The explosion at Mayfair School was caused by cooking with the pot stand supports facing downward, heating the butane gas canister housed within the stove and blowing it up.
Directions on the product warn not to do so and the resulting explosion on Tuesday burnt the arm of a parent. She was taken to Hawke's Bay Hospital with moderates injuries and discharged later that day.
The portable cooker was used as part of an outdoor education exercise where students would create their own meat patties which parents would cook.
Mayfair School principal Tanya Bunny acknowledged there had been an element of human error but said there was a "strong possibility" of product fault due to the risks posed by misuse of the equipment.
"The exercise for the children was that they designed and created their meat patties, and then the parent helpers cooked them as part of an outdoor education week," she said. "I met with board representatives in the afternoon and we've undertaken a review of safety procedures when cooking at school, and I [have] already made the changes needed to keep everybody safe so that this doesn't happen again."