When asbestos gets in the way of our nation's need for fertiliser

Tuesday, 11 September 2018

A warehouse at the Ballance Agri-Nutrients site in Tauranga has been locked down after high levels of asbestos were detected.

The manufacture of fertiliser can be a dangerous business. An asbestos scare that's shut down part of a factory shows how. National correspondent Tony Wall reports as part of Stuff's 'Growing Pain' series, examining our dangerous addiction to fertiliser.

Thousands of people drive past the Ballance fertiliser factory every day as they cross the bridge from Tauranga to Mount Maunganui, but many don't even realise it's there.

Hidden behind a tall hedge, the facility on a piece of land next to Tauranga harbour is mostly obscured from view.

The public has no idea that since June, part of the site has been locked down because of an asbestos scare.

High levels of the potentially deadly mineral were discovered in stores of serpentine rock, which is ground up and added to phosphate for a product called Serpentine Super, which farmers use to put magnesium into their soil.

The rock is mined from four or five quarries mostly in the South Island, and some seams can contain naturally-occurring deposits of white asbestos, or chrysotile.

When this material is crushed, it has the potential to form respirable asbestos fibres and put worker health at risk.

Since April, the quarries have by law been required to have asbestos management plans in place, including testing for the presence of the mineral.

Critics say the agricultural industry has been slow to adapt and use alternative sources of magnesium, but the fertiliser companies say it is the best option for soil maintenance and reduces run-off.

Stuff has learned that the asbestos found in Tauranga was in serpentine rock mined from a quarry at Brightwater, near Nelson and sent north by ship.

The quarry company, Lee Processors, is alleged to have dispatched the rock without having an asbestos management plan in place.

WorkSafe has shut the quarry down and also placed prohibition notices on a storage shed at Ballance's site, where 80 tonnes of the asbestos-tainted rock remains.

A specialist removal company will be engaged to dispose of the material and the plant and machinery will have to be cleaned, which is expected to be a costly exercise.

Lee Processors near Nelson provided serpentine rock for fertiliser with higher than permitted levels of asbestos.

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Ballance and WorkSafe say there is no risk to the public.

Ballance operations manager Rob Larman in front of the store where the serpentine rock is kept.

The alarm was first raised when Lee Processors received laboratory test results in June, which showed that some of the serpentine it had been mining contained more than the workplace exposure limit of 0.01 respirable asbestos fibres per millilitre of air.

A 750-tonne shipment of rock, in 28 containers, was already on its way to Tauranga when Lee Processors alerted Ballance and WorkSafe.

The shipment was placed in quarantine and returned to the quarry.

Asbestos fibres can be difficult to detect and tests on Ballance's remaining stores of serpentine initially came back clear. But further tests ordered by WorkSafe showed that it too was over the allowable limit.

Rob Larman, operations manager for Ballance, says the company immediately shut down that part of the site and set up decontamination units.

'As far as we're concerned anything above the limit is significant - it puts our staff at risk so we don't want anything to do with it.'

Staff who'd worked with the serpentine had been offered additional medical assessments, on top of their regular checks, and a couple had taken that up.

Larman says the management plan that Ballance and Lee Processors agreed to said that no raw material would be dispatched until tests had cleared it.

Ballance has stopped using the quarry as a source of serpentine because of the incident.

David Irvine, owner of Lee Processors, says the problem was that the New Zealand laboratory he'd been using for asbestos testing had been giving incorrect results.

'We thought where we were working [in the quarry] was fine because the results were showing it was fine - then all of a sudden there was a change in the testing method and we're up over the limit.'

He would not name the lab involved.

He says he shut down operations when the 'shock' results arrived.

Danger signs have been placed on the serpentine rock store at Ballance Agri-Nutrients after asbestos was discovered.

'We stopped of our own accord, we don't want to be supplying a product that's a problem, that's for sure.'

Irvine says he might have to fold the business.

'Our customer [Ballance] has thrown their toys out of the cot. We've done everything according to the book but had to bear the brunt of the problem. We're in a really bad position.'

Irvine insists that he had an asbestos management plan, but WorkSafe disputes that.

Darren Handforth, WorkSafe's southern region chief inspector for assessments, says the quarry did not have a plan as required by April 1 and the company has been prohibited from doing any further work at the site until one is in place.

Handforth says three quarries which were shut down last October while management plans were developed all now have plans in place.

These decontamination units were set up after asbestos was discovered.

He says serpentine powder has been used in New Zealand as a source of magnesium for over 40 years and WorkSafe had not found any link to adverse health outcomes.

But sources say the industry has been slow to react to asbestos concerns.

'It [Serpentine Super] is quite an old fashioned product,' a source says. 'They are starting to ask whether the risk as a business in trucking around asbestos-containing material is worth the amount of money they get out of it.'

There are alternative sources for magnesium, the source says.

'The agricultural community, certainly around this fertiliser, has been slow to adapt, probably because the other products that are available … are more expensive and carry some risks around pasture burn.'

A Ballance spokesman says there is strong demand for Serpentine Super, particularly for the dairy sector, and it has environmental benefits.

The company has switched to a Southland supplier, which provides a raw material called Dunite.

Bob Pearson of Southland Serpentine, one of those shut down by WorkSafe last year until a management plan was put in place, says testing for asbestos is a big problem as often non-asbestos fibres are falsely identified as chrysotile.

His company uses a laboratory in Australia.

'We don't trust the New Zealand labs - they're not up to it.'

Soil scientist Bert Quin, an independent fertiliser company operator, says he believes there has been a 'cover-up' over the years about the use of asbestos-containing serpentine rock.

It's only in the past two decades that reliable analytical tests had been developed to determine how much asbestos was present in serpentine deposits, he says.

'Owners of some serpentine mines played the 'deny, deny, deny' tactic until samples were sent to expert overseas asbestos laboratories,' he says.

He accuses them of wanting to hide evidence in case asbestos starts showing up in livestock.