Ochratoxins are produced by several species of the fungal genera Aspergillus and Penicillium. These fungi are ubiquitous and the potential for the contamination of foodstuffs and animal feed is widespread. Ochratoxin A, the major compound has been found in a number of countries in Australasia, Europe, and North America. Ochratoxin formation by Aspergillus species appears to be Limited to conditions of high humidity and temperature, whereas at least some Penicilliurn species may produce ochra-toxin at temperatures as low as 5 °C.