Kellogg says higher levels of chemicals in cereal box liners caused the weird smell and taste that led to the recall of 28 million boxes of Apple Jacks, Corn Pops, Froot Loops and Honey Smacks last month. Twenty people complained to the company about the cereal, including five who felt nausea and vomiting. The breakfast delights tasted waxy, soapy or stale thanks to extra hydrocarbons, including methyl naphthalene, in the packaging. Those chemicals typically appear in lower levels in the wax on liners as well as protective coatings on cheese and raw produce, but the risks of moderate exposure to them is unknown. Kellogg said exposure to the stuff isn’t risky, but the FDA is reviewing the information provided by the food giant.