Fourteen students and three adults at Highlands Intermediate School were treated after the odor of the insecticide malathion was detected at the Pearl City school yesterday afternoon.

Bryan Cheplic, spokesman for the Department of Emergency Services, said all 17 complained of nausea, irritated throats and eyes, and slight dizziness. Two students under the age of 15 were taken in stable condition to a hospital at the request of their parents, a school official said.

Principal Amy Martinson said the entire school of nearly 1,000 students was moved to three self-contained, air-conditioned buildings — the school library, cafeteria and band room — just after 1 p.m. after the odor was detected.

Martinson said the pesticide was being used about two blocks away from the school.

The Environmental Protection Agency has registered malathion as an insecticide for agriculture, residential gardens and public recreation areas, and in public health pest control programs since 1956.

Martinson said "the odor was quite powerful" and the strongest she has experienced.

Two years ago a resident on Hoomalimali Street spilled a pint of malathion, and winds carried the smell makai to the Highlands campus at 1450 Hoolaulea St. The odor caused 17 students and a staff member to complain of headaches, watery eyes, dizziness and nausea.

One student was treated at the scene, and four others were taken in stable condition to a nearby hospital.

After the March 6, 2008, incident, firefighters canvassed the neighborhood and discovered the source of the smell. The resident was apologetic and unaware he was causing the problems.

Martinson said the students and staff practice the school’s emergency plan at least twice a year, most recently in August.

"The students knew exactly what to do," she said. "Our crisis plan is practiced, practiced and practiced."

Cheplic commended school officials for the way they carried out their emergency plan, noting it helped paramedics isolate and treat affected students after they arrived.

Martinson said firefighters were able to neutralize the smell of the insecticide immediately, but from past experience she expects the smell to linger. This is the second or third time the school has had to activate its emergency plan, Martinson said.

A letter was sent to the parents of all Highlands students explaining what happened, asking them to observe their child and to seek medical attention if anything suspicious occurs, Martinson said.