Hazmat crews checked out an apparent leak in Allentown Thursday morning.
The incident happened around 6:30 a.m. at Acme Cryogenics at 1 W. Allen St., under the Tilghman Street bridge.
A liquid carbon dioxide tank was leaking, and the cloud that forms from the substance can cause suffocation, fire officials said.
A truck driver familiar with the equipment was able to make his way to a shut-off valve on the tank, which stopped the leak.
Businesses in the industrial park were evacuated as a precaution, but residences weren't evacuated as the wind was blowing toward the river, officials said.
No one was hurt.