Choose dark chocolates with the lowest levels of heavy metals. CR’s tests found five chocolates—one each from Mast, Taza, and Valrhona, and two from Ghirardelli—with relatively low levels of both lead and cadmium. Eight more are lower in only lead, and 10 others in just cadmium. Only five bars—one each from Green & Black’s, Lily’s (owned by the Hershey company), and Trader Joe’s, and two from Theo—were higher for both heavy metals.