The lecture hall in Evans Lab was evacuated Monday morning after a graduate student mistakenly caused a foul-smelling chemical to leak into the building’s ventilation system, said John Herrington, the safety coordinator for Ohio State’s Department of Chemistry.

Occupants of the building thought there was a gas leak because the chemical, t-butyl mercaptan, is what gas companies put into natural gas so that leaks can be detected. Natural gas is odorless.

Columbus Fire Department engines and rescue vehicles responded at about 1 p.m, said Bob Armstrong, director of Emergency Management. OSU Emergency Management and Environmental Safety also came to the scene.

No injuries occurred and no damage was done to the building.

Emergency services determined that there was no danger and classes continued as normal.

“It’s a normal chemical reaction we did in our group. It leaked out into the air, but it’s non-toxic,” said Toby Sanan, a graduate student who is part of the lab group that works with the chemical in Evans.

Mercaptan is heavier than air and it spreads fast, said Gerhard Raimann, chief administrative officer for the chemistry department.

The odor traveled throughout the building and onto the street.
Brooke Nye, a second-year in business, noticed the odor 15 minutes into her class on the second floor.

“It just started smelling like gas and it got really strong,” Nye said.
Nye said her teacher noticed it too, but the class wasn’t evacuated.

Herrington said the graduate student research group was using mercaptan in its purest form at the smallest quantity.

Sanan isn’t sure how the Columbus Fire Department was notified, but he suspects that someone called 911 because they believed it was a gas leak.