Melissa: 00:09

Hey. I'm Melissa.

Jam: 00:11

I'm Jam.

Melissa: 00:11

And I'm a chemist.

Jam: 00:12

And I'm not.

Melissa: 00:13

And welcome to chemistry for your life.

Jam: 00:15

The podcast that helps you understand the chemistry of your everyday life.

Melissa: 00:19

Okay, Jam. Today, we're gonna be talking about the light side of chemistry.

Jam: 00:25

The light side.

Melissa: 00:26

Okay. But not The light as in the light.

Jam: 00:29

Okay. Okay.

Melissa: 00:30

But we talk a lot about the dark side of chemistry where chemists basically ruin people's lives with their Inventions? Right.

Jam: 00:35

And most of chemistry is a dark side. Right?

Melissa: 00:37

No. Definitely not. Chemistry is beautiful and productive and builds us up and saves lives in many ways, and we're gonna talk about one of those today.

Jam: 00:45

But, also, chemistry hurts our eyes when we cut onions. Remember?

Melissa: 00:48

That's true.

Jam: 00:50

So okay. But there's a good side today.

Melissa: 00:52

This is a good side. Yes. Good side of chemistry. This made me really happy when I learned about it.

Jam: 00:56

Okay. I'm here for that.

Melissa: 00:57

So a friend of the show, Sam In, said that he had a chemical burn on his arm that he got from an accident where an airbag deployed that he was in.

Jam: 01:06

Oh, wow. Recently? Or

Melissa: 01:07

No. It was a long time ago.

Jam: 01:09

I've heard about that car accident he was in.

Melissa: 01:11

And I'm not sure what prompted him to think about it this week.

Jam: 01:14

Uh-huh.

Melissa: 01:15

But he messaged me asking about it, and I got really excited because I didn't realize that airbags work chemistry. I love it when I find new chemistry applications.

Jam: 01:26

Uh-huh. Uh-huh.

Melissa: 01:27

So I got very excited, and I said, we're doing this episode right now.

Jam: 01:32

Thanks. Sweet. Great idea, Sam.

Melissa: 01:34

Yeah. Good job, Sam. And I was pretty busy this week and had not had time to think through a good topic idea, so he kinda saved me.

Jam: 01:40

Nice.

Melissa: 01:41

Anna saved my tail a little bit, so thanks, Sam.

Jam: 01:44

Just like airbags do when we're really in a bad situation. You know?

Melissa: 01:47

That is so true. Okay. So Some facts about airbags that I'm gonna start us off with.

Jam: 01:54

Okay.

Melissa: 01:55

The National Highway Traffic Safety Administration, also known as Which I think these facts are based in the states primarily and not worldwide. Mhmm.

Jam: 02:06

Okay.

Melissa: 02:06

But I couldn't find out that for sure. But since it's a national Organization. I thought maybe that was true, and the numbers seem a little low. So what they told me was in 2017, So that's the latest data available. Mhmm.

Melissa: 02:20

Airbags have saved an estimated that year, they saved an estimated 2,790 lives.

Jam: 02:27

Okay.

Melissa: 02:28

In total, from when they were invented in 1987 to now, they have saved 50,457 lives.

Jam: 02:36

Interesting.

Melissa: 02:38

But I do think that's just in the United States.

Jam: 02:40

Yeah. It makes sense. It's weird because I don't really know what I expected, but there's not a ton of people Mhmm. Really. But when you think about How that's still a lot of people and so worth the invention of it.

Jam: 02:52

I mean, it's

Melissa: 02:52

like Right.

Jam: 02:53

In sip 2017, it being, like, around 3,000 people or whatever. Right? Is still great.

Melissa: 02:59

It's 3,000 people who didn't die.

Jam: 03:01

Yeah. Preventable deaths.

Melissa: 03:02

Our friend Sam probably would have died in that accident. He is a pretty 10s 1.

Jam: 03:06

Yeah. Seriously. Yeah.

Melissa: 03:08

So Worth it. Worth it. Every single life saved is worth it. Mhmm. But, also, They're pretty low risk.

Melissa: 03:15

So I looked just to see if there was any injuries or death attributed to airbags not functioning properly. Mhmm. And I found, not from an official source, but I found something that said, there were 24 deaths worldwide due to airbags deploying wrongly, which that is not very many compared to the number it saved.

Jam: 03:33

Oh, yeah. That's yeah. Yeah. Great point.

Melissa: 03:35

Just that there's only 24 in the United States. A pretty small percentage. Yeah. And 250 injuries were attributed to them not functioning properly.

Jam: 03:44

Okay.

Melissa: 03:45

Most of those were before 2008. Uh-huh. And, also, most of those didn't have seatbelts on, which could have saved the them further.

Jam: 03:54

Right. Right.

Melissa: 03:55

But that was not from an official source.

Jam: 03:57

Okay.

Melissa: 03:58

So and I think they maybe switched the technology up little bit in 2008 so the airbags were less likely to deploy unnecessarily. Mhmm. Mhmm. Okay. So when your car hits another car, it takes 50 milliseconds.

Melissa: 04:16

Mhmm. That is 5 hundredth of a second.

Jam: 04:21

Uh-huh.

Melissa: 04:22

So not very many for your head to hit the steering wheel. K. Because even though your car stops, you don't stop.

Jam: 04:33

Right.

Melissa: 04:33

If you're traveling 70 miles an hour, your car suddenly stops. Mhmm. You are still traveling at 70 miles an hour.

Jam: 04:41

And it's called inertia. Right?

Melissa: 04:43

I think so.

Jam: 04:46

The physics part of me says that is right.

Melissa: 04:49

But That probably is right. So you're still moving even though your car is not, and that causes really scary damage.

Jam: 04:57

Yeah. Dang. 70 miles an hour. That's serious.

Melissa: 05:00

Yeah. I think that

Jam: 05:01

anything even a little bit lower with these still.

Melissa: 05:03

Anything is scary. Yeah. I don't think we have a good sense of how fast we're going when we're in cars because when I would ride my bike And there was this one super cool hill where you could hit 25 miles an hour, and it was terrifying.

Jam: 05:14

Uh-huh. Uh-huh. Yeah.

Melissa: 05:16

And 25 miles an hour in my car is as if I'm Crawling.

Jam: 05:20

Right. Right.

Melissa: 05:21

So that's just so interesting that we lose that perspective of how fast our bodies are going, and it's not natural or safe.

Jam: 05:28

Yeah.

Melissa: 05:29

And then we just get on our phones.

Jam: 05:30

Yeah. Mhmm.

Melissa: 05:32

I would never text and go down the hill on a bike at 25 miles an hour.

Jam: 05:36

Yeah. Seriously.

Melissa: 05:36

Because you're aware of the danger you're

Jam: 05:38

It's like we've made our cars really safe, but there's also isolated us from really knowing Mhmm. How fast we're going. Like, we can't feel it. Obviously, we have windshields and windows and all that stuff.

Melissa: 05:47

Right.

Jam: 05:48

And so it just feels totally normal. Yeah. Wow.

Melissa: 05:52

And I do think that 50 milliseconds or the 500th of a second is Somewhat variable based on how fast you're going and whether or not you're wearing a seat belt and all that, but that's roughly the area it's in.

Jam: 06:04

Okay.

Melissa: 06:05

So to be able to cushion your head before it hits the steering wheel, an airbag has to act faster than that. Mhmm. Mhmm. So if you think about the technology behind them, it's kind of incredible. Yeah.

Melissa: 06:17

Because they have to be able to Deploy, inflate, and then actually be coming down from the inflation all within less time Then you're 50 milliseconds.

Jam: 06:30

Wow.

Melissa: 06:31

Because if that is inflating while you hit it, it'd be the same basically as hitting a dashboard or worse because it's traveling towards you.

Jam: 06:38

It's pushing against you. Yeah. Yeah.

Melissa: 06:39

Yeah. So the they can't have that happen.

Jam: 06:42

Uh-huh.

Melissa: 06:42

So from the time your car strikes an object, they have five 100th of a second or less to be deflating.

Jam: 06:50

Dang. Wow. I mean, I've always thought of them as being fast, but I didn't think about how Pretty sure that it would be that I have to thread the needle on that, you know Yeah. Really fast. But, also, everything else is happening fast too.

Jam: 07:02

Yep. And also get all the inflated and then be able to kinda be deflating. Wow. Yeah. Someone hits it.

Jam: 07:08

That's crazy.

Melissa: 07:09

So they have to have a sensor which detects This stop that is dangerous. Mhmm. They also have to be made of something that will stay stable despite being in a wide range of environments. You know, cold, hot temperatures going down bumpy roads. Some chemicals will just explode or react upon shock.

Jam: 07:28

Uh-huh.

Melissa: 07:29

Like, Just going down a bump in the road.

Jam: 07:31

Right.

Melissa: 07:31

So you can't have that. But when the time is right, you have to have something that inflates so rapidly that You have time for the sensor to detect, for the thing to happen, and the airbag to inflate and then deflate. Mhmm. And you have to have just the right amount as

Jam: 07:46

well. Right.

Jam: 07:48

Man, that is such a challenge.

Melissa: 07:50

And you have to have an airbag that can handle all of that.

Jam: 07:54

Yeah. Dang.

Melissa: 07:58

So when I thought about that, I suddenly realized how insane it is that we have airbags.

Jam: 08:04

Right.

Melissa: 08:05

And they were invented in 1987.

Jam: 08:07

Yeah. That's impressive.

Melissa: 08:08

That was way before we had the type of technology we have now. Yeah. Computers weren't even really widespread at all.

Jam: 08:14

Right. Right.

Melissa: 08:15

They're just giant computers in a room where they had 4 air conditioning units or whatever. Yeah. Yeah. Maybe not in the eighties, but we didn't have We didn't have computers until later in my childhood, and I was born in 91. Mhmm.

Melissa: 08:29

So

Jam: 08:30

Yeah.

Melissa: 08:30

I just think that's incredible.

Jam: 08:32

It really is.

Melissa: 08:33

So how they figured out how to do all that? Chemistry. Really? Is chemistry

Jam: 08:39

Are you sure?

Melissa: 08:40

It's chemistry. The bag that contains the air Uh-huh. Is a polymer.

Jam: 08:48

Okay.

Melissa: 08:48

Yay. Chemistry saving lives.

Jam: 08:50

Is it some sort of kinda plastic or something? Or

Melissa: 08:53

I think it's polyamide, so it is like a plastic material, sort of.

Jam: 08:57

Okay.

Melissa: 08:58

But a more sturdy one.

Jam: 08:59

Got it.

Melissa: 09:00

So it's similar to polyester, but more sturdy.

Jam: 09:03

Okay. It always like I've I never touched in your bag, and I've never touched a parachute, But they always have looked similar enough to me.

Melissa: 09:09

Yeah. They do look similar.

Jam: 09:11

Strong but flexible.

Melissa: 09:13

Yeah. I think it's just a type of polymer, different types of repeating units instead of a polyester, but something similar.

Jam: 09:19

Nice. Nice.

Melissa: 09:20

And the thing that happens to fill the airbag is a chemical reaction

Jam: 09:25

Okay.

Melissa: 09:26

Which is so cool to me. So when your car hits something, a sensor goes off. Mhmm. That ignite that sensor tells An igniter to ignite. And once the molecules or the reaction that they've chosen to use, once These are heated.

Melissa: 09:43

Mhmm. A reaction takes place.

Jam: 09:46

Okay.

Melissa: 09:47

There's 2 main chemicals that they use. One is called guanidine nitrate

Jam: 09:53

Mhmm.

Melissa: 09:54

And the other is called sodium azide.

Jam: 09:56

Okay.

Melissa: 09:57

The the sodium azide is, I think, one of the more old school ways that they use.

Jam: 10:03

Okay.

Melissa: 10:03

But it's also a little bit more Simple, so I'm gonna use that as the explanation.

Jam: 10:07

Okay.

Melissa: 10:08

But I think they've updated some of these chemicals.

Jam: 10:10

Got it. And is these is the sensor maybe didn't go into that stuff, but is that, like, These days, electronic computer kind of

Melissa: 10:18

I think so.

Jam: 10:19

Pressure sensor, something like that that

Melissa: 10:21

And it seemed pretty advanced. Like, Some sensors can even tell if you have your seat belt on or not, and so they'll deploy differently based on that.

Jam: 10:31

Wow. I guess cars, no. Our first seat belts are on now Yeah. Most of the time.

Melissa: 10:34

So Cars, no. And some even said based on your weight. Oh, and I also wanted to say, You know, there's a safety zone where you need to sit so that the reason they have that where they call it this is a safe area for you to sit in your car Mhmm. Is far enough away from the steering wheel that the airbag will be deflating Mhmm. Within that time frame.

Jam: 10:58

Got it.

Melissa: 10:59

But If you've ever listened to the podcast 99% Invisible, they interviewed a book author, and she wrote a book, I believe, called The Invisible Woman.

Jam: 11:07

Mhmm.

Melissa: 11:07

And it's basically about how the world is designed for men because men are the one whose were in power when those things were invented.

Jam: 11:14

Right. Right.

Melissa: 11:15

And vehicles are Actually designed for an average male.

Jam: 11:20

Right.

Melissa: 11:20

So for a woman to be sitting close enough to the steering wheel for her legs, An average woman, for her legs to reach the steering wheel, she is not in a safety zone. And Women are, I think, 50% more likely to be seriously injured and, like, 17%, something around there, more likely to die in a serious car accident.

Jam: 11:41

Yikes.

Melissa: 11:41

And it could be saved if we just had pedal extenders instead of moving our seat forward. Isn't that crazy?

Jam: 11:48

Yes. That's a simple Change.

Melissa: 11:50

Mhmm. And there's no crash test required for a female crash test dummy. It's always just the average male. In the UK, they started to require a female crash test dummy, which was basically just a smaller male. Uh-huh.

Melissa: 12:05

They didn't have the weight distribution or anything that women typically have. Uh-huh. And it's only in the passenger seat.

Jam: 12:11

Interesting.

Melissa: 12:13

So that is something that's a little aside, but it was a really interesting podcast episode That I think just helps us think through the realities that if you're only considering the population you're a part of, some things are gonna get missed.

Jam: 12:26

Right.

Melissa: 12:27

And just the way the industry is, it's cheaper to leave things the way they are, so no one's really advocating to change that.

Jam: 12:32

Yeah. Dang. That's kinda crazy. I and my first thought would be If I was the one doing that kind of stuff, I don't know. I mean, I might have made it the same mistake they made if I was doing this, like, in the eighties.

Melissa: 12:44

But Right.

Jam: 12:45

Right now, I would think just average everything. Like, you can't obviously make everything for every type of body type. There's tons of tons of people. My thought would be, like, let's average all of it, and then at least men and women. You know?

Jam: 12:59

And at least we're getting somewhere, and it's not immediately Ruling out a whole half of our population. Yeah. You know? But whatever.

Melissa: 13:09

The other thing I think that would be pretty easy is really if instead of making the seat Super adjustable. Having a point at which the seat can't go past this safety zone.

Jam: 13:18

Right.

Melissa: 13:18

Now we'll have pedicle extenders if you still can't reach. Yeah. That should be a pretty simple fix.

Jam: 13:23

Totally.

Melissa: 13:23

Totally. Really smart engineers working on cars. Mhmm. Your car has a setting where you can push a button, and it'll switch from where your wife sits to where you sit. Yeah.

Melissa: 13:32

If we could figure that out, we could figure out pedal extenders.

Jam: 13:34

That's a great point. One good thing that I'm just realizing now is that I sit so much or closer and upright than Em does. Mhmm. So she's probably well within the safety zone without even trying to be.

Melissa: 13:46

Probably so.

Jam: 13:47

She's much more like the laid back kind of Yeah. You know, look cool while you're driving person.

Melissa: 13:51

That's a good that's a relief.

Jam: 13:52

Yeah. And I'm a much more of a, like, be a grandma while I'm driving kinda person, so maybe I should get some extenders. I don't know.

Melissa: 13:59

My mom somehow knew about this, though, and she always told me to draw like, put your arms straight out. Mhmm. And that's roughly, like you you need to be able to straighten your arms, and then you're safely in the zone

Jam: 14:10

kind of.

Melissa: 14:11

Yeah. Anyway, I thought that was interesting. Just sort of an interesting aside to talk about some oversights even in the research and development side. That's more of an engineering than a chemistry.

Jam: 14:22

Mhmm.

Melissa: 14:22

But just thought it was an interesting connection.

Jam: 14:25

Totally.

Melissa: 14:26

Back to the chemistry at hand. But I do highly recommend that book and that podcast Episode about the book is so interesting and really opened my eyes to the status quo.

Jam: 14:37

Yeah. That sounds great.

Melissa: 14:39

So, just to get us back in the mood of where we were at before, so when your car hits an object, the sensor goes off. It It tells an igniter to ignite

Jam: 14:50

Mhmm.

Melissa: 14:50

And that that heats up a chemical that as a chemical reaction.

Jam: 14:56

Okay. Okay.

Melissa: 14:57

And so there's 2 different kinds, the guanidine nitri nitrate and the sodium azide. Okay. And I think the guanidine nitrate is more common now. Sodium azide is the more traditional example. Mhmm.

Melissa: 15:09

It's also easier to visualize.

Jam: 15:11

Okay.

Melissa: 15:12

So I'll just tell you. Basically, sodium azide is made up of a sodium atom

Jam: 15:17

Okay.

Melissa: 15:18

And 3 nitrogen atoms.

Jam: 15:20

Okay.

Melissa: 15:21

So if you take 2 of them and they combine, you'll get 3. This is you gotta visualize it in your head. So imagine n a n three. Okay. Imagine that twice.

Melissa: 15:36

Okay. You have 6 nitrogens

Jam: 15:38

K.

Melissa: 15:38

And 2 sodiums.

Jam: 15:40

Right. Right.

Melissa: 15:41

So nitrogen gas is exists in our air as in 2. Okay. There's 2 to make nitrogen gas, it's 2 nitrogens buddied up, bonded together. Okay. You have 6 nitrogens Uh-huh.

Melissa: 15:54

That can make Three molecules of nitrogen gas. 3 and twos come from 6 nitrogens.

Jam: 16:01

Got it. So Before that, it's in the solid or liquid form?

Melissa: 16:06

I think it's a solid state. Sodium azide is like a sothoma, so I would assume it would be in a solid Powdery form or something like that.

Jam: 16:14

Got it. Got it.

Melissa: 16:15

And then when it's heated, it sort of reacts with itself to release For every 2 molecules, it'll release 3 molecules of nitrogen gas.

Jam: 16:25

Got it. Okay. Cool. Cool. I'm I'm think I'm tracking.

Melissa: 16:28

That goes back to high school chemistry. For those of you who had that class or remember, there's the term moles. And for every mole of Sodium Azide, You'll make 3 moles of nitrogen gas. You know? It goes back to that.

Melissa: 16:42

I don't think you need to worry about that too much for our purposes, but just know that When this is heated, it basically releases a bunch of nitrogen gas.

Jam: 16:51

Okay. Got it.

Melissa: 16:51

And it can do that really quickly.

Jam: 16:53

Okay. Dude, yeah. Moles. Oh my gosh. That is one of the things that that I remember being so hard for me to wrap my head around

Melissa: 17:00

Yeah.

Jam: 17:00

In high school chemistry. And I'm very sorry, Miss Pittard, that I I did not retain any knowledge of moles except that I did not get them, and it's not your fault.

Melissa: 17:13

I'm sure she was a great teacher. There it's a weird concept. It's kind of like trying to teach someone what fruit is. Uh-huh. This is an apple.

Melissa: 17:21

This is an orange. The these are each a fruit. Uh-huh. But how are they each a fruit? I just weird, you know.

Jam: 17:28

Yeah. Yeah. That's very Yeah. I see

Melissa: 17:34

what you're saying. So that's what happens. Your car hits an object. The sensor detects it. If it's the right conditions for the airbag to go off, the igniter will ignite.

Melissa: 17:40

It heats up the sodium azide or the quantity nitrate or whatever you have Mhmm. In your airbag. And then it, Upon heating, will react and very quickly release a bunch of nitrogen gas.

Jam: 17:51

Got it. Got it.

Melissa: 17:53

And that is very safe. Nitrogen gas is safe for us breathe, there's a lot of nitrogen gas in the atmosphere. Uh-huh. Here's where the chemical burns may come in.

Jam: 18:02

Okay.

Melissa: 18:03

There is something else in sodium azide.

Jam: 18:06

Okay.

Melissa: 18:07

Sodium.

Jam: 18:08

Right.

Melissa: 18:09

It's sodium with 3 nitrogens.

Jam: 18:11

Right. Right.

Melissa: 18:13

That sodium actually, After it reacts, it's sodium metal. Mhmm. And I don't know if you've ever seen the videos where people will drop sodium metal in water Mhmm. And it'll explode. Yeah.

Melissa: 18:24

Sodium metal will react very quickly with the moisture in the air Uh-huh. To make sodium hydroxide Uh-huh. Which is corrosive.

Jam: 18:33

K. Got it.

Melissa: 18:34

So I'm assuming if our friend Sam, when he was in his accident, had an older car, The airbag probably had sodium azide in it.

Jam: 18:43

Oh, I see.

Melissa: 18:46

The reaction happened.

Jam: 18:47

Uh-huh.

Melissa: 18:48

Nitrogen gas was released. Uh-huh. And possibly there was some side effect of some sodium hydroxide.

Jam: 18:54

Mhmm. Mhmm.

Melissa: 18:55

Now I will say scientists know that sodium hydroxide is formed. Mhmm. They're not crazy or anything.

Jam: 19:01

Yeah. Yeah. Yeah.

Melissa: 19:01

And so they put some other molecules in there, some other chemicals in there that react with the sodium hydroxide and try to neutralize it very quickly.

Jam: 19:09

Okay.

Melissa: 19:10

But no reaction usually goes to a 100%.

Jam: 19:12

Okay.

Melissa: 19:13

And Even more safe chemicals that aren't gonna damage too much. If you're exposed to a lot of them really hot, really fast, I could see they would cause problems.

Jam: 19:22

Uh-huh. Mhmm.

Melissa: 19:23

But I do think there probably was some of the sodium hydroxide remaining as a possibility also of what caused a chemical burn there.

Jam: 19:30

Right.

Melissa: 19:31

Also, with the newer airbags that use the guanidine nitrate, I'm assuming they give off less. One of the benefits of them is probably they give us less Those scary side products like sodium metal. Uh-huh. But it is still an irritant. So even if that was what was in his airbags, I think your skin coming into contact with a lot of different chemicals can result in some kind of chemical burn.

Jam: 19:55

Right. Right.

Melissa: 19:56

So that's what I think actually is what causes the chemical burns from airbags is probably not I mean, definitely not the nitrogen that Yeah. Releases into the airbag. It's probably more likely from the chemical side products that are also being released as nitrogen gas is being released. Okay. Okay.

Melissa: 20:14

I also think it's possible to get burns from how quickly that bag is being filled up. I think they said It could be a a 100 miles an hour as the house is traveling when it fills up. Uh-huh. So if your arm is right next to it and gets grazed, that also probably cause burnout or something.

Jam: 20:31

That's a good point. Almost anything, yeah, going across your skin that fast would probably cause something

Melissa: 20:36

Yeah. Regardless of the material. Exactly.

Jam: 20:38

Yeah. Interesting.

Melissa: 20:40

So that's the science behind an airbag. I will say that whole process happens in 300th of a second.

Jam: 20:48

Nice. They made it.

Melissa: 20:49

They made it. It's already deflating by the time you're there. It starts deflating, I think, at 3 100th a second or is in the deflating process already at that point? Uh-huh. Think about how much math that required or this the exact nature of the math where they have to know The exact volume of the bag Mhmm.

Melissa: 21:07

Hopefully, the bag doesn't have a hole, so that would mess up the calculations. You know?

Jam: 21:10

Right.

Melissa: 21:11

It's going to fill at the exact time frame. I'm assuming the bag fills in less than that because from the time the sensor goes off to when the bag is deflating, it's 3 100ths of a second.

Jam: 21:20

Mhmm. Mhmm.

Melissa: 21:21

So I'm assuming That bag is maybe filling in 1 or 2 100ths of a second.

Jam: 21:26

Right.

Melissa: 21:27

Right. How fast the sensor goes just has to be the exact right amount. It has to go at the exact right speed, and they figured all that out and made it safe.

Jam: 21:35

Yeah. Wow. That's crazy.

Melissa: 21:38

It's amazing.

Jam: 21:39

Yeah. It really, really is. Jeez.

Melissa: 21:43

They had to they had to figure out so much to get it right.

Jam: 21:46

And most what's fun funny too is that, you know, if it does this if if lots of things do their job, This is a very much a fail safe last resort in a lot of ways. Many of us will live and die and not ever experience an airbag.

Melissa: 21:59

Yep.

Jam: 22:00

But it's great that they put all that work into it Mhmm. Because their cars are so much safer to drive around.

Melissa: 22:05

Right.

Jam: 22:06

But it's funny that This that very impressive science

Melissa: 22:10

Yeah.

Jam: 22:10

Hopefully, ideally, does not even have to be used for most of us.

Melissa: 22:13

Well and I did find an article, and I didn't wanna include too much of this because it was an older article, so technology may have updated since. Uh-huh. But they talked about how many cars If the airbag is deflated, it's harmless, essentially. Mhmm. But at the end of the reaction, it's not gonna do any damage.

Melissa: 22:32

If the airbag isn't inflated, actually, sodium azide just by itself is pretty toxic. And so our landfills are filling up with sodium azide In cars that have not had their airbags detonated. Mhmm. Mhmm. So that's an interesting problem.

Melissa: 22:48

I don't know. I couldn't find any up to date Resources on that. It was an older article, so I didn't wanna dwell on that too long. Mhmm. But it is interesting that so many of us experience life without that ever happening.

Jam: 22:59

I know that if they can be reused, that that that people reuse them. There's even a interesting. Pretty big market for, like Sometimes people even steal airbags out of cars and stuff because

Melissa: 23:10

Wow.

Jam: 23:11

They're expensive. And so

Melissa: 23:13

That's heartbreaking.

Jam: 23:13

I think if a car, say, is, like, in a, you know, salvage yard or whatever, they would as long as the the airbags hadn't already been deflated or weren't unsafely too old or something.

Melissa: 23:24

Right.

Jam: 23:25

I'm pretty sure there's a huge market for trying to reuse them.

Melissa: 23:28

Nice.

Jam: 23:28

So, just because of how valuable they are in the 1st place

Melissa: 23:32

That's Good to know.

Jam: 23:33

Rather than remaking them, but I don't know how many end up just, you know, sitting in yards and stuff Yeah. For whatever reason. I'm sure there's some reason to not Reused one, maybe it's, like, 20 years old or something like that. Yeah. Maybe there's a limit there, but, but our friend who's a mechanic has talked about that a lot.

Jam: 23:48

Different weird kinda car, things like that that I would never have thought about. But

Melissa: 23:52

That's very interesting. Well, that makes me happy that it's not just filling up our landfills.

Jam: 23:57

Yeah. Dang crazy, dude.

Melissa: 23:59

Yeah. So do you wanna take a stab at telling that back to me?

Jam: 24:02

Yes. I'd love to. So When you're driving

Melissa: 24:07

Mhmm.

Jam: 24:08

And hopefully, it never happens to any of us. But if it does, and you very suddenly strike Something, another car. And it's all the right conditions that that sensor thinks, okay. This is really a car accident, not just, You know, hit a piece of trash on on the road. Right.

Jam: 24:31

It very quickly, everything's slow motion, you are starting to your head starting to head Toward Yes. The steering wheel because you are still moving at 70 miles an hour or whatever you were driving at. Your car stopped. Quickly, the little electrical impulse thing goes from the sensor to the airbag.

Melissa: 24:54

Mhmm.

Jam: 24:55

And It ignites the sodium azide

Melissa: 25:00

Or whatever chemical they chose to use.

Jam: 25:01

Or whatever chemical. And the goal there is to ignite it so that it can try to quickly create

Melissa: 25:11

Mhmm.

Jam: 25:12

A bunch of gas, to fill the airbag. So in the other chemicals, it'd be the same goal, but might they might use different Chemical Yes. Different molecules.

Melissa: 25:24

And they all produce nitrogen gas as far as I know.

Jam: 25:26

Okay. Cool. Cool. So producing a lot of nitrogen gas. And in the case of the sodium azide, each molecule has 1 sodium and 3 nitrogens.

Melissa: 25:37

That's right.

Jam: 25:38

And so if you have 2 of those, you end up having 2 sodiums and 6 nitrogens.

Melissa: 25:45

That's right.

Jam: 25:46

And once it ignites and heats up that amount of stuff that's in the airbag, Quickly, all of that stuff can start to react, and the nitrogens can go from the solids that they're currently in.

Melissa: 26:02

Mhmm.

Jam: 26:03

They can Find a buddy. They wanna have a they wanna have 2 natrogens in order to become gas.

Melissa: 26:11

That's right.

Jam: 26:12

So they start buddying up super fast.

Melissa: 26:15

Mhmm.

Jam: 26:15

This is also happening while your head is still slow motion Headed toward a very hard and not very fun to hit with your head steering wheel.

Melissa: 26:25

That's right.

Jam: 26:25

And so ignites. Boom. These natrogens quickly buddy up. They're like, hurry.

Melissa: 26:29

Come on. Let's get together. We gotta have a go and guess.

Jam: 26:32

And this is something else to think about we haven't talked about in a little while, but because The the the amount of something in a solid can be, like, say, small and fit in your steering wheel.

Melissa: 26:43

Right.

Jam: 26:44

But gases we've talked about

Melissa: 26:46

Mhmm.

Jam: 26:47

Fill up the space that they're in Yes. And expand out and stuff.

Melissa: 26:51

Yes.

Jam: 26:52

And so once those nitrogens buddy up together and have become heated to react to be able to become gas, They can just start filling the space because they want

Melissa: 27:02

to Mhmm.

Jam: 27:03

Now that they're a gas. And then they fill it up pretty quickly.

Melissa: 27:07

Mhmm.

Jam: 27:08

In 200th of a second.

Melissa: 27:10

Roughish. Mhmm. All the

Jam: 27:12

way to the point where then it can reach its capacity and then start deflating a little bit so that your head will hit it instead Mhmm. And be cushioned

Melissa: 27:26

Mhmm.

Jam: 27:26

From the firmness of the steering wheel.

Melissa: 27:31

That's exactly right.

Jam: 27:33

But then the downside, in some cases, is that things like sodium metal cannot be great for our skin. Mhmm. Any number of chemicals probably are that way. Right. So there's a chance that you could maybe get Chemical burn from sodium or from the other chemicals they have in there to try to, neutralize the sodium a little bit.

Jam: 27:55

But at the end of the day, it's still worth that to try to cushion your sweet head.

Melissa: 28:01

Yes. But Sweet head.

Jam: 28:03

Yeah. All you all your sweet heads, are worth that slight chance of that happening.

Melissa: 28:10

Right.

Jam: 28:10

Or it could be that you get Sort of burned by the friction of the airbag or whatever. But

Melissa: 28:18

I will also say I was speculating. I know that it forms sodium, and that can react with oxygen to make sodium hydroxide, which is caustic. It's what you pour down the sink whenever you use something like Drano. Okay. Serious chemical.

Melissa: 28:33

Yeah. But I was speculating that's what call causes the chemical burns. I assume that's what it is. I know it makes that. I know they have other chemicals in there to try to neutralize it.

Melissa: 28:44

Uh-huh. But That is a possibility based on my knowledge of the reaction.

Jam: 28:50

Got it.

Melissa: 28:51

Got it. But I think that was a really good explanation. I also realized while you're talking, We never specified, but all these facts and all this information in terms of the number of lives saved, etcetera, was about frontal airbags.

Jam: 29:03

Oh, right. Right. Right.

Melissa: 29:04

I think This similar type of chemistry is used for side airbags, you know, the curtain airbags and

Jam: 29:09

all that. Uh-huh.

Melissa: 29:11

Also, I did forget to mention, if you guys remember maybe from high school chemistry, you could took that. If not, Pivnerd or PV equals NRT might sound familiar to you. Mhmm. And that is about gas laws and how gases will Basically behave. So when you're considering how a gas is gonna behave, you have to consider the pressure, atmospheric pressure, The volume that it might be able to fill, so, like, the volume of that airbag Mhmm.

Melissa: 29:40

The temperature. So in that case, that's the temperature of the gas, And you probably have to figure out the temperature of the ambient atmosphere to Yeah. Get an okay sense of how much it's gonna fill.

Jam: 29:51

Got it.

Melissa: 29:51

And then the number of atoms or moles is how it's described in chemistry Uh-huh. That's gonna fill up the space. All those things have to be considered. So that is also part of the chemistry they're thinking about. When it goes from the solid to the gas, they're also thinking about how that gas is gonna behave.

Melissa: 30:08

So there's so much chemistry Yeah. So much math, So many factors to consider, and they they get it perfectly to where it saves lives most of the time.

Jam: 30:16

Wow, Ben. That's crazy.

Melissa: 30:18

Even for that to work Just once is amazing

Jam: 30:20

Yeah.

Melissa: 30:21

But that it's such an everyday object to us. Hopefully not that it's deploying every day. But car accidents happen so often, And it gets it right most of the time

Jam: 30:30

Mhmm. Mhmm.

Melissa: 30:31

Is amazing.

Jam: 30:32

In in some parts of the US, we are super dependent on our cars. So Yeah. Not public transit as much. So it's like we are using our cars all the time.

Melissa: 30:40

Right.

Jam: 30:40

So it is still every day. Yeah. You know? Even though They don't go off for a day. But

Melissa: 30:44

Pretty incredible.

Jam: 30:45

Wow. That's awesome.

Melissa: 30:47

I know. The chemistry of that is just so amazing to me, and it just gets me so excited. And, actually, that Kind of transitions well into what I wanna share my happy thing for this week.

Jam: 30:58

Okay. Nice.

Melissa: 30:59

So A lot of you know I used to do organic chemistry. Mhmm. And I enjoyed it, but it did not excite me to the level that my new field does. Yes. Mhmm.

Melissa: 31:09

Mhmm. So I transitioned after I got my master's into what's called chemistry education research.

Jam: 31:13

Uh-huh.

Melissa: 31:14

We study how people learn chemistry.

Jam: 31:17

Uh-huh.

Melissa: 31:17

And there's so many factors that go into that. And I was invited to come with my adviser, so she brought me along to presentation she was giving at a group in Germany. Mhmm. It's really early in the morning. It is so exciting, and she shared some about my work.

Melissa: 31:32

Uh-huh. And they were excited about it, and they thought it's gonna be a really great tool once it's in its final stages and ready to use. And I was just so excited about that. It's really validating. I felt like I did a lot of the development of that before I knew as much as I know now.

Jam: 31:46

Uh-huh. Uh-huh.

Melissa: 31:47

And so it just made me feel excited and proud and kind of Put me on a chemistry education research high and then had a great meeting with my someone on my committee who helps decide if I'm gonna Yeah. My PhD or not. I had a great meeting with my advisers, and then there's a really cool conference this morning. It was in the UK, I think, so we had to wake up at 5 AM, but it was so fun.

Jam: 32:11

Mhmm.

Melissa: 32:11

So many great talks, and I just feel so happy about chemistry and my job and all of it. And it's just been a really good Week in terms of I love my research. I love the work I'm doing. It's really fun.

Jam: 32:25

Yeah.

Melissa: 32:26

So and I'm preparing a A manuscript to try to submit for publication. And once that's published, I can share with you guys more about what the work I'm doing is like. So, hopefully, that happens pretty soon.

Jam: 32:37

Awesome. Dude, that's great. Very cool.

Melissa: 32:39

It's been a fun week for chemistry. For me, I've just really enjoyed it. So what about you, Jim? Have you had any fun things this week? I kind of usurped your You normally talk first to that part.

Jam: 32:49

That's okay. Totally fine. Yours is more relevant on the topic of chemistry. So, I was gonna share one thing, but I'm gonna change my mind now. So I found out about a month ago, but then in fact, I can share it now because my Brother and sister-in-law, are pregnant.

Melissa: 33:07

Oh my god. And

Jam: 33:08

they they went ahead and announced and spiked that this past week, so I feel like it's fine to share. So exciting. And they found out that they are having a boy.

Melissa: 33:16

Oh, so your son can also have another little buddy.

Jam: 33:18

Yes. That'll be fun. And so

Melissa: 33:20

That's So exciting.

Jam: 33:21

So on our side of the family, they have a daughter, then we have a son, and then now they're gonna have a son. So it's kind of just funny to see how things shake out.

Melissa: 33:29

You need to have Daughter to keep the pattern going.

Jam: 33:31

Right. Right. And so seeing how things shake out with, like, the cousins and that kinda thing on the side of the family is fun.

Melissa: 33:36

That's crazy to be on this side of cousins. You know? Like, when you're growing up, you just have cousins. It's just the way it is. They just are there.

Melissa: 33:42

Yeah. And now we're the parents or I'm not a parent, but, you know Yeah. Our age group is the one Making the cousins.

Jam: 33:49

Yes.

Melissa: 33:49

It's just weird.

Jam: 33:50

And I remember having so much fun with the cousins I had growing up. They were close to my age.

Melissa: 33:54

Me too. I love my cousins

Jam: 33:56

And it's just kinda cool, and I looked up to the ones that were older than me, I looked up to them.

Melissa: 33:59

Mhmm.

Jam: 33:59

And then the ones that were kinda my age, I hung out with them, and it was just yeah. It was fun. So it's it's kind of Fun to start envisioning what that would be like for Yeah. Our kids and stuff. So

Melissa: 34:08

That's crazy to think about.

Jam: 34:09

Anyway, that's that's kind of the biggest highlight for me.

Melissa: 34:11

That's a huge highlight. That's really exciting. In another way, that is also chemistry. Mhmm. Because our cells, the makeup babies and makeup human beings are made up of atoms.

Jam: 34:21

Mhmm.

Melissa: 34:22

That's also chemistry.

Jam: 34:24

Yes. Good point.

Melissa: 34:24

Chemistry for your nephew's life.

Jam: 34:27

Yep. Yep. Amen.

Melissa: 34:31

Well, thanks, Jam, so much for being excited about airbags. I love sharing that with you. And thanks All to all of you listeners for coming every week and listening, sharing your questions, thoughts. I never would have come up with this idea. I had never wondered about airbags.

Melissa: 34:44

So thanks, Sam Inn, for sharing that. We could not do this without you.

Jam: 34:48

Yes. And if you, like Sam, have a question that is probably in some way chemistry related, please read that to us. Melissa and I have a lot of ideas of our own, but, also, y'all's ideas are amazing. So please send us your ideas and questions on Gmail, Twitter, Instagram, or Facebook at Kim for your life. That's Kim, f o r, your life, to share your thoughts and ideas.

Jam: 35:08

If you'd like to help us keep our show going and contribute to cover the cost of making it, Go to kodashfi.com/chem for your life and donate the cost of a cup of coffee. If you're not able to donate, can still help us by subscribing on your favorite podcast app and rating and writing our review on Apple Podcasts. That really helps us to share chemistry with even more people.

Melissa: 35:27

This episode of Chemistry For Your Life was created by Melissa Collini and Jam Robinson. References for this episode can be found in our show notes or on our website. Jim Robinson is our producer, and we'd like to give a special thanks to A. Kyuzang and A. Hefner who reviewed this episode.