EU proposals to restrict the use of CCA (chromated copper arsenate) were greeted with surprise and consternation when they emerged some three years ago. At the time, the UK was thought to be consuming approaching half of the 15,000 tonnes of CCA used in Europe each year. However, close co-operation between industry bodies, treaters and preservative suppliers has ensured a relatively smooth transition to alternatives where necessary.

Transposed into national law by The Environmental Protection (Control on Dangerous Substances) Regulations 2003, the new requirements restrict the use of CCA-treated timber to a limited number of applications where the structural integrity of the wood is required for human or livestock safety and where skin contact by the public during service life is unlikely. These include: structural timber in public and agricultural buildings; bridges; highway safety fencing and barriers; earth-retaining structures; electricity transmission and telecommunications poles; and underground railway sleepers. In addition, the regulations do not apply to CCA-treated wood already in place.

The industry’s input throughout the consultation and transition stages was co-ordinated by the British Wood Preserving & Damp-proofing Association (BWPDA). According to its director Dr Chris Coggins, the June 30, 2004 deadline for complying with the new regulations was met because “suppliers had been given sufficient notice and had the resources to cope with a major switch [away from CCA]”. He added: “If the preservative industry had not done its homework, the prospects for treated timber would have been pretty bleak. For suppliers, the restrictions brought forward the time when they could get a commercial return for their products.”

In effect, the regulations left users with two choices: to move across to “copper organic” preservatives or to stay with a similar but arsenic-free product. The former option was more costly because storage tanks had to be emptied and cleaned out but ultimately helped treaters to achieve “future proofing”. The latter approach may have been cheaper but, as Dr Coggins warned, chromium is already under discussion at EU level while the Biocidal Products Directive entailed a review of all active ingredients by member states and therefore “a degree of risk for almost any of them”.

Discussions are ongoing with a number of key end users affected by the new restrictions, Dr Coggins explained. For example, the BWPDA has been working with the National House-Building Council on updating the latter’s manuals, and specifications already call for the use of non CCA-treated timber.

Some timber treaters supplying the exempted application areas have been forced to adopt alternatives because they also sell into non-exempted markets and have only the one treatment plant. Indeed, it is understood that only one plant with CCA capacity has survived beyond the June 30 deadline.

Osmose‘s UK general manager Gordon Ewbank described the transition as “relatively smooth”, with a large proportion of companies “making the change [from CCA] well in advance”. The majority of preservatives now on the market are copper-based systems with organic biocides and these are expected to provide “the bedrock for the next few years because they meet customer and regulatory requirements”. However, it is “absolutely crucial”, he said, that preservative producers continued to monitor legislative developments and invest in R&D since the lead time on new products is typically seven or eight years.

According to Mr Ewbank, it has been “a challenging time” for preservative producers and treaters alike, but they have “risen to that challenge”.

Boost to environmental credentials

Wolman’s UK & Ireland business manager Jean-Claude Bergot argued that, in many cases, customers’ treatment costs “have not risen anywhere near as dramatically as expected” and, indeed, “have been reduced for certain applications”. The restrictions on CCA have prompted treaters to become more informed and more professional, while the switch to more benign treatment products has boosted their environmental credentials.

Mr Bergot noted that many treaters may have effectively delayed making a decision by moving away from CCA but not from chromium-containing preservatives since chromium is under the microscope at EU level. “There will be a continuing shift away from chromium over the next 18 months, as has been happening in other markets,” he said.

According to Janet Brown, marketing manager of Arch Timber Protection, her company had been “well prepared” for the transition. In-house research leading to the development of Arch’s new generation product Tanalith E began as early as the mid-1980s, thus allowing time to “establish long-term field trials to underpin the performance of the product” and to ensure the product was “compatible with plant materials and timber fixings”.

In the run-up to, and during, the transition period, Arch helped to ensure that buyers were kept abreast of latest information and relevant decisions at EU level. “This allowed individual customers to take a proactive decision about when to convert, plus a phased conversion could take place in co-operation with all our customers,” Ms Brown explained. “We converted each and every one of them in advance of the deadline.”

Companies treating timber on a large scale also appear to have experienced few major problems in changing from CCA. At Dalbeattie-based Howie Forest Products, where a new treatment plant based using Osmose products was commissioned in late summer 2003, joint managing director Hamish Macleod said: “The push was initiated by our customers, so you could say it was market driven. Our customers were relaxed with our intention when we announced we would be putting in a new treatment plant for construction-grade timber.”

The installation demanded a substantial capital investment but benefited the company in ways beyond simply bringing it into line with customer and regulatory requirements. Mr Macleod said: “Our total treated timber sales have increased – although I’m not sure if that’s down to increased awareness of treatment per se. And we were always capacity-restricted with our old plant and perhaps would have been replacing it some time this decade any way.” The new plant has a capacity of around 45,000m3 compared with some 32,000m3 for its predecessor, enabling the company to switch from a three-shift operation to little more than a single shift.

The only downside of the changeover, according to Mr Macleod, has been the rise in treatment costs which, for the present at least, the company has not been able to pass on in full to its customers.

Optimising operations

According to David Twigg, a director of Severn Valley Woodworks, CCA restrictions provided an opportunity to optimise the company’s treatment operations by, for example, highlighting instances where “we were treating to too high a standard”. While acknowledging that the transition process had been relatively untroubled for treater and customer alike, he noted that his company had had to come up with a tailored response for one application where high salt retention was key. “CCA had done this comfortably but it was difficult to find an alternative that met this requirement,” he said.

Creosote regulations

While CCA restrictions had amounted to “a de facto ban” on its use, The Creosote (Prohibition on Use and Marketing) (No 2) Regulations 2003 had been a different matter, according to Dr Coggins. These restricted the use of all forms of creosoted timber after June 30, 2003, including inside buildings and in playgrounds, parks, outdoor leisure facilities, garden furniture and packaging that may come into contact with raw materials, intermediate or finished products destined for human and/or animal consumption. However, according to the BWPDA’s director, “the market for creosote-treated timber has survived the regulations”.