Is a water purifier filter sterile? Even just drinking water can grow 'slimy biofilms'

Many office workers habitually use their thermal mugs for coffee, tea, or milk, but often just rinse them with water before using them again. That sticky feeling on the inner wall of the mug is actually a breeding ground for microorganisms. If you stick your finger in and it feels slippery, it means a bacterial army has set up camp there. This 'slippery' substance is actually a 'biofilm'. When sugars, proteins, and moisture from drinks remain in the warm, sealed environment of a thermal mug, it becomes a hotbed for bacteria and mold. Simply rinsing with water won't remove this bacterial colony clinging to the metal surface. These bacteria can cause gastrointestinal discomfort, diarrhea, and even food poisoning. Especially the rubber seal inside the lid is prone to accumulating dirt, and even if invisible to the naked eye, it's already teeming with microorganisms. When cleaning daily, be sure to follow these three steps: 'Disassemble, Scrub, Dry': 🔸 Disassemble: Take apart all removable parts like the lid, straw, and sealing rings (don't force parts that aren't meant to be removed). 🔸 Scrub: Use a neutral dish detergent with a sponge or a long-handled brush, thoroughly cleaning the threads around the mouth of the cup and the grooves of the sealing rings. 🔸 Dry: After washing, place the parts separately on a drying rack. Reassemble only after they are completely dry to prevent moisture from being trapped inside. Don't underestimate this slimy film. It not only breeds bacteria but can also cause drinks to spoil and produce odors. Stop letting your thermal mug be a hidden killer of your health. Regular deep cleaning is the only way to ensure every sip you take is clean and safe. Eh... I just rinse mine with water too 🤣