Why Don’t Dictators Premix Their Chemical Weapons?

Answers to your questions about the news.
Dec. 3 2012 5:52 PM

Why Is Syria Mixing Sarin?

A mini-Explainer on the process of making chemical weapons.

Syrian protesters dance during a demonstration against the regime.
Syrian protesters dance during a demonstration against the Bashar al-Assad regime in Aleppo on Nov. 9.

Photo by Achilleas Zavallis/AFP/Getty Images.

U.S. intelligence sources indicate that the Assad regime is “mixing chemicals” to make sarin gas for use against Syrian rebels. Secretary of State Hillary Clinton said chemical warfare was a “red line,” and the United States would take action if the Assad regime deployed sarin. Why don’t dictators premix their sarin?

Because it’s dangerous, volatile, and corrosive. There are several recipes for sarin, but they all require mixing together some combination of chemicals, such as hydrochloric acid, isopropyl alcohol, hydrogen fluoride, phosphorous trichloride, and difluoromethylphosphonate. Kept separately, some of these chemicals pose minimal threat to handlers or the public. Once mixed, one drop of sarin can kill a person in a matter of minutes. That’s why the United States and other countries have historically maintained the unmixed components of sarin in separate buildings. Sarin is also highly corrosive. The Nazis used solid silver containers to mix sarin, and today’s despots use specialized corrosion-resistant metal alloys to concoct the deadly mixture.

Mixing sarin is actually a rather simple process. In fact, during the 1960s, the United States developed a projectile called the M 687 GB that featured two containers. One container was filled with difluoromethylphosphonate and the other with a combination of isopropyl alcohol and a chemical catalyst called isopropylamine. When the projectile was fired, the launch caused the membrane separating the two substances to break and the spinning action of the flight stirred together the chemicals. By the time the canister reached its destination, the chemical reaction was complete. The United States successfully tested the M 687 with sarin in 1969 and conducted thousands of additional tests with nonlethal chemicals.

Advertisement

The technical challenge for users of sarin is the dispersal. When the Japanese terrorist cult Aum Shinrikyo released sarin on the Tokyo subway in 1995, the attack could have killed hundreds of people. However, the group packaged the chemical in lunchbox-like containers and broke them open with umbrellas. The leaking fluid managed to kill 12 people and hospitalize thousands, but the death toll on the crowded, rush-hour subways would have been far higher had the chemical been aerosolized.

Got a question about today’s news? Ask the Explainer.

Brian Palmer writes about science, medicine, and the environment for Slate and the Natural Resources Defense Council. Email him at explainerbrian@gmail.com. Follow him on Twitter.

TODAY IN SLATE

The Slatest

Ben Bradlee Dead at 93

The legendary Washington Post editor presided over the paper’s Watergate coverage.

This Scene From All The President’s Men Captures Ben Bradlee’s Genius

Renée Zellweger’s New Face Is Too Real

Sleater-Kinney Was Once America’s Best Rock Band

Can it be again?

Whole Foods Is Desperate for Customers to Feel Warm and Fuzzy Again

The XX Factor

I’m 25. I Have $250.03.

My doctors want me to freeze my eggs.

The XX Factor
Oct. 20 2014 6:17 PM I’m 25. I Have $250.03. My doctors want me to freeze my eggs.
Technocracy

Forget Oculus Rift

This $25 cardboard box turns your phone into an incredibly fun virtual reality experience.

George Tiller’s Murderer Threatens Another Abortion Provider, Claims Free Speech

The Congressional Republican Digging Through Scientists’ Grant Proposals

  News & Politics
The World
Oct. 21 2014 3:13 PM Why Countries Make Human Rights Pledges They Have No Intention of Honoring
  Business
Moneybox
Oct. 21 2014 5:57 PM Soda and Fries Have Lost Their Charm for Both Consumers and Investors
  Life
The Vault
Oct. 21 2014 2:23 PM A Data-Packed Map of American Immigration in 1903
  Double X
The XX Factor
Oct. 21 2014 3:03 PM Renée Zellweger’s New Face Is Too Real
  Slate Plus
Behind the Scenes
Oct. 21 2014 1:02 PM Where Are Slate Plus Members From? This Weird Cartogram Explains. A weird-looking cartogram of Slate Plus memberships by state.
  Arts
Brow Beat
Oct. 21 2014 9:42 PM The All The President’s Men Scene That Perfectly Captured Ben Bradlee’s Genius
  Technology
Technology
Oct. 21 2014 11:44 PM Driving in Circles The autonomous Google car may never actually happen.
  Health & Science
Climate Desk
Oct. 21 2014 11:53 AM Taking Research for Granted Texas Republican Lamar Smith continues his crusade against independence in science.
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.