Wood is great – it's hygienic, renewable, environmentally-friendly
Wood is just brilliant!
Scientifically proven: wood is more hygienic than plastic.
Source: Holzzentralblatt no. 34/2001
New studies from the German Federal Biological Research Centre for Agriculture and Forestry (Biologische Bundesanstalt für Land- und Forstwirtschaft, BBA) question the bans placed on the use of wood in the food industry. The BBA examined how various domestic timber types (pine, spruce, larch, maple, beech, oak and poplar) interact with bacteria. Applying the same amount of bacteria to the tested timbers, they found that the number of viable bacteria fell over time depending on the type of timber (see Holzzentralblatt 147/2000).
It is commonly believed that plastic is a hygienic material due to its closed surface and the fact that it can be cleaned. Wood, on the other hand, has tended to be associated with poorer hygienic properties. As a consequence, given all the systems we have for risk analysis and self-monitoring in the food industry, wood has been displaced in microbiologically sensitive areas, where preference is often given to plastic.
The new studies have now proved that pine wood has the greatest ability to kill germs. The number of bacteria falls not only on the surface of the wood but equally in the inside too. This anti-bacterial property is even retained when bacteria are repeatedly introduced.
In fact, the viability of bacteria is higher on plastic (polyethylene) than wood. Germ numbers only noticeably start to fall after 12 to 24 hours and the number of viable bacteria even increases when bacteria are repeatedly introduced. Cleaning and disinfecting the plastic surfaces only provides a short-term solution. The reasons for the anti-bacterial properties of wood lie in its hygroscopic nature and its constituent parts. The research findings were then tested in practice. The German Institute of Food Technologies monitored a field trial involving 14 companies from the meat and dairy industry and firms processing vegetables and producing bakery products. These companies used standard wooden pallets, 500 special hygienic wooden pallets and plastic pallets. The so-called hygienic wooden pallets were made from pine heart wood and had had their hygienic properties enhanced by a special drying process. Six months and 15 000 measurements later, and the result were in. The average number of germs on standard wooden pallets of various timber types was around 15% lower than that on plastic pallets. The use of hygienic pallets made from pine heart wood produced an even better picture. Here the level of microbe activity was half that of plastic pallets on average. Hygienic properties can therefore be further optimised through the right choice of timber and correct treatment.
The Federal Association of Timber Packaging believes that industry should reconsider its use of wood. In particular, there are calls for the laws and ordinances banning or limiting the use of wood in the food industry to be modified. Dirk-Uwe Klaas, CEO of the Main Association of the Wood Processing Industry (HDH), also says: "It's high time we ended the discrimination against wood in the food industry."