Ricin: How Often Do People Use the 'Breaking Bad' Poison?

A hazardous materials team investigates potential ricin. Steve Marcus/ Reuters

It's one of the most memorable moments from AMC's Breaking Bad: Walter White, the chemistry teacher turned meth mastermind, slips a deadly poison into a rival's tea, killing her without a trace.

That poison is called ricin, and earlier this week a "wannabe Walter White" (as the New York Daily News dubbed him) went on trial in Manhattan on charges of trying to obtain it. Instead of making the poison like White did, the authorities allege 22-year-old Cheng Le attempted to buy it on the Internet. Like White, his goal was allegedly to kill someone. But the vendor turned out to be an undercover FBI agent, and Le, who denies the charges, was arrested.

He isn't the only one who has allegedly tried to obtain the deadly substance. Since 2010, there have been 23 arrests in the U.S. involving actual ricin, according the FBI. There have also been 65 arrests due to ricin-related threats during that same period, the bureau says. "Ricin manufacture, threat and possession are all potential federal crimes" and depending on the jurisdiction, there might also be local laws on ricin, according to an FBI spokesman. In one recent case, a Pennsylvania man sent a "ricin-laced scratch and sniff card" to his "romantic rival," according to The Philadelphia Inquirer. He received a 20- to 40-year prison sentence.

As Walter White explained, ricin is an appealing poison because it's easily obtainable and hard to trace. The poison is made from castor beans. As it turns out, castor beans aren't beans. They are the seeds of the castor plant which, according to Popular Science, is a common ornamental species. The castor plant's seeds contain oil, which is safely used as a laxative, among other routine purposes, Popular Science says.

When people do use it as poison, ricin can be delivered as a "powder, a mist, or a pellet, or it can be dissolved in water or weak acid," the Centers for Disease Control and Prevention's website explains.

But don't worry about accidentally poisoning yourself—it's probably not going to happen. "It would take a deliberate act to make ricin and use it to poison people," explains the CDC website. "Unintentional exposure to ricin is highly unlikely, except through the ingestion of castor beans."

According to Popular Science, 1.78 milligrams of injected or inhaled ricin can kill an adult, "about the size of a few grains of table salt—which ricin resembles visually." If you happened to consume the seeds, four to eight could be a lethal dose, Popular Science reports.