Sometime in the last few weeks, I read something that said the injuries inflicted by chemical weapons are not any more painful and less deadly than the injuries caused by artillery and explosives. Chemical injuries, this thing read, are actually easier to recover from, in comparison. The claim struck me as interesting, but I didn’t know anything about chemical weapons to really evaluate it.
Today, I’m going to provide some cheerful descriptions of what a few well-known chemical weapons will do to you if you’re exposed without proper precautions. You can get the general idea from the category name alone, so if you’re not into gory details, I suggest a brief skim.
But if you have a morbid curiosity, read on. And since this goes pretty long, you can skip a bunch and just go to the area of interest (I suggest “blister”).
Some chemical weapons are the overuse or misapplication of a chemical that is actually very prevalent in industry and is considered useful. These fall into “Schedule 3.” Some have a few useful applications but are primarily weapons. These are “Schedule 2.” And then there are varieties – I’m sure you’ve caught on to the naming trend here – assigned to “Schedule 1” that have very little or absolutely no useful application outside of hurting people. 
Chlorine is a familiar substance present in many useful forms – combined with sodium, it’s table salt; by itself, it’s a common disinfectant for households and pools. It can be liquefied and transported in pressurized containers.
Once released from that container, it becomes a heavy, pale green gas that sinks to the ground and creeps along slowly. It gets into your body primarily through inhalation, but if you decide wait around and wallow in the mysterious green fog long enough, it’ll soak into your skin.
Because it is water-soluble, chlorine will get incorporated into your body’s water content – which means your eyes, nose, and other mucous-laden regions (yum) will be inflamed and irritated. Your vision will blur as your eyes water and sting, breathing will suck, your lungs will start protesting, you’ll start coughing and wheezing. If you absorb enough, your body will try to expel this intruder by vomiting. And if you continue your exposure, you’ll develop pulmonary edema – that is, your lungs will fill with fluid.
With enough skin exposure, your skin will start blistering. You could develop frostbite-like symptoms.
Remember — chlorine is very visible, smells strongly of bleach, and takes time to build up in your body. You can impede its takeover of your body by simply breathing through a wet cloth, keeping your clothes on, and amscraying as fast as you can. 
Phosgene oxime (CX).
Like chlorine, phosgene is a familiar player in the industrial world. Phosgene’s primary commercial role is a pesticide, and it can manifest itself as a visible, heavy gas that smells like moldy hay. If inhaled, it will cause some pretty nasty respiratory problems. But where chlorine’s effects are progressive and can develop slowly or quickly depending on the amount in the air, phosgene’s effects are almost instantaneous no matter the amount.
You immediately feel incapacitating pain, and for good reason. The tender tissues in your nose will quickly start dying. Your eyes will become inflamed and watery, and you’ll temporary go blind. Your airways and lungs will start rupturing, resulting in fluid and blood clots building up in your lungs. Within seconds, your skin will start blanching, maybe develop red rings. You’ll start itching, develop hives, and parts of your skin will simply die.
Because of phosgene’s speed, there isn’t an antidote yet. The best way to treat the effects of this chemical is just immediate decontamination: running away, washing thoroughly. According to the CDC, its mechanism of action is unknown, and it’s also unknown why it works so quickly. Unlike with chlorine, clothes and gas masks are not really effective barriers (at least, not for long).
An extra fun fact is that phosgene reacts pretty badly with most metals – which means if there’s metal in the area, phosgene will react with it, corrode the metal, and produce another noxious, poisonous gas. So that’s exciting.
Also in this category: Diphosgene (DP) and chloropicrin (PS).
Sulfur mustard (HD).
When inhaled, mustard will hang around in your system, silently wreaking havoc before making itself known. This means that hours after you’re exposed (so you won’t know how much you’ve inhaled), you may develop chemical burns in all the familiar areas – eyes, skin, and respiratory tract – as well as some pretty devastating (read: permanent) problems with your immune and nervous system.
The skin and mucous membrane damage occurs the same way the choking agents work: absorption into your watery body through inhalation or skin contact. However, mustard will cause large, watery blisters on your skin, meaning that your skin cells are dying at a fairly deep level (your skin has three layers: the epidermis (surface), the dermis, and the underlying fat layer). But the deepest skin damage of all won’t even show blisters, and the hidden dying cells can cause blood poisoning if not treated in time.
Mustard is also an alkylating agent. This means that it can stop protein synthesis by replacing hydrogen atoms in DNA with alkyl groups. This is really cool on a theoretical level, but obviously anything that messes with your DNA messes with all that is you.
This alkylating property particularly affects your bone marrow so that your blood cell production goes wonky. You know the importance of red blood cells for transporting oxygen, I assume, but don’t forget that white blood cells are the hard-hitters of your immune system. They’ll be down for the count. In the long run, you may be more prone to cancer.
And there’s one more thing.
Mustard activates a certain chemical receptor called acetylcholine that controls the parasympathetic nervous system. The parasympathetic nervous system controls your digestion, so when it becomes overactive, you start salivating monstrously, your stomach starts churning, and your intestines may give you diarrhea.
So that’s, uh, that’s that. Much of this damage is technically treatable, even though there’s no cure-all for every effect. But all of this is going on at the same time, so recovery will be slow. 
Lewisite smells like geraniums, so that’s something new and pleasant. But like the rest of the family, it causes damage to the skin, eyes, and respiratory system. Unlike mustard gas, its respiratory effects are immediate, so you do have some warning. Skin problems like blisters can come later, but the effects are decreased if you escape exposure quickly.
Like mustard gas, it can cause problems with the immune and gastrointestinal systems, but as an added bonus, high doses mess with your cardiovascular system and fluids balance.
The speed difference between lewisite and mustard gas indicates a different mechanism by which it affects the body. Though the effects are similar, lewisite is arsenical. Arsenicals increase capillary permeability, meaning that it lets fluids leave our veins more easily. This causes low blood pressure and stresses the heart.
Also in this category: sometimes phosgene oxime and nitrogen mustard.
Hydrogen cyanide (AC).
Hydrogen cyanide, compared to the previously described chemicals, seems almost gentle. It doesn’t cause the extreme skin or eye problems that the others have so far because it doesn’t target mucous membranes. Instead, it targets entire systems. It affects every organ of the body by essentially depriving them of oxygen.
Once inhaled, hydrogen cyanide starts affecting you within minutes, sometimes seconds if the dosage is high enough. Hydrogen cyanide acts on enzymes in your body that contain metal, including an iron-bearing enzyme called cytochrome oxidase. This enzyme is an important player in cellular respiration.
Cellular respiration is the process by which our cells get any energy to work, so if that process stops working, then our cells start dying. And by association, your organs start dying, and then you start dying. You essentially suffocate even though you’re still breathing.
This poison may have been the gas of choice in Nazi concentration camps, though this hasn’t been completely verified.
Sarin, sarin, sarin. This little demon is the reason chemical weapons are being discussed these days. It is reputedly the fastest and deadliest chemical weapon in the known arsenal, and it’s hard to detect. A splash from a shot glass’s worth onto bare skin is enough to kill you in minutes. But a few seconds of inhalation is also enough to get the ball rolling downhill.
As a nerve agent, sarin targets the nervous system, disabling an enzyme that lets your muscles relax. This overstimulates your muscles like a continuous electric shock, causing the twitching and seizure-like movements and appearances witnessed in Sarin victims. Your body will essentially wear itself out, as if it’s exercising too much, too fast, and your breathing eventually just can’t keep up with the activity.
Anything you read on soman will probably begin by saying it acts like an organophosphate insecticide, which is an annoying comparison because if you’re like me, this means nothing.
Organophosphate poisoning inhibits an enzyme that lives where your brain synapses communicate with muscle nerves. The enzyme known as acetylcholinesterase regulates a neurotransmitter called acetylcholine that passes messages from your muscle nerves to the brain (also the same neurotransmitter that mustard gas acts on to stimulate your parasympathetic nervous system).
When soman disables that enzyme, the neurotransmitters go wild. This effect in moderation is actually sought after in some treatments for Alzheimer’s patients — but for soman victims, this means their muscles can be stimulated out of control, similar to what sarin victims experience.
One of the main differences between soman and sarin is the rate of evaporation. Soman is much slower, so there are no sudden surprise attacks using soman. But that also means that if it’s left untouched for long periods of time, it can contaminate the environment for much, much longer. 
Also in this category: VX.
Are chemical weapons less lethal than regular artillery and explosive bombs? Well, the nerd in me says that all of these sound vaguely like the Crutiatus Curse in Harry Potter; that is, a sudden, shocking torture that can be done from a distance. It doesn’t seem anything like getting all four of your limbs or jaw shot off, but I’d hesitate to say that it’s any less traumatizing.
I wouldn’t know.
But I think that, regardless of the actual quantity of people killed or maimed, using chemicals over another kind of weapon isn’t going make a population remember, fear, and hate the ones that used it upon them any less.
Hannah Cheng is a freelance writer. She tweets every now and then @haychling.