Ceramic mug no toxic side effects, because it is fired clay, but also because of this, many small manufacturers in the choice of materials cost when strict, with some in the raw materials which are harmful trace elements, heavy metals, such as chromium, copper, lead and so on. Glazed or painted also have this problem.
But slightly more expensive the regular factory product is no problem, the domestic consumption is still very strict guard vessels, but I'll give you one tip is to eat dishes like the best pure white, as well as a cup or other utensils decorated with underglaze color glaze was divided, with many overglaze flower paper printed up, you touch the feeling of when there will be uneven, so that the vessels of the above color, if done well then, it is easy to fall off, there will be some harm to the human body, try to use underglaze color.
But no matter how to say, even if there is damage is very small, you need not worry, I usually burn things to drink with their meals, and I also quite good.