A Harvard University researcher whose coffee was spiked with a dangerous chemical said he believes the staff was intentionally poisoned with a toxic preservative used widely in the medical school's laboratory.
"I can not think it would be an accident," Matteo Iannacone told ABCNews.com today. "Fortunately, I drank just a sip."
Despite drinking just a sip Iannacone, 33, was one of six people who became ill on Aug. 26 after drinking coffee from a communal espresso machine on the eighth floor of Harvard Medical School's New Research building.
Toxicology results, he said, showed the coffee contained a "very high concentration" of sodium azide, a powerful chemical preservative that can be fatal in high doses, causing respiratory failure.
"All the research labs have it," Iannacone said. "It's very common."
Iannacone said he and two students from the pathology department had gone over to the single-serve coffee machine, a daily ritual, around and he noticed right away that there was something off.
"As soon as we tasted a sip of the coffee, we noticed the taste was strange," he said.
Within seconds, they experienced tachycardia, or a rapid heartbeat, and an increase in blood pressure.
"We were sweating and we had to sit down, almost like we were fainting," he said.
Iannacone said that because he takes his coffee black -- "I'm Italian," he explained -- he was able to notice the chemical right away. But they later learned that some of the other coffee drinkers had put sugar and milk in their cups, masking the altered taste, and drank the entire thing.
Two people fainted, he said, and one of those people was hospitalized overnight. For Iannacone and the two students he was with, the symptoms began to disappear after about 10 minutes.
Cameron said all six involved with the poisoning were back at work within a day or two.
Iannacone said he wasn't particularly nervous about someone within the school trying to harm the students and employees, but that he found it "disturbing." Others, he said, are worried something might happen again.
David Cameron, spokesman for Harvard Medical School, said the coffee machine is not connected to the water supply. The water reserve tank is filled periodically by anyone who notices the water level getting low. Each re-fill can make several cups of coffee, he said, though it is unclear whether all six people got coffee from the same water supply.
The eighth floor coffee machine also served researchers and students on the 9th floor, he said, about 200 people total. The machine has since been removed.
"We are now going to the Starbucks downstairs," Iannacone said, adding that the medical school is also installing new security cameras.
The university and it's police department have remained tight-lipped about the poisonings.
Cameron told ABCNews.com today that the university has contracted with an independent toxicologist as part of the Harvard University Police Department's investigation.
No students or employees have been disciplined, he said, and no arrests have been made.
"The bottom line is they are looking very carefully and exhaustively at every single cause," Cameron said.
According to the Centers for Disease Control that in addition to the chemical's common use in medical laboratories, sodium azide is used as the explosive agent in automobile airbags.