Horowhenua College was evacuated after a potentially unstable chemical was discovered in a science laboratory.
Police were alerted at about 10.20am on Tuesday, August 25, after a science technician found a flask containing a substance identified as potentially unstable.
The substance was reported to be Tollens’ reagent, a solution containing silver ions and ammonia.
Emergency services, including Police, Fire and Emergency and ambulance crews, attended the Levin school.
A New Zealand Defence Force Explosive Ordnance Disposal team was also called to assess and remove the material.
The chemical was safely disposed of in the school’s back field at about 3pm under the supervision of specialists.
The evacuation was carried out as a precaution.
The Horowhenua College incident was followed by similar discoveries at schools in Auckland and Porirua.
The Ministry of Education said the incidents were a reminder for schools to review the chemicals stored on their sites and ensure they were being appropriately managed and disposed of.
Schools concerned about potentially hazardous chemicals were advised to seek specialist help and contact emergency services if there was an immediate safety risk.
The Ministry also advised schools not to move or handle a substance where there were safety concerns.