ANN ARBOR (WWJ) - Operations inside the University of Michigan Cancer Center are back to normal after a hazardous materials incident Tuesday afternoon inside a research area.

U-M Public Safety Spokeswoman Diane Brown explained what happened:

"It was determined that a solvent, that is often used in our research environment, had been put into an autoclave machine, which does sterilization and it created a tremendous odor," said Brown.

The solvent, a cleaner, was contained -- so there was never any exposure -- but as a precaution the building was evacuated of non-essential personnel.

Four researchers did seek medical evaluation as precaution and were quickly released.

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