This part of EN 335 offers guidance on the application to solid wood of the use classes, as defined in Part 1 of EN 335, in relation to the biological agents that can attack solid wood and solid wood panels. NOTE Due to their specific behaviour against biological agents, solid wood panels are considered in this part of EN 335, as solid wood. This Part shall be used in conjunction with Part 1 of EN 335. Annex A gives information and guidance for the user to determine the appropriate use class and to select a suitable level of durability (either natural or conferred by preservative treatment). It does not give guidance on protective measures other than preservative treatment.