Wood plastic composites were prepared by thermocatalytic polymerization of styrene in beech wood. Accelerated weathering was carried out on both wood plastic composites and untreated controls by placing them in close contact with rusting iron while they were in turn: soaked in water, frozen, thawed while being subjected to infrared and ultraviolet radiation, and finally dried. Each four-stage cycle required 48 hours; samples were tested for up to 24 such cycles. Tensile strength parallel to grain, in both water-saturated and oven-dry condition, was the criterion of degradation. Tensile samples were one millimeter thick, with a necked central region through the center of which a hole was drilled on the wide face to receive an iron rod, so degradation was accentuated in the critical region of the specimens. Specimens were separated by iron plates for maximum contact with rusting iron. The rusting iron caused substantial degradation of both untreated wood and wood plastic composites after even the first few cycles of degradation, with increasing severity for all 24 cycles. However, the polystyrene wood plastic composites had nearly twice the resistance to degradation when in contact with rusting iron than did untreated wood, as measured by tensile strength. -- AATA