An estimated 5kg of mercury was spilt in a residential Napier property yesterday, triggering a major hazardous chemicals response by emergency services which required road closures and mobile shower units.

What began as a simple garage clean out just after 1.30pm ended in road closures and traffic diversions as emergency services worked to clean up the chemical spill.

A mercury spill can be dangerous due to the risk of ongoing exposure to its toxic vapours, with mercury poisoning often presenting as flu-like symptoms.

The occupant of the Kennedy Rd, Onekawa, house said he had no idea the mercury was there as up to 30 firefighters came and went from the scene - each crew member who helped deal with the spill going through rigorous showers and scrub-downs.


The man, who asked not to be named, said he was carrying out a pre-Christmas clean out of old tools and other items stored in the garage.

Many of the items, including the container of mercury, had come from his grandfather who had been a farmer.

The man said he had no idea what the mercury would have been used for.

"I've only been in the house for about six months, but I've had the tools for years, we were just going to get rid of it."

The container had been placed in a large fruit bin and he was carrying it outside when it fell out and broke. He and a friend helping him recognised it as mercury and carefully swept up as much as they could with a brush and shovel.

"I reckon we got about 95 per cent of it," he said, adding that the rest had spilled down into cracks in the pavement. "We didn't know how to get it out of the cracks so rang the National Poisons Centre and they told us to go down and see the fire department."

Realising his children and others would be in the backyard area on Christmas Day, the two went quickly to the Napier Fire Station to raise the alarm and get some advice about the spill.

"We just didn't want to take any risks with young kids around."

Senior firefighter and scene commander Mark Magill said he had never come across a mercury spill before in his long career - nor had other officers.

They took no chances, calling in specialist hazardous chemical officers and alerting the District Health Board and the Hawke's Bay Regional Council.

The two men were taken back to the scene and went through an extensive body wash and a thorough check by St John Ambulance staff.

Mr Magill said the National Poisons Centre had advised on the clean up, but it was the biggest spill its staff had come across.

"It's normally a little bit out of a thermometer, never had this kind of spill." Six fire appliances as well as the Hazmat unit attended, along with the mobile shower wash units which were set up in the front yard of the Masonic building near the intersection with Riverbend Rd. A 300m stretch of Kennedy Rd from Riverbend Rd through to the first median break was closed off, with Taradale-bound traffic being diverted into one of the city-bound two lanes.

By 3.15pm Mr Magill said the spill was contained, but the removal was difficult.

After advice from chemical experts it was decided to use syringes and pipettes to draw the mercury out of the cracks.

"Relief crews are coming in to help with that as the boys all have to be in splash suits, it can get to about 45 degrees in those."

While there was no major danger from fumes, the occupants of the house immediately next door and downwind were advised to close all doors and windows. An adviser at the National Poisons Centre said the main concern with a mercury spill was the risk of ongoing exposure to mercury vapour.

"The problem with mercury is that it flows all over the place. Especially in a household situation, if it spills on carpet it has to be replaced because young children and pets, who are down at that level, can be exposed to vapours."

As Hawke's Bay Today went to press a fire unit protected the scene until specialist equipment arrived from Auckland, enabling the recovery operation to continue.