AbstractDowngraded medium density fiberboard (MDF), particleboard (PB), and oriented strandboard (OSB) panels were individually subjected to steam explosion treatment. Downgraded MDF and PB panels were separately treated with thermal chemical impregnation using 0.5% butanetetracarboxylic acid (BTCA). And downgraded PB panels were processed with mechanical hammermilling. The pH, buffer capacity, fiber length, and particle size of these recycled materials were evaluated. After the steam explosion and thermal chemical impregnation treatments, the pH and buffer capacity of recycled urea formaldehyde resin (UF)-bonded MDF and PB furnishes increased and the fiber length decreased. The hammermilling of recycled PB was less likely to break particles down into sizes less than 1 mm2.