CreoSub – New protection technology to substitute creosote in railway sleepers, timber bridges, and utility poles
U Hundhausen, K-C Mahnert, A Gellerich, H Militz
Creosote oil is one of the oldest industrially used wood preservatives. Due to its toxic profile, the European Commission has restricted the use of creosote specific applications, but it is highly controversial within the European Commission. Its approval for use after 2018 is very questionable and may depend on derived research results until then, i.e., the viability of alternatives developed to replace creosote as a preservative of wood products in heavy-duty applications outdoors, like railway sleepers, timber bridges, utility poles, and piles in marine applications. The overall objective of the three year WoodWisdom research project CreSub is the development of a new protection technology to substitute creosote in railway sleepers, timber bridges, and utility poles. The technological objective is to develop production processes for railway sleepers, timber bridges, utility poles, and piles treated with new wood protection systems from laboratory to industrial scale and test the products under real conditions in the field. This implies to individually consider process-related, economic and environmental aspects for each of the three different product groups mentioned above. Alternative products to creosote have to be hydrophobic and biocidal effective, particularly with respect to soft rot and copper tolerant fungi. Last-mentioned are mainly responsible for that conventional impregnations with solely copper-based salts do not provide sufficient protection of products in heavy-duty applications outdoors. In addition, alternative protection technology must be economically viable. In this regard, one-step treatment processes, which preferably can be carried out in existing creosote plants, are desirable. Last but not least, new technologies should have better human toxicological as well as environmental toxicological profiles than creosote technology.
Keywords: creosote, bridges, poles, sleepers, alternative protection systems, research project, Wood Wisdom