By Tony Wall
AUCKLAND - Workers at an Otahuhu industrial site heard a buildup of pressure in the hours leading to an explosion that blew a hole in a chemical factory yesterday.
The explosion about 11 am was so powerful it ripped a hole in the side of the Koppers-Hickson Timber Protection
factory and cracked the concrete wall of a neighbouring building.
Ambulance staff treated 13 workers who came into contact with arsenic acid from a holding tank ruptured by the explosion. None was taken to hospital, but the Fire Service said it was extremely lucky that no one was seriously injured or killed.
The chief fire officer for Auckland East, Ray Warby, said a hydrogen peroxide container exploded, damaging the pipes and tanks holding the arsenic acid used for timber treatment.
Up to 10,000 litres of acid spilled on to the factory floor. Firefighters wearing chemical protection suits made an earth dam to stop the toxic chemical getting into stormwater drains.
Mr Warby said some runoff got into the drains before the Fire Service arrived.
The business manager of Koppers-Hickson, Mark Boyle, said the cleanup went smoothly and all safety procedures had been followed during the emergency.
It was too early to speculate on the cause of the blast.
But Rod Crawford, the manager of the neighbouring business, said he was concerned that his staff had heard hissing sounds they attributed to pressure buildup during the morning.
A driver for his firm noticed that a pressure valve on an outside water cooling tank was showing signs of overload and he was on his way to tell Koppers-Hickson staff when the explosion happened.
"That [moving away] is probably what saved the driver's life."
Mr Crawford said eight industrial lights crashed down when the explosion rocked his building, and a concrete wall was cracked.
"My initial reaction was that it was an earthquake ... then I had thoughts of an aeroplane landing on the roof."
Some of his workers raced to investigate and inhaled fumes.
