[whatupmiked]

"Copper content (177±16 ppb) in water stored in copper pots was well within the permissible limits of the World Health Organization. Copper holds promise as a point-of-use solution for microbial purification of drinking-water, especially in developing countries."

[std_throwaway]

Safety standards aren't as black-and-white as the law. Some people will suffer way earlier than other people. Some people can tolerate some substances in way higher concentrations than the average person.

[Houshalter]

Yeah but they didn't test waters of different ph levels. I'm not sure if that would be an issue though.

[std_throwaway]

It could be an exponential curve and also be influenced by other ions in the water.