The wood preservation laboratory of Cirad is accredited by COFRAC (French accreditation
committee – accreditation No. 1-1686) for tests on (1) durability of wood and wood-based
products; (2) protective efficacy of wood preservatives; (3) efficacy of termite control
products. In order to test the efficacy of wood preservatives, non-durable wood blocks are
treated using different product doses and exposed to the attack of xylophageous organisms
(fungi, insects). To reproduce the ageing of treated wood blocks, some laboratory
procedures are available. Amongst them, there is an evaporation procedure, reproducing the
action of a warm air flow onto treated wood. This ageing step is very discriminant, as
only the formulations fixing effectively the active ingredients will pass the biological
test afterwards. This ageing by evaporation is described in the EN73 standard.
Nevertheless, many points remain difficult to overcome. The tunnels used for the
evaporation are all prototypes; as such equipment is not available currently on the
market. So each laboratory has got its own tunnel device. Moreover the way to measure the
temperature and speed of the air flow is very difficult to achieve considering the
prescriptions of the EN73 standard. The EN73 standard is being revised by the European
standardization group (CEN TC38) and despite the metrological aspects were crucial and
inadequate in former version, they were not considered as they should. The wood
preservation laboratory has forwarded remarks in order to supersede some points of the
revision document in order to consider the metrological aspects. This is of main
importance as the ageing procedure is commonly used prior to most of the biological test,
and such tested products are put on the market based on the efficacy results.