People often don’t realize that pure caffeine is so potent that it qualifies as a “toxic” compound under transportation shipping rules.

Sadly, an autopsy conducted on a young man who died days before graduating high school shows his death was caused by an overdose of this stimulant.

Logan Stiner, a popular student and wrestler, was in his final week at Keystone High School when he suddenly collapsed in his home May 27.

A month after his death, an autopsy answered the pressing question of what killed him.

It was pure caffeine.

The 18-year-old Stiner was found about 11 a.m. May 27 on the floor of his home in the 400 block of Hendrix Boulevard. The same day his mother, Katie Stiner, said she found bags of caffeine powder in the house.

The case initially perplexed Logan’s friends and family, who remember Stiner as a healthy student who didn’t do drugs and only occasionally drank a cup of coffee.

The autopsy this week revealed a lethal amount of caffeine in Stiner’s system, said Lorain County Coroner Dr. Stephen Evans.

“It’s a complete shock to the entire family,” said Logan’s aunt, Kelly Stiner.

Evans said he has heard of only 18 other deaths from caffeine overdoses in the United States.

Stiner was found with more than 70 micrograms of caffeine per milliliter of blood in his system, Evans said, adding that the normal amount of caffeine in an energy drink is three to 15 micrograms.

Fifty micrograms is considered a lethal dose, Evans said.

“He was a young, healthy guy. People don’t realize (caffeine) could potentially kill you,” Evans said.

Logan Stiner — who didn’t have any heart conditions — had taken pure caffeine powder the day of his death, Evans said. The powder caused Stiner to have a cardiac arrhythmia and a seizure, which together, killed him.

“Since it’s a powder, he probably doesn’t know how much he was taking,” Evans said.