The toothpaste sealing foil black
Not to mention that toothpaste contains heavy metals, this trace of heavy metals with aluminum foil is not out of the test!
Toothpaste products are supposed to need to go through the relevant departments of the state inspection and acceptance of products, is the national standard.
You said the foil should be foil. It must be some sort of acids in toothpaste react with its phenomenon, there are many organic compounds can occur. The kind of dark reaction and aluminum toothpaste and did not change the black Baiyao does not explain what the problem is.
