Commission relents on arsenic curbs

Restrictions on the use of arsenic as a wood preservative will take effect in June 2004 under an EU Directive published in January.1 But they will be much less sweeping than expected following vociferous complaints from industry about the European Commission's original legislative proposals.

The Commission sent shock waves through the timber products and wood preservation industries at the end of 2001 when it proposed that arsenic-based preservatives should be allowed to remain in use for just three applications - railway sleepers, electricity and telephone poles, and industrial cooling towers (ENDS Report 323, p 53 ).

Copper chrome arsenic (CCA) formulations have been used in wood preservation for decades, and are regarded in the industry as the most effective chemicals for maintaining the long-term durability of softwood products.

However, risk assessments for the Commission concluded that CCA-treated wood poses unacceptable health risks, especially to children exposed to arsenic via playground equipment and to people burning treated wood as domestic fuel. They also concluded that there may be no threshold for the carcinogenicity of arsenic.

The Commission's proposals attracted heated objections from industry. The British Wood Preserving and Damp-proofing Association branded them "extremely irresponsible" and "completely out of proportion" to the risks posed by exposure to arsenic from treated timber.

The UK faced particular difficulties under the draft legislation. It accounts for half of Europe's total CCA consumption of around 15,000 tonnes per year, and has three of the EU's four CCA manufacturing plants.

Industry argued that the proposals amounted to a de facto ban on CCA. This is because the three permitted uses account for very small sales - only around 100 tonnes per year in the UK - which would not have been enough for CCA manufacturers to support the chemical through a separate authorisation procedure under the 1998 Directive on biocidal products.

Manufacturers have already invested €1.5 million in studies for the authorisation process and complained bitterly that this investment would be made redundant by the proposed restrictions on CCA.

Other objections included the higher costs of alternatives to CCA and lack of knowledge about their health and environmental hazards. There was also concern that some of these substitutes might themselves either not be submitted for authorisation under the 1998 Directive or get through the process successfully, leading to possible shortages of timber treatment chemicals.

The Building Research Establishment chipped in with a further argument, pointing out that life-cycle assessments for poles, fencing and joinery had shown "convincingly" that wood treated with CCA is environmentally "much more favourable" than alternatives made from concrete, steel or plastics. There was, it warned, every prospect that timber treated with more expensive chemicals would lose out to these products in a highly competitive market, resulting in serious environmental disbenefits.

Another objector was the Timber Decking Association. The UK has seen exceptionally strong recent growth in demand for timber decking, with sales rocketing from £5 million in 1997 to £100 million in 2001.

Almost all of this material is treated with CCA, and the TDA warned that the Commission's proposal "could create considerable anxiety in the marketplace, particularly among those people who have already invested in a deck built from a CCA-treated softwood....The current UK market is still in a very embryonic stage and any adverse publicity could damage, halt or even reverse any further potential for wood."

Faced with this barrage of criticisms, the Commission has drawn back from its proposals, allowing a series of extra uses on the grounds of "low human exposure and professional control."

The new Directive will allow the use of CCA-treated wood for structural timbers in public buildings, offices and industrial premises; bridges; constructions in brackish and fresh waters; noise barriers; avalanche control; highway fencing; livestock fence posts; earth-retaining structures; electricity and telephone poles; and underground railway sleepers.

In all these cases, marketing of CCA-treated timber will be permitted only "for professional and industrial use provided that the structural integrity of the wood is required for human or livestock safety and skin contact by the general public during its service life is unlikely."

The Directive expressly prohibits the use of CCA-treated timber for domestic constructions "whatever the purpose" - presumably precluding its use in decking; in any applications where there is a risk of skin contact; in marine waters; for agricultural purposes other than livestock fence posts and buildings; and where the timber may come into contact with food or feed.

1 OJ L4, 9 January 2003, HMSO.

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