Wood as a natural material is subject to degradation by wood-destroying fungi and insects unless protected by suitable wood preservatives. These contain one or more precisely matched biocidally active ingredients in order to provide long-lasting protection. This should therefore maintain the wood’s function when treated.
Protective agents are used in industrial factories in a vacuum pressure process in order to achieve the best penetration and distribution of the active ingredients.
Wood preservatives are subject to strict legal regulations like all products containing biocides. Before being approved, they must endure an official approval process in accordance with the European biocides law (BizidV (EU) 528/2012). They must prove their effectiveness for their intended application. There must also be a comprehensive assessment of their health and environmental effects. Approval is only granted if the product is safe to manufacture, for the intended application, and during the service life of the protected wood.
Of course, this also applies to the new generation oil and aqueous preparations used to impregnate wooden sleepers: When properly used, sleepers treated with these preservatives are sustainably protected; their use has no unacceptable effects on people, animals, or the environment.
But our study association is already looking to the future: It has invested a lot of time and money in recent years in searching possible alternatives to coal tar oil (creosote), which is tried and tested. This is the main product used today to impregnate wooden sleepers. The aim is to ensure that suitable subsequent products are available in the event that approval for this protective agent should expire. The wood preservative industry also belongs to our association. This is an important aid to wood sleeper manufacturers, suppliers, and service companies as well as their customers.
Some state railways are currently running tests in which railway sleepers impregnated with alternative wood preservatives are being tested on certain routes. The aim is to determine which of these new products can provide the required safety in real-world conditions. Initial results are extremely promising, suggesting that the industry is on the right track with its initiative.
Wooden sleepers impregnated with approved protective agents from specialist companies:
Permanent, safe, and pointing to the future.