The effects of pH on the migration of melamine from children’s bowls

Background Contamination of pet foods and infant formula with high levels of melamine has resulted in a number of cases of illness and deaths among pets and children; however, the long-term effects of low dose exposures is poorly understood. Exposure to melamine from the consumption of foods using melamine-based tableware has been identified as a potential source of concern due to the role that melamine may play in human kidney disease, especially among children. In this study, the migration of melamine into solutions of varying pH was characterized in order to better understand the migration risk associated with foods of different chemical characteristics. Results Two brands of bowls marketed toward children’s use were tested in pH 3.0, 5.0, 7.0, 9.0, and 11.0 solutions at 95 °C over a series of ten 30 min exposures runs. Melamine migration was significantly greater in the pH 3.0 solution than others and migration was significantly different between the two brands. Migration dropped substantially after the initial run and reached consistent values by the fifth run. Conclusions Despite the potential for long term melamine exposure to contribute to human disease, melamine based products are widely available. Exposures to foods cooked in bowls of this type would be less than Tolerable Daily Intake (TDI) levels; however, gaps in the understanding of chronic exposure to melamine may warrant caution among consumers, especially parents of young children. Currently, labeling requirements are inadequate to inform consumers of the potential for exposure to melamine.