Tag Archives: safety

Onerous ovens: why is cleaning the cooker such a chore?

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As I write Thanksgiving was a few days ago, when most Americans traditionally cook a very large meal based around roasted turkey. Most Brits – and other countries of course – have the same thing coming up soon in the form of Christmas, and there are lots of other celebrations around this time of year that seem to feature cooking and food quite heavily.

Whatever your traditions, then, it’s a time when many of us frown critically at the dark, sticky depths of our oven and wonder if, perhaps, we should attempt to give it a clean. Or at least pay someone else to come and clean it.

Why is oven cleaning such a difficult and unpleasant job, anyway? It’s not that hard to clean other surfaces, is it? Why are ovens so particularly awful?

Well, to explain this, we first need to understand fats.

Fats vaporise during cooking.

Most of the grime in your oven is fat, combined with the carbonised remains of… something or other. The sorts of fats that are common in animal and plant products have boiling points around the 300 oC mark (animal fats typically having higher values than plant oils), but they start to form vapours at much lower temperatures, and certainly at typical cooking temperatures there’s plenty vaporised oil around. Besides, under typical conditions most oils will “smoke” – i.e. start to burn – long before they get close to boiling.

We’re all familiar with the idea that fats don’t mix well with water, and herein lies the problem: all that fatty gloop that’s stuck to the inside of your oven just doesn’t want to come off with standard cleaning methods, particularly when it’s built up over time.

Can chemistry help us here? What are fats, chemically? Well, they’re esters. Which may or may not mean anything to you, depending on how much chemistry you can remember from school. But even if you don’t remember the name, trust me, you know the smell. In particular, nail polishes and nail polish removers contain the simple ester known as ethyl acetate, otherwise known as ethyl ethanoate. (Some people say this chemical smells like pear drops which… only really helps if you know what pear drops smell like. Look, it smells of nail polish, okay?)

Fats are esters (image source)

Anyway, the point is that esters have a particular sequence of atoms that has a carbon bonded to an oxygen, which is bonded to another carbon, which is in turn double-bonded to oxygen. This is a bit of a mouthful, so chemists often write it as COOC. In the diagram here, oxygen atoms are red while carbon atoms are black.

There are actually three ester groups in fat molecules – which explains why fats are also known as triglycerides.

In terms of general chemistry, esters form when a carboxylic acid (a molecule which contains a COOH group) reacts with an alcohol (a molecule that contains an OH group). And this is where it all starts to come together – honest – because you’ve probably heard of fatty acids, right? If nothing else, the words turn up in certain food additive names, in particular E471 mono- and diglycerides of fatty acids, which is really common in lots of foods, from ice cream to bread rolls.

Glycerol is a polyol — a molecule that contains several alcohol groups (image source)

Well, this reaction is reversible, and as a result fats (which are esters, remember) break up into fatty acids and glycerol – which is a polyol, that is, a molecule with several alcohol groups. Or, to look at it the other way around: fats are made by combining fatty acids with glycerol.

And the reason it’s useful to understand all this is that the way you break up esters, and therefore fat, is with alkalis. (Well, you can do it with acid, too, but let’s not worry about that for now.)

Strong alkalis break up fats in a chemical reaction called hydrolysis — the word comes from the Greek for water (hydro) and unbind (lysis) and so literally means “split up with water”. Humans have known about this particular bit of chemistry for a long time, because it’s fundamental to making soap. As I said a few months ago when I was banging on about hand-washing, the ancient Babylonians were making soap some 4800 years ago, by boiling fats with ashes – which works because alkaline compounds of calcium and potassium form when wood is burnt at high temperatures.

The grime in ovens is mostly fat.

The really clever thing about all this is that two things are happening when we mix alkali with fat: not only are we breaking up the fat molecules, but also the substances they break up into are water-soluble (whereas fats, as I said at the start, aren’t). Which makes them much easier to clean away with water. Obviously this is the very point of soap, but it’s also handy when trying to get all that baked-on gunk off your oven walls.

Now, in theory, this means you could get some lye (aka sodium hydroxide, probably), smear it all over your oven and voilà. But I don’t recommend it, for a few reasons. Firstly, it’s going to be difficult to apply, since sodium hydroxide is mostly sold as pellets or flakes (it’s pretty easy to buy, because people use it to make soap).

Sodium hydroxide, sometimes called lye, is often sold in the form of pellets.

But, you say, couldn’t I just dissolve it in water and spray or spread it on? Yes, yes you could. But it gets really, really hot when you mix it with water. So you need to be incredibly careful. Because, and this is my next point, chemically your skin is basically fat and protein, and this reaction we’re trying to do on oven sludge works equally well on your skin. Only, you know, more painfully, and with scarring and stuff. In short, if you’re handing lye, wear good nitrile on vinyl gloves and eye protection.

Actually, regardless of how you’re cleaning your oven you should wear gloves and eye protection, because the chemicals are still designed to break down fats and so… all of the above applies. It’s just that specially-designed oven cleaners tend to come with easier (and safer) ways to apply them. For example, they might come as a gel which you can paint on, and/or with bags that you can put the racks into, and may also be sold with gloves and arm protectors (but rarely goggles – get some separately). They might also have an extra surfactant, such as sodium laureth sulfate, added to help with breaking down grease. The main ingredient is still either potassium hydroxide or sodium hydroxide, though.

Well, possibly, but also not really, if you’re sensible.

As an aside, it makes me smile when I come across an article like this which talks about the “serious” chemicals in oven cleaners and more “natural” ways to clean your oven. The “natural” ways are invariably weak acids or alkalis such as lemon juice or baking soda, respectively. They’re essentially ineffective ways of trying to do exactly the same chemistry.

And okay, sure, the gel and the bag and so on in the modern kits are newer tech, but the strong alkali? Nothing more natural than that. As I said at the start, humans have literally been using it for thousands of years.

A point which really cannot be repeated enough: natural does not mean safe.

Fumes can be irritating to skin, eyes and lungs.

Speaking of which, you will get fumes during oven cleaning. Depending on the exact cleaning mixture involved, these will probably be an alkaline vapour, basically (haha) forming as everything gets hot. Such vapour is potentially irritating to skin, eyes and lungs, but not actually deadly toxic. Not that I recommend you stick your head in your freshly-scrubbed oven and inhale deeply, but you take my point. It might give food a soapy, possibly bitter (contrary to what’s stated in some text books, not all alkalis taste bitter, but do not experiment with this) taste if you really over-do it.

In short, if you’re cleaning your oven yourself: follow the manufacturer’s instructions, make sure your kitchen is well-ventilated, leave the oven door open for a while after you’ve finished and, to be really sure, give all the surfaces an extra wash down with plenty of water.

Put the cleaning off until January – after all, the oven’s only going to get dirty again.

And that’s… it, really. Whether you’re cleaning your own oven or getting someone else to do it for you, the chemistry involved is really, really old. And yes, the chemicals involved are hazardous, but not because they’re not “natural”. Quite the opposite.

Or you could just leave it. I mean, it’s only going to get dirty again when you cook Christmas dinner, right?

If you’re studying chemistry, have you got your Pocket Chemist yet? Why not grab one? It’s a hugely useful tool, and by buying one you’ll be supporting this site – it’s win-win! If you happen to know a chemist, it would make a brilliant stocking-filler! As would a set of chemistry word magnets!

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Refilling bottles: why it may not be as simple as you thought

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Two years or so ago most of us had given relatively little thought to single-use plastics. We bought things, we used things, we put the packaging in the bin. Possibly the recycling bin. Hopefully the right recycling bin. And we thought no more about it.

Then Blue Planet II aired on BBC One, specifically episode 7, and suddenly everyone was obsessed with where all this plastic was ending up. Rightly so, since it was clearly ending up in the wrong places, and causing all sorts of havoc in the process.

People started buying reusable cups, eschewing plastic straws and demanding the option of loose fruit and vegetables in supermarkets. Wooden disposable cutlery, oven-cook food containers, and bamboo straws became increasingly common.

And people started to ask more questions about refilling containers. Why do I need a new bottle each time I buy more shampoo or washing up liquid or ketchup, they asked. Why can’t we just refill the bottle? For that matter, couldn’t I take a container to the shop and just… fill it up?

Infinity Foods allow customers to refill containers.

Shops started to offer exactly that. One such place was Infinity Foods, based in Brighton in the UK. Actually, they’d always taken a strong line when it came to recycling and reducing waste, and had been offering refills of some products for years.

Where this gets interesting from a chemistry point of view is a Facebook post they made at the beginning of this month. It said, from the 1st of November, “your empty bottle can only be refilled with the same contents as was originally intended. This includes different brands and fragrances.”

Naturally this spawned lots of comments, many suggesting the change was “daft” and saying things like “I bet it is major corporations not wanting us to reuse the bottle.”

Infinity Foods argued that they were tightening up their policy in order to comply with legislation, specifically the Classification, Labelling and packaging of substances and mixtures (CLP) Regulation (EC) No 1272/2008 and others.

This post, and the comments, got me thinking. I’m old enough, just, to remember the days when random glass bottles were routinely filled with random substances. You wandered into the garage (it was always the garage) and there’d be something pink, or blue, or green, or yellow in a bottle. And it might have a hand-written label, and it might not, and even if it did, the label wasn’t guaranteed to actually be representative of the contents. The “open it and sniff” method of identification was common. The really brave might take their chances with tasting. Home-brew wine might well be next to the lawnmower fuel, and if they got mixed up, well, it probably wouldn’t be fatal.

Probably.

Bottles may be single-use, but they’ve also been designed to be as safe as possible.

You know, I’m not sure we ought to be keen to go back to that, even if it does save plastic. Sealed bottles with hard-to-remove child safety caps, nozzles that only dispense small amounts (making it difficult if not impossible to drink the contents, by accident or otherwise) and accurate ingredients lists are, well, they’re safe.

And we’ve all grown used to them. Which means that now, if I pick up a bottle, I expect the label to tell me what’s in it. I trust the label. If I went to someone else’s house and found a bottle of, say, something that looked like washing up liquid by the sink, I’d assume it was what the label said it was. I wouldn’t even think to check.

You might think, well, so what? You fill a bottle, you know what’s in it. It’s up to you. But what about all the other people that might come into contact with that bottle, having no idea of its origins? What if a visitor has an allergy to a particular ingredient? They look at the label, check it doesn’t contain that ingredient, and use it. Only, someone has refilled that bottle with something else, and maybe that something else does contain the thing they’re allergic to.

Even simpler, someone goes to a shop that sells refills, fills a hair conditioner bottle with fabric softener and doesn’t think to label it. They know what it is, right? They leave it in the kitchen, someone else picks up that bottle, and takes it into the shower. They get it in their eyes and… maybe it causes real harm.

Toilet cleaner must never be mixed with toilet bleach.

Then there are the very real hazards associated with mixing chemicals. One that always worries me is the confusion between toilet cleaner and toilet bleach. Many people have no idea what the difference is. The bottles even look quite similar. But they are not the same substance. Toilet cleaner is usually a strong acid, often hydrochloric acid, while toilet bleach contains sodium hypochlorite, NaClO. Mixing the two is a very bad idea, because the chemical reaction that occurs produces chlorine gas, which is particularly hazardous in a small, enclosed space such as a bathroom.

Okay, fine, toilet bleach and cleaner, noted, check. Is anyone selling those as refills anyway? Probably not. (Seriously, though, if you finish one bottle, make sure you don’t mix them in the toilet bowl as you open the next.)

But it may not be as straightforward as that. Have you ever used a citrus-scented cleaning product? They can be quite acidic. Combine them with bleach and, yep, same problem. What if someone refilled a container that contained traces of a bleach cleaner with one that was acidic, not realising? Not only would it be harmful to them, it could also be harmful for other people around them, including employees, especially if they suffer from a respiratory condition such as asthma.

There are risks associated with the type of container, too. Some plastics aren’t suitable to hold certain substances. Infinity Foods themselves pointed out that some people were trying to find drinking water bottles and plastic milk bottles with cleaning products. These types of bottles are usually made of high-density polyethylene (HDPE). This type of plastic is a good barrier for water, but not oily substances and solvents. Cleaning products could weaken the plastic, resulting in a leak which would be messy at best, dangerous at worst. That’s before we even think about the (un)suitability of the cap.

The type of plastic used to make water bottles isn’t suitable to hold oily substances.

Plus, think of the poor salesperson. How are they supposed to judge, in a shop, whether a particular bottle is safe for a particular product? I wouldn’t feel at all confident about that decision myself. It’s not even always easy to identify which plastic a bottle is made of, and that’s before you even start to consider the potential risks of mixing substances.

In fact, the more you think about it, the more Infinity Foods’ policy makes sense. If you say that you can only refill a bottle with the exact same substance it originally contained, and you insist that the labels have to match, well, that’s easy to check. It’s easy to be sure it’s safe. Yes, it might mean buying a bottle you wouldn’t have otherwise bought, but if you’re going to reuse it, at least it’s just the one bottle.

These concerns all arise from wanting to make sure the world is a safer and healthy place. We do need to cut down on single-use plastics, but taking risks with people’s health to do so surely misses the point.

Like the Chronicle Flask’s Facebook page for regular updates, or follow @chronicleflask on Twitter. Content is © Kat Day 2019. You may share or link to anything here, but you must reference this site if you do. If you enjoy reading my blog, please consider buying me a coffee through Ko-fi using the button below.
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No need for slime panic: it’s not going to poison anyone

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This is one of my favourite photos, so I’m using it again.

The school summer holidays are fast approaching and, for some reason, this always seems to get people talking about slime. Whether it’s because it’s a fun end-of-term activity, or it’s an easy bit of science for kids to do at home, or a bit of both, the summer months seem to love slimy stories. In fact, I wrote a piece about it myself in August 2017.

Which (hoho) brings me to the consumer group Which? because, on 17th July this year, they posted an article with the headline: “Children’s toy slime on sale with up to four times EU safety limit of potentially unsafe chemical” and the sub-heading: “Eight out of 11 popular children’s slimes we tested failed safety testing.”

The article is illustrated with lots of pots of colourful commercial slime pots with equally colourful names like Jupiter Juice. It says that, “exposure to excessive levels of boron could cause irritation, diarrhoea, vomiting and cramps in the short term,” and goes on to talk about possible risks of birth defects and developmental delays. Yikes. Apparently the retailer Amazon has removed several slime toys from sale since Which? got on the case.

The piece was, as you might expect, picked up by practically every news outlet there is, and within hours the internet was full of headlines warning of the dire consequences of handling multicoloured gloopy stuff.

Before I go any further, here’s a quick reminder: most slime is made by taking polyvinyl alcohol (PVA – the white glue stuff) and adding a borax solution, aka sodium tetraborate, which contains the element boron. The sodium tetraborate forms cross-links between the PVA polymer chains, and as a result you get viscous, slimy slime in place of runny, gluey stuff. Check out this lovely graphic created by @compoundchem for c&en’s Periodic Graphics:

The Chemistry of Slime from cen.acs.org (click image for link), created by Andy Brunning of @compoundchem

And so, back to the Which? article. Is the alarm justified? Should you ban your child from ever going near slime ever again?

Nah. Followers will remember that back in August last year, after I posted my own slime piece, I had a chat with boron-specialist David Schubert. He said at the time: “Borax has been repeated[ly] shown to be safe for skin contact. Absorption through intact skin is lower than the B consumed in a healthy diet” (B is the chemical symbol for the element boron). And then he directed me to a research paper backing up his comments.

Borax is a fine white powder, Mixed with water it can be used to make slime.

This, by the way, is all referring to the chemical borax – which you might use if you’re making slime. In pre-made slime the borax has chemically bonded with the PVA, and that very probably makes it even safer – because it’s then even more difficult for any boron to be absorbed through skin.

Of course, and this really falls under the category of “things no one should have to say,” don’t eat slime. Don’t let your kids eat slime. Although even if they did, the risks are really small. As David said when we asked this time: “Borates have low acute toxicity. Consumption of the amount of borax present in a handful of slime would make one sick to their stomach and possibly cause vomiting, but no other harm would result. The only way [they] could harm themselves is by eating that amount daily.”

It is true that borax comes with a “reproductive hazard” warning label. Which? pointed out in their article that there is EU guidance on safe boron levels, and the permitted level in children’s’ toys has been set at 300 mg/kg for liquids and sticky substances (Edited 18th July, see * in Notes section below).

EU safety limits are always very cautious – an additional factor of at least 100 is usually incorporated. In other words, for example, if 1 g/kg exposure of a substance is considered safe, the EU limit is likely to be set at 0.01 g/kg – so as to make sure that even someone who’s really going to town with a thing would be unlikely to suffer negative consequences as a result.

The boron limit is particularly cautious and is based on animal studies (and it has been challenged). The chemists I spoke to told me it’s not representative of the actual hazards. Boron chemist Beth Bosley pointed out that while it is true that boric acid exposure has been shown to cause fetal abnormalities when it’s fed to pregnant rats, this finding hasn’t been reproduced in humans. Workers handling large quantities of borate in China and Turkey have been studied and no reproductive effects have been seen.

Rat studies, she said, aren’t wholly comparable because rats are unable to vomit, which is significant because it means a rat can be fed a large quantity of a boron-containing substance and it’ll stay in their system. Whereas a human who accidentally ingested a similar dose would almost certainly throw up. Plus, again, this is all based on consuming substances such as borax, not slime where the boron is tied up in polymer chains. There really is no way anyone could conceivably eat enough slime to absorb these sorts of amounts†.

These arguments aside, we all let our children handle things that might be harmful if they ate them. Swallowing a whole tube of toothpaste would probably give your child an upset stomach, and it could even be dangerous if they did it on a regular basis, but we haven’t banned toothpaste “just in case”. We keep it out of reach when they’re not supposed to be brushing their teeth, and we teach them not to do silly things like eating an entire tube of Oral-B. Same basic principle applies to slime, even if it does turn out to contain more boron than the EU guidelines permit.

In conclusion: pots of pre-made slime are safe, certainly from a borax/boron point of view‡, so long as you don’t eat them. The tiny amounts of boron that might be absorbed through skin are smaller than the amounts you’d get from eating nuts and pulses, and not at all hazardous.

Making slime at home can also be safe, if you follow some sensible guidelines like, say, these ones:

Stay safe with slime by following this guidance

Slime on, my chemistry-loving friends!

Notes:
* When I looked for boron safety limits the first time, the only number I could find was the rather higher 1200 mg/kg. So I asked Twitter if anyone could direct me to the value Which? were using. I was sent a couple of links, one of which contained a lot of technical documentation, but I think the most useful is probably a “guide to international toy safety” pamphlet which includes a “Soluble Element Migration Requirements” table. In the row for boron, under “Category II: Liquid or sticky materials”, the value is indeed given as 300 mg/kg.

BUT, there is also ” Category I: Dry, brittle, powder like or pliable materials” and the value there is the much higher 1,200 mg/kg. Which begs the question: does slime count as “pliable” or “sticky”? It suggests to me that, say, a modelling clay product (pliable) would have the 4x higher limit. But surely the risk of exposure would be essentially the same? If 1,200 mg/kg is okay for modelling clay, I can’t see why it shouldn’t be for slime. In the Which? testing, only the Jupiter Juice product exceeded the Category I limit, and then not by that much (1,400 mg/kg).

Also (the notes are going to end up being longer than the post if I’m not careful), these values are migration limits, not limits on the amount allowed in the substance in total. Can anyone show that more than 300 mg/kg is able to migrate from the slime to the person handling it? Very unlikey. But again, don’t eat slime.

† This is not an invitation to try and prove me wrong.

‡ I suppose it’s possible that someone could sell slime that’s contaminated with some other toxic thing. But that could happen with anything. The general advice to “wash your/their hands and don’t eat it” will take you a long way.

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The Chronicles of the Chronicle Flask: 2017

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We’ve made it! Not only to 2018 (which was starting to look doubtful earlier in the year), but also to the Chronicle Flask’s 100th post. Which doesn’t seem that many, really, but since posts on here frequently run to 1500 words, that adds up to a rather more impressive-sounding 150,000 words or so. I mean, that’s like… half a Brandon Sanderson novel. Oh.

Anyway, it’s time for a yearly round-up. Here goes!

Last January I began with a post about acrylamide. We’d all been enjoying lots of lovely crispy food over Christmas; it was time to tell us about the terrible dangers of such reckless indulgence. The newspapers were covered with pictures of delicious-looking chips, toast and roast potatoes alongside scary headlines such as:  “Crunchy toast could give you cancer, FSA warns”. The truth was not quite so dramatic. Acrylamide does form when foods are cooked to crispiness, and it is potentially harmful, but the quantities which form in food are tiny, and very unlikely to cause you any serious harm unless you literally live on nothing but burnt toast. The FSA (Food Standards Agency) hadn’t significantly revised their guidelines, it turned out, but were in fact only suggesting that the food industry should be mindful of acrylamide levels in food and seek to reduce them as much as possible. That wouldn’t have made for quite such a good “your food is going to killllll you!” story though, I suppose.

In February the spikey topic of vaccination came up. Again. Vaccines are awesome. They protect us from deadly diseases. No, I don’t want to hear any nonsense about “Big Pharma“, and I definitely don’t want to hear how “natural immunity” is better. It’s not. At best, it might provide a similar level of protection (but not in every case), but it comes with having to suffer through a horrible, dangerous disease, whereas vaccination doesn’t. It ought to be a no-brainer. Just vaccinate your kids. And yourself.

It was Red Nose Day in the UK in March, which brought some chemistry jokes. Turns out all the best ones aren’t gone, after all. Did you hear about the PhD student who accidentally cooled herself to absolute zero? She’s 0K now.

April brought a post which ought to have been an April Fool’s joke, but wasn’t. Sceptics often point out that homeopathy is just sugar and water, but the trouble is, sometimes, it’s not. There’s virtually no regulation of homeopathy. As far as I’ve been able to establish, no one tests homeopathic products; no one checks the dilutions. Since a lot of the starting materials are dangerously toxic substances such as arsenic, belladona, lead and hemlock, this ought to worry people more than it does. There has been more than one accidental poisoning (perhaps most shockingly, one involving baby teething products). It really is time this stuff was banned, maybe 2018 will be the year.

In May I turned to something which was to become a bit of a theme for 2017: alkaline water. It’s not so much that it doesn’t do anything (although it really doesn’t), more the fact that someone is charging a premium for a product which you could literally make yourself for pennies. It’s only a matter of dissolving a pinch of baking soda (sodium bicarbonate) in some water.

June brought a selection of periodic tables because, well, why not? This is a chemistry blog, after all! And now we’ve finally filled up period seven they do have a rather elegant completness. 2019, by the way, has just been announced as the International Year of the Periodic Table of Chemical Elements, to coincide with IUPAC’s 100th anniversary and the 150th anniversary of Mendeelev’s discovery of periodicity (his presentation, The Dependence Between the Properties of of the Atomic Weights of the Elements, was made on 6th March 1869). Looks like 2019 will be an exciting year for chemists!

In July it was back to the nonsense of alkaline diets again, when Robert O. Young was finally sentenced to 3 years, 8 months in custody for conning vulnerable cancer patients into giving him large sums of money for ineffective and dangerous treatments. Good. Moving on.

August brought me back to a post that I’d actually started earlier in the year when I went to a March for Science event in April. It was all about slime, and August seemed like a good time to finally finish it, with the school holidays in full swing – what could be more fun on a rainy day at home than making slime? Slime was a bit of a 2017 craze, and there have been a few stories featuring children with severely irritated skin. But is this likely to be caused by borax? Not really. Turns out it’s actually very safe. Laundry detergents in general, not so much. In short, if you want to make slime the traditional way with PVA glue and borax, fill your boots. (Not really – your parents will be uninpressed.)

In September it was back to quackery: black salve. A nasty, corrosive concoction which is sold as a cancer cure. It won’t cure your cancer. It will burn a nasty great big hole in your skin. Do not mess with this stuff.

October carried on in a similar vein, literally. This time with a piece about naturopaths recommending hydrogen peroxide IVs as a treatment for lots of things, not least – you guessed it – cancer. Yes, hydrogen peroxide. The stuff you used to bleach hair. Intraveneously. Argh.

The puking pumpkin!

The end of the month featured a far better use for hydrogen peroxide, that of the puking pumpkin. Definitely one to roll out if, for any reason, you ever find yourself having to demonstrate catalysis.

November brought us, somewhat unseasonally, to tomatoes. Where is the best place to store them? Fridge or windowsill? Turns out the answer involves more chemistry than you might have imagined.

And then, finally, December. Looking for a last-minute Christmas gift? Why not buy a case of blk water? I mean, other than it’s an exorbitantly priced bottle of mysterious black stuff which doesn’t do any of the things it claims to do, and might actually get its colour from coal deposits, that is.

And that, dear friends and followers, is it for 2017! Happy New Year! Remember to be sceptical when the inevitable “deadly food” story appears in a few weeks….

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Vaccines are one of humankind’s best achievements, and we should all be shouting about it

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science-fiction-1819026_960_720Imagine aliens finally get around to visiting our planet…

“About two hundred years ago,” explains the alien scientific advisor – let’s call him Spuck – “humans developed a way to prevent disease which they call vaccination. It’s really quite fascinating. They use a needle to place a tiny quantity of a fluid into the muscle under the skin of their arm or leg. The substances are then absorbed into their bodies and cause their highly-evolved immune systems to generate an immune response without, and this is really quite ingenious, Captain, their having to contact the actual diseases or suffer the symptoms. This simple procedure has saved millions of lives worldwide, and saved many millions more from having to suffer less fatal, but none the less still deeply unpleasant, consequences of serious illnesses.”

“Sounds great, Spuck,” says the Captain – let’s call him Birk – “is there a downside?”

“Not really, Captain. Side effects are rare and extremely minor compared to the seriousness of the illnesses themselves.”

“Fantastic. Why are you telling me all this? I’ve got some green-skinned action I’d like to get back to, if you know what I mean.”

“Well, it’s interesting that you should mention unusual skin tones, Captain. A leader has recently come to power who, amongst other things, has expressed concerns about vaccination.”

“Valid concerns?”

“The scientific evidence suggests not, sir.”

“Sounds like an idiot, Spuck.”

“I couldn’t possibly comment, sir.”

“Huh. Sounds like he could definitely be detrimental to the future of their race, and besides, I’m bored. Let’s go and shoot some stuff in direct contravention of the Cardinal Directive. Set blazers to ki- I mean, stun. Beam me down, Dottie!”

***

Vaccination. It’s a hot topic at the moment, and one which is so important that I think anyone who has anything to do with science communication ought to be talking about it. I’m not a medical doctor, or an immunologist, or even a biochemist (for more qualified input on the subject, I refer you here, here and here), but I AM capable of recognising scientific consensus and of separating good-quality evidence-based information from conspiracy theory dross.

Vaccination is awesome.

Awesome is a word that is somewhat overused. But I mean it literally. As in, inspires awe. We should stop, for a moment, and just look at how bloody amazing vaccination is. Thanks to these simple, near-painless, injections – most of which we receive as young children and therefore don’t even remember – we are largely protected from the horrors of….

  • Polio – symptoms and complications include fever, vomiting, headache, back pain, joint pain and stiffness, permanent muscle weakness, permanent paralysis and death.
  • Mumps – symptoms and complications include fever, headache, meningitis, painful testicular swelling in males and ovarian inflammation in females, both of which can  result in permanent infertility, pancreatic inflammation and, occasionally, hearing loss. Death from mumps is rare, but does occur in about 1 in 10,000 cases.
  • Tuberculosis – symptoms and complications include fever, loss of appetite, severe fatigue, chest pain, coughing up of blood, scarring of the lungs, internal bleeding and death (death is considerably more likely if the patient does not have access to medical care).
  • Measles – symptoms and complications include fever, painful skin rash, diarrhoea, vomiting, ear infection which can result in deafness, eye infection which can result in blindness, laryngitis, pneumonia, bronchitis, liver infection, encephalitis, and increased likelihood of re-contracting diseases previously survived (measles essentially “wipes” your immune system). Oh yes, and death. As many as 1% of measles patients will die from the disease.

… and umpteen other, horrible diseases, the majority of which most people reading this will have never experienced. Because of vaccination.

Measles rash

A child with a measles rash. The disease can cause serious complications, including immune suppression.

The risks of vaccination are tiny. The most common complications are redness and swelling around the injection site and/or slight temperature which is easily treated with an antipyretic such as paracetamol or ibuprofen. Very occasionally people suffer a serious allergic reaction, but this inevitably happens quickly after the injection is given. Since vaccinations are usually administered in a medical setting, any allergic reaction that does occur can be quickly managed. There have been a few other genuine cases of serious, adverse reactions to vaccines, but problems are still very rare (the swine flu-narcolepsy link, for example, affected 1 in 55,000) and specific to particular vaccines, and the vaccine in question has been quickly investigated.

Like Birk, if you’ve had nothing to do with the anti-vaccination community, you may be thinking this all sounds good. Benefits massive, risks tiny. Fab. Let’s go.

However, the anti-vaccination crowd – a real, and not entirely new, thing – will tell you that this is all lies. They will tell you this loudly, and at length, and repeatedly. They believe that vaccinations cause every health problem from acne to zygomycosis, but particularly the neurodevelopmental condition known as autism.

Vaccines do not cause autism. At all. As Spuck said, the scientific evidence is clear. It’s absolutely ice-from-a-moutain-stream-in-the-middle-of-nowhere crystal clear. Just for one example, a meta analysis published in the journal Vaccine in 2014 looked at studies involving over a million children. The data revealed no relationship between vaccination and autism. None. Nada.

Vaccines, you see, do not cause autism. And actually, it’s about time we stopped wasting precious resources proving that over and over and over and over again and instead focused on what does cause autism, because that would be a question worth answering.

Infection rates dropped enormously in the US after the measles vaccination was introduced.

Infection rates dropped enormously in the US after the measles vaccination was introduced.

Anti-vaxxers will often repeatedly talk about mercury in vaccines. There’s mercury in vaccines, they’ll say, and that’s nasty stuff, so even if we haven’t proved it yet, they must be causing something bad. One problem there: there isn’t any mercury in vaccines. There’s a preservative called thimerosal (or thiomersal) in some flu vaccines – which are not the ones usually given to children – but thimerosal is no more mercury than salt is chlorine.

The anti-vax crowd get whackier after this. Some of them will tell you that vaccinations don’t, in fact, protect against against disease at all – despite huge evidence to the contrary (see also here), not to mention the simple fact that many of our grandparents and even parents remember these diseases, and their complications, as horribly commonplace.

Anti-vaxxers often state that deaths from these diseases were dropping before the vaccines were introduced. This is true. Deaths did drop, because medical science was developing rapidly. A measles patient receiving medical care is, indeed, less likely to die than one left to her own devices. If I may say so, duh.

What vaccines did is to massively reduce infection rates. But just to state the obvious: if people don’t catch a disease, they also can’t die from it.

In short, if an anti-vaxxer shows you a graph, it’s smart to check to the axes labels.

After that they get really loony, and some of them will even tell you things such as smallpox wasn’t eradicated, it was just renamed acne. Or polio has been reclassified as Guillain-Barré syndrome. These ideas are so utterly ridiculous they don’t even deserve rebuke.

This has started up again in the last few days, particularly in the UK, because of the nasty deposit of conspiracy crap that is the film Vaxxed. It’s available online, but I shall not be linking to it here.

The film claims to reveal a massive cover-up at the Centre for Disease Control (the CDC) in America, and evidence that vaccines are generally evil and cause all manner of heinous negative health outcomes. Very little of it is true, and where a tiny nugget of true fact has been included it’s been so beaten and manipulated as to have lost all of its original meaning. There’s an excellent piece about it on Skeptical Raptor website, which I recommend reading before you google the term “vaxxed”. Consider it a sort of inoculation against the nonsense, if you like (hoho).

A Guardian article from 2010 reports on Wakefield.

A Guardian article from 2010 (click for link).

The main brain behind the film is Mr Andrew Wakefield, a former British doctor who was struck off the General Medical Council in 2010, when the GMC said he had acted “dishonestly and irresponsibly.” Wakefield was, it turned out, trying to patent his own measles vaccine. In an effort to further his own aims, he set out to discredit the widely-used MMR (measles, mumps and rubella vaccine) by fabricating results and, in particular, suggesting a link between the MMR and autism. He denied all this, of course, but a libel judge disagreed.

Wakefield is still pushing his message. He is not a particularly nice individual. Listen to him in this video clip, for example, where he responds to Bill Gates comment, made in 2015, that he (Gates) fears a pandemic could wipe out humanity in his lifetime. Actually, I’ll save you the trouble:

“Ho Chi Minh City, you may have seen this, an outbreak of [laughs] the plague in Ho Chi Minh City. The outbreak that they were not prepared for, they never prepared for, and that is the number of children with autism in Ho Chi Minh City has increased by nearly one hundred and sixty times over eight years. So, Bill, just for your edification, the plague that you’re talking about, the next plague, the next epidemic, it’s already here. It’s already here.”

Yes, you heard that right, according to Wakefield autism is a “plague”. Anyone reading this with an autism diagnosis? You have the plague. Nice, huh?

Andrew Wakefield describes autism as a "plague".

Andrew Wakefield describes autism as a “plague”.

For the record, the number of autism diagnoses in Ho Chi Minh has increased sharply over recent years, but this is may well be – as often turns out to be the case – largely due to to better diagnosis. Certainly there’s absolutely no suggestion that it’s linked to the introduction of a vaccine or vaccines. There might be an environmental factor – some sort of pollutant perhaps – but no one is certain at the moment. (To repeat myself: perhaps if we stopped wasting time endlessly disproving the link between vaccines and autism, we’d have a better idea.)

By the way, the woman in that video clip is Polly Tommey. She has an autistic son who’s now in his twenties. Back in 2010 she chose to try and raise awareness of autism by posing in a Wonderbra-style advert, and these days she follows the campaign trail with Wakefield, repeating the message that they “will win”. What exactly they’re going to win isn’t entirely clear. Would preventing vaccination, at the cost of many lives, really be a win?

Vaxxed was due to be shown at the Curzon cinema in Soho, London on Valentine’s Day. It was pulled after the cinema realised what the film was – they had merely leased their premises to private individuals and only realised what was going on when a number of science advocates started complaining.

In a statement, a spokesperson for Curzon Cinemas said:

“We do not wish to profit from a film that has demonstrably caused great distress.”

The heyevent.uk page on Vaxxed, explaining that the location will be "annnounced" two hours before the screening.

The heyevent.uk page on Vaxxed explains that the location will be “annnounced” two hours before the screening.

Tommey was predictably unimpressed by this outcome, which she blamed on “our little five trolls in England,” saying “Britain being who they are, being big wussy pussies, just strike it off.”

Unfortunately, the cancellation turned out to be less of a victory than it first appeared. The anti-vaxx crowd then set out to find a new venue. And this time, they kept it quiet. There are many, many places that will rent you a space to screen a film, and I’ll wager that few of them really check the nature of that film. So, the anti-vaxxers correctly reasoned, if we don’t tell people where it is, no one will be able to stop us. People who had previously bought tickets were told it would be in “Central London”, and that the venue would be revealed two hours before the show.

And so, it happened. At Regent’s University London, a private university which was, incidentally, recently identified as the most expensive place to study in the UK.

In hindsight, this might actually have been worse than a screening at an independent cinema. Dodgy film in a cinema – so what? “Official” screening at a university with Q&A sessions afterwards? Hm, sounds important and… academic. The press, naturally, made the most of it, with headlines such as “Disgraced anti‑MMR vaccine doctor Andrew Wakefield gets invitation to university in London.” Sure, the first line of the actual article says the university has been criticised, but who actually reads beyond the headlines these days? Sounds like he’s being taken seriously, doesn’t it?

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Regent’s University’s response on Twitter on February 15th

Regent’s University responded pretty quickly to say that they hadn’t known what the film was, that they didn’t endorse its views, and that they would be revetting all their clients.

This provoked lots of complaints about freedom of speech, because many people seem to be under the misapprehension that freedom of speech means that any and all organisations and venues have a duty to allow them to repeat their nonsense. This is not what freedom of speech means. Freedom of speech means you can’t be chucked in prison for saying a thing (with some exceptions). It does NOT mean that everyone has to listen to you, or that you can say your thing wherever and whenever you like, whether the place renting you the space likes it or not.

More alarming still was the Q&A session at the end of the screening of Vaxxed. I watched some of it (one for the team, you’re welcome). There was much talk of “getting the message out there”, “sowing the seeds”, “people have to hear the message x times before they’ll start to accept it” and so on. In short, if you didn’t know it was all about vaccines it would start to sound an awful lot like…. well, at best a religion, and at worst a cult.

Wakefield was also asked if he would ever get his name cleared. This was his response:

Wakefield speaking at the end of the Vaxxed screening.

Wakefield speaking at the end of the Vaxxed screening.

“Well, cleared by whom? Here’s a… it’s a really important… cleared by whom? Do I want to be part of the medical profession again? [muttering from the audience] Do I want to be exonerated by the General Medical Council? Do I want to pay them an annual retainer fee? To be part of… Do I really? Is that… that takes time and effort. What is more important? Making films like this? Or trying to clear my name? [applause]“

Hang on. If he really cared about getting the science right, about doing the right thing by patients, wouldn’t getting his name cleared and being reinstated as a medical doctor be of utmost importance? If he’s right about vaccines, particularly the MMR vaccine, and if he truly wants to prove it for the good of humanity, what better way than to be exonerated?

But as he says, “that takes time and effort.” What he doesn’t add, of course, is that making films like Vaxxed, travelling around the world spreading his message and hobnobbing with Donald Trump, almost certainly makes him a lot more money than being a doctor ever did. And I’ll bet it’s more fun. Why would he go back to the long hours and hard work that being a regular old doctor entails?

Wakefield is playing an extremely unpleasant and disingenuous game. The really worrying thing is that he and other anti-vaccination campaigners might be gaining ground. Robert F. Kennedy Jr. and Robert De Niro recently announced a $100,000 “challenge” to prove the safety of thimerosal vaccines. Thimerosal has already been extensively investigated – no evidence has ever been found that its inclusion in vaccines causes neurological effects, but anyway, it’s only in a few flu vaccines. Of course, the implication is that all vaccines are unsafe and that no one can prove otherwise – and now those headlines are out there, and that seed has been planted, will people really read further into it? Or will they just decide to skip the visit to the doctor?

The consequences of that are potentially serious. A mumps outbreak was reported in Washington State a week ago, and cases of mumps and measles have also just been reported in Salt Lake County. Last autumn the Guardian reported that the proportion of under-twos receiving their first dose of the MMR vaccine had fallen for the third consecutive year, and there were several reports of measles outbreaks in the UK. Flu outbreaks are also a real concern: years of hearing the phrase “mild flu-like symptoms” have created the misconception that influenza itself is a mild disease. It is not. There have been over 100 deaths from flu in Germany this year alone. People in Germany have access to good healthcare. People are still dying.

Outbreaks put everyone at risk: vaccination is effective, but nothing is 100% effective. In the midst of a full outbreak, even the vaccinated are at risk of catching the disease, and of course, those who are too young to receive the vaccine, or who can’t have it because of a genuine allergy, or because they’re immunocompromised, will be in real trouble. Let’s not forget: measles in particular is a disease with a host of horrible complications, not to mention the potential to reduce a person’s previously acquired immunity to other diseases.

Do we really want to see measles and mumps come back? Really? Because that will ultimately be the result of all of this.

And unfortunately, Captain Birk and Mr Spuck aren’t actually there to fix this mess for us. We need to see sense ourselves.

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Glow sticks or sparklers: which is riskier?

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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.

screen-shot-2016-11-04-at-21-51-33

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.

Hmmm.

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.

phenyl_oxalate_ester

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 HowStuffWorks.com - click image for more)

How Light Sticks work (from HowStuffWorks.com – 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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