The agency collected 119 samples, representing 52 products, at retail, with some purchased on-line. The 15-month survey began in July 2018 and ended in October 2019. The FDA found that four of the 52 products sampled (12 of 119 samples), all dark chocolate bars, had potentially hazardous levels of milk allergen. The levels, ranging from 600 to 3,100 parts per million (ppm), had the potential to cause severe reactions in consumers with milk allergy. In response to these findings, the manufacturers recalled all four products.