Classes at New Bedford High School were canceled Friday due to a senior prank.
New Bedford police told NBC 10 a combination of fire extinguisher emissions, food and flour was splayed around a large area of the school.
Superintendent Pia Durkin said the mess was discovered when staff arrived Friday morning. The flour and food came from a classroom in the home economics department.
While the custodial staff was able to clean the affected area, school officials were concerned about airborne particles from the fire extinguishers.
School officials said they will be having an industrial hygiene professional inspect the school.
The students were dismissed and parents were notified by the automated call system. Calls were also made to the parents of students with special needs to make sure someone was home when the school dropped them off.
Durkin praised the staff for their work during the cleanup.