Aspartame, used in products from Coca-Cola diet sodas to Mars’ Extra chewing gum and some Snapple drinks, will be listed in July as “possibly carcinogenic to humans” for the first time by the International Agency for Research on Cancer (IARC), the World Health Organization’s (WHO) cancer research arm, the sources said.

The change, made by the WHO’s International Agency for Research on Cancer (IARC), will come in to effect next month.

The IARC ruling will declare the sweetener a potential hazard, but it does not take into account how much a person can safely consume.