It should be noted that Harvel’s standard formulation of PVC compound (H707) used in the manufacture of our rigid pipe contains 1-1/2% titanium dioxide (Ti02), a natural UV inhibitor. Harvel’s Corzan compounds used in the manufacture of rigid CPVC pipe contains at least 2% Titanium Dioxide (Ti02). Harvel’s Clear PVC piping products do not contain UV inhibitors and should not be exposed to UV radiation.