While French fries and potato chips are the most well-known sources of the carcinogen acrylamide, prompting a lawsuit by California's attorney general, there are many other food sources of the chemical, including black olives, coffee, bread, and breakfast cereal.

Present in 40 Percent of Calories

Acrylamide was once believed only to be the product of industrial waste; it was not until 2002 that it was discovered to be almost everywhere in the human diet. It is a tasteless, invisible byproduct formed when foods -- particularly high-carbohydrate foods -- are fried or baked at high temperatures.

The chemical is present in 40 percent of the caloric intake of most Americans, although French fries and potato chips contain the highest concentrations.

Universal Presence Affects Lawsuit

The almost universal presence of the chemical has led to some doubts about the possibility of success in the California attorney general's lawsuit against fast food companies and potato chip manufacturers.

The suit argues that the companies are required, under California law, to warn the public about toxic chemicals in their food.

Eight Hundred Times the Safe Dose

The EPA considers acrylamide so dangerous that it has the safe level for human consumption at almost zero; the maximum safe level in drinking water is 0.5 parts per billion. A small serving of French fries contains over 400 parts per billion of the chemical.

It is universally agreed that acrylamide causes cancer; however, no one is certain exactly how much of the chemical represents a dangerous dose.