The possibility of developing wood preservation standards with a global remit has a number of obvious advantages as well as far reaching ramifications, many of which are undefined as yet. The commercial implications of adopting international standards are clearly considerable, but equally, such a development is likely to focus attention on the conceptual differences in the way that different regions view standards, especially with regard to test methodology and assessment. Boron-based wood preservatives have been used world-wide for a number of decades. Coupled with the fact that they have been used in a wide range of environments, this track record makes borates an excellent vehicle for exploring how international standardisation might proceed. Particular attention is paid to the protected, above ground situation and the challenge posed by potentially inappropriate test criteria, conflicting results obtained with different tests and timber variability. The underlying reasons for countries stipulating different retentions for essentially the same level of biological hazard are considered, following review of actual toxic values obtained using a variety of standard tests. Following discussion, a proposed international requirement for borate wood preservatives is given. This 'case study' concludes that there are good reasons to be optimistic about deriving working standards for wood preservatives which can usefully be adopted on an international basis. However, it has also been recognised that the task is easier in this particular case than for other preservative systems and this is discussed.

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