replying to TomR, David wrote:
Rooto Professional is a 93% sulfuric acid says Rooto website:

ROOTO PROFESSIONAL DRAIN OPENER 16, 32, 64 & 128 OZ - 93% VIRGIN SULFURIC ACID
PVC of the pipes does get affected by sulfuric acid, which is perhaps the main
reason you will not see the word "safe" used by this manufacturer or by other
companies making similar products. Over time PVC pipe exposed to sulfuric acid
will become brittle, develop cracks and eventually fail. But it all depends on
the length of exposure time. I have seen results of studies of the effects of
sulfuric acid on various pipe plastics, including PVC, based on 97% sulfuric
acid. The first signs of trouble start to appear way past the 100 hours mark
(more like 300-500hrs).

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