Less environmental impact of wood preservatives by considering the risk of attack in addition to the hazard class system
Hazard classes, which are standardized in Europe in EN 335, are most useful to direct chemical wood preservation towards the organisms which may attack wood in the various fields of utilisation. However, hazard only signifies the fact that an attack may occur without considering the actual risk to attack. To minimize the application of chemicals with respect of less environmental impact it is necessary to consider both, the hazard of attack and the risk which implies the probability, how often attack may occur and how important this will be. In addition, also the consequences of the failure of a wooden commodity will influence the need of chemical wood preservation. It is therefore proposed to combine the hazard classes as specified in EN 335 or in similar non European regulations with a risk assessment including time assessment as a basis for the requirement on chemical wood preservation. For this, details are given in the paper.