Things I would to remind are drip tips, and LED atomizer. I saw some stainless steel, aluminum drip tips are hot selling, because it looks very colorful and cool, nobody think about safety. Actually all metal material do harm to our body so strongly, how can we let metal parts touch our mouth directly and so frequently? Not only metal materials of e cig, but also factories plate nickel or chrome to have nice looking finish, all those contain a lot of harmful substance.
We can use food grade materials for drip tip, mouth tip, cartridges and any other parts touch our mouth directly, such as FDA approved silicone and plastic food grade materials. Just like soft drinks, nipples, the raw materials need to be under serious control to fit FDA food grade requirements and regulations.
Another thing is LED atomizer, many people like to use LED atomizer with different light color, it looks cool, because remember you are hurting your body. LED are electronic components, all electronic components have harmful substance and cannot go out our body. LED light inside atomizer and emit harmful substance into liquid, then they are going into your body with those vapors together.