The union representing Hawaii’s public school teachers has filed a grievance over teaching assignments at a Big Island school.

The Hawaii Tribune-Herald  reported Friday the union alleges teachers at Honokaa High and Intermediate School have been assigned to classes they’re not qualified for.

Hawaii State Teachers Association President Wil Okabe said the union will send representatives to the school next week to investigate claims certified teachers are being asked to teach classes outside the scope of their certifications.

“If you have a teacher certified in English, you want them teaching English, not math,” he said.

Filing a grievance with the state Department of Education is a very rare step for the union, Okabe said. Putting teachers in classrooms where they aren’t prepared to teach can negatively impact performance assessments, he said. Compensation is tied to teacher performance.

“But I think the key issue is about the students,” he said. “Making sure they have qualified teachers and making sure they have a teacher licensed in the subject area they’re teaching.”

Principal Marcella McClelland said she can’t discuss details because of collective bargaining agreements. But she said some teachers have been asked to teach subjects outside their certifications because of vacancies.

“We have had some vacancies created midyear because of retirements or resignations, or because of people taking jobs elsewhere,” she said. “That does create vacancies and we don’t have a pool of qualified teachers to fill those positions.”

A spokesman for the state Department of Education declined to comment on the grievance, citing personnel issues.

County Councilwoman Valerie Poindexter said she received some complaints about teacher assignments at the school for the upcoming academic year.