During their lifespan there is a high probability that wooden pallets and packaging material will be exposed to rainfall or rewetting conditions, increasing the risk of growth of discolouring fungi. Kiln-drying of wooden pallets and packaging material without anti-sapstain treatment does not give efficient protection against wood discolouring fungi during rewetting periods. However additional temporary protection can be achieved, when pallets and packaging material are manufactured from timber treated with anti-sapstain preservatives. In order to compare the performance of kiln-dried pallets and air-dried pallets treated with an anti-sapstain preservative against blue-stain and mould infestation, three practical use scenarios of rewetting were investigated. The first scenario was the simulation of rainfall, followed by indoor storage under moist and warm conditions representing shipping of wet pallets in closed trucks or container. The second scenario simulates storage of humid goods or goods which can release moisture like, e.g., fruits or vegetables which have been stored under plastic foil in a changing temperature climate like e.g. during night and day. Condensed water can be formed on the foil building water droplets which will increase the wood moisture. The third scenario was the simulation of pallet movement of cooled goods from a cold storage warehouse into humid and warm climate area, studying the influence of the condensed water on the surface of a pre-cooled good, packed with foil on the pallet and subsequently stored or transported under high humidity and elevated temperature. The evaluation of the specimens was carried out by optical assessment according to CEN/TS 15082. After 28 days in all of the simulated scenarios the kiln-dried pallets were three times more affected by moulds and sapstain fungi than the pallets treated with anti-sapstain preservatives.

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