Methylnaphthalene in Food Packaging and Cadmium in Food Packaging and Household Items: Overview of Exposure, Toxicology, Regulatory Aspects, and Research Needs

Abstract

This chapter provides an overview of two toxicants, methylnaphthalene and cadmium. Both of these chemicals are examples of toxicants for which there are significant research data gaps. Reports of an off-odor and off-flavor in certain breakfast cereals led to a recall of certain Kellogg’s®-brand breakfast cereals in 2010, with subsequent identification of methylnaphthalene as the chemical used in the wax liners of these cereal boxes. While orally- and dermally-treated laboratory rodents have displayed pulmonary alveolar proteinosis in response to methylnaphthalene exposure, very few other toxicological endpoints have been evaluated for exposures to either 1- or 2-methylnaphthalene. While cadmium is an established heavy metal toxicant, with the lung, kidney, and immune system as primary target organs, recent studies of non-occupationally exposed populations suggest that the risk of cardiovascular and peripheral artery disease may be associated with higher levels of urinary cadmium. While diet and tobacco use are known sources of non-occupational exposure to cadmium, there is emerging evidence that consumer products also may be a source of exposure to general populations. There are reports of cadmium leaching from glazes and decorations used in ceramics and glassware, and detection in plastic housings of cell phones. There is limited data characterizing exposures from cadmium use as a pigment in household or food contact plastics. More research is needed to characterize exposures as affected by the type of cadmium pigment, type of plastic, effects of wear and age, as well as the leaching of cadmium from end-of-use products in landfills.