When selecting a plastic shower set, prioritize ABS (Acrylonitrile Butadiene Styrene) over standard PVC or PP. ABS is the industry standard for high-quality plastic bathroom fixtures because it offers superior impact resistance, heat stability, and structural rigidity. Ensure the surface is treated with multi-layer electroplating (Chrome or PVD) to prevent peeling and corrosion in humid environments. For internal components, look for ceramic valve cores which are tested for 500,000 cycles to prevent leaks.