Noelani Elementary School in Manoa is releasing students early because of an unknown chemical odor that sickened 10 students.

Donalyn Dela Cruz, Department of Education spokeswoman, said school officials are notifying parents and that students were released for the day, starting at about 12:45 p.m. Classes will resume Tuesday as scheduled.

She said the school decided to end classes early after several children reported feeling nauseous. Those children were released to their parents.

Emergency Medical Services paramedics treated 10 children for nausea and related, mild symptoms. Paramedics did not transport any of the children to a hospital.  

Honolulu Fire Department spokesman Terry Seelig said school officials reported the odor near the school’s library about 8 a.m. Monday, and firefighters found the odor came from the sewer manholes on campus. There were no students in the library, but the school moved students from Building B downwind of the library to another location on campus.

Seelig said on Monday morning that firefighters were trying to determine the origin of the odor. Firefighters checked sewer manholes along Woodlawn Drive and nearby areas. Their meters determined the odor belongs to a class of explosive-level chemicals, but the product remains unknown. The sewer also had a higher-than-normal level of carbon monoxide.

Seelig said HFD notified the city Department of Environmental Services and the state Department of Health.