It can permanently pit or discolor decorative metal finishes.
For 90% of household clogs, a plunger, a drain snake, or a caustic (lye) cleaner is safer and equally effective. Sulfuric acid should only be used when those fail and the drain is confirmed to be compatible. virgin sulfuric acid drain cleaner
Virgin sulfuric acid, stored properly, is nearly indefinite in shelf life. Keep it in the original HDPE (high-density polyethylene) container with a tight-sealing, chemically resistant cap. Store in a cool, dry, well-ventilated area, away from: It can permanently pit or discolor decorative metal finishes
If a sink is completely full, adding acid can cause a "volcano" effect where boiling acid splashes back at the user. Virgin sulfuric acid, stored properly, is nearly indefinite
Virgin sulfuric acid is not a "first response" drain cleaner. It is a weapon of last resort for specific clogs that resist milder methods. It excels at: