Trust in Performance Through Testing

The testing of wood preservatives is a well-documented procedure, covering both laboratory and field testing. In the development of new products across Europe and the UK, wood preservatives are commonly referenced against CCA and tested to the following Standards:

  • EN 252 – This European Standard specifies a field test method for evaluating the effectiveness of wood preservatives in a ground contact situation. To assess the protective effect of the preservative, wood treated with a reference preservative is included for comparison.

  • EN599-1:2009 + A1:2013 – For each of the five use classes defined in EN 335-1, this Standard specifies the biological tests required for evaluating the efficacy of wood preservatives for the preventive treatment of solid timber, together with the minimum ageing tests required for the respective use class.

Whilst the above EN Standards have played a significant part in the development of Tanasote®, they typically are used to predict a service life of between 15 to 30 years. For heavy duty timbers, it is imperative that a longer service life is provided, so as a business we have engaged in additional testing that goes above and beyond standard requirements.

To prove real world performance in the most demanding of environments, Tanasote® has been subject to additional testing in high humidity and aggressive field test sites as well as laboratory fungal studies. Testing of water-repellent properties has also been undertaken.

Accelerated Field Stake Tests

In the development of Tanasote® we adopted the Fahlstrom stake test method, which is an accepted fast approach to determine decay in a real-world environment through the use of thin stakes. The combination of a very small size and harsh conditions at the aggressive, high humidity field site in Florida, has enabled us to evaluate the long-term performance of Tanasote® treated timber compared with CCA as the reference preservative. In this testing we went beyond the standard CCA retention to demonstrate performance against preservative retention known to deliver a service life of 40 years. In addition, we also compared Tanasote® with a water-based copper wood preservative treatment.

Florida field test showing the Fahlstrom stake test method for TanasotePhotograph above: Florida field test showing the Fahlstrom stake test method

Peer Review of Tanasote® Test Data

In order to demonstrate efficacy of wood preservatives for Use Class 3 & 4 applications, various laboratory fungal tests (EN113 & ENV807), insect / termite tests (EN47 & EN117) and field tests (EN252), as well as non-standard decay tests, have been conducted on Tanasote® treated timber. 

Interpretation of this data requires expert assessment, which has been undertaken by BM TRADA, a reputable independent third-party assessor. The BM TRADA report summary states:


‘…This review showed that the empirical data submitted, satisfied the test requirements of BS EN 599-1, and, in so doing, enabled a judgement to be made on whether Tanasote® S40, used at commercial loadings of 100 kg/m³, would be capable of conferring preservative protection against a range of biological agents for timbers in ground contact in Use Class 3 & 4 situations for prolonged periods of up to 40 years’ duration… the technical arguments presented by the manufacturer, in addition to field stake test data and fungal cellar tests, accepted as providing accelerated decay data, enabled BM TRADA to come to the view that the Tanasote® S40 formulation used at a commercial product retention of 100 kg/m³ would likely deliver a desired service life for timbers in a Use Class 4 scenario of up to 40 years’

For more information on BM TRADA, visit