First – the cancer is not cancer, it is delamination of the safety glass. A particularly dangerous situation as the safety glass is no longer working the way it was designed.
Water has penetrated between the 2 panes of glass and the PVB interlayer causing it to lift and separate – this allows in air and moisture, with the result of the dark patches. When this occurs the glass is no longer bonded today and acting like a safety glass, it is merely 2 pieces of standard glass in the areas of separation and prone to act exactly like standard glass when broken with shards coming away.
So now the warning is over – can it be cleaned away the answer is no. Unfortunately it has occurred and aside from replacing the glass or the entire shower there is nothing you can do about it. But we would encourage you to consider changing the glass as it does pose a safety issue.
As far as the water staining you see on the glass, this can certainly be lessened and depending on the degree of staining to the glass removed all together with the stain remover available in our on line store (click here for more information).
If you have a burning question about something in your home – then drops us a quick email to email@example.com and we will be happy to provide some information.
Remember what you envision – we create at Central Glass and Aluminium ph 5535 2000.