Food is often divided into “good” and “bad” categories. But some foods are truly dangerous. 

These foods contain toxins, are prone to bacteria, or have physical properties that make them hazardous if not prepared properly.

To compile a list of foods you didn’t know could make you sick (or kill you), 24/7 Tempo reviewed articles on the subject from websites of The World Health Organization, The Canadian Institute of Food Safety, The University of Melbourne Scientific Scribbles, and WebMD.

Most of the items on our list can be consumed safely if they’re properly prepared or you eat the right parts of them. In many cases, you’d have to eat huge quantities to experience any ill effects. Others might be more problematic, but are so obscure that only the most adventurous epicures would be apt to try a bite – for instance Iceland’s beloved hákarl, or fermented shark. (These are nine vegetables you should never eat raw.)

Perhaps the most fearsome food listed here is fugu, or blowfish. It contains lethal toxins in its organs and can only be prepared safely by expert chefs.

The death-cap mushroom is also highly poisonous. Other foods like chicken and eggs can contain salmonella or other bacteria that cause food poisoning if not cooked thoroughly. Bay leaves can puncture the digestive tract if swallowed whole.  (These restaurant foods are most likely to cause food poisoning.)

While these foods are not necessarily “bad,” they require caution and proper handling to eat safely. As long as you carefully prepare them and avoid toxic parts, even risky foods can be consumed without harm. The key is awareness of which foods may be dangerous and how to eat them safely.

Click here to read about 25 foods that can make you sick – or kill you