SAN ANTONIO, TEXAS ? The FBI determined a powdery substance found in a roll of quarters at a University of Texas dormitory was not ricin after initial state tests had indicated it was the potentially deadly poison, a spokesman said Sunday.

The FBI tests did not identify the substance, but they came back negative for the poison that is extracted from castor beans, said San Antonio FBI spokesman Rene Salinas.

“There were no proteins in there to indicate it was in fact ricin,” Salinas said. He said further testing was unlikely.

Texas health officials did “just a quick test and they don’t check for the proteins in ricin,” Salinas said.

The mystery powder spilled onto Kelly Heinbaugh’s hands as she unwrapped a roll of quarters in her dorm room on Thursday. She said she’d used five other rolls of quarters her mother had gotten from the same bank and none had powder in them.

The a 19-year-old freshman and her roommate were both evaluated for possible exposure to ricin and cleared at a hospital.