Temperature-dependent leaching of chemical elements from mineral water bottle materials

It is well established that minute amounts of chemical elements will leach from bottle materials (glass or PET – polyethylene terephthalate) to water stored in such bottles. This study investigated whether leaching increases with storage temperature. For glass bottles this is clearly the case for a long list of elements: Ag, Al, As, B, Ba, Ca, Co, Cr, Cs, Cu, Fe, Ga, Ge, K, La, Li, Mg, Mo, Na, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ti, U, V, W and Zr. However, for glass bottles drinking water maximum admissible concentration values as defined by European authorities are not exceeded even after 1 week of leaching at 80 °C. The critical temperature limit where leaching substantially increases for many elements appears to be 45 °C. For PET bottles, Sb is the only element where leaching is observed at all temperatures and again leaching strongly increases at 45 °C. For PET bottles Sb concentrations observed in water after 1 week storage at 80 °C reach almost four times the maximum admissible concentration values for drinking water but do not exceed the relevant higher limit for food (including water) packaged in PET.