It happened around 10:00 a.m. at the Atlantic County Institute of Technology at 5080 Atlantic Avenue in Mays Landing, N.J.
Investigators said the odor came from a men's bathroom in the main campus building.
Five students were treated at the scene after complaining of throat irritation.
HAZMAT crews were not able to detect any specific substance in the air.
The cause of the odor remains a mystery.