Glow sticks or sparklers: which is riskier?

by Unknown artist,print,(circa 1605)

Remember, remember the 5th of November… (Image by Unknown artist, circa 1605)

It’s fireworks night in the UK – the day when we celebrate a small group of terrorists nearly managing to blow up the Houses of Parliament in 1605 by, er, setting fire to stuff. No, it makes perfect sense, honestly, because…. look, it’s fun, all right?

Anyway, logical or not, Brits light fireworks on this day to mark the occasion. Fireworks, of course, are dangerous things, and there’s been more than one petition to ban their sale to members of the general public because of safety concerns. It hasn’t happened yet, but public firework displays, rather than private ones at home, are more and more popular.

Which brings me to this snippet from a letter a friend of mine recently received.


In case you can’t read it, it says:

“NO SPARKLERS PLEASE – with so many children runni[ng] around, we believe it is too dangerous fro children to be [words missing] lighted sparklers around.
Last year we had a few incidents of children drinking the [words missing] glowsticks – please advise against this.”

Now there are some words missing here, but it’s fairly clear that sparklers are prohibited at this event, and it seems to be suggesting that children have managed to get into, and swallow, the contents of glowsticks. But they, by contrast, haven’t been banned. Indeed, parents are merely being asked to “advise” against it.


Does this seem like an appropriate response? Well, let’s see…

1024px-sparklers_moving_slow_shutter_speedWhat are these things? Let’s begin with sparklers. They’re hand-held fireworks, usually made of a stiff metal wire, about 20 cm long, the end of which is dipped in a thick mixture of metallic particles, fuel and an oxidising agent. The metal particles are most commonly magnesium and/or iron. The fuel usually involves charcoal, and the oxidiser is likely to be potassium nitrate. Sometimes metal salts are also added to produce pretty colours.

Sparklers are designed to burn hot and fast. The chemical-dipped end can reach temperatures between 1000-1600 oC, but the bit you hold doesn’t have time to heat up before the firework goes out (although gloves are still recommended). The sparks, likewise, are extremely hot but burn out in seconds. This makes sparklers relatively safe, if they’re held well way from the face and body, and if the hot end isn’t touched.

If. Every year there are injuries. Sparkler injuries aren’t recorded separately from other firework injuries in the UK, but the data we do have suggest we might be looking at a few thousand A&E admissions each year, and probably a lot more minor injuries which are treated at home.

Sparklers are most dangerous once they've gone out.

Sparklers are most dangerous after they’ve gone out.

The biggest danger comes from people, usually children, picking up ‘spent’ sparklers. The burny end takes a long time to cool down, but once the sparkles are finished and it’s stopped glowing it’s impossible to judge how hot it is just by looking.

The burns caused by picking up hot sparklers are undoubtedly very, very nasty, but they’re also relatively easy to avoid. Supply buckets of cold water, and drill everyone to put their spent sparklers into the buckets as soon as they go out. Hazard minimised. Well, assuming everyone follows instructions of course, which isn’t always a given. Other risks are people getting poked with hot sparkers – which can be avoided by insisting sparkler-users stand in a line, facing the same way, with plenty of space in front of them – and people lighting several sparklers at once and getting a flare. Again, fairly easily avoided in a public setting, where you can threaten and nag everyone about safety and keep an eye on what they’re doing.

Although I do understand the instinct to simply ban the potentially-dangerous thing, and thus remove the risk, the idea does worry me a little bit. I was born in the 70s and I grew up with fire. I remember the coal truck delivering coal to us and our neighbours. I was taught how to light a match at an early age, and cautioned not to play with them (and then I did, obviously, because in those days it was usual for kids to spend hours and hours entirely unsupervised – but fortunately I emerged unscathed). Pretty much everyone kept a supply of candles in a drawer, in case the lights went out. And bonfires were a semi-regular event – this being long before garden waste collections.

These days things are very different. It’s not unusual to meet a child who, by age 11, has never lit a match. If their home oven and hob are electric, they may never have seen a flame outside of yearly birthday cake candles. But so what? You may be thinking. Aren’t fewer burns and house fires a good thing?

Of course they are, but people who’ve never dealt with fire tend to panic when faced with it. If the only flame you’ve ever met is a birthday cake candle, your instinct might well be to blow when faced with something bigger. This can be disastrous – it can make the fire worse, and it can spread hot embers to other nearby flammable items.

I’m personally of the opinion that children ought to be taught to handle fire safely, how to safely extinguish a small fire, when to call in the experts, and not to disintegrate into hysterics the presence of anything warmer than a cup of tea. Sparklers, I think, can be part of that. Particularly if they’re used in a well-supervised setting, with plenty of safety measures and guidance on-hand. (As opposed to, say, picking them up for the first time at university with some drunk mates, setting fire to half a dozen at once and immediately dropping them.)

Now. Onto glowsticks. They’re pretty neat, aren’t they? We’ve already established that I’m quite old, and I remember these appearing in shops for the first time, sometime in the very early 90s, and being utterly mesmerised by that eerie, cold light.


Diphenyl oxalate (trademark name Cyalume)

They work thanks to two chemicals. Usually, these are hydrogen peroxide (H2O2 – also used to bleach hair, as a general disinfectant, and as the subject of a well-known punny joke involving two scientists in a bar) and another solution containing a phenyl oxalate ester and a fluorescent dye.

These two solutions are separated, with the hydrogen peroxide in a thin-walled, sealed glass vial which is floating in the mixture of ester and dye solution. The whole thing is then sealed in a tough, plastic coating. When you bend the glowstick the glass breaks, the chemicals mix, and a series of chemical reactions happen which ultimately produce light.

How Light Sticks work (from - click image for more)

How Light Sticks work (from – click image for more)

Which is all very well. Certainly nice and safe, you’d think. Glowsticks don’t get hot. The chemicals are all sealed in a tube. What could go wrong?

I thought that too, once. Until I gave some glowsticks to some teenagers and they, being teenagers, immediately ripped them apart. You see, it’s actually not that difficult to break the outer plastic coating, particularly on those thin glow sticks that are often used to make bracelets and necklaces. Scissors will do it easily, and teeth will also work, with a bit of determination.

How dangerous is that? Well… it’s almost impossible to get into a glowstick without activating it (the glass vial will break), so it’s less the reactants we need to worry about, more the products.

And those are? Firstly, carbon dioxide, which is no big deal. We breathe that in and out all the time. Then there’s some activated fluorescent dye. Now, these vary by colour and by manufacturer, but as a general rule they’re not something anyone should be drinking. Some fluorescent dyes are known to cause adverse reactions such as nausea and vomiting, and if someone turns out to be allergic to the dye the consequences could be serious. This is fairly unlikely, but still.

Another product of the chemical reactions is phenol, which is potentially very nasty stuff, and definitely not something anyone should be getting on their skin if they can avoid it, let alone drinking.

Inside every activated glowstick are fragments of broken glass.

Inside every activated glowstick are fragments of broken glass.

And then, of course, let’s not forget the broken glass. Inside every activated glowstick are fragments of broken glass – it’s how they’re designed to work. If you break the plastic coating, that glass is exposed. If someone drinks the solution inside a glow stick they could, potentially, swallow that glass. Do I need to spell out the fact that this would be a Bad Thing™?

The thing with hazards is that, sometimes, something that’s obviously risky actually ends up being pretty safe. Because people take care over it. They put safety precautions in place. They write risk assessments. They think.

Whereas something that everyone assumes is safe can actually be more dangerous, precisely because no one thinks about it. How many people know that glowsticks contain broken glass, for instance? Probably not the writer of that letter back there, else they might have used stronger language than “please advise against this.”

So glowsticks or sparklers? Personally, I’d have both. Light on a dark night, after all, is endlessly fascinating. But I’d make sure the sparkler users had buckets of water, cordons and someone to supervise. And glowstick users also ought to be supervised (at least by their parents), warned in the strongest terms not to attempt to break the plastic, and all efforts should be made to ensure that the pretty glowy things don’t fall into the hands of a child still young enough to immediately stuff everything into his or her mouth.

The most important thing about managing risks is not to eliminate every potentially hazardous thing, but rather to understand and plan for the dangers.

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What IS a chemical?


You at the back there! Get your nose out of that dictionary and pay attention!

What do we mean when we use the word “chemical”? It seems like a simple enough question, but is it, really? I write about chemicals all the time – in fact my last WhatCulture article was about just that – and I’ve mentioned lots of different definitions before. But I’ll be honest, some of them have bothered me.

I don’t often like the definitions you find in dictionaries. Lexicography and chemistry don’t seem to be common bedfellows, and dictionary compilers haven’t, generally speaking, spent their formative years being incessantly nagged by weary chemistry teachers about their choice of vocabulary.

For example, in the Cambridge Dictionary we find:
any basic substance that is used in or produced by a reaction involving changes to atoms or molecules.”

Hm. Firstly, “basic” has a specific meaning in chemistry. Obviously the definition doesn’t mean to imply that acids aren’t chemicals, but it sort of accidentally does. Then there’s the implication that a chemical reaction has to be involved. So inert substances aren’t chemicals? Admittedly, “used in” doesn’t necessarily imply reacts – it could be some sort of inert solvent, say – but, again, it’s bothersome. Finally, “atoms or molecules”. Ionic substances not chemicals either, then?

Yes, it’s picky, but chemists are picky. Be glad that we are. A misplaced word, or even letter, on a label could have serious consequences. Trust me, you do not want to mix up the methanol with the ethanol if you’re planning cocktails. Similarly, fluorine is a whole other kettle of piranhas compared to fluoride ions. This stuff, excuse the pun, matters.

Dictionary definitions have their problems.

Dictionary definitions have their problems.

Let’s look at some more definitions (of the word as a noun):

The Free Dictionary tells us that a chemical is:
“A substance with a distinct molecular composition that is produced by or used in a chemical process.”

Merriam Webster says:
“of, relating to, used in, or produced by chemistry or the phenomena of chemistry <chemical reactions>”

And goes with the simple:
“a substance produced by or used in a chemical process.”

That idea that a chemical reaction must be involved somehow seems to be pervasive. It’s understandable, since that’s the way the word is mostly used, but it’s not really right. Helium, after all, is still very much a chemical, despite being stubbornly unreactive.

Possibly the best of the bunch is found in the Oxford Living Dictionary:
“A distinct compound or substance, especially one which has been artificially prepared or purified.”

Not bad. Well done Oxford. No mention of chemical reactions here – it’s just a substance. We do most often think of chemicals as things which have been “prepared” somehow. Which is fair enough, although it can lead to trouble. In particular, ridiculous references to “chemical-free” which actually mean “this alternative stuff is naturally-occurring.” (Except of course it often isn’t: see this article about baby wipes.) The implication, of course, is that thing in question is safe(r), but there are lots and lots of very nasty chemicals in nature: natural does not mean safe.

You keep using that word. I do not think it means what you think it means.

Sometimes people will go the other way and say “everything is chemicals.” We know what this means, but it has its problems, too. Light isn’t a chemical. Sound isn’t a chemical. All right, those are forms of energy. What about neutrinos, then? Or a single proton? Or a single atom? Or, going the other way, some complicated bit of living (or once living) material? In one debate about this someone suggested to me that a “chemical was anything you could put in a jar,” at which point I pedantically said, “I keep coffee in a jar. Is that a chemical?” Obviously there are chemicals in coffee, it works from the “everything is chemicals” perspective, but it’s a single substance that’s not a chemical.

Language is annoying. This is why chemists like symbols and numbers so much.

Anyway, what have we learned? Firstly, something doesn’t necessarily have to be part of a chemical reaction to be a chemical. Secondly, we need to include the idea that it’s something with a defined composition (rather than a complex, variable mixture, like coffee), thirdly that chemical implies matter – light, sound etc don’t count, and fourthly that it also implies a certain quantity of stuff (we probably wouldn’t think of a single atom as a chemical, but collect a bunch together into a sample of gas and we probably would).

So with all that in mind, I think I shall go with:

So what IS a chemical?

A chemical is…

(Drum roll please….)

Any substance made of atoms, molecules and/or ions which has a fixed composition.

I’m not entirely convinced this is perfect, but I think it more or less works.

If you have a better idea, please do comment and let me know!

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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.

This is my first article for WhatCulture Science – please do click the link and read the rest!

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I love my naturally-occurring pesticide


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99.99%, by weight, of all the pesticides we consume are naturally-occurring.

That’s a pretty amazing statement, isn’t it? It comes from a paper about dietary pesticides that was published in 1990, and referred to the American diet, but it’s almost certainly still not far from the truth – pesticide use, despite what some of the crazier corners of the internet will tell you – hasn’t increased significantly in the last 26 years. The authors of the paper concluded that “the comparative hazards of synthetic pesticide residues are insignificant” and it’s a valid point. Many of these natural pesticides – chemicals which plants use to defend themselves – have never been fully tested, and some of them are actually well-known toxins.

Plants have been on this planet for a very long time, 700 million years give or take, which means they’ve had an awful lot of time to evolve defences. Some of these are physical, like thorns or spines, but chemistry plays a key role.

For example, one of the most common toxins is solanine. It turns up in potatoes which, as any good gardener will tell you, are part of the nightshade family. Yep, like deadly nightshade. But don’t panic, it’s mostly in the parts of the plant we don’t eat, namely the leaves and stems, with only very small amounts found in the skin and virtually none in the flesh.



Unless, that is, your potatoes are exposed to light. Then the tubers start producing lots of extra solanine (and another alkaloid called chaconine), as a defence to stop the uncovered tuber from being eaten. At the same time, they produce extra chlorophyll, which causes them to turn green. The chlorophyll is harmless, but the solanine most definitely is not. It causes vomiting and diarrhoea, and can even be fatal – although this is really only a risk for people who are undernourished. Still, if your potatoes have turned green its safest to throw them out, since cooking doesn’t break the toxins down. Even if they’re not green, if they have a bitter taste it’s safest to get rid of them if you don’t want to risk an extended visit to the porcelain throne.

But solanine is just the tip of the lettuce. Capsaicin (the stuff in chillies) also evolved as a defence mechanism to repel and kill insects, and there’s evidence that it may be carcinogenic under some circumstances. 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) is another chemical which is found in corn, wheat, rye and other grasses and which has been shown to cause carcinogenic changes in human cell lines. Then there are all the various substances in herbs and spices, such as tetradecanoic acid in nutmegpulegone in peppermint, carvacrol in oregano and eugenol in cloves, nutmeg and basil.

But not to panic. None of these chemicals are dangerous in the quantities that we usually consume them. And neither, while we’re here, are the really teeny, tiny amounts of synthetic pesticides that we might be exposed to. So just relax and eat your greens. Well, not if they’re potatoes. You know what I mean.

Anyway, there’s one substance I haven’t mentioned yet, and it’s a biggie – it’s something most of us consume on a regular basis. In fact, it might be the source of over a gram of naturally-occurring pesticide a day, and few of us even give it a thought.

What is it? Coffee. Yes, your daily dose of americano is a veritable cocktail of chemicals. As the dietary pesticides paper points out, “13 g of roasted coffee per person per day contains about 765 mg of chlorogenic acid, neochlorogenic acid, caffeic acid, and caffeine.” A single espresso shot uses about 8 grams of ground coffee, so a mere two shots will take you up to best part of a gram of chemically-goodness, and who restrains themselves to two shots a day?

But there’s good news. Some of these substances could actually be beneficial. Chlorogenic acid appears to moderately lower blood pressureNeochlorogenic acid might actually help to prevent certain cancers, as might caffeic acid (although results are mixed in this case).


The world’s most widely-consumed psychoactive drug.

And then, of course, there’s caffeine itself – the world’s most widely consumed psychoactive drug. It has umpteen (technical term) effects not the body, both positive and negative, the most famous being its ability to keep us alert and awake. It’s performance-enhancing and its use was at one point restricted for Olympic athletes, until 2004 when officials decided to remove those restrictions – presumably because they were proving impossible to enforce.

But caffeine didn’t evolve for the convenience of humans, although we have, of course, played our part in farming and selectively-breeding plants. No, it originally evolved to paralyse and kill predator insects. Basically, to stop the plant being eaten which, from the plant’s point of view, is quite important. Interestingly, there’s evidence that it evolved separately in coffee, tea and cacao, suggesting it really is a pretty advantageous thing for a plant to make. But in case you’re wondering, it’s broken down by UV light, which explains why it’s not used as an insecticide spray on other plants.

So, if you’re worrying about pesticides with a cup of coffee in your hand, you can stop. You’re probably consuming more pesticide, daily, than you will get from carrots in your lifetime. Drink up!


Do you love your naturally-occurring pesticide?

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MMS and CD chemistry – the facts

The TL:DR version.

The TL:DR version.

About a year ago I wrote a post on the subject of MMS and CD. Many people have since praised that post, but others have complained that it’s rather long (it is) and contains too much opinion.

I believe that anyone that wants them should have easy access to the facts on this subject, and not just the information provided by proponents of MMS/CD use.

With this in mind I’ve written this post as a summary of the basics. I ask only that you credit me if you use this to write an article. A mention of my Twitter account, @chronicleflask, or a link to this page will suffice.

What is MMS?


MMS is usually sold as water purification drops

MMS stands for ‘master mineral solution’ or sometimes ‘miracle mineral solution’. It is a 22.4% solution of sodium chlorite in water. Sodium chlorite has the chemical formula NaClO2. So, MMS is 22.4 grams of NaClO2 dissolved in 100 mls of water. Sodium chlorite/MMS does not, on its own, act as a bleach.

Sodium chlorite’s LD50 (for rats) is 350 mg/kg. This means that, on average, if you feed rats 350 mg of it per kg of body weight, half the rats will die. If we assume its toxicity is similar in humans (and there’s no reason it should not be) that means that 5.25 grams would probably be enough to kill an average 4-year-old child weighing about 15 kg.

MMS is usually sold as ‘water purification drops’. Search for ‘sodium chlorite water purification’ in Google and you will quickly find it (usually alongside an ‘activator’ solution). Bottles for sale are usually 4 oz, or 114 mls. One quarter of one of these bottles would probably be lethal to a 15 kg 4-year-old.

What is CD (or CDS)?

CD is chlorine dioxide (and CDS stands for chlorine dioxide solution). Chlorine dioxide is ClO2. It is a bleach, used industrially to bleach wood pulp. It is also used to purify water and kill pathogens on certain foodstuffs. It is considered more effective than plain chlorine for water purification – it’s less corrosive and is particularly good at destroying legionella bacteria, as well as many viruses and protozoa.

Chlorine dioxide is more toxic than sodium chlorite. It’s LD50 is 292 mg/kg (the lower the number, the more toxic something is). For this reason, the concentrations used in food/water applications are very low. The US Environmental Protection Agency have set a maximum level of 0.8 mg/L chlorine dioxide in drinking water. That’s 0.00008 grams per 100 ml of water.

What’s the connection between MMS and CDS?

The chemistry of sodium chlorite (the substance in MMS) with acids.

The chemistry of sodium chlorite (the substance in MMS) with acids.

Chlorine dioxide evaporates quickly from solution, which means CD solutions cannot be stored – they have be made freshly as they’re needed. When sodium chlorite is mixed with an acid, usually citric acid (the acid in oranges and lemons), it forms chlorine dioxide. In short:
MMS + acid = CDS.

The chemistry behind this is complicated. It’s simpler if the acid used is hydrochloric acid (HCl), and this particular method of ‘activation’ is sometimes recommended by proponents of MMS/CD use.

If sodium chlorite is mixed with citric acid is used the reaction doesn’t happen in one step. Rather, chlorous acid (HClO2) forms, which ultimately breaks down to form ClO2. Several reactions are involved in this process. The concentration of chlorine dioxide in a solution made in this way is likely to be lower than if hydrochloric acid is used. However, it’s important to realise the the resulting solution is a mixture of harmful substances. Less chlorine dioxide does not necessarily mean safer.

How much chlorine dioxide forms when MMS is ‘activated’?

It’s not possible to answer this precisely, because it depends on several different factors. To begin with, it depends on whether hydrochloric acid or another acid (such as citric acid) is used. It further depends on temperature, and how much acid is added. We have no way of knowing exactly what someone mixing up these solutions at home is doing.

A document on acidified sodium chlorite published by the Joint Expert Committee on Food Additives (JECFA) suggests that, at a pH of 2.3, a 50 ppm solution of sodium chlorite would produce 16 ppm chlorous acid (less at higher pHs). Starting with a 22.4% solution (as in MMS), and allowing for the stoichiometry suggested by the equations above, this could produce something in the region of 36 g of chlorine dioxide per litre of water.

The US EPA’s recommended safe limit for chlorine dioxide is 0.00008 grams per litre of water. Compare this to 36 grams per litre. Even if only a fraction is converted to chlorine dioxide, the resulting mixture is likely to be tens of thousands in excess of safe limits.

How are CD solutions used in food & drink production?

Very dilute solutions, with just a few ppm of chlorine dioxide, are used as sprays or dipping solutions for poultry, meats, vegetables fruit and seafood. However, in these applications the chlorine dioxide evaporates from the food long before anyone eats it – it’s not present in the final food product. Chlorine dioxide is also used in water treatment plants, but the concentration in the final water supply is strictly controlled so that it’s less than the recommended safe limits.

How are CD solutions used as ‘alternative treatments’?

There are groups of people who believe that drinking CD solutions, or using them to perform enemas can cure any and all diseases, illnesses and conditions. However, there is no evidence that CDS is at all efficacious, and no reasonable mechanism has ever been given for its supposed mode of action. Jim Humble, who coined the name MMS ten years ago and sparked the use of these ‘treatments’, claimed that he worked with the Red Cross to successfully treat a group of malaria patients in Uganda. The Red Cross strenuously deny these claims. Other commentators have explained very clearly why Humble’s claims are impossible.

There is a large group online, led by Kerri Rivera, who believe that CD solutions can cure autism. This is not true. Autism is a neurodevelopment disorder. There is no cure, although certain therapies may help those on the autistic spectrum to manage better in day-to-day life. The cause of autism is unclear, but it appears to have a strong genetic basis.

Humble and Rivera advocate drinking CD solutions and/or using them in enemas. Protocols for such treatments involve adding drops of CDS to water, milk or other liquids.

The number of drops used varies. Humble reportedly used 18 drops at a time in his malaria treatment. Usually this is added to further liquid, for example in a 250 ml bottle. Assuming a drop is 0.1 mls, this could be as much as 0.065 g of chlorine dioxide in 250 mls, or 0.26 grams per litre. Once again, US EPA’s recommended safe limit for chlorine dioxide is 0.00008 grams per litre.

The amounts recommended by MMS/CD protocols are likely to be at least 3000 times safe limits, and may be considerably more. Protocols exist which recommend drinking these mixtures every one or two hours, eight times a day or even more.

What would happen if someone drank a CD solution?

It would be ironic if it weren't so tragic.

Chlorine dioxide exposure may actually cause delays in the development of the brain.

It would depend on the concentration. The very low levels used in normal water purification are not be harmful (that’s why safe limits exist), however drinking large amounts (such as those usually recommended in MMS/CD protocols) would cause irritation to the mouth, oesophagus, and stomach. There is no evidence that chlorine dioxide causes cancer. The ATSDR‘s (Agency for Toxic Substances and Disease Registry) entry for chlorine dioxide says that “studies in rats have shown that exposure of pregnant animals to chlorine dioxide or exposure of pups shortly after birth can cause delays in the development of the brain” (see also PMID: 2213920).

Why are CDS enemas used, and what would be the effect?

Rivera in particular advocates CDS enemas to kill the ‘parasites’ which she and her followers believe cause autism. There is no evidence for the existence of these ‘parasites’. Photos published online which purport to show them have been condemned as actually showing intestinal lining and mucus, excreted as the direct result of harsh enema procedures.

Enemas, regardless of the liquid used, have risks. Repeated enemas can cause electrolyte imbalance, rupture of the bowel and damage to the rectal tissues. Enemas with CDS are likely to be particularly dangerous since it is corrosive. Proponents of CDS use claim it is ‘selective’ and only kills ‘harmful’ bacteria and parasites. This is not possible; chlorine dioxide is a strong oxidising agent and damages all cells it comes into contact with, regardless of the nature of those cells.

Children have thinner tissues than adults. The risks of regular enemas, particularly with a corrosive agent such as chlorine dioxide, and particularly when carried out at home by someone with no medical training, are likely to be considerably higher for children.

Is there any way to tell if someone has been using CDS in high concentrations?

Unless someone admits to using CDS, there isn’t really any way to tell. For this reason there are very few reported cases of harm caused by CDS, as users tend to be extremely secretive. Unless an enema causes major trauma (which is a real risk) the symptoms are likely to be fairly vague gastrointestinal distress, which could be caused by any number of other things. There is no routine medical test to measure chlorine dioxide or chlorite in the body. There is a special test to measure chlorite in tissues, blood, urine, and feces, but the test cannot tell the extent of the exposure or whether harmful effects will occur. This test wouldn’t be performed unless exposure was expected. In other words, unless someone admits to using CDS on themselves or their child, it’s unlikely anyone will ever find out.

Has MMS/CDS been in the news?

Yes, on several occasions:

If there’s no cure for autism/cancer/some other condition, mightn’t it be worth trying…?

Medicine is all about risks vs. benefits. The benefit of using a particular treatment must always exceed the risk of using that treatment. In this case, there are no proven benefits of using MMS/CDS. There are considerable risks, as described above. The only thing MMS/CDS will do is make you feel sick and generally more unwell than you (or your child) might already. So no, it isn’t worth trying. Please don’t.


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Puzzling pool problems?

We’re half way thorough the Rio 2016 Olypics, and it will have escaped no one’s notice that there have been a few little problems with one of the pools.

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

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

First, the water turned a mysterious green colour. Then there were reports of a ‘sulfurous’ smell, with German diver Stephan Feck reported as saying it smelled like a “fart”.

The diving pool seemed to be the worst affected, but the water-polo pool next to it also suffered problems, and competitors complained of stinging eyes.

So what on earth was happening? An early suggestion was that copper salts were contaminating the water. It’s not unheard of for copper compounds to get into water supplies, and it would certainly explain the colour; copper chloride solutions in particular are famously greeny-blue. But what about that sulfurous smell? Copper chloride doesn’t smell of sulfur.

Was the strange pool colour due to algae bloom?

Was the strange pool colour due to an algae bloom, like this one in Lake Erie?

The most likely culprit was some sort of algae bloom – in other words rapid algae growth – with the smell probably coming from dimethyl sulfide, or DMS. There’s a singled-celled phytoplankton called Emiliania huxleyi which is particularly famous for producing this smelly compound. In fact, it actually has more than one very important role in nature: the smell is thought to alert marine life that there’s food nearby, but it also seeps into the atmosphere and helps with cloud formation, helping to control our planet’s temperature. Without these reactions, Earth might not be nearly so habitable.

But how did algae manage to grow in the pool? The pool chemicals should have prevented it, so what had happened? An Olympic official then went on to make the comment that “chemistry is not an exact science,” which of course led to much hilarity all around. Chemistry is, after all, incredibly exact. What chemistry student doesn’t remember all those calculations, with answers to three significant figures? The endless balancing of equations? The careful addition of one solution to another, drop by drop? How much more ‘exact’ would you like it to be?

But I had a bit of sympathy with the official, because I suspect that what they actually meant – if not said – was that swimming pool chemistry is not an exact science. And while that, too, is hardly accurate, it is true that swimming pool chemistry is very complicated and things can easily go wrong, particularly when you’re trying to work on an extremely tight schedule. They could hardly, after all, close down all the pools and spend several days carrying out extensive testing in the middle of the sixteen-day-long Olympic Games.

Rio 2016 Olympics Aquatics Stadium (Image: Myrtha Pools)

Rio 2016 Olympics Aquatics Stadium (Image: Myrtha Pools)

When a pool is first built and filled, things are, theoretically, simple. You know exactly how many cubic litres of water there are, and you know exactly how much of each chemical needs to be added to keep the water free of bacteria and other nasties. Those chemicals are added, possibly (particularly in a pool this size) via some kind of automated system, and the pH is carefully monitored to ensure the water is neither too alkaline (basic) nor too acidic.

There’s a certain amount of proprietary variation of swimming pool chemicals, but it essentially all comes down to chlorine, which has been used to make water safe now for over 120 years.

Originally, water was treated to make it alkaline and then chlorine gas itself was added. This produced compounds which killed bacteria, in particular sodium hypochlorite, but the practice was risky. Chlorine gas is extremely nasty stuff – it has, after all, been used as a chemical weapon – and storing it, not to mention actually using it, was a dangerous business.

However, hundreds of people swimming in untreated water is a recipe for catching all kinds of water-borne disease, so it wasn’t long before alternatives were developed.

The Chemistry of Swimming Pools (Image: Compound Interest - click for more info)

The Chemistry of Swimming Pools (Image: Compound Interest – click graphic for more info)

Those alternatives made use of the chemistry that was happening anyway in the water, but  allowed the dangerous bit, with the elemental chlorine, to happen somewhere else. And so hypochlorite salts began to be manufactured to be used in swimming pools.

As the lovely graphic from Compound Interest illustrates, sodium hypochlorite reacts with water to form hypochlorous acid, which in turn goes on to form hypochlorite ions. These two substances sit in an equilibrium, and both are oxidants, which is good because oxidants are good at blasting bacteria. The equilibria in question are affected by pH though, which is one reason why, quite apart from the potential effects on swimmers, it’s so important to manage the pH of pool water.

There are a couple of different chemicals which can be added to adjust pH. Sodium bicarbonate, for example, can be used to nudge the pH up if needed. On the other hand, sodium bisulfate can be used to lower pH if the water becomes too alkaline.

Open-air pools have particular problems

UV light breaks down the chemicals that are used to keep swimming pool water clean.

This can all be managed extremely precisely in an unused, enclosed pool. But once you open that pool up, things become less simple. Open-air pools have a particular problem with UV light. Chlorine compounds are often sensitive to UV – this is why CFCs are such a problem for the ozone layer – and hypochlorite is no exception. In the presence of UV it breaks down in a process called photolysis to form chloride ions and oxygen. This means that outdoor pools require more frequent treatments, or the addition of extra chemicals to stabilise the ‘free available chlorine’ (FAC) levels.

Sadly, I haven’t managed to make it over to Rio, but from what I’ve seen the Aquatic Centre has a roof which opens up, which means that the pool water is indeed being exposed to UV light.

So perhaps the chemical levels simply dropped too low, which allowed algae to proliferate? Possibly aggravated by environmental conditions? Indeed, initially this seemed to be the explanation. FINA, the international governing body of aquatics, issued a statement on Wednesday afternoon which said:

“FINA can confirm that the reason for the unusual water color observed during the Rio diving competitions is that the water tanks ran out of some of the chemicals used in the water treatment process. As a result, the pH level of the water was outside the usual range, causing the discoloration. The FINA Sport Medicine Committee conducted tests on the water quality and concluded that there was no risk to the health and safety of the athletes, and no reason for the competition to be affected.”

This prompted people to wonder how on earth chemical levels were allowed to run out in an event as significant as the Olympics – did someone forget to click send on the order? – but still, it seemed to explain what had happened.

FINA issued a new statement

FINA issued a new statement on Sunday

Until today (Sunday), when more information surfaced as Olympic officials announced that they were going to drain at least one of the swimming pools and refill it. This is no small feat and will involve considerable cost: after all, we’re talking about millions of gallons of water. But it seems to be necessary. As Rio 2016’s director of venue management Gustavo Nascimento said:

“On the day of the Opening Ceremonies of the Games, 80 litres of hydrogen peroxide was put in the water. This creates a reaction to the chlorine which neutralises the ability of the chlorine to kill organics. This is not a problem for the health of anyone.”

Whoops. Yes indeed. Hydrogen peroxide reacts with chlorine to produce oxygen and hydrochloric acid. In fact, hydrogen peroxide is actually used to dechlorinate water which contains levels of chlorine that are too high. It might not be the very worst thing you could add to the water (when you think of all the things that could end up swimming pools) but it’s definitely up there.

Why and how this happened doesn’t, at the moment, appear to be clear. Presumably someone is for the high jump, and not just on the athletics field.

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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?!


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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