Peanuts, wheat, corn (maize), beans, and rice stored for a long time in a moist, warm atmosphere tend to go mouldy due to the growth of a fungus called Aspergillus flavus. This fungus produces complex organic poisons, called aflatoxins, that damage the liver if eaten in large amounts. People infected with the hepatitis B virus are particularly susceptible to the harmful effects of the toxins. In addition, aflatoxins are highly carcinogenic. Stored peanuts are particularly vulnerable to the fungus. Even freshly picked peanuts contain some aflatoxins, but the level is usually too low to be harmful. Most processed nuts are subjected to rigorous controls to prevent contamination. Salt also protects against the mould. However, peanuts or peanut products showing any sign of mould should be discarded. The mould can usually be detected by a white or brownish bloom on the nuts, or by a musty taste.