How Sarin Works


Sarin gas was used in an attack in the Tokyo Metro system in 1995.
Sarin gas was used in an attack in the Tokyo Metro system in 1995.
© Noboru Hashimoto/Sygma/Corbis

Each day we're bombarded by news stories of bombs and bullets killing and maiming people in all corners of the world. The effects of those conventional weapons are horrifying ... and frequent enough to be mind numbing. A chemical gas attack, on the other hand, still has the ability grab headlines, provoking responses from concerned citizens and government agencies everywhere.

That's especially true when sarin gas (also known by the military designation GB) is the chemical in question. Sarin is a nightmarish, human-made concoction that's classified as a nerve agent, meaning it wreaks havoc on the nervous system. It takes only a tiny amount of sarin to cause serious harm, and people exposed to this agent often die as the muscles they use to breathe seize.

Sarin is an insidious substance. It has no taste, no color and no odor. Often, people have no idea that it's even present. Humans are affected when they breathe in the gas or when it touches just about any part of their bodies.

The effects of a moderate to high exposure take hold immediately, and if a lethal dose occurs, there's almost nothing that can prevent death. In the case of lower doses, a person may have a window of opportunity to seek medical treatment to prevent death or permanent nerve damage.

If there's a bit of good news about sarin, it's this -- not many people are ruthless or heartless enough to put it to use. The gas is roundly condemned by governments around the globe as an unconscionable weapon of mass destruction, and one that warrants unbridled retaliation against those who would deploy it as a means to an end.

That said, sarin is still a player in the game of world power. Whether it's wielded by psychotic despots or determined terrorists, this deadly gas is a sure way to bring attention to a cause, or simply rain down despair and suffering.

Keep reading and you'll see where sarin came from and how the powers that be try to keep this poison under control.

Sarin's Gruesome Genesis

Sarin was invented in 1938 by the Germans in the run-up to World War II. Its name is derived from the names of the four chemists (Schrader, Ambros, Rudiger and Van der Linde) who created it.

The scientists who concocted sarin initially wanted to make more effective pesticide for their company, IG Farben. It was Gerhard Schrader who accidentally made the breakthrough discovery.

In 1936, Schrader was testing a range of chemicals called organophosphates, which killed insects by disrupting their nervous systems. His experiments resulted in tabun (GA), a liquid that has no taste or color but that causes serious harm to the nervous systems of many creatures, including mammals. Schrader discovered tabun's effectiveness the hard way when he accidentally exposed himself to it and subsequently needed weeks to recover.

In spite of that setback, he was enthusiastic enough about his discovery that he reported it to the chemical weapons officials of the Third Reich. They immediately classified his work and ordered more experiments. Two years later, the Nazis developed sarin, which was 10 times as potent as tabun. Yay for scientific research, right?

Sarin and tabun were two of the so-called G-agents made by the Germans during the war era. The other two were soman (GD) and cyclosarin (GF). No matter the name, all of these inventions were horrifying in their own special ways.

These days, roughly 70 substances are classified as chemical weapons, and they can take the form of solids, gasses or liquids. They are sub-categorized in groups named for the bodily systems they effect, such as blister agents, pulmonary agents, blood agents, vomiting agents or in sarin's case, nerve agents.

Sarin is not only exceptionally deadly, but it's cheap and easy to make. On the next page you'll read all about why sarin is such an effective chemical weapon.

Synthetic Evil

This molecular model of sarin shows the carbon atoms in gray, hydrogen in white,  fluorine in blue, oxygen in red and phosphorus in orange.
This molecular model of sarin shows the carbon atoms in gray, hydrogen in white, fluorine in blue, oxygen in red and phosphorus in orange.
©LAGUNA DESIGN/Getty

Sarin is an entirely synthetic compound. It has exactly one use -- as a weapon in chemical warfare.

It looks harmless enough. At room temperature, sarin is a colorless liquid. Left in an open container, it evaporates and quickly breaks apart, chemically speaking. This volatility means that sarin has a relatively short shelf life of only a few weeks or months depending on the quality of the ingredients used to make it.

To prevent sarin from degrading before it's used, engineers may add stabilizing chemicals. Alternately, they may build compartmentalized weapons that prevent the ingredients from mixing until the shell is launched towards its target. Along the flight path, the shell's spinning motion combines the interior chemicals, resulting in sarin gas, and then bursts in a plume that kills anyone nearby.

One chemical name for sarin is (RS)-Propan-2-yl methylphosphonofluoridate, although the esoteric notation of the molecular compounds masks the true wretchedness of its effects. Ultimately, sarin is a series of chemicals that blocks an enzyme called acetylcholinesterase. Without this enzyme, your body basically overloads on a neurotransmitter called acetylcholine.

Too much acetylcholine and your muscles remain in a state of contraction and subsequently, extreme fatigue. This has a lot of eventual effects on the human body, but the one that causes death is respiratory failure, as the muscles that keep you breathing quickly become exhausted.

It's a wretched way to die. Keep reading and you'll find ways to potentially survive a sarin attack.

Run Away, Run Away

Sarin exposure happens in all sorts of ways. You might breathe it, eat it on contaminated food or drink it in poisoned water. Your skin, especially mucus membranes like those around your eyes, may absorb it. Sarin is most commonly dispersed as an aerosol so that victims breathe it.

Depending on the amount of sarin you're exposed to, symptoms may vary. Typical telltale signs include constricted pupils, runny nose, drooling, watery eyes, headache, weakness, change in heart rate and vomiting.

It takes very little sarin before exposure becomes evident. A lethal dose via skin absorption may be as minuscule as a few droplets. Death can occur in less than a quarter of an hour. A massive dose can kill in just one minute. A milder level of exposure may not manifest itself through symptoms until nearly 20 hours later.

A lower exposure may not cause death, but victims may experience neurological problems for weeks after the event. Unluckier people may suffer permanent health problems, possibly to their respiratory or nervous systems.

If a person is fortunate enough to survive for more than a few minutes, there are antidotes available. Two antidotes are atropine and pralidoxime chloride. The latter must be administered within a few hours following exposure or it does very little good. Neither antidote is effective if they are given prior to sarin exposure.

Preventing exposure means wearing all-compassing personal protective equipment (PPE). So in areas where sarin is anticipated, people must wear a chemical, biological, radiological and nuclear (CBRN) suit paired with a self-contained breathing apparatus. That means you're covered from head to toe against the worst of the worst ... including sarin.

Analyzing the Origin

Before troops are exposed  to live Sarin & VX nerve agents, soldiers test their masks using fragrance and/or caustic agents.
Before troops are exposed to live Sarin & VX nerve agents, soldiers test their masks using fragrance and/or caustic agents.
© Leif Skoogfors/Corbis

Sarin is heavier than air, so it tends to settle in lower areas, such as valleys or even basements -- the places a lot of people would hide to escape conventional weapons like mortar shells or bullets. If there's no wind, it can hang in the air for six to eight hours before it fully dissipates.

In most cases, though, the aerosolized particles tend to evaporate or disperse rather quickly. This is a good thing for anyone who happens to be in the targeted area. But sarin's disappearing act complicates the efforts of experts who try to confirm the chemical's use and who deployed it.

To confirm a sarin attack, investigators must immediately begin their search for clues or risk losing the trail altogether. Within a few hours, the human body renders sarin itself nearly undetectable. However, as sarin deteriorates, it leaves behind smaller molecular particles such as isopropyl methylphosphonic acid (IMPA) or cyclohexyl methylphosphonic acid (CMPA).

To confirm IMPA or other sarin byproducts, scientists lean on high-tech tools. These tools, such as gas or liquid mass spectrometers, can provide a detailed profile of a whole range of chemicals with a given sample.

Scientists can attempt to gather and analyze samples in the field, too. To do so, they draw blood samples and test for acetylcholinesterase, which as you already know enables normal muscle contraction processes in the body. The less acetylcholinesterase they find, the greater the possibility that a nerve agent was present.

There is one notable caveat, though. Gathering samples in an attack zone is notoriously difficult, for a whole lot of obvious reasons. These are inherently dangerous areas that could be subjected to further violence, including the possibility of follow-up sarin use.

The flip side, of course, is that samples must be obtained as soon as possible, otherwise authorities risk losing opportunities to analyze potential chemical evidence before it disappears.

Sarin in Action

The Tokyo Fire Department and Tokyo Metropolitan Police Department conducting disaster drills in the Tokyo subway in March 2005.
The Tokyo Fire Department and Tokyo Metropolitan Police Department conducting disaster drills in the Tokyo subway in March 2005.
© ISSEI KATO/Reuters/Corbis

We know that sarin is scary stuff. Its potential horribleness is such that even in their darkest hours, the Nazis didn't use it during WWII, in spite of having created a stockpile of sarin and other nerve agents. Following the war, numerous countries, such as the U.S. and the Soviet Union, learned to develop sarin and began storing it.

For decades following its creation, no one really used sarin on a large scale. In 1991, the United Nations condemned sarin as a weapon of mass destruction. And in 1993, the Chemical Weapons Convention outlawed the gas's production and storage.

Sadly, a few people have demonstrated the gall to use sarin outside of a laboratory setting. The worst confirmed sarin attack occurred in 1988, when Iraqi leader Saddam Hussein ordered gas bombs dropped on the Kurdish village of Halabja. Around 5,000 people died.

Hussein didn't stop there. He also deployed sarin at least four times in the Iran-Iraq war. His ruthlessness paid off, as the sarin attacks, which were targeted thanks to the assistance of reconnaissance performed by the U.S., helped turned the momentum of the war back against the Iranians.

Sarin appeared again in 1994, when a Japanese religious cult called Aum Shinrikyo released the gas in Matsumoto, killing eight people. Only nine months later, the cult struck again, this time puncturing bags of liquid sarin in multiple parts of the Tokyo subway tunnel system. Thirteen people died and nearly 1,000 were affected.

Then, the specter of sarin lay quiet for more than a decade. It made headlines again in 2013 during the Syrian civil war. In August, hundreds of civilians died in the suburbs of Damascus, yet none of them fell victim to bullets. They had few external injuries at all.

Weapons experts immediately suspected that someone had unleashed sarin on the unsuspected populace. A United Nations inspection team visited the attack site to test for signs of sarin in hair, tissue, clothing, urine and blood samples, and supposedly confirmed decomposition products that pointed to sarin exposure.

However, because sarin dissipates in the air and breaks down within the body, it's possible that other chemicals could have caused the deaths. And of course, assigning blame is another task altogether, and one that's littered with diplomatic landmines of all kinds.

The Rogue Weapon

Sarin is a nasty chemical that destroys lives in unimaginable ways. Whether it's really worse than any number of conventional weapons is rather subjective in the long term. Still, nations all over the world seem to agree that eliminating chemicals like sarin make war a bit less horrific.

The inherently unpredictable nature of chemical attacks is one thing that makes them so awful. There's no such thing as a precision strike when it comes to sarin -- the attackers simply drop the gas in a place where they hope to do the most damage. That means civilian casualties are difficult to minimize. What's more, it means that the overall strategic and military pros of deploying sarin are low, especially when compared to the cons. It also means, frighteningly, that opposing forces may consider fighting back with chemical weapons of their own.

That's why the United Nations has banned sarin. And that's why so many countries have agreed not to use it in a fight. Rogue countries that insist on using "unfair" weapons such as sarin may find themselves subjected to retaliation in the form of economic sanctions or military strikes.

So long as stockpiles of sarin and other chemical weapons exist, the shadow of these weapons will darken modern civilization. Unfortunately, due to the easy chemistry behind sarin and the fact that terrorist organizations are willing to use any weapon they can get their hands on, it's likely that we'll read about sarin for years to come.

Author's Note: How Sarin Works

Sarin is essentially a pesticide for people. Only someone with the ultimate disdain for human life would dare to leverage sarin as a weapon. Here's to hoping that the nations of the world continue to condemn sarin ... and that they destroy their own stockpiles, too.

Related Articles

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