Distribution of Toxic Elements in Douglas-Fir Plywood Treated with Czaa Preservative

Fifteen Douglas-fir plywood panels were treated with a copper-zinc-arsenic additive preservative (CZAA) in an ammoniacal solution in a full-cell process. Individual plies from the centers of the treated panels were assayed for CuO. ZnO, and As2 O5 on the basis of Cu, Zn, and As content by atomic adsorption spectrophotometry. Retentions of preservative oxides and their distribution in the plies as judged from copper-containing compounds indicated that treated panels could be well protected against biodegradation.Microscopic identification of species revealed that inner plies were made from fir, spruce, and hemlock. The preservative in them, monitored by copper-containing compounds, was evenly spread in the core plies