This part of EN 351 establishes classification for preservative-treated wood in terms of preservative penetration and gives guidance on a classification of retention. These should be used as a basis for specifying preservative treatments for particular products.

This part of EN 351 provides terminology to be used by the specifier when preparing a preservative treatment specification or product standard. It is not a treatment specification in itself.

This part of EN 351 is applicable to the production of preservative-treated solid wood, including glued laminated timber, suitable for use in those service conditions defined by the use classes in EN 335‑1. It does not apply to any subsequent examination of treated wood in service.

This part of EN 351 is applicable to the protection of wood against attack by wood-destroying and wood-disfiguring fungi, insects and marine organisms.

This part of EN 351 does not consider other properties of treated wood, for example odour, corrosiveness and compatibility with other materials, nor does it consider any properties from the health, safety and environmental point of view.

This part of EN 351 does not apply to wood treated with formulations that are applied to timber in service to eliminate or control an existing fungal or insect infestation, or to prevent attack by sapstain fungi, or insects in green timber.