WEBVTT 00:00:00.000 --> 00:00:02.359 Welcome back to the Deep Dive. I am so glad you 00:00:02.359 --> 00:00:04.400 could join us today because we are getting into 00:00:04.400 --> 00:00:09.560 a topic that is equal parts brilliant, terrifying, 00:00:10.140 --> 00:00:12.640 and just completely essential to modern history. 00:00:12.720 --> 00:00:15.779 Oh, absolutely. Today we are looking at the evolution 00:00:15.779 --> 00:00:18.539 and the highly specialized science of the gas 00:00:18.539 --> 00:00:20.579 mask. It really is a profound subject. I mean, 00:00:20.620 --> 00:00:23.059 when we think of a gas mask today, we typically 00:00:23.059 --> 00:00:25.640 picture a very specific, you know, modern piece 00:00:25.640 --> 00:00:28.769 of military or industrial hardware. Right. But 00:00:28.769 --> 00:00:30.730 the journey to engineer that piece of equipment 00:00:30.730 --> 00:00:33.189 is incredibly long, complex, and filled with 00:00:33.189 --> 00:00:35.810 some truly unexpected scientific breakthroughs. 00:00:35.969 --> 00:00:38.890 It is. And for today's Deep Dive, we have gathered 00:00:38.890 --> 00:00:41.509 a really comprehensive stack of material anchored 00:00:41.509 --> 00:00:44.210 by a super detailed Wikipedia article on the 00:00:44.210 --> 00:00:47.130 subject. Yes. It traces this technology all the 00:00:47.130 --> 00:00:51.009 way from ancient Greek sponges to the cutting 00:00:51.009 --> 00:00:53.509 edge chemical filtration used in modern warfare. 00:00:53.850 --> 00:00:55.649 And what makes this such a compelling discussion 00:00:55.649 --> 00:00:58.380 for you listening today is how perfectly illustrates 00:00:58.380 --> 00:01:01.219 human ingenuity responding to extreme pressure. 00:01:01.579 --> 00:01:04.239 The history of this technology is driven by industrialization. 00:01:04.959 --> 00:01:07.319 Unfortunately some of the darkest chapters of 00:01:07.319 --> 00:01:10.099 global conflict. So our mission today is to trace 00:01:10.099 --> 00:01:13.159 how a very simple idea just wanting to filter 00:01:13.159 --> 00:01:16.359 the air we breathe, evolved into a complex life 00:01:16.359 --> 00:01:19.140 -saving technology. Spot on. We want to uncover 00:01:19.140 --> 00:01:21.780 the surprising chemistry of how we actually protect 00:01:21.780 --> 00:01:25.180 our lungs and look closely at the intense historical 00:01:25.180 --> 00:01:27.819 catalysts that force this technology forward. 00:01:28.859 --> 00:01:30.959 OK, let's unpack this. Let's do it. We should 00:01:30.959 --> 00:01:33.019 begin by looking at the earliest attempts to 00:01:33.019 --> 00:01:35.200 manipulate the air we breathe. We really have 00:01:35.200 --> 00:01:37.540 to go back to the earliest origins. In ancient 00:01:37.540 --> 00:01:40.060 Greece, the common sea sponge was actually used 00:01:40.060 --> 00:01:42.420 as a kind of proto gas mask. Just a physical 00:01:42.420 --> 00:01:44.500 sponge. Yeah, just held over the face to try 00:01:44.500 --> 00:01:47.079 and block out smoke or dust. It makes a certain 00:01:47.079 --> 00:01:49.319 kind of intuitive sense. You know, you take a 00:01:49.319 --> 00:01:51.200 porous material and use it as a physical barrier. 00:01:51.920 --> 00:01:54.599 But the leap from a simple sponge to an engineered 00:01:54.599 --> 00:01:57.500 breathing device took centuries. Right. The next 00:01:57.500 --> 00:02:00.939 major milestone doesn't happen until 1799. That 00:02:00.939 --> 00:02:03.980 was Alexander von Humboldt. He was working as 00:02:03.980 --> 00:02:06.480 a mining engineer in Prussia and introduced one 00:02:06.480 --> 00:02:08.599 of the first primitive respirators specifically 00:02:08.599 --> 00:02:11.460 for miners. Which is entirely logical when you 00:02:11.460 --> 00:02:13.909 think about the environment. Working underground 00:02:13.909 --> 00:02:16.669 in the 18th century, miners were constantly hitting 00:02:16.669 --> 00:02:20.409 pockets of unbreathable toxic gases and dealing 00:02:20.409 --> 00:02:23.789 with heavy particulate dust. So industrial necessity 00:02:23.789 --> 00:02:27.090 became the first real driver for respiratory 00:02:27.090 --> 00:02:29.770 protection. Exactly. And that industrial need 00:02:29.770 --> 00:02:32.650 kept pushing things forward. By 1847, we see 00:02:32.650 --> 00:02:35.229 the forerunner to the modern gas mask invented 00:02:35.229 --> 00:02:38.620 by Louis P. Hazlitt. Yes. He was granted a patent 00:02:38.620 --> 00:02:41.419 for it in 1849 under the incredible name the 00:02:41.419 --> 00:02:43.960 Lung Protector. It is a very descriptive title. 00:02:44.659 --> 00:02:47.139 Hazlis design was essentially an inhaler that 00:02:47.139 --> 00:02:49.280 filtered dust out of the air. It was purely mechanical. 00:02:49.500 --> 00:02:51.759 It had a bulb -shaped filter, right? Right, utilizing 00:02:51.759 --> 00:02:53.639 a bulb -shaped filter and valves that allowed 00:02:53.639 --> 00:02:56.139 you to breathe air in through a mouthpiece and 00:02:56.139 --> 00:02:58.379 then vent your exhaled air back out into the 00:02:58.379 --> 00:03:01.120 room. But one of the most visually striking early 00:03:01.120 --> 00:03:04.520 designs has to be the one patented in 1914 by 00:03:04.520 --> 00:03:06.879 Garrett Morgan. Oh, the safety hood. Yeah, the 00:03:06.879 --> 00:03:09.580 safety hood and smoke protector. The design is 00:03:09.580 --> 00:03:11.500 just wild to picture. It was a cotton hood that 00:03:11.500 --> 00:03:13.879 went entirely over your head, but it featured 00:03:13.870 --> 00:03:16.509 two long hoses that hung all the way down to 00:03:16.509 --> 00:03:19.909 the floor. There is brilliant thermodynamic logic 00:03:19.909 --> 00:03:22.930 to that design. How so? Well, in a burning building 00:03:22.930 --> 00:03:26.379 the heat and smoke rise. Therefore, the safest, 00:03:26.599 --> 00:03:29.599 most breathable, and coolest air is right down 00:03:29.599 --> 00:03:32.159 at floor level. That makes total sense. And at 00:03:32.159 --> 00:03:34.240 the end of those hoses dragging on the floor, 00:03:34.800 --> 00:03:36.919 Morgan inserted moist sponges to help filter 00:03:36.919 --> 00:03:39.199 the air even further before it traveled up the 00:03:39.199 --> 00:03:41.460 tubes to the user. Right. It is a very clever, 00:03:41.759 --> 00:03:44.599 entirely mechanical solution to a hazardous environment. 00:03:44.659 --> 00:03:47.500 It is clever. It is. But it brings us to a really 00:03:47.500 --> 00:03:49.520 crucial scientific distinction that we need to 00:03:49.520 --> 00:03:52.120 define early on, the fundamental difference between 00:03:52.120 --> 00:03:55.569 absorption and adsorption. Understanding this 00:03:55.569 --> 00:03:57.469 difference is the only way to understand how 00:03:57.469 --> 00:03:59.990 early devices functioned and why they ultimately 00:03:59.990 --> 00:04:02.569 had to evolve into complex chemical filters. 00:04:02.729 --> 00:04:04.110 Wait, can we slow down on that for a second? 00:04:04.129 --> 00:04:06.349 Because absorption and adsorptions sound like 00:04:06.349 --> 00:04:08.310 the exact same word to most people. How do they 00:04:08.310 --> 00:04:12.189 actually differ? It is a vital distinction. Absorption 00:04:12.189 --> 00:04:15.289 with a B is the process of a substance being 00:04:15.289 --> 00:04:18.310 drawn into the volume of a larger body or substrate. 00:04:18.389 --> 00:04:20.870 Like a sponge. Exactly. Think of a dry kitchen 00:04:20.870 --> 00:04:24.120 sponge soaking up a spill on your counter. The 00:04:24.120 --> 00:04:26.459 water physically goes into the material of the 00:04:26.459 --> 00:04:30.459 sponge. Adsorption with a D is an entirely different 00:04:30.459 --> 00:04:33.279 mechanism. Okay, so what is that? It is the process 00:04:33.279 --> 00:04:36.339 of a substance depositing upon a surface. So 00:04:36.339 --> 00:04:38.459 instead of soaking in, the hazard is just sticking 00:04:38.459 --> 00:04:40.680 to the outside layer of the filter material. 00:04:40.899 --> 00:04:43.519 Precisely. Adsorption uses attractive electrical 00:04:43.519 --> 00:04:46.779 charges. A great way to visualize this is static 00:04:46.779 --> 00:04:49.199 electricity. Like a balloon? Yeah, if you rub 00:04:49.199 --> 00:04:50.879 a balloon on your head and stick it to a wall, 00:04:51.259 --> 00:04:53.240 the balloon is clinging to the surface because 00:04:53.240 --> 00:04:56.399 of attractive charges. Adsorption in gas masks 00:04:56.399 --> 00:04:58.480 works on a microscopic level just like that. 00:04:58.600 --> 00:05:00.899 That is fascinating. If the hazardous particles 00:05:00.899 --> 00:05:03.560 in the air have a specific charge, you engineer 00:05:03.560 --> 00:05:05.300 a filter substrate with the opposite charge, 00:05:05.319 --> 00:05:07.959 and the toxic particles essentially get magnetized 00:05:07.959 --> 00:05:09.720 and stick to the surface. What kind of materials 00:05:09.720 --> 00:05:12.310 actually do that? Things like activated carbon 00:05:12.310 --> 00:05:16.310 and materials called zeolites. Zeolites are just 00:05:16.310 --> 00:05:18.569 highly porous minerals. What do they look like? 00:05:18.810 --> 00:05:20.889 On a microscopic level, they look like a dense 00:05:20.889 --> 00:05:23.949 honeycomb. Because they are so porous, they have 00:05:23.949 --> 00:05:26.410 a massive amount of surface area, which provides 00:05:26.410 --> 00:05:29.649 millions of tiny attachment points for toxic 00:05:29.649 --> 00:05:32.009 molecules to get stuck to via those attractive 00:05:32.009 --> 00:05:34.970 charges. Wow. And understanding that difference 00:05:34.970 --> 00:05:37.750 completely debunks a very common survival myth 00:05:37.750 --> 00:05:39.790 that a lot of people listening might have heard. 00:05:39.980 --> 00:05:43.120 The damp cloth myth. Yes. We've all seen movies 00:05:43.120 --> 00:05:45.600 where someone grabs a damp cloth, ties it over 00:05:45.600 --> 00:05:47.620 their mouth and nose, and runs through a burning 00:05:47.620 --> 00:05:50.600 building perfectly fine. A wet cloth relies heavily 00:05:50.600 --> 00:05:53.680 on simply trapping physical particulates. It'll 00:05:53.680 --> 00:05:56.060 catch the large pieces of soot and the physical 00:05:56.060 --> 00:05:58.620 ash produced by the combustion. And that is genuinely 00:05:58.620 --> 00:06:01.000 helpful in keeping your airway clear of debris. 00:06:01.259 --> 00:06:04.300 It is. But here is the critical survival takeaway. 00:06:04.620 --> 00:06:07.980 it completely fails to stop toxic gases. Because 00:06:07.980 --> 00:06:10.259 it doesn't have the chemical properties to absorb 00:06:10.259 --> 00:06:13.540 a gas like carbon monoxide. Nothing at all. Carbon 00:06:13.540 --> 00:06:16.660 monoxide is a gas that displaces the oxygen you 00:06:16.660 --> 00:06:20.129 need to survive. A wet rag cannot perform the 00:06:20.129 --> 00:06:23.329 complex chemical filtration required to neutralize 00:06:23.329 --> 00:06:26.389 or trap that gas. So while it might keep you 00:06:26.389 --> 00:06:28.610 from coughing up ash, it will not prevent you 00:06:28.610 --> 00:06:30.990 from suffocating. Exactly. Which perfectly sets 00:06:30.990 --> 00:06:34.449 the stage for the moment in history where humanity 00:06:34.449 --> 00:06:37.769 suddenly and quite desperately needed complex 00:06:37.769 --> 00:06:39.910 chemical filtration. The outbreak of the First 00:06:39.910 --> 00:06:42.410 World War. The historical catalyst that changed 00:06:42.410 --> 00:06:45.550 the trajectory of this technology forever. April 00:06:45.550 --> 00:06:49.519 22, 1915. the Second Battle of Ypres in Belgium. 00:06:49.600 --> 00:06:52.259 Yes. The German army successfully used poison 00:06:52.259 --> 00:06:55.360 gas, specifically chlorine gas, for the first 00:06:55.360 --> 00:06:57.959 time against Allied troops. When you read about 00:06:57.959 --> 00:07:00.540 this moment in history, the sheer panic and lack 00:07:00.540 --> 00:07:03.500 of preparation is staggering. The initial responses 00:07:03.500 --> 00:07:05.639 were entirely improvised on the battlefield. 00:07:06.120 --> 00:07:08.639 By May 1st, just over a week after the attack, 00:07:08.899 --> 00:07:11.160 troops were simply being issued cotton wool wrapped 00:07:11.160 --> 00:07:12.959 in muslin. Just a piece of cotton. They were 00:07:12.959 --> 00:07:14.560 just desperate to have anything over their faces. 00:07:14.639 --> 00:07:17.240 Then came the Black Veil Resp - which was invented 00:07:17.240 --> 00:07:19.860 by John Scott Haldane. That was basically just 00:07:19.860 --> 00:07:22.680 a cotton pad soaked in an absorbent chemical 00:07:22.680 --> 00:07:25.180 solution tied over the mouth with black cotton 00:07:25.180 --> 00:07:28.459 veiling. But that wasn't providing enough protection 00:07:28.459 --> 00:07:31.420 either, was it? It wasn't. So a man named Clooney 00:07:31.420 --> 00:07:33.560 McPherson stepped in with a design that gets 00:07:33.560 --> 00:07:35.699 much closer to what we recognize today. What 00:07:35.699 --> 00:07:39.120 did he do? McPherson designed a canvas hood that 00:07:39.120 --> 00:07:42.269 fitted over the entire head. The canvas was heavily 00:07:42.269 --> 00:07:44.750 treated with chlorine absorbing chemicals, and 00:07:44.750 --> 00:07:47.829 he fitted it with a transparent mica eyepiece 00:07:47.829 --> 00:07:50.189 so the soldiers could actually see while wearing 00:07:50.189 --> 00:07:52.670 it. And he presented that idea to the British 00:07:52.670 --> 00:07:55.490 War Office anti -gas department on May 10th, 00:07:55.490 --> 00:07:58.470 1915. Within weeks of the first attack, they 00:07:58.470 --> 00:08:01.230 are adopting his design. It moved incredibly 00:08:01.230 --> 00:08:03.449 fast. But here's what I don't quite understand. 00:08:03.569 --> 00:08:05.910 As the war dragged on, the gases got deadlier. 00:08:05.990 --> 00:08:08.829 They moved from chlorine to things like phosgene 00:08:08.829 --> 00:08:11.319 and chloropocrine. They did. How did the masks 00:08:11.319 --> 00:08:13.540 keep up? Did they just soak the canvas hoods 00:08:13.540 --> 00:08:15.399 and even more chemicals? Oh, the canvas hoods 00:08:15.399 --> 00:08:17.560 quickly became obsolete against those new threats. 00:08:18.199 --> 00:08:20.699 And to answer your question, phosgene is a particularly 00:08:20.699 --> 00:08:24.360 insidious gas. It's colorless and smells faintly 00:08:24.360 --> 00:08:27.779 of musty hay. But it causes severe suffocation, 00:08:27.980 --> 00:08:31.779 sometimes hours after exposure. And a chloropocrine 00:08:31.779 --> 00:08:34.919 is a severe irritant that causes intense vomiting. 00:08:35.960 --> 00:08:38.100 The strategic goal of chloropocrine was to force 00:08:38.100 --> 00:08:40.659 soldiers to throw up. making them rip off their 00:08:40.659 --> 00:08:43.259 gas masks. Oh wow, which then exposed them to 00:08:43.259 --> 00:08:45.860 the lethal phos gene gas that was often fired 00:08:45.860 --> 00:08:49.139 alongside it. Exactly. To combat these complex 00:08:49.139 --> 00:08:51.480 attacks, they needed a totally new filtration 00:08:51.480 --> 00:08:53.500 method. Here's where it gets really interesting. 00:08:53.600 --> 00:08:56.399 They turned to a very specific, yet incredibly 00:08:56.399 --> 00:09:00.440 basic material. Charcoal. In 1915, a Russian 00:09:00.440 --> 00:09:03.840 chemist named Nikolai Zelinsky invented the first 00:09:03.840 --> 00:09:06.759 effective filtering -activated charcoal gas mask. 00:09:06.899 --> 00:09:08.799 Yes, he did. But they realized pretty quickly 00:09:08.799 --> 00:09:11.059 that standard wood charcoal wasn't entirely sufficient, 00:09:11.379 --> 00:09:13.799 right? Exactly. Wood charcoal was okay, but by 00:09:13.799 --> 00:09:16.419 1918, militaries made a fascinating discovery. 00:09:17.019 --> 00:09:19.159 Charcoals made from the shells and seeds of fruits 00:09:19.159 --> 00:09:21.399 and nuts performed vastly better. Like what kind 00:09:21.399 --> 00:09:23.539 of fruits and nuts? We were talking about coconuts, 00:09:23.639 --> 00:09:25.840 chestnuts, horse chestnuts, and specifically 00:09:25.840 --> 00:09:28.960 peach stones. Why would a peach stone work better 00:09:28.960 --> 00:09:31.779 than a piece of wood for filtering toxic gas? 00:09:32.220 --> 00:09:34.500 It comes back to that concept of adsorption and 00:09:34.500 --> 00:09:37.539 surface area. When you carbonize a dense hard 00:09:37.539 --> 00:09:40.320 shell like a coconut or a peach pit, it creates 00:09:40.320 --> 00:09:43.460 an incredibly dense network of microscopic pores. 00:09:43.580 --> 00:09:46.340 I see. It provides a massively higher surface 00:09:46.340 --> 00:09:49.000 area for those toxic molecules to get trapped 00:09:49.000 --> 00:09:51.720 in compared to wood, which is relatively soft 00:09:51.720 --> 00:09:54.389 and less structurally dense. And that structural 00:09:54.389 --> 00:09:57.169 density led to these massive public recycling 00:09:57.169 --> 00:09:59.970 programs across the globe. It really did. Citizens 00:09:59.970 --> 00:10:02.289 were actively collecting fruit pits to support 00:10:02.289 --> 00:10:04.850 the war effort. You had families saving their 00:10:04.850 --> 00:10:06.710 peach pits after dinner so they could be shipped 00:10:06.710 --> 00:10:09.590 off and burned into charcoal to build gas masks 00:10:09.590 --> 00:10:11.850 for the front lines. It is a surreal historical 00:10:11.850 --> 00:10:14.649 reality. And the sheer scale of the chemical 00:10:14.649 --> 00:10:17.230 warfare during this period led to another grim 00:10:17.230 --> 00:10:19.129 development. They weren't just manufacturing 00:10:19.129 --> 00:10:22.350 masks for human soldiers. Right they had to develop 00:10:22.350 --> 00:10:25.549 and manufacture special gas masks engineered 00:10:25.549 --> 00:10:28.470 specifically for the snouts of dogs. The messenger 00:10:28.470 --> 00:10:31.429 dogs. Yeah, which were frequently used as messengers 00:10:31.429 --> 00:10:34.330 on the front lines and for the horses operating 00:10:34.330 --> 00:10:36.809 in the mounted units and pulling artillery. When 00:10:36.809 --> 00:10:39.269 you realize that thousands of custom masks had 00:10:39.269 --> 00:10:42.649 to be engineered for animals, it paints a devastating 00:10:42.649 --> 00:10:45.529 picture of what the air quality on those battlefields 00:10:45.529 --> 00:10:48.649 was actually like. Complete environmental saturation. 00:10:48.830 --> 00:10:51.470 It's really hard to even picture. So how did 00:10:51.470 --> 00:10:53.730 the designs change as we moved out of World War 00:10:53.730 --> 00:10:55.909 One and into World War Two? The evolution was 00:10:55.909 --> 00:10:58.470 largely driven by a thematic shift in how war 00:10:58.379 --> 00:11:01.700 were fought. World War I was defined by static 00:11:01.700 --> 00:11:04.320 trench warfare. Right, everyone was mostly staying 00:11:04.320 --> 00:11:07.360 put. Exactly. A soldier could tolerate wearing 00:11:07.360 --> 00:11:09.860 a bulky canvas hood with a heavy hose leading 00:11:09.860 --> 00:11:12.539 to a large box respirator because they largely 00:11:12.539 --> 00:11:15.320 stayed in one place. World War II, however, was 00:11:15.320 --> 00:11:17.519 highly mobile. So they needed completely different 00:11:17.519 --> 00:11:20.820 gear. troops started to move fast, which necessitated 00:11:20.820 --> 00:11:23.440 lighter, less cumbersome gear. That makes perfect 00:11:23.440 --> 00:11:27.080 sense. In 1943, the British developed the light 00:11:27.080 --> 00:11:29.840 anti -gas respirator. They started utilizing 00:11:29.840 --> 00:11:32.220 early plastics and rubber -like materials, which 00:11:32.220 --> 00:11:35.299 made the masks significantly lighter. They also 00:11:35.299 --> 00:11:38.549 vastly improved the form factor. Instead of those 00:11:38.549 --> 00:11:41.929 heavy, dragging hoses, they moved to filter canisters 00:11:41.929 --> 00:11:44.769 that could easily and quickly screw directly 00:11:44.769 --> 00:11:46.429 onto the side or the front of the facepiece. 00:11:46.529 --> 00:11:49.289 A huge improvement. And those Britterglass and 00:11:49.289 --> 00:11:52.970 Micah eyepieces were replaced with durable, replaceable 00:11:52.970 --> 00:11:55.750 plastic lenses. But as the defensive technology 00:11:55.750 --> 00:11:59.029 improved, the offensive weapons became unimaginably 00:11:59.029 --> 00:12:02.659 worse. Moving into the Cold War era, the global 00:12:02.659 --> 00:12:05.759 threat evolves into NBC. Nuclear, biological, 00:12:06.000 --> 00:12:07.720 and chemical weapons. Yes, and this is where 00:12:07.720 --> 00:12:10.299 the traditional gas mask runs into a very hard 00:12:10.299 --> 00:12:12.629 physical limit. This raises an important question. 00:12:12.850 --> 00:12:15.409 What exactly is a standard gas mask protecting? 00:12:15.570 --> 00:12:17.970 Just the airway. Right. For agents that cause 00:12:17.970 --> 00:12:20.450 harm through contact or penetration of the skin, 00:12:20.889 --> 00:12:23.789 like blister agents such as mustard gas or advanced 00:12:23.789 --> 00:12:27.330 nerve agents like VX, a gas mask alone is simply 00:12:27.330 --> 00:12:29.409 not enough. Wait. So even if the mask is working 00:12:29.409 --> 00:12:31.789 perfectly and it is successfully filtering all 00:12:31.789 --> 00:12:33.610 the toxic elements out of the air you breathe, 00:12:34.110 --> 00:12:36.090 the user is still in lethal danger. How does 00:12:36.090 --> 00:12:38.909 the gas bypass the lungs entirely? Because your 00:12:38.909 --> 00:12:41.809 skin is an organ. and it is highly absorbent. 00:12:42.289 --> 00:12:44.549 Nerve agents attack the nervous system and can 00:12:44.549 --> 00:12:47.470 cause fatal systemic failure just by making contact 00:12:47.470 --> 00:12:50.409 with exposed skin. That is terrifying. Lister 00:12:50.409 --> 00:12:53.009 agents cause massive debilitating tissue damage 00:12:53.009 --> 00:12:55.730 upon contact. To survive those specific threats, 00:12:56.129 --> 00:12:58.929 you have to wear a full hermetically sealed protective 00:12:58.929 --> 00:13:02.529 suit in addition to the mask. A gas mask only 00:13:02.529 --> 00:13:05.009 protects your respiratory system. That is a critical 00:13:05.009 --> 00:13:07.210 distinction, especially when you consider how 00:13:07.210 --> 00:13:10.909 many civilians purchase surplus gas masks online, 00:13:11.490 --> 00:13:13.950 mistakenly believing that a mask alone makes 00:13:13.950 --> 00:13:16.490 them invincible to any kind of modern chemical 00:13:16.490 --> 00:13:19.370 attack. Relying on faulty, incomplete, or inappropriate 00:13:19.370 --> 00:13:21.769 protective equipment can lead to absolute tragedy. 00:13:22.269 --> 00:13:24.570 When you look at the Iran -Iraq War, which lasted 00:13:24.570 --> 00:13:28.190 from 1980 to 1988, you see a devastating example 00:13:28.190 --> 00:13:30.190 of what happens when this technology fails on 00:13:30.190 --> 00:13:32.620 a national scale. Iraq was heavily developing 00:13:32.620 --> 00:13:34.899 its chemical weapons program during that time, 00:13:35.159 --> 00:13:37.039 and they deployed those weapons on a massive 00:13:37.039 --> 00:13:39.580 scale against Iranian forces. And Iran was caught 00:13:39.580 --> 00:13:41.659 completely unprepared for a chemical war. In 00:13:41.659 --> 00:13:44.980 1984, Iran was scrambling to procure protection 00:13:44.980 --> 00:13:47.720 for its troops. They managed to buy masks from 00:13:47.720 --> 00:13:49.659 the Republic of Korea, but there were immediate 00:13:49.659 --> 00:13:52.659 massive logistical issues. First, the filters 00:13:52.659 --> 00:13:55.440 on these Korean masks only lasted for 15 minutes. 00:13:55.659 --> 00:13:58.820 A 15 -minute window of protection during a sustained, 00:13:59.360 --> 00:14:03.179 hours -long chemical bombardment is terrifyingly 00:14:03.179 --> 00:14:05.919 brief. It is almost completely ineffective. Furthermore, 00:14:06.080 --> 00:14:08.200 the Korean masks were specifically designed for 00:14:08.200 --> 00:14:11.080 East Asian facial structures. When issued to 00:14:11.080 --> 00:14:14.059 Iranian troops, the masks didn't conform properly 00:14:14.059 --> 00:14:16.620 to their faces, which meant they couldn't achieve 00:14:16.620 --> 00:14:19.179 an airtight seal. A mask without a feel is useless. 00:14:19.360 --> 00:14:22.039 Exactly. But the situation got even worse when 00:14:22.039 --> 00:14:24.980 Iran purchased 5 ,000 masks from East Germany. 00:14:25.179 --> 00:14:27.279 What's fascinating here is, and I say fascinating 00:14:27.279 --> 00:14:30.049 in the darkest, most tragic possible sense, Those 00:14:30.049 --> 00:14:32.490 East German masks weren't actually gas masks 00:14:32.490 --> 00:14:34.909 at all. They were spray painting goggles. Exactly. 00:14:35.149 --> 00:14:37.710 Industrial spray painting goggles. Sold to a 00:14:37.710 --> 00:14:40.110 nation desperate for defense against weaponized 00:14:40.110 --> 00:14:42.370 chemical agents. Unbelievable. It is an appalling 00:14:42.370 --> 00:14:45.029 historical detail that resulted in massive casualties. 00:14:45.450 --> 00:14:48.250 It forced Iran to completely shift gears. They 00:14:48.250 --> 00:14:50.350 realized they couldn't rely on foreign imports. 00:14:50.889 --> 00:14:54.649 By 1986, Iranian diplomats were actively traveling 00:14:54.649 --> 00:14:57.809 across Europe just to buy raw active charcoal 00:14:57.809 --> 00:15:00.169 and various filter models. so their engineers 00:15:00.169 --> 00:15:02.169 could figure out how to reverse engineer them. 00:15:02.330 --> 00:15:05.230 A massive undertaking. And by 1988, they finally 00:15:05.230 --> 00:15:07.490 started domestic production of reliable masks 00:15:07.490 --> 00:15:11.429 at the Iranyasa factories. It's a brutal, costly 00:15:11.429 --> 00:15:14.830 lesson in the absolute necessity of specialized, 00:15:15.289 --> 00:15:18.120 reliable chemical filtration. Which brings us 00:15:18.120 --> 00:15:20.600 to how modern filters actually function today 00:15:20.600 --> 00:15:23.279 because it is no longer just a canvas sack full 00:15:23.279 --> 00:15:25.559 of crushed peach stones. Right. The chemistry 00:15:25.559 --> 00:15:27.759 behind modern filters is incredibly specific. 00:15:27.980 --> 00:15:30.320 Today, filtration relies on substances engineered 00:15:30.320 --> 00:15:32.360 to be more reactive than the air itself. Yes. 00:15:32.460 --> 00:15:34.820 They use advanced materials like synthetic resins 00:15:34.820 --> 00:15:36.940 that are created with specific groups of atoms 00:15:36.940 --> 00:15:38.779 attached to them, which are called functional 00:15:38.779 --> 00:15:41.679 groups. Think of a functional group as a microscopic 00:15:41.679 --> 00:15:44.440 chemical lock engineered to only snap together 00:15:44.440 --> 00:15:47.159 with a very specific chemical key. The key being 00:15:47.159 --> 00:15:49.820 the toxin. Exactly. It is essentially custom 00:15:49.820 --> 00:15:52.539 chemical tailoring. You can design a synthetic 00:15:52.539 --> 00:15:55.220 resin to actively bond with a specific toxic 00:15:55.220 --> 00:15:58.100 group. When the contaminated air pulls through 00:15:58.100 --> 00:16:00.720 the filter, the reactive substance bonds with 00:16:00.720 --> 00:16:03.379 the toxin. ripping it out of the airstream and 00:16:03.379 --> 00:16:05.220 locking it into the filter before it ever hits 00:16:05.220 --> 00:16:07.559 your lungs. Because different chemical weapons 00:16:07.559 --> 00:16:09.759 or industrial toxins require different chemical 00:16:09.759 --> 00:16:12.700 reactions to neutralize them, modern filters 00:16:12.700 --> 00:16:15.500 use a universal color code so the user knows 00:16:15.500 --> 00:16:17.940 exactly what they're protected against. It is 00:16:17.940 --> 00:16:20.940 a very rigid, life -saving classification system. 00:16:21.620 --> 00:16:24.419 For example... under the EU classification, if 00:16:24.419 --> 00:16:26.480 you see a brown strike on a filter canister. 00:16:27.100 --> 00:16:29.019 You know that filter contains these specific 00:16:29.019 --> 00:16:30.940 functional groups designed to protect against 00:16:30.940 --> 00:16:33.559 organic compounds. And a green stripe. A green 00:16:33.559 --> 00:16:36.200 stripe protects against ammonia and amines. What 00:16:36.200 --> 00:16:38.620 are amines? Amines are derivatives of ammonia, 00:16:38.980 --> 00:16:41.440 often used in industrial chemicals and pesticides, 00:16:41.960 --> 00:16:43.779 and they are highly irritating and dangerous 00:16:43.779 --> 00:16:46.299 to the respiratory tract. A red stripe protects 00:16:46.299 --> 00:16:48.820 specifically against mercury vapor. There is 00:16:48.820 --> 00:16:51.139 black for carbon monoxide, yellow for acidic 00:16:51.139 --> 00:16:54.279 gases. It is a literal color code for survival. 00:16:54.580 --> 00:16:56.860 It really is. But of course, all of that brilliant 00:16:56.860 --> 00:16:59.580 chemistry doesn't matter even a little bit if 00:16:59.580 --> 00:17:02.179 the mask doesn't fit your face perfectly. The 00:17:02.179 --> 00:17:04.779 physical seal against the skin is everything. 00:17:05.220 --> 00:17:07.660 Fit testing is a mandatory protocol. You cannot 00:17:07.660 --> 00:17:10.119 just strap a mask on, tighten the straps, and 00:17:10.119 --> 00:17:12.440 hope for the best. You have to verify the seal. 00:17:12.759 --> 00:17:15.180 The way they actually test the seal on these 00:17:15.180 --> 00:17:18.640 modern masks is so incredibly simple yet effective. 00:17:18.940 --> 00:17:22.140 They use the banana test. Yes, using isomal acetate. 00:17:22.329 --> 00:17:25.349 They use a synthetic banana flavorant or sometimes 00:17:25.349 --> 00:17:27.670 camphor. You put the mask on, you secure the 00:17:27.670 --> 00:17:29.950 straps, and they release this strong banana scent 00:17:29.950 --> 00:17:32.890 into the air around you. And the logic is simple. 00:17:33.150 --> 00:17:35.230 Right. If you can smell bananas while wearing 00:17:35.230 --> 00:17:37.410 the mask, you have a leak and you are not protected. 00:17:37.869 --> 00:17:40.130 It is an innocuous challenge agent. It safely 00:17:40.130 --> 00:17:42.230 tells you if the seal is compromised without 00:17:42.230 --> 00:17:44.710 putting your health in danger, though it is worth 00:17:44.710 --> 00:17:46.630 noting that the military takes a slightly more 00:17:46.630 --> 00:17:49.160 intense, realistic approach to fit testing. They 00:17:49.160 --> 00:17:51.900 use actual tear gas, don't they? They do. In 00:17:51.900 --> 00:17:54.099 military training, they will use agents like 00:17:54.099 --> 00:17:57.559 CN, CS gas or stanic chloride in a sealed chamber. 00:17:57.759 --> 00:18:00.259 That sounds intense. The logic there is psychological 00:18:00.259 --> 00:18:03.000 as much as it is physical. If a soldier stands 00:18:03.000 --> 00:18:05.619 in a room completely filled with dense tear gas 00:18:05.619 --> 00:18:09.140 and feels absolutely fine, it gives them absolute 00:18:09.140 --> 00:18:12.259 unwavering confidence in their gear. They know 00:18:12.259 --> 00:18:14.519 without a doubt that it works when their life 00:18:14.519 --> 00:18:16.750 depends on it. Speaking of trusting your gear, 00:18:16.950 --> 00:18:19.029 there is a very important warning we need to 00:18:19.029 --> 00:18:22.269 pass along regarding vintage gas masks. If you 00:18:22.269 --> 00:18:24.849 are ever at a military surplus store or an antique 00:18:24.849 --> 00:18:27.609 shop and you find an old gas mask from the mid 00:18:27.609 --> 00:18:30.069 20th century, do not put it on. Do not put it 00:18:30.069 --> 00:18:32.289 on your face and absolutely do not try to breathe 00:18:32.289 --> 00:18:34.230 through a vintage filter. This is a critical 00:18:34.230 --> 00:18:36.910 safety warning. Old gas masks are inherently 00:18:36.910 --> 00:18:40.930 dangerous for a few reasons. First, rubber aggressively 00:18:40.930 --> 00:18:43.839 degrades over time. A vintage mask will likely 00:18:43.839 --> 00:18:46.339 have micro -cracks and will leak, offering zero 00:18:46.339 --> 00:18:48.140 protection. That makes sense. But the actual 00:18:48.140 --> 00:18:50.500 hazard lies within the vintage filters themselves. 00:18:50.839 --> 00:18:53.619 Many World War II and Soviet Cold War era masks, 00:18:53.880 --> 00:18:56.779 like the incredibly common Soviet GP -5 masks, 00:18:57.500 --> 00:19:00.960 contain asbestos. Specifically, they used crecital 00:19:00.960 --> 00:19:04.160 or crecitalite asbestos. At the time, they didn't 00:19:04.160 --> 00:19:06.859 fully understand how harmful it was, and asbestos 00:19:06.859 --> 00:19:09.240 is actually a highly effective particulate filter. 00:19:09.380 --> 00:19:12.319 But inhaling it... is deadly. Inhaling decades 00:19:12.319 --> 00:19:15.319 old, degrading asbestos dust directly into your 00:19:15.319 --> 00:19:18.420 lungs is a recipe for severe respiratory diseases 00:19:18.420 --> 00:19:21.200 including mesothelioma. And it isn't just the 00:19:21.200 --> 00:19:25.400 very old Soviet masks. The U .S. Army's C2 black 00:19:25.400 --> 00:19:28.720 canister contains hexavalent chromium, which 00:19:28.720 --> 00:19:31.960 is a known potent carcinogen. Which is incredibly 00:19:31.960 --> 00:19:34.660 dangerous. The U .S. Army Chemical Corps stunned 00:19:34.660 --> 00:19:37.140 it and stated the exposure levels were technically 00:19:37.140 --> 00:19:40.140 acceptable, but they still explicitly urge caution 00:19:40.140 --> 00:19:42.720 when handling or using it. So again, leave the 00:19:42.720 --> 00:19:45.420 vintage masks on the shelf as historical curiosities. 00:19:45.460 --> 00:19:48.200 Do not wear them. Absolutely. However, even if 00:19:48.200 --> 00:19:50.420 you have a brand new state of the art mask perfectly 00:19:50.420 --> 00:19:53.099 fit tested with zero leaks and a brand new color 00:19:53.099 --> 00:19:56.240 -coded filter, there is still a massive physiological 00:19:56.240 --> 00:19:58.460 drawback to wearing one. Okay, so what does this 00:19:58.460 --> 00:20:00.619 all mean? If the mask is working perfectly and 00:20:00.619 --> 00:20:02.960 the air coming in is totally clean, aren't you 00:20:02.960 --> 00:20:05.319 completely safe? You are safe from the external 00:20:05.319 --> 00:20:08.180 chemical threat, yes. But by wearing the mask, 00:20:08.640 --> 00:20:11.359 you are introducing a new internal threat to 00:20:11.359 --> 00:20:14.420 your body. Your own exhaled breath. Because of 00:20:14.420 --> 00:20:17.250 the dead space. Exactly. When you wear a typical 00:20:17.250 --> 00:20:20.250 gas mask, there is a physical gap between the 00:20:20.250 --> 00:20:22.250 inside of the face piece and your actual face. 00:20:22.849 --> 00:20:26.410 That gap is the dead space. Every time you exhale, 00:20:26.630 --> 00:20:28.990 your breath, which is heavily laden with carbon 00:20:28.990 --> 00:20:32.369 dioxide, fills that confined space. And because 00:20:32.369 --> 00:20:35.230 you are sealed into the mask, you end up re -inhaling 00:20:35.230 --> 00:20:37.730 a significant portion of your own carbon dioxide 00:20:37.730 --> 00:20:40.339 with your very next breath. The numbers regarding 00:20:40.339 --> 00:20:42.359 this are actually quite shocking. The standard 00:20:42.359 --> 00:20:44.500 occupational exposure limit for carbon dioxide 00:20:44.500 --> 00:20:46.599 over a normal eight hour shift is about 0 .5 00:20:46.599 --> 00:20:49.420 percent by volume. Yes. But inside the dead space 00:20:49.420 --> 00:20:52.380 of a gas mask, the CO2 exposure can skyrocket 00:20:52.380 --> 00:20:55.740 to 2 .6 percent. That is a massive physiological 00:20:55.740 --> 00:20:58.339 burden. To put that 2 .6 percent into real world 00:20:58.339 --> 00:21:00.640 context is essentially like breathing into a 00:21:00.640 --> 00:21:03.220 paper bag for an hour straight while simultaneously 00:21:03.220 --> 00:21:05.539 trying to do intense manual labor or navigate 00:21:05.539 --> 00:21:07.759 a highly stressful, dangerous environment. It 00:21:07.759 --> 00:21:10.009 takes extra physical effort. just to pull air 00:21:10.009 --> 00:21:12.069 through the dense chemical filters which tires 00:21:12.069 --> 00:21:14.230 out your respiratory muscles. Yes, it is exhausting. 00:21:14.349 --> 00:21:17.630 Add in breathing 2 .6 % carbon dioxide and it 00:21:17.630 --> 00:21:20.750 leads to intense debilitating headaches. Not 00:21:20.750 --> 00:21:23.569 to mention the severe skin issues. Long -term 00:21:23.569 --> 00:21:26.049 use causes painful dermatitis and severe acne 00:21:26.049 --> 00:21:28.210 from the sweat and oils trapped against the skin 00:21:28.210 --> 00:21:30.549 by the rubber seal. The physical toll on the 00:21:30.549 --> 00:21:33.750 human body is so severe that the UK Health and 00:21:33.750 --> 00:21:36.970 Safety Executive textbook explicitly recommends 00:21:36.970 --> 00:21:39.200 limiting the use of sta... standard respirators 00:21:39.200 --> 00:21:42.099 without an independent air supply to just one 00:21:42.099 --> 00:21:44.599 single hour. Just one hour. That is incredible. 00:21:44.799 --> 00:21:47.160 After 60 minutes, the very tool that is keeping 00:21:47.160 --> 00:21:49.920 you alive is actively making you sick. It really 00:21:49.920 --> 00:21:51.900 puts the entire technology into perspective. 00:21:52.079 --> 00:21:54.819 It absolutely does. We have traced an incredible 00:21:54.819 --> 00:21:57.259 journey today, starting from ancient Greeks holding 00:21:57.259 --> 00:22:00.380 sea sponges over their mouths to Alexander von 00:22:00.380 --> 00:22:03.000 Humboldt protecting Prussian miners. Right through 00:22:03.000 --> 00:22:05.440 the frantic, desperate innovations of World War 00:22:05.440 --> 00:22:08.009 I. We're citizens. We're recycling peach stones 00:22:08.009 --> 00:22:11.549 for charcoal all the way to modern, highly specialized 00:22:11.549 --> 00:22:14.630 synthetic resins engineered with microscopic 00:22:14.630 --> 00:22:17.089 chemical locks. If we connect this to the bigger 00:22:17.089 --> 00:22:19.910 picture, it is the ultimate balancing act. We 00:22:19.910 --> 00:22:22.490 are constantly engineering brilliant ways to 00:22:22.490 --> 00:22:25.069 protect the human lungs from the lethal hazards 00:22:25.069 --> 00:22:27.930 of the outside world while simultaneously trying 00:22:27.930 --> 00:22:30.490 not to suffocate on the exhaust of our own internal 00:22:30.490 --> 00:22:32.970 biology. Which leaves us with a fascinating thought 00:22:32.970 --> 00:22:36.019 to end on today. If the history of the gas mask 00:22:36.019 --> 00:22:38.299 is a direct mirror to the escalating history 00:22:38.299 --> 00:22:41.539 of chemical warfare, and our absolute best modern 00:22:41.539 --> 00:22:44.279 protection still leaves us choking on our own 00:22:44.279 --> 00:22:46.920 exhaled breath after just 60 minutes. It's a 00:22:46.920 --> 00:22:49.680 sobering reality. It really is. How will we engineer 00:22:49.680 --> 00:22:51.880 the personal protective equipment of the future? 00:22:52.180 --> 00:22:54.440 When the hazards become entirely microscopic, 00:22:54.819 --> 00:22:57.259 novel, or genetically tailored, how do we protect 00:22:57.259 --> 00:22:59.359 ourselves without becoming trapped in a toxic 00:22:59.359 --> 00:23:01.900 unbreathable bubble of our own making? That is 00:23:01.900 --> 00:23:03.759 the daunting challenge for the next generation. 00:23:03.660 --> 00:23:07.119 of engineers and chemists. It really is. Thank 00:23:07.119 --> 00:23:08.960 you so much for joining us on this deep dive. 00:23:09.059 --> 00:23:10.759 We hope you learned something new and we will 00:23:10.759 --> 00:23:12.059 catch you next time.