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Cutting the cost of toxic timber

7 May 20 The demolition industry is working towards a code of practice for the handling of potentially contaminated waste wood. Mark Smulian reports

Who would want to clutter their office with a large quantity of waste wood? Howard Button, chief executive of the National Federation of Demolition Contractors (NFDC) would, for one.

Earlier this year he had a large accumulation of old wood ready to send for testing in an exercise that could save demolition firms millions of pounds if it succeeds.

Button’s unconventional office equipment collection arose from a plea made in January by the Wood Recyclers Association (WRA) for samples of wood from pre-2007 to be offered for testing.

It warned demolition firms that they faced a £100m-a-year bill unless it had enough samples to make a success of the Waste Wood Classification Project.

This seeks to establish whether wood used in buildings before regulations changed in 2007 was treated with chemicals that could release toxic material into the atmosphere when burnt in biomass boilers.

If such toxins are present then the Environment Agency (EA) could classify the offending wood as hazardous, which would mean only a handful of specialised incinerators in the UK could handle it, with high gate fees, transport costs and potentially export costs facing the demolition industry.

The Waste Wood Classification Project began in 2017 when the government came under pressure from the European Union to explain why the UK appeared to have a surprisingly low level of waste wood deemed hazardous, at under 0.5% compared with 15% in Germany.

Faced with a large bill for hazardous waste disposal, the WRA and NFDC agreed with the agency a ‘regulatory position statement’ – effectively a standstill arrangement – until 31st July this year, while the industry seeks to test enough waste wood to establish the extent of toxicity when it was burnt.


The intention is that the WRA and NFDC will each produce a code of practice for their members that is accepted by the EA. If the sampling shows that only a low proportion of wood is affected by toxic chemicals it will be judged non-hazardous so long as firms follow these codes.

Behind the EA’s action was undoubtedly political pressure. It is almost always controversial to propose to burn anything on a large scale – even without involving hazardous waste – because of real or imaginary public fears about the impact on health of releases of gas and materials from burning waste.

Testing began but by the end of 2019 insufficient samples had been procured for this from the industry, leading to a plea from WRA director Julia Turner.

She said then that the WRA needed the samples “to avert what it sees as a potential crisis that could cost the demolition sector over a £100m a year”.

This was based on it costing at least £250 per tonne to dispose of wood as hazardous waste.

Turner explained: “If the demolition contractors don’t actively engage with us now and allow the testing of these specific waste wood items to take place, it will have a catastrophic effect on the whole industry, and indeed environment, by increasing hazardous disposal.

“We know there is actually less hazardous material in the demolition sector, based on the chemical wood treatments applied at that time, than any of us originally believed. However, if we don’t prove what is hazardous now, the demolition sector will be left footing the bill to prove it themselves on a job-by-job basis.”

Put another way, if the industry could not present hard evidence on hazardous waste to the EA, the regulator would likely assume the worst.

The WRA has established that for the construction demolition sector there are three types of wood which are of concern: structural timbers (sole plates, external wall studs, ground and upper floor joists and roof timbers); roof tiling battens and external joinery (window frames, door stiles, soffit/fascia and barge boards) from pre-2007 buildings.

These types of wood were sometimes treated with preservatives that can be hazardous in certain concentrations and the testing seeks to find the presence of heavy metals content and substances like permethrin, dieldrin and lindane.

Chemical content of preservative treatments changed in 2007 so wood used after that year is not affected.

Button, speaking from his wood-filled office, fears the cost to his members could be significant if the classification project fails, since some 250,000 tonnes of wood waste is handled each year and disposal of wood judged non-hazardous costs only £30 – £40 per tonne.

He says: “Waste wood goes for burning in biomass but if it had to go to specialist incinerators there is a high cost and cost of transport.

“The problem is that if waste is said to be hazardous there are only three or four UK plants that will incinerate it and there’s quite a transport cost.

“For example I think the nearest one to London is in Bedford. If it has to go there we could expect gate fees to rise too, and if it has to be exported there would be even higher costs.”

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Although the regulation involved came originally from the EU, Button does not expect Brexit to make any difference to its enforcement.

“The Environment Agency has made it clear it will have no inclination to relax this after Brexit,” he says. “We’ve been told the Department for the Environment, Food and Rural Affairs is driving it because it wants to satisfy the public, as there would be uproar if people thought poisonous fumes were being sent into the air.”

Button says the main problem is with timber from the 1950s to 1970s when it was common to use chemicals to try to extend the life of the material.

There is also a particular problem with power station cooling towers, in which wood was coated in copper chrome arsenic to preserve the material “and that’s fine in place and you can handle it but when its burnt it gives off toxic fumes”, he says.


If the project succeeds and the demolition code of practice is adopted Button says there will be a need to train operatives to follow it. But he says “I don’t think it will be a problem to train them to sort wood waste from other waste once we have a training module set up.

“Our members nowadays use grabs which are like a giant pair of pincers on the end of the machine, and a trained operative can pick up a pencil, so they can certainly segregate wood.”

Even if the codes of practice are agreed and the classification project is successful in identifying that the problem is relatively small, firms could face an increased number of inspections and penalties if they fail to follow the codes.

Rod Hunt, a partner at law firm Clyde & Co, says: “The EA agreed a regulatory position statement and that will operate until 31st July 2020. And if businesses follow that they will not normally face enforcement action.

“There should then be the two codes of practice, and I think both the WRA and NFDC are hopeful of publishing them far enough in advance for businesses to familiarise themselves with them in advance.

“I would expect a flurry of site inspections by the EA after 31st July to ensure that these codes are being complied with given the high profile of this issue,” continues Hunt. 

“If firms did not comply you could see prosecutions for breaches of duty of care, and environmental sentencing guidelines are such that the courts are imposing more severe penalties.”

Should the project fail without the EA agreeing any extension to the present concession “you would see enforcement under normal pollution legislation, but I would be surprised though if the codes of practice are not agreed by then,” Hunt says.

The industry will surely hope he is right in this optimism. Turner has warned that if regulation reverts after 31stJuly to the usual ‘duty of care’ regime then demolition contractors would be responsible for ensuring compliance with the law. 

They would either have to provide evidence that their waste wood materials were non-hazardous prior to being allowed to move them from their site, or pay additional fees to specialist incinerators.

“If we end up with a situation where the demolition contractors have to prove the material is non-hazardous before they can move it from their site, it will be disastrous and costly for demolition companies,” Turner says.

“They will be required by law to carry out the testing work before they can pass material onto a skip company or wood reprocessor.”

She says such testing can take up to 10 days during which backlogs of wood would accumulate on sites unsuitable for its storage.

The project is additionally sampling wood from household waste recycling centres.

Evidence so far suggests there is less hazardous material in the demolition sector containing the chemical wood treatments than was originally believed. 

However, this has to be proven or the industry must pay to demonstrate this on a job-by-job basis.

The wood that reposed in Howard Button’s office should by now have been sent to laboratories for testing – the results of which will, the industry hopes, remove this costly threat hanging over it.

This article was first published in the April 2020 issue of The Construction Index Magazine 

UK readers can have their own copy of the magazine, in real paper, posted through their letterbox each month by taking out an annual subscription. Click for details.

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