Why has USP waited until now to revise standards for elemental impurities? Was there a specific event that prompted the revision?
A. USP undergoes regular re–evaluation and revision of all its standards to update their scientific and public health relevance. There was no specific event that triggered the revision of elemental impurities standards, but our scientific experts felt that the elemental impurity standards should be updated to incorporate modern methods and health information. As we have gained a better understanding of the limitations of the current methods, it has become clear that a revision is called for.