Borosilicate glass or soda-lime glass are not good for storing ultrapure water because sodium ions will be leeched from the glass. This is not something that w

Borosilicate glass or soda-lime glass are not good for storing ultrapure water because sodium ions will be leeched from the glass. This is not something that would matter in any food-contact application. While PTFE neither is modified by food nor any part of it is leeched into the food, it can retain minute amounts of food in its pores, which may be retained despite further attempts to clean it, which does not happen with glass. When a PTFE container is used to store different kinds of food, it can transfer the scent of one of them to the other. The PTFE recipients used for chemical experiments may be cleaned by aggressive methods, e.g. with strong acids and/or strong oxidants, which would destroy any organic substances. Such cleaning methods cannot be applied in a common household. Therefore borosilicate glass or soda-lime glass are better food-contact materials than PTFE, even if they can react with various chemicals that would have no effect on PTFE, but none of those chemicals are encountered in food.