The rusting appears inside of the stainless steel water bottle, which seems to be unhealthy and unsafe to keep drinking water.
Here’s the question “Why is stainless steel water bottle rusting?”.
1. There are many different grades of stainless steel. And it is nearly known to all that material of stainless steel 18-8 (SUS 304) kitchen food grade and SUS 316 medical grade are perfect options. A water bottle made by poor quality raw material would be easy to have rusting despite the fact that you do clean the bottle seriously.
2. There’s a electrolysis coating on the inner wall of the stainless steel bottle, which can keep the bottle away from rusting. However, wrong cleaning method would damage the electrolysis surface and it is exactly one of the reasons why stainless steel bottles get rusting, you can click here to know HOW TO CLEAN STAINLESS STEEL BOTTLE?
TIPS What We Can’t Put into Stainless Steel Bottle
Tip 01: Dry Ice, Carbonated Drink
Dry ice and carbonated beverages should not be placed in the thermos to avoid the danger of rising internal pressure, causing the bottle to fail to open or the contents to spray out
Tip 02: Not Suitable for Making Tea
If you use a thermos cup to make tea, the tea leaves will go through high temperature inside the water bottle for a long time. In consequences, a lot of vitamins in the tea will be destroyed, aromatic oils will be volatilized and tannin will be leached out. The nutritional value of tea is reduced, the tea juice is unscented, the tea tastes bitter and astringent, and even because of the long steeping time, the tea may release heavy metals, which is harmful to health.
In addition, the color of thermos stainless steel cup will change when keeping hot tea inside of it for a long time.
Tip 03: Liquids That Are Not Suitable for Saline (Such as Salt Water)
As the inner liner of the insulation cup is sandblasted and electrolytic, electrolytic liner can avoid direct contact between water and stainless steel material causing physical reaction, while the corrosive nature of salt may cause damage to it, so it is not suitable for long-term installation in the insulation cup.
Tip 04: Not Suitable for Milk, Dairy Products, Juice
Some people put hot milk in vacuum bottles so that it is easy to carry and drink. However, this practice allows the microorganisms in the milk to multiply rapidly at the right temperature, leading to spoilage that can easily cause diarrhea and abdominal pain.
In the high temperature environment of milk, vitamins and other nutrients will be destroyed. At the same time, the acidic substances in the milk will also chemically react with the inner wall of the vacuum flask, which will affect human health.