Consumer Reports called on Hershey (HSY.N) to lower the levels of heavy metals in its chocolate after seeing “concerning” levels of lead and cadmium in one-third of the different chocolate products it tested recently.

16 of the 48 goods from different manufacturers that the non-profit consumer group’s scientists evaluated had potentially dangerous amounts of lead, cadmium, or both.

Consumer Reports tested products in seven categories: dark chocolate bars, milk chocolate bars, cocoa powder, chocolate chips, and mixes for brownies, chocolate cake and hot chocolate.

Products found to contain excessive metal content included a dark chocolate bar and hot chocolate mix from Walmart (WMT.N), cocoa powder from Hershey’s and Droste, semi-sweet chocolate chips from Target (TGT.N), and hot chocolate mixes from Trader Joe’s, Nestle (NESN.S) and Starbucks (SBUX.O).