What is the only real threat to deteriorating PVC conduit?

The correct answer is sunlight. PVC (polyvinyl chloride) conduit is designed to be resistant to many environmental factors, but prolonged exposure to ultraviolet (UV) light from sunlight can cause the material to deteriorate over time. This deterioration manifests as chalking, loss of impact strength, and eventual brittleness, which can compromise the conduit’s integrity and its ability to protect electrical wiring.

While moisture, extreme temperatures, and physical impact can also affect PVC conduit, they do not pose the same level of long-term threat as sunlight does. Moisture can lead to corrosion in the connectors and fittings used with PVC, but it does not deteriorate the conduit itself. Extreme temperatures may cause thermal expansion or contraction but typically do not lead directly to material failure. Physical impact can cause immediate damage, but it is not a gradual process like UV degradation. Therefore, when considering the longevity and protective nature of PVC conduit, sunlight remains the primary concern that should be addressed during installation and maintenance.