Gutter oil is a term used to refer to recycled oil in China and Taiwan, which is used for cooking and frying food. It is typically made from a variety of food waste sources, including sewer drains, grease traps, discarded animal parts, and restaurant oil dumps. Once extracted, the oil is mixed, boiled at high temperature, and sold to food vendors throughout China at significantly discounted rates. Gutter oil can be recognized by its dark color and unpleasant smell, and consuming it can have negative consequences on peoples health. According to experts, gutter oil is extremely toxic and riddled with carcinogens, like aflatoxin and benzopyrene. Consuming gutter oil can also lead to diabetes, heart disease, Alzheimers, and developmental problems in children. Despite intervention from authorities, the underground gutter oil industry endures, and it is difficult to prove and prosecute those involved in the illegal trade. Legitimate producers of gutter oil sell the processed oil for use in the chemical or energy industries, but such refiners can also have illegal side businesses, as the prices attained by selling it as cooking oil are much higher than if it is sold to the chemical or energy industries.