Chemical cabinet saves school from explosion

20:58, Dec 05 2012
Chemical fire
Close call: Kaikoura fire chief Ian Walker and Kaikoura High School head of science Jo Fissenden put chemicals into oil after potassium stored in a cupboard caused an explosion at the school yesterday afternoon. Two firefighters in the foreground wearing protective gear went into the science lab to bring the chemicals out

Emergency services were called to their second potentially hazardous situation in as many days yesterday afternoon when smoke was spotted coming from the Kaikoura High School science laboratory.

Kaikoura fire chief Ian Walker said the callout happened just after 3pm, and it was fortunate students were just leaving for the day.

Potassium that had not been stored properly had come in contact with either air or water, causing an explosion in a chemical cupboard.

Once the brigade had established the likely cause of the explosion, two firefighters wearing chemical suits and breathing apparatus were sent into the building to open the cabinet. Quantities of calcium, lithium, sodium and potassium were removed from the building and made safe outside by submerging them in oil, Mr Walker said.

The potassium, which reacts violently with water and air, was fortunately contained when the heat of the explosion had caused the container lid to weld shut.

School head of science Jo Fissenden said the potassium, which was like a bomb, had been used earlier in the day.


It appeared that it had not been correctly stored again after it had been used.

"Potassium needs to be stored under oil," she said. "Either there was not enough oil or some air or water had got to it somehow."

The metal chemical cabinet in which the potassium and other chemicals were stored had saved the school, Ms Fissenden said.

Some superficial burn and smoke marks were visible around the doors of the cabinet but the situation would have been far worse without it, she said.

A technician in the lab at the time had heard a muffled bang and seen smoke, before the alarm was raised and the building evacuated.

Acting principal Gayle Cameron praised the fire brigade and police for the response. Their reaction times were swift and the response team knew what they were doing.

The school had only just had a drill with the fire brigade a week ago, and six of the students were in the brigade, which was unusual for a school of Kaikoura's size.

"It was lovely to see past and present students turning up to save the school," she said.

Mr Walker said Environment Canterbury (ECan) had been informed of the incident and would dispose of the chemicals and containers.

The first chemical incident of the week for the brigade was a truck carrying hazardous substances that tipped over on State Highway 1 near Peketa, south of Kaikoura, early Wednesday.

The Marlborough Express