1. What is Caustic Soda? Caustic soda (NaOH) is a strong alkaline chemical. In drain cleaners, it appears as dry white flakes, pellets, or a liquid gel. It works not by dissolving organic matter physically, but by creating a highly exothermic (heat-producing) chemical reaction that hydrolyzes fats, grease, and hair.
Fat + NaOH → Glycerol + Soap (water-soluble) Hair (protein) + NaOH → Water-soluble amino acid salts how to unblock drains with caustic soda
It does dissolve mineral scale (limescale), rust, or hard plastic objects. 2. When to Use It (And When Not To) | Suitable for | Unsuitable for | |--------------|----------------| | Kitchen sink (grease, oil, food scraps) | Toilets (can crack porcelain) | | Bathroom sink (hair, soap scum) | Aluminum or galvanized pipes (caustic corrodes them rapidly) | | Shower drains (hair, body oils) | Old cast iron pipes (can worsen rust if used repeatedly) | | Plastic PVC pipes (safe if used correctly) | Complete blockages (liquid cannot reach the clog) | | | Standing water (caustic reacts violently, causing splashing) | In drain cleaners, it appears as dry white