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Inventory of biocides used in Denmark

Appendix 2
Background information to product-type 8

The following appendix comprises background information regarding import/export of industrial preserved wood.

It is assumed that the preserved wood is found under the same commodity numbers as the numbers used by Hansen et al. 1997 and that only conifer wood is preserved.

The amount of chromium and creosote in preserved wood has been derived from a recent assessment by Hansen et al. (2000 a, b) and the following only comprise the background for the estimate of the consumption of the other biocides.

Registered import, export and production 1998 according to Statistics Denmark are shown in the following table.

Table A2.1
Registered import, export and production 1998 according to Statistics Denmark

1) The production is in the statistics 'Manufacturers Sales of Commodities' /Statistics Denmark 1999 B/ only represented in m³ and value. Tonnes to value ratios for exported products is used to estimate the weight of the production

According to Hansen et al. (2000 b), only a minor part of the production and export of preserved wood is actually included in the trade statistics. The explanation may be that the pressure preservation is carried out for small companies below the lower limit of the Manufacturers Sales of Commodities. Based on the statistic of Danish Control of Preserved Wood and direct inquiries to actors on the market, the following figures on preserved wood have been estimated by Hansen et al. The figures include both pressure-preserved and surface preserved products, but exclude poles, railway sleepers and window and door frames i.e. they cover the commodity numbers 4403.10.90 and 4404.10.00. The figures in table A2.2 are used for the estimates instead of the data from Statistics Denmark regarding commodity numbers 4403.10.90 and 4404.10.00.

Table A2.2
Import, export and supply of preserved wood according to Hansen et al. (2000 b)

Three different estimation methods are used for vacuum, pressure and surface treatment, respectively.

It is roughly estimated that 0-20 of the preserved wood in table A2.2 is preserved with a surface treatment and the remaining 80-100% is pressure-preserved.

It is based on Table A2.2 assumed that the supply (net consumption) of the organic biocides with pressure-preserved wood is in the order of 1-1.4 times the consumption for production in Denmark, whereas for boron and copper compounds it is estimated at 1.2-1.5 times the consumption for production in Denmark (copper and boron follow chromium in the CCB preservatives). It is roughly estimated that the biocides contained in consumed wood are the same as in produced wood (except for creosote).

The net consumption of biocides with vacuum-preserved wood is estimated on the basis of the registered production, import and export of window and doorframes in Table A2.1 (4418.10.50 and 4418.20.50). The commodity numbers of the statistics also include non-preserved products, and a significant part of the products in 4418.10.50 is not wood. It is estimated that 90% of the wood in products produced in Denmark is preserved, and that vacuum and surface treatment each account for about half of this (Henriksen, 1999). It is assumed that the same applies to exported products, and products imported from the Nordic countries. It is assumed that 20-35% of commodity number 4418.10.50 is wood and that 35-55% of the wood is vacuum-preserved. Commodity number 4418.20.50 is assumed to be 100% wood. It is in addition assumed that there is an interdependency between production and export/import as regards the percentage of the wood vacuum-preserved. On this basis and the figures in Table A2.1, the net export is estimated to equal about 20% of the production. It is presumed that the biocides contained in consumed wood product is the same as used for production of vacuum-preserved wood in Denmark. This assumption is estimated to add an uncertainty to the total consumption of ± 20%.

Import and export of biocides with surface preserved wood are estimated by the assumption that the wood has been treated with 7 - 11 litres preservative per tonnes. This is based on the assumption that the preservatives cover 6-8 mē per litre (information from Danish producer) and that the wood-products have a thickness of 2-3 cm. It is roughly assumed that 35-55% of produced and exported products of commodity number 4418.10.50 and 4418.20.50 is surface preserved (of the first, wood only accounts for 20-35% of the weight). In addition, it is assumed that up to 10% of the import of 4403.10.90 is surface treated (Henriksen1999). As the data of table A2.2 replace 4403.10.90, it is assumed that 5-15% of the Cr-free wood is surface treated. It is in addition presumed that the biocides in imported/exported wood resemble the biocides used for surface treatment in Denmark. The uncertainty on this assumption is estimated to add an uncertainty on net import of ± 20%.

References:

Hansen, O.C; Færgemann, H.; Møller S.; Andersen L.K.; Poll, C. 1997. Træbeskyttelsesmidler og imprægneret træ. Massestrømsanalyse, miljø- og sundhedsvurdering. Working Report no. 57/1997. Danish EPA, Copenhagen.

Statistic Denmark.1999 A. External Trade by commodities and countries 1998. Statistics Denmark, Copenhagen.

Statistic Denmark.1999 B. Manufacturers Sales of Commodities. Statistics Denmark, Copenhagen.

Hansen, O.C, K.H. Henriksen & C.J. Kofod. 2000a. Massestrømsanalyse for træ imprægneret med creosot. Danish Technological Institute for the Danish EPA. Draft version.

Hansen, O.C, K.H. Henriksen & C.J. Kofod. 2000b. Massestrømsanalyse for træ imprægneret med chrom. Danish Technological Institute for the Danish EPA. Draft version.

Henriksen, K. Technological Institute, Taastrup. Personal communication, December 1999.

Dansk Imprægneringskontrol. 1998. Dansk Imprægneringsstatistik

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