If water still drains slowly, wait 24 hours and repeat the process. Overuse can damage older metal or thin plastic pipes.
Before proceeding, it is vital to understand that sodium hydroxide is a strong base that generates significant heat when mixed with water. This exothermic reaction can cause "boiling over" or splashing, which leads to immediate chemical burns on contact with skin or eyes. Furthermore, the heat produced can weaken or melt PVC pipes and damage the seals in a plumbing system, potentially leading to costly leaks. how to use caustic soda to unblock drains