There's a hidden ingredient used as a whitener in an array of foods, from candies and pastries to cheeses and gum. It's called titanium dioxide, and while commonly used in the US, it's being banned in the EU as a possible carcinogen. The additive, also known as E171, joins a host of other chemicals that are banned in foods in the European Union but allowed in the US. These include Azodicarbonamide, a whitening agent found in food such as breads, bagels, pizza, and pastries in the US, which has been banned in the EU for more than a decade. Known as the "yoga mat'' chemical because it is often found in foamed plastic, the additive has been linked to asthma and respiratory issues in exposed workers and, when baked, to cancer in mice studies. Potassium bromate, an oxidizing agent often found in bread and dough and linked in animal studies to kidney and thyroid cancers, has been banned in the EU since 1990 but is still commonly used in the US. Brominated vegetable oil is also banned in the EU but is used as an emulsifier in citrus sodas and drinks in the US. Long-term exposure has been linked to headaches, memory loss and impaired coordination. The Food and Drug Administration classifies these food chemicals, and many others prohibited by the EU, as "generally recognized as safe". Chemical safety processes in the EU and US work in starkly different ways. Where European policy tends to take a precautionary approach " trying to prevent harm before it happens " the US is usually more reactive.