When a drain is completely clogged and plungers haven’t worked, many homeowners turn to a "nuclear option": chemical drain cleaners containing acid. Often labeled as "professional strength" or "industrial grade," these products—commonly based on or hydrochloric acid —are among the most powerful and dangerous tools in a plumbing arsenal.
While some acids are safe for PVC, the heat generated by sulfuric acid can occasionally warp or melt PVC pipes if the concentration is too high or if it remains in the pipe for too long. plumbing acid
Then, silence.