post comments on other pages in this site to get around the fact that comments have been closed.