Caffeine is such an ordinary part of many people's days that most don't consider it dangerous.
But ever since an Ohio teen died of a caffeine overdose, the stimulant has been in the spotlight.
Tama Sawyer, a clinical toxicologist who heads the University of Kansas Hospital's Poison Control Center, said the form of caffeine that killed that teen is easy enough to come by.
"You can buy this on Amazon for $12.95," Sawyer said.
She says those who've died have ranged from late teens to early 50s.
"We're talking about really rapid heart rate, where the heart can't keep up," Sawyer said.
Just days before his graduation, 18-year-old Logan Stiner was found dead in his home. Doctors say he took a lethal dose of caffeine powder.
But this isn't a teen party craze. It's marketed for mental alertness – energy people can sprinkle on anything – and it's potent.
A teaspoon is the equivalent of at least 32 mugs of coffee, depending on what size mug people use.
It's not the only powdered form of caffeine out there. There are drink mixes containing caffeine.
But those are in measured bottles or pouches. The pure powder has to be measured by people themselves.
Sawyer said that is likely the cause for the overdoses.
"I'm thinking it's just a lack of label reading," Sawyer said. "You get this stuff it's in a powder and you think, 'I'll start with a teaspoon, see how I do with that.' And that's way too much."
A suggested serving of the pharmaceutical-grade powdered caffeine is 1/16 of a teaspoon. That's a minute amount and not one easily measured with kitchen-store measuring spoons, which rarely get that small.
Expert opinion varies about how much of the powder caffeine would be needed to kill an average adult.
One toxicologist gave an estimate of two to three teaspoons. Sawyer said one teaspoon could kill.
"One dose that high and you could be in the emergency room and possibly die," Sawyer said.
Especially dangerous would be having the powder near children. It would take much less to kill a child.
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