A stockpile of nearly 800 litres of flammable chemicals found in a Dunedin home could have triggered a "catastrophic" explosion, an expert says.
Up to 40 boxes of the chemicals, destined for use in a Dunedin manicure business at the Meridian mall, were found piled inside the basement of a woman's rented Mornington home, in September last year.
Some of the boxes were exposed to sunlight, despite the need to be kept cool, and others were stored next to a laundry containing electrical equipment and wiring.
The brick bungalow, in a high density residential area, was also just 100 metres from Mornington Primary School.
Lien Duong (25), of Dunedin, appeared in the Dunedin District Court yesterday, after earlier pleading guilty to four charges relating to the storage of hazardous chemicals in the basement of the home.
She was remanded on bail for sentencing on September 3, after Judge Paul Kellar reserved his decision.
Council staff were alerted after the stockpile of 778 litres of flammable chemicals was discovered by a real estate agent inspecting the property.
Former firefighter and hazardous substances expert Rex Alexander, of Dunedin, told the Otago Daily Times the situation had the potential to "turn into something really quite nasty".
"In my professional career I have never been faced with a situation that presents a greater level of danger in a residential neighbourhood.
"For a residential property, I have never seen any worse."
Mr Alexander, who was asked by council staff to assess the risk the chemicals posed, had been a Dunedin firefighter for 11 years, and a dangerous goods inspector for the council for 15 years.
He said the storage of the chemicals was "hugely inappropriate" in a residential area and could have had "quite enormous" repercussions for neighbours and firefighters responding to a fire at the address.
"The woman had absolutely no idea what she was doing," he said.
Mr Alexander, now the technical director of Envirocom NZ Ltd, said the explosion of even a single chemical container could have lifted the roof off the home or sent a a "jet of flame" through the doorway of the basement and outside.
An explosion igniting all 778 litres would have destroyed the home and sent material flying "some distance", he said.
"It would be quite serious and quite violent, windows blowing across the street . . . if the whole lot went up it would demolish the house in fairly short order."
Firefighters responding to reports of a fire in the basement could also have been caught up in a subsequent explosion, if it did not occur immediately, he said.
"That could be fatal," he said.
The resulting fire would have been "quite fierce", and beyond what firefighters responding to a normal garage fire would expect, with nearly invisible flames from the burning chemicals, and "extremely toxic" smoke, he said.
The smoke could have affected children at the nearby Mornington School, and require firefighters and neighbours over a wide area to seek medical attention, he said.
"I wouldn't be entirely comfortable being a neighbour there. I wouldn't be entirely comfortable having a child at that school," he said.
Duong's prosecution was believed to be the first of its kind in New Zealand since the introduction of the Hazardous Substances and New Organisms (HAZNO) Act 1996.
Duong declined to comment before next month's sentencing when approached by the ODT yesterday.
