SHEPHERD, Texas -

An overpowering odor sent more than 140 students home early from Shepherd High School on Friday.

The incident happened at Shepherd High School, 1 Pirate Lane, on Friday morning.

The smell was compared to that of raw sewage. Administrators were able to trace it to the school cafeteria, where a floor scrubber battery had been charging.

"The Fire Marshal came out and he brought air quality monitors and found nothing that was a health risk concern," said Jody Cronin, superintendent of Shepherd I.S.D.

Students were removed from the area but the school was not evacuated. Some of the students complained of headaches, but the district superintendent said safety was never an issue.

No ambulances were called to the school and no students went to the nurse's office, school district officials said.

Parents were notified of the incident by telephone messages. While some picked up their students, classes at the campus continued as normal.

Officials said they checked the quality of the air and did not find any abnormalities. The school's doors were opened to air out the building.