Mycotoxins are secondary metabolites produced by a variety of moulds on several agricultural commodities under specific environmental conditions. It has been estimated that at least 25% of the grain produced each year worldwide is contaminated with mycotoxins. Canada’s indigenous mycotoxins occur mainly in cereal grains and corn, although occasionally there have been reports of contamination of other crops such as alfalfa and oilseeds, and foods such as coffee, cocoa, rice, beer and wine. As analytical techniques evolve to become more sensitive and widely available, the documentation of widespread contamination in a variety of commodities and of new mycotoxins no doubt, will increase. The toxicology of many mycotoxins, particularly those commonly encountered, has been well documented for several animal species including humans. The signs of the many mycotoxicoses are diverse, numerous and often dependent on species, sex, age, stress, reproductive and health status of the animal. They include: feed refusal and vomiting; impaired reproductive function and reduced fertility; nephrotoxicosis; neurotoxicosis; lung disease; hepatotoxicosis; cancer and death. If a livestock species that is tolerant to a particular mycotoxin is fed a contaminated diet, there is a potential for the “carry-over” of toxin into animal products, such as milk or meat, destined for human consumption. In addition, the by-products of certain food processes, have the potential for being highly contaminated with certain mycotoxins and may cause severe adverse effects if subsequently fed to a species particularly sensitive to the contaminating mycotoxin or toxins. In both these cases a certain degree of care and monitoring is required to ensure the safety of humans and animals. When contamination does occur, mould spores and mycotoxins are often concentrated in the fines and dust of grains as well as shriveled kernals. Use of masks to avoid inhalation and ingestion of dust by grain handlers is recommended. Contamination may be reduced by density segregation to remove dust and the lighter, more highly contaminated kernels. Soaking, dehulling, or high velocity air cleaning of kernels can be used to remove surface contamination. Roasting may reduce mycotoxin contamination by burning surface contaminants and removing volatile, heat labile toxins and other mould metabolites. Other approaches to reducing mycotoxin concentrations and effects on the animal are: improving the nutrient density of the feed; avoiding feeding contaminated commodities to sensitive animal species. Many countries have established regulations or guidelines to protect consumers from the harmful effects of AF in foods and feedstuffs, the maximum permissible levels vary greatly among countries as do the guidelines and/or regulations or lack thereof regarding other mycotoxins. Several international agencies currently strive to achieve universal standardization of regulatory limits for mycotoxins. This is an extremely difficult task because many factors have to be considered when deciding on regulatory standards. In addition to scientific factors, such as risk assessment (exposure and toxicological data), and analytical accuracy, economical and political factors, such as the commercial interests of each country, and the constant necessity of a sufficient food supply also play a role in the decision-making process. Nevertheless, despite these obstacles most countries within the European Union have come to a common agreement on a standardized policy for regulation of AF levels in different feedstuffs and feedstuff ingredients.