T8 Extra contains plenty of iron, and iron tends to oxidize. T8 Extra can be stored for a long period of time in a closed bottle with the storage conditions being observed (temperature mode, a tightly closed lid, etc.). A loosely closed bottle, as well as a habit to stir the concentrate with a pipette right in the glass of water or some other drink, can lead to the gradual oxidation of the iron contained in the composition. Outwardly it looks like flakes or coat on the surface of the pipette. By itself, this coat is not harmful for health, it only indicates the presence of a large quantity of iron. However, we still recommend that you do not mix drinks with a pipette and store the bottle tightly closed.