KAHUKU (KHNL) - The state is still trying to figure out what made some Oahu students sick last week.
Kahuku High and Intermediate was closed again on Tuesday, because of a lingering chemical odor.
A state toxicologist visited the school but determined the campus is free of contaminants.
It started last Thursday, when students and teachers fell ill because of fumes. Employees at a nearby sod farm, Ameri-Turf, sprayed the pesticide, Orthene, on a 9,000-square-foot area of their property.
But agriculture officials said it's unusual that Orthene would linger for days.
"Normally, Orthene would be dissipated or eaten by the plants by that time," said Bob Boesch, state pesticides program manager.
Boesch took samples from the school last Friday and will get results back in two weeks. But this isn't the first time the state has contacted Ameri-Turf.
Last year, the Department of Agriculture issued them a warning, because an employee wasn't wearing the right amount of protective wear while spraying a pesticide.
Ameri-Turf could face fines, if test samples show the pesticide drifted on campus. But right now, no one knows for sure what made students and teachers sick.
"It could possibly be something else that's irritating out there," said Boesch.