The Grenfell cladding

This BBC podcast is supported by ads outside the UK.

At Arizona State University, we've made online education better, smarter, and more personalized so you can go further in your aspiring field.

I decided to pursue medicine once I realized that ASU did have the online program for biological sciences.

You're still required to learn the same curriculum.

You're still being tested on the same content that anyone would be tested on in person.

The comprehensiveness of the program prepared me so well for medical school.

Explore over 350 plus programs at ASUOnline.asu.edu.

When disaster takes control of your life, ServePro helps you take it back.

ServePro shows up faster to any size disaster to make things right, starting with a single call, that's all.

Because the number one name in cleanup and restoration has the scale and the expertise to get you back up to speed quicker than you ever thought possible.

So whenever never thought this would happen actually happens, ServePro's got you.

Call 1-800-SURFPRO or visit SurfPro.com today to help make it like it never even happened.

BBC Sounds, music, radio, podcasts.

You're listening to BBC Inside Science presented by me, Victoria Gill.

The biggest problem is that building was wrapped in...

You could have taken a whole box of fire lighters.

you know, from a, you know, a DIY store that you use on a barbecue and just wrapped the building in that.

It was that simple.

That was architect and TV presenter George Clark talking about the material that was used to clad Grenfell Tower.

And as the long-awaited final report into the blaze that killed 72 people is finally made public this week, we're looking in detail at that cladding, a flammable building material that's been at the center of the story for seven years.

Joining me now is Richard Hull, an expert in chemistry and fire science, who's been looking at the Grenfell report.

Richard, welcome to Inside Science.

Thanks for joining us.

Thank you.

So, can we get straight into the chemistry of this material?

Can you tell me a bit more about it?

What is it?

What was this cladding?

It's two sheets of aluminium, half a millimetre thick, with three millimetres of polythene in between.

And both polythene and aluminium are fairly flexible, but when you stick them all together, they turn into this pretty rigid board which can be painted and made to look architecturally very pleasing.

And we heard briefly from George Clark at the top of the programme talking about it being like wrapping the building in fire lighters.

Is the chemistry comparable?

Well the chemistry of polythene is the same as the chemistry of petrol.

They both burn and they release a large amount of heat.

So what happens when this material is heated up when it catches fire?

The polythene melts and it starts to pour down and once it ignites then it'll cause more of the polythene to melt and it'll all start to drip down eventually melting the aluminium and then causing the insulation to start burning.

So you have two problems the fire will go upwards in the gap like a chimney but it will also produce molten droplets that will drip downwards.

Is that what happened at Grenfell in that and caused that terrible fire that we've seen so many pictures of?

Tragically yes I think from the expert witness reports the fire appeared to move up one of the pillars and then it got into the crown around the top of the building.

And then once it had spread around the crown,

because of these burning molten droplets, it was able to spread down the other pillars and then spread to the rest of the cladding.

Right.

So that spread of the fire, that melting and dripping, did that entirely carry the fire on the outside of the building?

Was it this cladding that ignited that terrible blaze that we saw when Grenfell caught fire?

Well, no, not really, because the concrete walls had 15 centimetres of insulation foam put onto them, and then a gap of five centimetres,

and then this very flammable aluminium polythene composite.

And the aluminium polythene composite spread the flame very quickly, but then it ignited the insulation foam, which burnt much more slowly.

And that meant that the fire really took hold.

There are other examples where you've just had the polythene aluminium, and the fire has never entered the building.

And the report said this is something you've written about: that those 72 people who died in that fire weren't killed by the fire, but by inhaling toxic gases, and that came from the cladding being burnt.

What happens chemically, and what kind of gases are we talking about from this material?

The insulation foam that they used on Grenfell was PIR, which is a kind of polyurethane, and that contains nitrogen.

And when it burns, it produces hydrogen cyanide as well as carbon monoxide.

And so as the insulation was burning, it was filling people's flats with this toxic gas.

The hydrogen cyanide causes very rapid unconsciousness, and so people were collapsing, unable to escape.

And so they would carry on breathing the gases until finally they died.

And

going back to the cladding and its use,

it would have to go through some sort of testing.

Would testing pick up that problem of the gases that are released?

Or

how did this pass a test and be used to clad such a huge building that was home to so many people?

Well, the testing's a complicated issue, but the foam has a test which is put onto a mock-up of a facade,

and there is no test at all for the toxicity of the gases coming off.

The

polythene aluminium is tested on its face so effectively only the aluminium is exposed to the radiation and so it gets a much higher rating than it would get if you actually look at how it behaved in a fire.

We tried to do a test where we used the Grenfell type cladding and we had to stop the test after 12 minutes.

What happened in that test?

Why did you stop it?

It just ignites, and the fire spreads so quickly and so dangerously.

In our case, some of the steel on the top of the building that we were using was starting to buckle, and so there was a risk of collapse.

But the fire just spreads as quickly as it did on Grenfell.

And this type of cladding was banned in 2022.

Has it gone away now?

Are there still buildings that are clad in this material?

Has it just been banned for use in new builds?

In new builds and refurbishment, combustible materials, so that's both the foam and the polythene aluminium, are no longer allowed to be used.

But as you correctly say, of the, I think, around 11,000 buildings that were identified as having combustible materials on them, tall residential buildings, I think there are still four and a half thousand left with people living in them, knowing that the government now deems that unsafe, but they haven't been put right.

Four and a half thousand.

And so, do you know what is going to happen with those buildings?

I can't imagine what people who

those buildings are their homes are feeling like now in the wake of Grenfell.

I can't imagine it either, but I think ultimately it's a case of time

and you've still got this buck passing.

It's ended up in legal disputes that really shouldn't be taking place.

They should be looking after the people who live in the buildings.

Yeah, because meanwhile people are still unsafe.

And what about the testing now?

You walked us through how the testing for the flammability was inadequate, and there was no testing of what happens when this material catches fire and those toxic gases.

In the seven years since the terrible tragedy at Grenfell, how has that changed?

Well, the government had a £600,000 project to look at measuring smoke toxicity so that the people perhaps putting foam on Grenfell would have known that the PIR foam was five times more toxic when it burned than the closest product, phenolic foam.

So far they've had a four-year project.

We're eagerly awaiting the results of that.

it may be that they're going to be some years away from actually regulating smoke toxicity.

So you can make a product which is 100 times more toxic in a fire than one that's currently available and the government have no power to stop you selling it.

And as a chemist and a researcher in fire science, what did you think when you saw the report of how this tragedy happened?

Really a sense of frustration because to a chemist, combustible is a very clearly defined concept and there were arguments at the time that these materials weren't combustible and they so obviously were.

Well, thank you very much, Richard Hull, who is Professor of Chemistry and Fire Science at the University of Central Lancashire.

You are listening to BBC Inside Science with me, Victoria Gill.

Coming up.

Imagine being in a capsule 250 miles above Earth's surface, and you hear that.

I don't know about you, but I would be alarmed.

We'll investigate the phenomenon of spooky noises in space.

And we'll definitely be finding out how waiting in a queue for Oasis tickets affects your brain.

No maybes about it.

Now, Team GB has racked up more than 30 gold medals in the Paris Paralympics.

This has been enabled in part by advances in assistive technology, prosthetics, wheelchairs, and other equipment that's customised for elite para-athletes.

I've been speaking to Bryce Dyer, who designs some of this specialist technology.

It allows me to sort of bypass a few million years years of evolution in some ways in that we can create devices that essentially are tailored specifically to the needs of the athlete and their sport and we can do it in a better way in many cases than waiting for evolution to catch up with us or try and hope the human body does things it's actually not designed that well to do such as swimming or running very very fast through technology we can make that process easier, more comfortable and more enjoyable for the participants and that's really you know what gets me out of bed in the morning with this kind of stuff.

I guess one of the most familiar types of prostheses when we think about the the Paralympics in sport would be blades for runners

and they look absolutely nothing like a human leg and a foot.

How does it work and why is that the approach that is used by engineers that develop these prostheses?

In the case of running blades it's essentially a spring.

So as the runner moves along a track their body weight puts energy into the actual prosthetic limb.

It then compresses with that load and then very, very quickly and hopefully in the direction of travel, it then returns that energy back by then extending again and propels the runner actually forward.

Apparently the original concept it was designed by a man called Van Phillips who was inspired by cheetah legs, the rear legs of a cheetah.

And it's really where nature or what we often call in design biomimicry where we're inspired by the natural world around us to drive change.

But it's also more about being problem focused.

So to give you an example, if I ask you to design a teapot, you'd design me a teapot.

But if I ask you to design me something that boils water in 30 seconds, then actually the solution you provide for me might actually look different and appear different.

And it's the same with these prosthetic legs.

They've tried to work out how can we get energy into a running track and back to the runner to allow them to be propelled forward as efficiently as possible.

And that doesn't actually involve necessarily creating something that looks like a human leg.

I had no idea that that inspiration came from the back leg of a tutor.

That's that's fascinating.

And there's been some concern, even some controversy, discussion about that giving an advantage, you know, maybe an unfair advantage to runners.

Do you think there's any

truth in that?

As always with all science, it depends.

But in this particular case, it is a completely different form of locomotion.

So there are pros and cons.

And some of those pros might be, for example, it is very mechanically efficient what they're doing.

But some of the cons are that those legs don't change their behaviour through the race.

So you can find yourself drifting in and out of harmony with that device, depending on the event and how fatigued that you're getting.

They don't operate particularly well in the wet.

Running around a wet running track is terrible.

But the crucial thing always is that it is different and it's very, very hard to compare one against the other directly.

I mean, with the Paralympics in competition, that's what you're doing, isn't it?

You're competing and comparing one athlete with another.

So how much does fairness and sort of being within that comparable range limit or affect what you design?

I guess you can't just go for what is as fast as possible.

Yes, I mean the critical debate here is that on one side you have a sports engineer like myself that will develop this equipment, but then there is also the responsibility of the sport to maintain fairness and what would be known as a level playing field.

And that constant tug of war between these two things is something that is a very, very fine line.

And where parasport differs considerably to other forms of sport is that often if you don't have good technology to hand, that race is over before the starting gun has gone.

And that is a worry for the sport as a whole, I think, a lot of the time.

But is there any room in the Paralympics for something where all engineering limits are off and you really can push the technology with these prosthetics so they are like performance enhancing?

Yeah, it's a really good question.

But the problem is when you do that, it then ultimately becomes a race of someone's checkbook.

There is a form of competition that doesn't have the same level of constraints or the emphasis on fairness between all the participants and that is in fact the cybathlon which is a sporting event made of eight different disciplines that is very very technology focused.

The athlete or the participant is allowed to utilize a virtually unrestrained level of technology.

So whereas current prosthetic limbs in the Paralympic Games do not enhance performance, the technology used at the cybathlon does enhance it.

It actually augments it as much as possible.

It sort of sounds like the engineering gloves are off when it comes to that event.

So, what sort of things will participants use?

Okay, so there are things like wheelchair racing, but where is using the racing wheelchairs we'll see at the Paralympic Games, which are essentially two push wheels and then a single wheel on the front.

They'll be using things like motorized caterpillar tracks, for example, at the cybathlon.

In the leg prosthesis race they have there, where you have to traverse a series of obstacles.

They'll be using computer-controlled, motorized prosthetic limbs.

There'll be things like exoskeleton races.

So that's where you're wearing an exoskeleton to move over a given distance.

So that human participant is having technology around them, almost like a shell, to help power them to move forward.

Or even a brain-computer interface race where your brain is actually controlling your motion.

This is fascinating stuff.

It sounds like it's a real sort of technology competition as well as a physical competition.

Absolutely.

It's techno-centric.

And the Paralympic Games are showing what is possible by human beings, whereas the Sabbath one is showing what is possible through technology.

But both of these things will inspire people of the future to achieve more, to do more.

And the technology itself will inspire academics like myself and others to really push the boundaries on what is possible to try and improve the quality of people's life and physical activity as much as possible.

And how does that affect just people in everyday life?

So not, you know, non-elite athlete people with physical disabilities.

what comes out of sports that

will help more people more broadly?

The way to really look at it is it's a bit like Formula One is with your everyday family saloon car in that over time, although it seems quite elitist and specific, over time that technology will trickle down into everyday devices that someone with a disability or an impairment will have in everyday life.

Because what you've got with elite athletes are people that are pushing technology to its absolute limits.

And these things will break when you go too hard for too long and too fast.

So that becomes a very good working environment for finding out how design should be optimized to take the stresses and strains of everyday use and tasks, whether it's running down an athletics track or going to the shop.

So there is this trickle-down effect that can take time, but sport is a very pure way of optimizing and refining technology to allow us to do that.

Thank you to Bryce Dyer there.

He's Associate Professor of Sports Technology at Bournemouth University.

And if there are any other transformative technologies that you'd like us to delve into on the program, please do email us at inside.science at bbc.co.uk.

With so many options, why choose Arizona State University?

For me, the only online option was ASU because of the quality.

Their faculty was really involved with their students and care about your personal journey.

The dedication to my personal development from my professors, that's been extremely valuable to me.

Earn your degree from the nation's most innovative university online.

That's a degree better.

Explore more than 350 plus undergraduate, graduate, and certificate programs at asuonline.asu.edu.

Looking to transform your business through Better HR and payroll?

Meet PACOR, a paychecks company, the powerhouse solution that empowers leaders to drive results.

From recruiting and development to payroll and analytics, PACOR connects you with the people, data, and expertise you need to succeed.

Their innovative platform helps you make smarter decisions about your most valuable asset, your people.

Ready to become a better leader?

Visit paycor.com/slash leaders to learn more.

That's paycor.com/slash leaders.

Now, cosmologist Andrew Ponson has been pondering a very strange sound that was recorded by NASA astronaut Butch Wilmore while he was orbiting Earth earlier this week.

There's a strange noise coming through the speaker.

I don't know what's making it, but

This is the eerie noise coming from the radio of the troubled Boeing Starliner spacecraft, currently docked with the International Space Station.

The noise set the internet alight with speculation that Starliner is haunted by space ghosts, though NASA quickly explained it was just a quirk in its audio settings.

Still, Starliner has suffered a series of malfunctions and is about to return empty to Earth, leaving its crew up on the space station for an unplanned holiday.

While there aren't any ghosts that we know of, space can be a spooky place with plenty of naturally occurring eerie signals to pick up on.

The film Alien taught us that, in space, no one can hear you scream, but it's not quite true.

That's radio emission from Saturn, made naturally when the planet passes through plumes of gas from the Sun.

Radio and sound aren't quite the same, of course, but turning one into the other is a great way to experience what we can't perceive directly.

And even if you don't have radio receivers, space isn't totally silent.

It's true that sound is normally carried by air.

If you sit next to me as I talk here on Earth, your ear is really detecting vibrations from my voice box.

Out in space, if there were nothing like air at all, there'd be nothing to carry those vibrations from me to you, and therefore no sound to listen to.

But the thing is, space isn't a total vacuum.

It does have gases everywhere, albeit with densities that are at least 100 billion billion times smaller than air here on Earth.

Even that trace of gas allows some sounds to carry, especially ones with a very low pitch.

So it's natural to point our ears to the sky and listen.

That's a sound in space, this time a galaxy cluster, a collection of stars and gas millions of light years across, rippling with sound energy from a huge black hole at its center.

So if you happen to be a black hole in space, people can hear you scream.

The only snag is that this has has been artificially manipulated, transposed up by the equivalent of 57 musical octaves to make it audible to human ears.

For something that vibrates at the right pitch to be heard directly, we can turn to gravitational waves, distinctive ripples that black holes generate when they collide.

These vibrations don't need any air or gas to travel through because they're waves in the fabric of space itself, so any note can carry.

But they are exceptionally quiet, so we didn't hear them until physicists built several ultra-sensitive, 4-kilometer-wide detectors to pick them up.

For all that effort, at first the result doesn't sound like much.

Yet, that unassuming bloop really was the collision of two black holes a billion light years away, and researchers are poring over sounds like these to find out how black holes work, how many of them there are, and how they are born.

New gravitational wave detectors are under construction, which in the 2030s will extend the range of our hearing even beyond the furthest we can see with traditional telescopes.

So, studying space noises turns out to be a great way to understand it better.

We wouldn't hear them with our unaided ears, but then nor can we see much of the universe's vast and intricate depths with our naked eyes either.

Since Galileo first used a telescope, building the right equipment has been key to unlocking cosmic secrets and experiencing space in a way that's tangible to us.

Even if Starliner's sounds had a mundane explanation, its marooned crew should definitely keep their ears open for the astonishing, if very quiet,

sounds of our universe.

I'll do it one more time and hold y'all scratch your heads and see if you can figure out what's going on.

Here we go.

Andrew Ponson there with some very strange noises.

Now, last week, people had a lot of time to feel nostalgic about 90s Brit Pop, as much of the nation sat in an hours-long online queue.

I'm talking, of course, about the Oasis reunion tour and the interminable wait that fans endured trying to get tickets.

It got us thinking, what happens to our brains and our decision-making abilities when we have to queue for that long.

Ginny Smith, science writer and neuroscientist, is here.

Ginny, did you join the queue?

I didn't, I must say, although I am a big fan of indie music, Oasis have never really been my thing.

Yeah, I was so disinterested.

And I think like as a northerner that was a child of the 90s, I must be like a bit of a rare species.

But I'm

with you.

I think they're a bit overrated, if I'm honest.

I'm not sure I should say that on the radio.

I did turn into a very controversial chat,

controversial neuroscience.

But a lot of people did.

And for those who were on the mission to get tickets, there was this weird thing called dynamic pricing.

So there were people sitting expecting to pay a certain amount, sort of queued up to say that their tickets were on price.

And then when they actually bought them, they ended up spending a lot more.

What's going on in our brains when that happens?

Well, I think there's a few different kind of psychology things that are going on here.

One of them is what's sometimes called the sunk cost fallacy.

So, this is also often framed as throwing good money after bad, but in this case, we're actually throwing good money after time.

Because basically, we don't like the idea of having nothing to show after we've put in a lot of time or effort or money into something.

And that can mean that we keep going with something

even though it would be more logical to stop and to cut our losses.

So, in this case, what you have is people who'd spent their entire day on the computer waiting for these tickets.

They get to that checkout point and okay, it's more expensive than I thought it was going to be, but if I don't get it, then I've spent my whole day doing this and I have nothing to show for it.

So for those of us like me who can't really imagine sitting, waiting and spending £300 on specifically on an OASIS ticket, you know, how does that sunk cost fallacy play out in other aspects of our lives?

So in a kind of individual perspective, one example might be that you have quite an old car that you've had for a while.

Maybe you've just taken it for its MOT and you've had to spend a few thousand pounds to get it through its MOT, then something else breaks.

At what point do you call it and say, No, this is silly.

I'm pouring more and more money into this car.

I should just buy a new car

and people are less likely to do that when they've just spent a load of money on it.

A sort of lower stakes one might be if you've started reading a book, or what happens to me usually is watching TV series.

Maybe the first season is really good and then it starts going downhill.

But you feel like you can't just stop watching it or reading the book.

Like you have to stick with it.

Now, there's no real logic in that.

You're just wasting more of your time.

If you're not enjoying the TV show, you should just stop watching it.

But because we've invested time in it, we feel like we have to keep going.

That rings so true with me.

And I just get more and more irritated and angry with the series/slash book

that I'm forcing myself to finish.

The amount of time people spent in this queue was huge.

I heard of people sitting in these queues for 12 hours.

So, apart from not wanting to waste that time when the ticket availability pops up, even though it's more expensive, how is just that long wait affecting people's decision-making?

Oh, well, I think one of the big things is that it would be really, really boring,

but also

stressful because especially if you're listening to OASIS albums

while you're waiting.

So, yeah, quite stressful, a lot of anxiety building up.

Absolutely.

And then when that pop-up would happen, you get this rush of adrenaline, this surge of excitement, emotion.

Suddenly, your time has come.

And I think that, again, doesn't necessarily put people in the best state for slow, logical, rational decision-making because you've got flooded with these emotional chemicals.

You don't have the time to take a step back, engage your prefrontal cortex, think rationally.

What does that impulsivity and that emotional decision-making do?

Why are we more driven to say, Yes, I'm going to spend a lot of money in that very quick emotional state?

Well, I think the other thing that was going on at that point is this fear of missing out, FOMO, as people call it.

And we have this really big fear of causing ourselves regret.

Regret is one of a human's least favourite emotions.

So we're very driven to do anything that will avoid us having regrets.

And I think there were probably a lot of people who were in that moment thinking, if I don't get this ticket, I'm going to miss out.

My friends are going, you know, it might be my only chance to see them.

And that fear of missing that opportunity, I think, would drive people to make slightly perhaps rash decisions that if they had a bit more time to think through, and I think we've had examples of people who have woken up the next day and been like, Oh my goodness, why did I spend so much money?

But in the heat of the moment, you're thinking about how it would feel to not get the ticket, and that is a bigger driver than how it would feel to spend the money in that sort of emotional state.

We maybe had some

ticket providers that knew a lot more about the neuroscientific drivers that were going to make people spend a lot more money than people appreciated.

Well, let's hope the Gallagher brothers make it through the entire tour without having a massive bust up so that people actually

get what they paid for.

But Ginny, that was fascinating.

Thank you very much indeed.

You're welcome.

Thanks for having me on.

Imagine if the whole music was just Wonderwall on repeat, doesn't they thinking about?

But we will not take up hours more of your precious time because that is all we have time for this week.

And you have been listening to BBC Inside Science with me, Victoria Gill.

The producers were Sophie Ormiston, Ella Hubber, and Jerry Holt.

Technical production was by Emily Preston and the show was made in Cardiff by BBC Wales and West.

Next week, we'll be asking where we can put nuclear waste that remains hazardous to humans for thousands of years.

Until then, thanks for listening and bye-bye.

BBC Sounds, Music, Radio, Podcasts.

The Mercedes-Benz Dream Days are back with offers on vehicles like the 2025 E-Class, CLE Coupe, C-Class, and EQE sedan.

Hurry in now through July 31st.

Visit your local authorized dealer or learn more at mbusa.com/slash dream.

This Labor Day, gear up, save big, and ride harder with cycle gear.

From August 22nd to September 1st, score up to 60% off motorcycle gear from your favorite brands.

RPM members get 50% off tire mount and balance with any new tire purchase.

Need to hit the road now?

Fast Lane Financing lets you ride now and pay later with 0% interest for three months.

And here's the big one: August 29th through September 1st only.

Buy any helmet $319 or more and get a free Cardo Spirit Bluetooth.

Supplies are limited.

Don't wait.

Cycle gear.

Get there.

Start here.