US Patent 7152884 Conduit box

A weatherproof non corrosive, non-metallic conduit box molded preferably of a sturdy plastic material, such as, for example, polyvinyl chloride, which is a fire resistant and resilient material. The conduit box is ultraviolet (UV) resistant and has high tensile strength for good impact resistance. The conduit box is resistant to corrosion from water exposure and has high impact resistance, with resistance to cracking. The polyvinyl chloride pipes also resist acid rain, which reacts to accelerate corrosion of either the aluminum or the metallic fasteners used for attachment due to differences in contact potential.