Honokaa Elementary, Intermediate and High schools, closed at midmorning Thursday due to a chemical odor that sickened about 50 people, will reopen Friday.

Fire personnel determined that the odor was coming from a nearby home where a pesticide was sprayed, the Hawaii County Fire Department said.

The Fire Department said the pesticide used was diazinon with Volck Oil (a registered trademark of Ortho), whose active ingredient is petroleum oil.

The Environmental Protection Agency outlawed the sale of diazinon outdoor, non-agricultural products after Dec. 31, 2004, to eliminate all residential uses of the insecticide. The EPA’s aim was “to protect children and the environment,” the EPA said in an online fact sheet.

The EPA fact sheet, updated in 2012, says consumers may use it if they follow all label directions and precautions. “However, consumers should know that EPA took this action to protect children and the environment,” it states.

The Fire Department’s hazard materials team was summoned about 9 a.m. when a teacher and students evacuated the woodshop classroom due to the pesticide smell. The hazmat team received more reports of a similar odor throughout the school, fire officials said.

DOE officials said about 40 students and 10 adults from Honokaa High & Intermediate who reported feeling symptoms of nausea, dizziness and