0:00:02 > 0:00:04This series is about the stuff we can't live without,
0:00:04 > 0:00:08whether it's products of personal hygiene, home cleaning, or even DIY,
0:00:08 > 0:00:11it's about those bottles, cans, sprays, jars and tubes
0:00:11 > 0:00:15crammed into our cupboards, drawers, handbags, sheds and cars.
0:00:15 > 0:00:19I want to know what's in all this stuff.
0:00:21 > 0:00:25'I'm Jane Moore and I'm on a journey to the limits of scientific knowledge.'
0:00:26 > 0:00:30That is quite unpleasant. 'And sometimes, the edge of reason.'
0:00:30 > 0:00:34Oh! 'I'm chucking away the packaging to find out what's doing
0:00:34 > 0:00:37'the really clever science inside those of bottles and canisters
0:00:37 > 0:00:39'we really can't do without.
0:00:39 > 0:00:44'Yes, I'm on a mission to find the wonderstuffs in our daily essentials
0:00:44 > 0:00:46'that make them so, well, essential.'
0:00:47 > 0:00:50'And it's promising to be quite a trip.' How effecti...
0:00:52 > 0:00:57Welcome to the extraordinary hidden world of Wonderstuff.
0:01:15 > 0:01:20'This particular journey promises to deliver some really crucial insights
0:01:20 > 0:01:25'as I bust open the stuff we rely on when it comes to waging domestic germ warfare.'
0:01:25 > 0:01:27So that's pretty badly contaminated.
0:01:27 > 0:01:29That's off the scale.
0:01:29 > 0:01:33I'm putting three of our most trusted household essentials to the test,
0:01:33 > 0:01:38toilet cleaners, anti-bacterial sprays and air fresheners,
0:01:38 > 0:01:41as we seek out the really clever wonderstuffs
0:01:41 > 0:01:46saving us on a daily basis from the worst kinds of household muck.
0:01:47 > 0:01:51'Later, my masterful materials guru, Mark Miodownik,
0:01:51 > 0:01:55'reckons he can demonstrate just how bleach kills bacteria.'
0:01:56 > 0:01:58Boing, boing!
0:01:58 > 0:02:02'And explain precisely how our noses detect a bad pong.'
0:02:02 > 0:02:09I don't have to smell it, I can... Oh, look at that. It's all damp and scuzzy.
0:02:12 > 0:02:16But first, I'm going to start with the grubbiest job of all.
0:02:16 > 0:02:21I'd love to know, are all loo cleaners created equal?
0:02:21 > 0:02:27I'd also love to know what's actually in this stuff that's doing the dirty work.
0:02:32 > 0:02:36Since moving our toilets inside our homes 100-odd years ago,
0:02:36 > 0:02:39preventing them from becoming a breeding ground for harmful bugs
0:02:39 > 0:02:41has been the most crucial of cleaning jobs.'
0:02:43 > 0:02:45And until someone invents a self-cleaning loo,
0:02:45 > 0:02:47we have to rely on chemistry.
0:02:49 > 0:02:51'So, to find out what's in loo cleaner,
0:02:51 > 0:02:55'I'm off to the headquarters of Jeyes, who make an awful lot of the stuff.'
0:02:55 > 0:03:00'Technical director Dr Max Gowland is going to unpack the science
0:03:00 > 0:03:02'that goes into the bendy bottle,
0:03:02 > 0:03:06'starting here in their rather unique testing facility.'
0:03:06 > 0:03:08Welcome to Jeyes, Jane.
0:03:08 > 0:03:10SHE LAUGHS
0:03:10 > 0:03:13Flushing Meadows, this is where we do our toilet testing.
0:03:13 > 0:03:15How many toilets have you got in here?
0:03:15 > 0:03:22We have about 250 toilet bowls plus cisterns. So it's a huge test facility.
0:03:22 > 0:03:26I would guess it's easily the biggest and most impressive facility in the world.
0:03:26 > 0:03:29This the most bizarre room I have ever been into in my life.
0:03:29 > 0:03:33- We have a computer here, which controls the flushing.- Right.
0:03:33 > 0:03:36Obviously, we have to test five flushes a day,
0:03:36 > 0:03:41- 20 flushes a day, 90 flushes... - I was going to say, five flushes a day wouldn't serve my house,
0:03:41 > 0:03:43I tell you, not with all my kids.
0:03:43 > 0:03:44- Oh! - FLUSHING
0:03:44 > 0:03:51Well. Here we go. We just... We're just in a flush cycle now.
0:03:55 > 0:03:56- Its like a loo symphony.- Yes.
0:04:00 > 0:04:04And if I thought the 200 loos in Flushing Meadows was odd,
0:04:04 > 0:04:08Max assures me I ain't seen nothing yet.
0:04:08 > 0:04:13Their smelling station allows the team to test the likeability and staying power
0:04:13 > 0:04:16'of the smells they add to loo cleaners.'
0:04:16 > 0:04:20Blimey, this is very much 2001: A Space Odyssey.
0:04:20 > 0:04:24So, how many fragrances are you testing in here today?
0:04:24 > 0:04:27Currently, we're testing three or four fragrances.
0:04:27 > 0:04:31If I open one of these doors, I'll be able to test a smell?
0:04:31 > 0:04:33- Absolutely. - Don't tell me what it is, I want to see
0:04:33 > 0:04:36whether the old bugle is working. Here we go.
0:04:37 > 0:04:42Ooh, there's a loo in here. I was expecting it to be a fragrance booth.
0:04:43 > 0:04:47That's lemony, to me, I think.
0:04:47 > 0:04:51- That's not bad.- Yeah, that smells sort of lemon...- Not bad.
0:04:51 > 0:04:55- Then you put some poncey word on the end like...- Fruity.
0:04:55 > 0:05:00- "Lemon breeze".- Yes. It is a fruity smell.- Is it, what is it?
0:05:00 > 0:05:02- I'm not exactly sure. - Let's ask the people who know.
0:05:02 > 0:05:04What's this one here, in here?
0:05:04 > 0:05:07Fruity...er, no, Fruity Punch.
0:05:07 > 0:05:10- Fruity Punch.- How's that for a name? - That wasn't too bad, was it?
0:05:11 > 0:05:14Yay! I'm going to come and work here.
0:05:16 > 0:05:20'And next, the hot room. Sounds promising!'
0:05:20 > 0:05:2237 degrees Centigrade, which is pretty warm,
0:05:22 > 0:05:25but it's also 75% controlled humidity.
0:05:25 > 0:05:27Ooh, lovely. Come on, let's give it a go.
0:05:27 > 0:05:29Don't lock me in there.
0:05:29 > 0:05:33'Who knew that keeping the loo clean required such appliance of science?'
0:05:33 > 0:05:36Very hot and very humid, because we need to make sure
0:05:36 > 0:05:39that our products are stable to various conditions,
0:05:39 > 0:05:43like warmth and humidity, especially if we are selling products overseas.
0:05:46 > 0:05:49Look, 20 seconds with me and a man's glasses steam up!
0:05:49 > 0:05:50HE LAUGHS
0:05:55 > 0:05:59I'm enjoying my tour of the toilet-cleaning house of fun,
0:05:59 > 0:06:01but time to get down to business.
0:06:01 > 0:06:07Max has laid out the full array of ingredients they work with when concocting their products.
0:06:07 > 0:06:09Here we are. There are quite a few ingredients.
0:06:09 > 0:06:15'Apparently there are 15 or so substances you can cram into the bottle.'
0:06:15 > 0:06:18'Colour, so you know where you are putting it.'
0:06:18 > 0:06:21'A foaming agent and a detergent.'
0:06:22 > 0:06:26'Thickener, to help the liquid cling to your toilet bowl.'
0:06:26 > 0:06:31'And something to help prevent calcium carbonate build-up, or lime scale.'
0:06:33 > 0:06:36'But there's one ingredient I really didn't expect.'
0:06:37 > 0:06:38'Flavouring?'
0:06:38 > 0:06:41This is called denatonium benzoate
0:06:41 > 0:06:43and this is a material which, allegedly,
0:06:43 > 0:06:45is the bitterest substance known to mankind.
0:06:45 > 0:06:49And all you need are a few parts per million of this in your product
0:06:49 > 0:06:51and nobody will want to touch it.
0:06:51 > 0:06:55So that's if little Johnny or Jemima, come along and might get some of that.
0:06:55 > 0:06:57It would put them off eating it.
0:06:57 > 0:07:00- Yes. Would you like to try some? - No, thank you very much.
0:07:02 > 0:07:03OK, I get the point.
0:07:03 > 0:07:06Your more complex toilet cleaner is multi-tasking.
0:07:06 > 0:07:11But none of the ingredients so far would stop a superbug in its tracks.
0:07:11 > 0:07:14So where's the wonderstuff I'm looking for?
0:07:14 > 0:07:19The real killer for germs, there is only one mega-material and that, of course,
0:07:19 > 0:07:23is chlorine bleach, otherwise known as sodium hypochlorite.
0:07:23 > 0:07:27'Despite the complex formulation, our wonderstuff is good old bleach.'
0:07:27 > 0:07:31Bleach is a fantastic chemical. It's highly efficacious.
0:07:31 > 0:07:38It foams, it cleans superbly, it kills every bug stone dead.
0:07:38 > 0:07:43And, also, it's absolutely perfectly safe for ceramic. So a fantastic ingredient.
0:07:45 > 0:07:47'But Max has a bit of a surprise for me
0:07:47 > 0:07:50'about exactly where bleach comes from.'
0:07:53 > 0:07:58Bleach basically starts life as common salt, or brine - salt in water.
0:07:58 > 0:08:02So the brine is turned into, using an electro-chemical process,
0:08:02 > 0:08:04into sodium hypochlorite bleach.
0:08:04 > 0:08:08- So bleach comes from salt water? - It does.
0:08:08 > 0:08:10Who'd have thought it?
0:08:11 > 0:08:15'But what makes bleach so good at killing germs?'
0:08:15 > 0:08:22'Luckily, I have my handy material scientist, Dr Mark Miodownik, on speed dial
0:08:22 > 0:08:23'to rustle up an answer.'
0:08:23 > 0:08:26- Hi, Mark!- Hi, Jane. - How are you?- I'm fine, thanks.
0:08:26 > 0:08:29We're here with this fantastic view and by the Thames.
0:08:29 > 0:08:32I guess, because we're talking about bleach, you brought me here
0:08:32 > 0:08:36because this used to be one gigantic sewer.
0:08:36 > 0:08:40Yeah. It was responsible for a lot of ill health and the Big Stink of London.
0:08:40 > 0:08:43Now we've built enormous pipes to funnel off this sewage
0:08:43 > 0:08:47and we've got bleach, which is dealing with a lot of the problems.
0:08:47 > 0:08:51'That's all well and good, but I'm hoping Mark can prove to me
0:08:51 > 0:08:55'that bleach is actually killing the invisible bacteria in my loo.'
0:08:55 > 0:09:00'He has a handy bottle of E. coli bacteria solution in his pocket, like you do(!)
0:09:00 > 0:09:05'Apparently the cloudiness is down to the live bacteria in there.'
0:09:05 > 0:09:08'Add bleach to it, however, and the liquid becomes clear,
0:09:08 > 0:09:10meaning the bacteria have been zapped.'
0:09:10 > 0:09:12'Bleach's killing power is obvious,
0:09:12 > 0:09:16but what's it actually doing to the bacteria?'
0:09:16 > 0:09:21'Cue half a dozen props. Mark reckons these raw eggs, with their shells removed,
0:09:21 > 0:09:24are a bit like giant E. coli bacteria.
0:09:24 > 0:09:28'Any bleach coming into contact with them goes on a two-pronged attack.'
0:09:28 > 0:09:32These things, actually, you'll get holes poked in them,
0:09:32 > 0:09:35so the sodium hypochlorite from the bleach is punching holes
0:09:35 > 0:09:38in the membrane of the bacteria and that means, as you can see,
0:09:38 > 0:09:42that the insides of it start spilling out, that's called cell lysing,
0:09:42 > 0:09:44and that spells death for the bacteria.
0:09:44 > 0:09:47What will happen is that things like this will happen. Boing, boing!
0:09:47 > 0:09:51- It's not feeling very well now. - I'm not surprised!
0:09:51 > 0:09:54"Hello, I used to be an egg."
0:09:54 > 0:09:57'As well as bursting open the bacteria,
0:09:57 > 0:10:01the bleach will also chemically cook the protein inside them,
0:10:01 > 0:10:06'which of course spells death to the bacteria.'
0:10:06 > 0:10:10'So, if bleach is so deadly to living cells, how come it's considered
0:10:10 > 0:10:16'safe enough to flush down our loos and be let loose into our waterways?'
0:10:16 > 0:10:20What happens after it's gone down the loo? What sort of reactions are you talking about?
0:10:20 > 0:10:25It turns out that it's so reactive, this bleach, that it reacts with almost anything.
0:10:25 > 0:10:29As it's on its way down your sink, down the drain,
0:10:29 > 0:10:33it's reacting away and almost all of it's reacted away into quite
0:10:33 > 0:10:35benign products like salt and water.
0:10:35 > 0:10:37- So pretty much how it started?- Yeah.
0:10:39 > 0:10:43'Apparently, the received wisdom is that bleach is one chemical
0:10:43 > 0:10:46'you can flush away without feeling guilty.'
0:10:49 > 0:10:52'This leaves me in no doubt that sodium hypochlorite
0:10:52 > 0:10:56'definitely qualifies as a bug-busting wonderstuff.
0:10:56 > 0:11:01'It's the bleach that has given us reliable germ killing for decades
0:11:01 > 0:11:05'In the war against bacteria it's still hard to beat.'
0:11:07 > 0:11:13But what about cleaning those surfaces you might literally want to eat from?
0:11:13 > 0:11:18After all, if we can't actually see the germs that certain products claim to get rid of,
0:11:18 > 0:11:21then how do we actually know they're doing their job?
0:11:21 > 0:11:25I reckon it's time to find out whether something in anti-bacterial
0:11:25 > 0:11:30spray is going to make it into our Wonderstuff Hall of Fame.
0:11:38 > 0:11:40I suppose it's since I've had kids
0:11:40 > 0:11:44and pets around the place that I've become more conscious of germs
0:11:44 > 0:11:47and whatever, but, when I look at this, it says that it kills
0:11:47 > 0:11:5099.9% of bacteria and viruses, so I think, "That's good."
0:11:50 > 0:11:53But then I read it says you can use it on changing mats,
0:11:53 > 0:11:56playpens, high chairs, so I then start to think,
0:11:56 > 0:12:00"If you can use it around kids and on the things that they use,
0:12:00 > 0:12:03"is it actually strong enough to do what it says on the bottle?"
0:12:05 > 0:12:11'To help find out if there's a different kind of wonderstuff making anti-bacterial spray
0:12:11 > 0:12:16'live up to its boasts, I'm bringing in a professional microbiologist.'
0:12:16 > 0:12:21'Dr Ron Cutler is Deputy Biomedical Director at Queen Mary University of London.
0:12:21 > 0:12:28'And he doesn't mess around! I'm told to make myself scarce.'
0:12:28 > 0:12:31It seems rather weird taking my dog out for a walk,
0:12:31 > 0:12:34knowing there's a bloke in my house, swabbing it for bugs.
0:12:34 > 0:12:35Eugh!
0:12:37 > 0:12:42'A couple of days ago, Ron asked me to prepare for an experiment that will demonstrate
0:12:42 > 0:12:47'how effective an anti-bacterial agent can be in areas where we prepare food.
0:12:47 > 0:12:51'He got me to cut up some raw chicken on a wooden chopping board
0:12:51 > 0:12:55'and not clean the board afterwards.
0:12:55 > 0:12:56'Now comes a techie gadget.
0:12:56 > 0:13:00'This looks like something they might have used in Ghostbusters,
0:13:00 > 0:13:04'but apparently it detects a substance called ATP
0:13:04 > 0:13:09'that's present in all organic matter, like on my contaminated chopping board.'
0:13:11 > 0:13:14So we'll just take the bacterial swab and we'll just go over
0:13:14 > 0:13:19an area here where it looks as if it's very, very dirty.
0:13:19 > 0:13:21I suspect it might be.
0:13:21 > 0:13:24And then what we'll do is we'll put it back into its tube,
0:13:24 > 0:13:29close it, and we just put the tube straight into here.
0:13:29 > 0:13:35- Gosh, it's clever, isn't it? - Then we close it and we press the little on button. OK.
0:13:35 > 0:13:39MACHINE BEEPS And, wow, it is really contaminated.
0:13:39 > 0:13:42Right, hang on, to my layman's eye, what does 193 do?
0:13:42 > 0:13:44That could mean...
0:13:44 > 0:13:47If you look into this little bit here,
0:13:47 > 0:13:49it tells you what the high and the low is.
0:13:49 > 0:13:53- Yep. 30 high, 10 low. - And you've got 193.
0:13:53 > 0:13:57- So that's pretty badly contaminated. - That's off the scale.
0:13:57 > 0:13:59- Off the scale, exactly.- Wow!
0:13:59 > 0:14:03'But what difference will a quick wipe down with water make?
0:14:03 > 0:14:07'Well, the answer is - not much.' That's like a difference of one.
0:14:07 > 0:14:12- That's nothing. It's just wiped the germs around a bit, really. - Absolutely.
0:14:12 > 0:14:17'Will my family-friendly anti-bacterial spray be more effective?'
0:14:17 > 0:14:19Spray away.
0:14:19 > 0:14:21Get a bit of a pump going there.
0:14:22 > 0:14:26- So just do as you would normally do with your cleaner.- Yeah.
0:14:27 > 0:14:30And let's see if it's an effective method or not.
0:14:37 > 0:14:42- One of the secrets of these things, of course, is that it smells effective.- Yeah, it does.
0:14:42 > 0:14:47- I'm feeling reassured already by the smell of disinfectant. - Disinfectant, yes.
0:14:49 > 0:14:54OK, right. Oh, I get to put that in as well now, see?
0:14:54 > 0:14:58- Close the lid.- Press OK.
0:14:58 > 0:15:02- Right, bets - what do you reckon? - Oh, 60 to 70.
0:15:04 > 0:15:0861. You've done this before. You cheated.
0:15:08 > 0:15:13'Given the board had been left to fester for two full days
0:15:13 > 0:15:14'that's a big difference.
0:15:14 > 0:15:18'There's clearly something in my anti-bacterial spray working.'
0:15:18 > 0:15:21That has really worked, hasn't it?
0:15:21 > 0:15:26'But it still hasn't done a full clean-up. Ron puts this down to not leaving the spray on long enough
0:15:26 > 0:15:28to be fully effective.'
0:15:30 > 0:15:35Because the material's almost ingrained onto this board,
0:15:35 > 0:15:40it's actually very difficult to remove stuff like this. Really, there's no excuse.
0:15:40 > 0:15:41You must clean the area
0:15:41 > 0:15:44and make sure that you get rid of the dirt
0:15:44 > 0:15:50and allow the anti-bacterial agent to actually destroy the bacterium that's there.
0:15:50 > 0:15:55'Ron's determined to show me that my anti-bacterial spray can kill
0:15:55 > 0:15:58'a lot more germs if left to work long enough.
0:15:58 > 0:16:01'So he's taking me back to his lab to prove it.
0:16:01 > 0:16:05'But, before he reveals the magic substance in there doing the bug-killing work,
0:16:05 > 0:16:07'I want Ron to put my mind at ease.
0:16:07 > 0:16:11'Will the rest of my house prove to be as fetid as my chopping board?
0:16:11 > 0:16:15'One look at my samples and my heart begins to sink.'
0:16:15 > 0:16:17The Petri Dishes of Shame.
0:16:17 > 0:16:22- 'But Ron's actually got some good news.'- There's nothing at all dangerous
0:16:22 > 0:16:24in any of these organisms here.
0:16:24 > 0:16:28What they are is completely safe micro-organisms that live in the environment.
0:16:28 > 0:16:32'Apparently, many of the benign kinds of bacteria
0:16:32 > 0:16:35'kicking around our houses actually keep our immune systems
0:16:35 > 0:16:39'primed for action should something more nasty come along.
0:16:40 > 0:16:43'But that's not the case with my chopping board.
0:16:43 > 0:16:45'Ron shows me exactly what's been growing there.
0:16:45 > 0:16:48'And it's pretty bad.'
0:16:48 > 0:16:53- Uh-oh!- This is what we actually managed to isolate.
0:16:53 > 0:16:57- This is an organism called Escherichia coli.- As in E. coli? - As in E. coli.
0:16:57 > 0:17:01There's a whole range of variations of E. coli,
0:17:01 > 0:17:05and chicken just happens to be one of the sources of these, especially raw chicken.
0:17:05 > 0:17:09'And remember, that's even after I'd cleaned it.
0:17:09 > 0:17:14'But Ron insists there is a killer ingredient in anti-bacterial spray
0:17:14 > 0:17:16'called benzalkonium chloride
0:17:16 > 0:17:20'And he's got a neat little trick up his sleeve that he thinks will prove it.
0:17:20 > 0:17:26'He's put a single drop of benzalkonium chloride into the middle of an E-coli colony.
0:17:26 > 0:17:30'after a few hours, something really amazing happens -
0:17:30 > 0:17:34'a clear circle has appeared in the centre of the Petri dish.
0:17:34 > 0:17:40'Compared to an untreated colony, the bacterial devastation is obvious.'
0:17:40 > 0:17:43You can actually see that there's a fantastic difference,
0:17:43 > 0:17:47so this is very effective at killing bacteria.
0:17:47 > 0:17:50I'm impressed. The evidence speaks for itself.
0:17:50 > 0:17:54This benzalkonium chloride in my anti-bacterial spray has proven itself
0:17:54 > 0:17:56against the might of E-coli.
0:17:56 > 0:18:02If you leave it to do its job, it's a really effective chemical to have around the house.
0:18:02 > 0:18:05It offers the bug killing of bleach without the unwanted taste and smell.
0:18:05 > 0:18:07You'll also find it in mould remover,
0:18:07 > 0:18:11and it's even safe enough to use in eyedrops and nasal sprays.
0:18:13 > 0:18:17On to a different kind of invisible dirt but one that's certainly
0:18:17 > 0:18:21harder to ignore - nasty odours.
0:18:21 > 0:18:24It's a problem that calls for a solution to be conjured
0:18:24 > 0:18:26literally from thin air.
0:18:32 > 0:18:33Eugh!
0:18:33 > 0:18:37'Your home might look like something from a style magazine
0:18:37 > 0:18:40'but throw in some bad odours and you're sure to make'
0:18:40 > 0:18:44a lasting impression for all the wrong reasons.
0:18:44 > 0:18:48Like most, I think smelling clean means clean
0:18:48 > 0:18:50and I do use air fresheners.
0:18:50 > 0:18:55But am I actually getting rid of the problem or just temporarily covering it up?
0:18:55 > 0:19:01Time to get some answers from one scientist who always comes up smelling of roses.
0:19:01 > 0:19:06Mark reckons he can show me how bad smells get right up my nose.
0:19:06 > 0:19:09Who is that? I can smell someone.
0:19:09 > 0:19:11- Hello, Jane.- Hello.
0:19:11 > 0:19:15- Now, you told me to bring something really smelly.- Yeah.
0:19:15 > 0:19:18This is my dog Jasper's bed.
0:19:18 > 0:19:21- Oh! That is dog smell.- Yeah.
0:19:21 > 0:19:25- It's damp, been in the pond dog smell.- You probably quite like that,
0:19:25 > 0:19:28- it's probably got an emotional attachment.- No, I don't at all.
0:19:28 > 0:19:31- I'd like to get rid of it.- OK. I've got a nice smell for you.- Go on.
0:19:31 > 0:19:33In contrast, this is my trainer.
0:19:35 > 0:19:40I don't have to smell it, I can see. Oh, look at that.
0:19:40 > 0:19:44- It's all damp and scuzzy. - It's actually remarkably...
0:19:44 > 0:19:47- You get used to it after a while. - I'm actually going to retch.
0:19:47 > 0:19:51'So what's happening when we smell something as rank as Mark's trainer?'
0:19:51 > 0:19:56A smell is a direct interaction from, let's say, this cheese.
0:19:56 > 0:20:00What you're smelling is a molecule. I'm going to represent this light as a molecule
0:20:00 > 0:20:03coming of this cheese. And it's bouncing around the air.
0:20:03 > 0:20:06Sooner or later, one of them is going to get near your nose,
0:20:06 > 0:20:09and it goes up your nose and it hits the mucus in your nose
0:20:09 > 0:20:12and it actually is absorbed into the mucus.
0:20:12 > 0:20:16So a bit of cheese is in your nose now. That's what you're smelling.
0:20:16 > 0:20:19It's actually a physical thing that you're getting in there.
0:20:19 > 0:20:23- So, if you smell dog poo, you've got a bit of dog poo in your nose?- Yes.
0:20:23 > 0:20:26That is amazing!
0:20:27 > 0:20:30Mmm. It's not amazing, it's rather hideous, actually, if I'm honest!
0:20:30 > 0:20:35Yes! And there are these receptors in the mucus which are picking up
0:20:35 > 0:20:40what's in there, and that goes to your brain and your brain says, "Hey, I smell dog poo."
0:20:40 > 0:20:45'For centuries, we apparently relied on just covering up horrendous whiffs
0:20:45 > 0:20:48'with nice smelling stuff like flowers.'
0:20:48 > 0:20:52- There you are, look at that. Lovely. - Great, I'll put those back on again.
0:20:52 > 0:20:54- That's worked.- It has, yeah. - It has, hasn't it?
0:20:58 > 0:21:03'But to my mind, for something in air freshener to qualify as a wonderstuff,
0:21:03 > 0:21:06'it's got to actually kill smells, not just mask them.
0:21:06 > 0:21:11'Many of your fancy odour eliminators claim to do just that.'
0:21:11 > 0:21:13It all kicked off in the 1950s.
0:21:13 > 0:21:17People started to realise that not only can you just put nice smells into the air,
0:21:17 > 0:21:21you can actually identify bad smells that are in the air and break them up
0:21:21 > 0:21:24before they hit your nose, so sort of grab them
0:21:24 > 0:21:28and kind of change their chemical nature.
0:21:28 > 0:21:30These are called deodorisers.
0:21:31 > 0:21:36'Deodorisers that attack and destroy smells in mid-air?
0:21:36 > 0:21:38'Sounds like clever advertising to me.
0:21:41 > 0:21:43'To get to the bottom of this,
0:21:43 > 0:21:47'I'm going to have to speak to some real smell super-boffins.
0:21:47 > 0:21:51'This is the rather fragrant global HQ of CPL Aromas.
0:21:51 > 0:21:57'They're responsible for creating some of the very latest high-tech ingredients in our deodorisers.'
0:21:59 > 0:22:01Now, that's what I call a house.
0:22:01 > 0:22:05I do hope Jeeves has got my gin and tonic ready.
0:22:06 > 0:22:10'My Jeeves turns out to be global head of research Tim Whiteley.
0:22:10 > 0:22:14'According to Tim, we all have unique smell receptors in our noses,
0:22:14 > 0:22:17'like a fingerprint, and he'll test how good mine are.'
0:22:17 > 0:22:19I'm quite nervous.
0:22:19 > 0:22:22I'm feeling the pressure now, Tim.
0:22:22 > 0:22:25'I think I've got a pretty good sense of smell,
0:22:25 > 0:22:28'but it turns out that, when it comes to identifying a pleasing aroma,
0:22:28 > 0:22:31'it's not as easy as you'd expect.'
0:22:31 > 0:22:33It's, I would say, like a lemon verbena.
0:22:33 > 0:22:37- The general character is actually rose.- Rose?!
0:22:37 > 0:22:39I'm seeing sweetie jars.
0:22:39 > 0:22:43Like, oh, blimey, like a cough sweet!
0:22:43 > 0:22:45- If you like pear drops... - Pear drops!
0:22:45 > 0:22:47Oh, my God, yes.
0:22:47 > 0:22:50'Blimey, this is a lot harder than my toilet cleaner smell test.'
0:22:50 > 0:22:55- This one is actually lavender oil. - That's what it is! Lavender!
0:22:55 > 0:22:57How could I not get lavender?
0:22:57 > 0:22:59I think that's peppermint.
0:22:59 > 0:23:00That's spear.
0:23:00 > 0:23:04- Very good. The first two were spearmint...- Yes!
0:23:04 > 0:23:06- ..and the last one's peppermint. - Yes!
0:23:06 > 0:23:07So, have I got a job?
0:23:07 > 0:23:10There's room for improvement, but I think we could work on you.
0:23:10 > 0:23:12That's a no, then.
0:23:12 > 0:23:14Darn it.
0:23:14 > 0:23:16'Weirdly, recognising nice smells is much harder
0:23:16 > 0:23:21'than identifying nasty ones, as Tim's about to prove.'
0:23:22 > 0:23:26Oh, I'm such a trusting soul, aren't I, eh?
0:23:26 > 0:23:28- I can smell it already. - Here we come.
0:23:28 > 0:23:30Just have a smell.
0:23:30 > 0:23:33Oh, God, I don't like fish at the best of times,
0:23:33 > 0:23:35- and that's fish that's very off, isn't it?- Yes, it is.
0:23:35 > 0:23:40'So, how come we register bad smells so much more easily than good ones?'
0:23:40 > 0:23:44Well, we've got two senses of smell, we have our olfactory sense,
0:23:44 > 0:23:47which is where we normally smell more pleasant items,
0:23:47 > 0:23:50but then we also have the trigeminal sense of smell,
0:23:50 > 0:23:53which is really our evolution, our older sense of smell.
0:23:53 > 0:23:57Materials that you smell that are likely to do you harm
0:23:57 > 0:23:59are the way you will smell trigeminal.
0:23:59 > 0:24:02It's our most direct route into the brain of any sense.
0:24:02 > 0:24:07'So apparently we've evolved a separate ultra-sensitive sense of smell
0:24:07 > 0:24:10'just for detecting strong, potentially dangerous, odours.
0:24:10 > 0:24:13'And that's what makes covering them up so difficult.
0:24:13 > 0:24:17'Apart from just masking smells, like Mark explained,
0:24:17 > 0:24:20'Tim's deodorisers contain some hi-tech aroma molecules
0:24:20 > 0:24:23'that actually attack and destroy bad smells
0:24:23 > 0:24:26'so that our noses can no longer smell them.
0:24:26 > 0:24:31'It's complicated, but he's got some balls to help me understand.
0:24:31 > 0:24:35'First up, a molecule that can make a bad smell disappear from thin air.'
0:24:35 > 0:24:40So, say this is our malodour, in a combination reaction,
0:24:40 > 0:24:45the aroma molecules combine together to give a much bigger molecule
0:24:45 > 0:24:47that's a lot heavier.
0:24:47 > 0:24:52It's actually so heavy that it will then physically drop out of the air.
0:24:52 > 0:24:55- Therefore it's not in the air and we're not smelling it?- That's right.
0:24:55 > 0:24:59'Clever stuff. And his second cunning deodoriser molecule
0:24:59 > 0:25:03'works directly in your nose by blocking the smell receptors.'
0:25:03 > 0:25:09This has enough similar shape to bind to the same receptor
0:25:09 > 0:25:14your bad smell would normally bind to, and so changes what you smell.
0:25:14 > 0:25:18It gets to the receptors in the nose first
0:25:18 > 0:25:21and sort of blocks that little bit of the jigsaw
0:25:21 > 0:25:24- so that the bad smell can't fit in there?- Exactly.
0:25:24 > 0:25:26'And the finale?
0:25:26 > 0:25:30'A molecule that tricks you into thinking a bad smell is a nice one.'
0:25:30 > 0:25:34You're actually changing the shape of the malodour molecule itself.
0:25:34 > 0:25:38That shape, in terms of how it binds to the receptor site,
0:25:38 > 0:25:41is different to that shape,
0:25:41 > 0:25:45so while that shape gives you your bad smell,
0:25:45 > 0:25:48that shape gives you your more pleasant smell.
0:25:48 > 0:25:52'And to show how effective it is, he's got one last test
0:25:52 > 0:25:53'for my exhausted nose.'
0:25:53 > 0:25:58This is a material that we would class as not particularly pleasant,
0:25:58 > 0:26:00it's found in quite a lot of malodours.
0:26:00 > 0:26:04It's sort of, erm, damp dog.
0:26:04 > 0:26:06'My smell arch-enemy,
0:26:06 > 0:26:10'to which Tim adds a few drops of his stereochemical binder.'
0:26:10 > 0:26:12Give that a little shake.
0:26:19 > 0:26:24Oh, yes, that's much more pleasant, yeah. It's, erm...
0:26:24 > 0:26:28- sort of fruity.- Fruity, orangey.
0:26:29 > 0:26:31Gosh, yes, that's much, much nicer.
0:26:31 > 0:26:34- That is utterly astonishing.- Yeah.
0:26:37 > 0:26:42'These stereochemical binders are genuinely wondrous.
0:26:42 > 0:26:45'They leap on our bad smells and turn them good.
0:26:45 > 0:26:50'Over the last 50 years, researchers have developed a range of potent cocktails
0:26:50 > 0:26:54'to attack different kinds of pong in mid-air.
0:26:54 > 0:26:57'Much as we'd love to tell you some catchy names
0:26:57 > 0:27:00'that you might read on ingredient labels, unfortunately,
0:27:00 > 0:27:04'like Coke and Colonel Sanders, they're a trade secret.
0:27:06 > 0:27:09'On this particular Wonderstuff hunt,
0:27:09 > 0:27:13'I've turned my home over to the microbial Mafia,
0:27:13 > 0:27:16'and I've learned that the simple brilliance of bleach
0:27:16 > 0:27:20'just can't be beaten when it comes to killing harmful germs.
0:27:20 > 0:27:23'But I suppose I've been most blown away to discover
0:27:23 > 0:27:29'that bad odours are actually just airborne little bits of filth floating around.'
0:27:29 > 0:27:33Yuck. But luckily for our nostrils, some of our best inventors
0:27:33 > 0:27:39have come up with some fancy chemical action that works in mid-air.
0:27:40 > 0:27:44'Next time, I come over all practical
0:27:44 > 0:27:49'and dive into the extraordinary world of the substances that hold our lives together.
0:27:49 > 0:27:53'I push sticky stuff and my nerves to breaking point...'
0:27:53 > 0:27:54SHE SHRIEKS
0:27:54 > 0:27:56'..in the search for the magic in glue.'
0:27:56 > 0:27:59It's a good job I've got a strong heart!
0:27:59 > 0:28:01'I dig down to find the surprise
0:28:01 > 0:28:04'at the core of the world's slipperiest substance.'
0:28:04 > 0:28:06It's like Raiders Of The Lost Ark down here.
0:28:06 > 0:28:10'And I uncover an unexpected genius wonderstuff
0:28:10 > 0:28:14'that links paint, paper and...cottage cheese?'
0:28:14 > 0:28:17If there's any organic matter near it, it makes it disintegrate.
0:28:17 > 0:28:20That sounds astonishingly clever.
0:28:34 > 0:28:38Subtitles by Red Bee Media Ltd
0:28:38 > 0:28:42E-mail - subtitling@bbc.co.uk