1. Damaged insulation core
When the insulation core of the thermos is damaged or leaking air, the insulation capacity of the thermos will also decrease significantly. This can cause the drinks in the thermos to not retain the desired temperature for as long as desired, affecting the flavor and safety of the food. In particular, some drinks containing milk, if not kept at a stable temperature, can become an ideal environment for bacteria to reside.
2. The thermos has rust
Rusts appearing on the body of the thermos, no matter how small or large, are signs that let you know: it's time to replace the thermos. Rust stains not only make the product less aesthetically pleasing, but more importantly, they pose a potential risk to your health.
When the thermos is rusted, toxic substances can seep into the drinks. You can use it without worrying about feeling anything unusual in the drinking water, which will be extremely harmful to your body in the long run. Therefore, once you see rust on the thermos, you should stop using it and consider buying a new one.
3. There is a bad smell or a stain that is difficult to clean
When the thermos has a bad smell or a stain that is difficult to clean, even though you always clean it thoroughly every day, then that is a warning sign that you should stop using the product. The bad smell or stain may be due to a problem with the inner shell of the thermos, or for some reason that allows bacteria to penetrate and grow. Therefore, if you continue to use the thermos in this condition, it is highly likely to cause food poisoning and harm your health.
4. The lid is broken
The lid is one of the important parts of the thermos. When the lid is broken or cannot be completely closed, drinks can spill during transportation, dirtying furniture or even causing burns if hot water is inside. And because it is not airtight, the ability to keep the drink warm will be significantly reduced. In addition, a loose lid can also create conditions for moisture to accumulate, causing bacteria and mold to grow, affecting the user's health.
5. Distorted or cracked bottle
If you accidentally drop a thermos and cause it to deform or crack, it is best to buy a new one to use. The impact process can cause the layers of material inside the bottle to crack, which is difficult to detect with the naked eye. This leads to heat leakage and the bottle no longer has superior heat retention ability.
In addition, cracks that appear on the body of the bottle, whether small or large, can become a place for bacteria to live. If you do not want to harm yourself, "throw away the old - use a new one" as soon as you see the bottle is dented and cracked.
6. Bottle used for a long time
If you have used a thermos for a long time, you should consider replacing it, even if you feel that the bottle is still working well. Because over time, the material inside the tank may have aged, causing its effectiveness to decrease or making the tank brittle and fragile.