Our PVC tank liners are used to provide corrosion resistance to a wide range of chemicals. Many of these chemicals are strong oxidizers or bleaching agents and can discolor a PVC liner. However, this discoloration is by no means an indication of its own that the liner is degrading or failing.
When exposed to a strong oxidizer flexible PVC can become stained. This is simply the result of a physical interaction between two dissimilar materials. Flexible PVC ages or degrades as the plasticizer migrates from the PVC. Staining itself is not an indication of plasticizer migration. Instead the flexiblity of the material should be the barometer of the future life expectancy of the PVC liner. A liner that is very hard or brittle is near the end of its service life.
Our PVC liners are intended to provide corrosion resistance to tanks, sumps, containment areas and so on. The liners we manufacture aren’t made for aesthetics purposes and therefore staining of a liner is of no concern provided the liner itself is still flexible and its liquid integrity still intact.
Plasticizer migration can be coupled with a change in the color of a liner. In particular if a liner sees excessive heat it may turn black besides turning very hard. So discoloration of a PVC liner should suggest an inspection of the liner to ensure its integrity, but discoloration on its own is not an indication that the liner has reached the end of its useful service life.