According to a survey by the US Food Standards Agency released on September 5, levels of mycotoxins in milk on sale in the UK are all within legal limits, with the vast majority having no detectable levels at all. The survey was part of the Agency's ongoing monitoring programme for mycotoxins in food. It tested 100 milk samples (50 retail and 50 directly from farm) for the mycotoxins aflatoxin M1 and ochratoxin A. Both these chemicals have the potential to cause cancer in humans. Aflatoxin M1 was detected in only 3 samples and never above the legal limit of 0.05 micrograms per kg. Ochratoxin A was not detected in any of the samples tested. Dr. Jon Bell, director of Food Safety at the Agency, said: "These results are very reassuring and raise no food safety concerns. Milk is such a good source of nutrition, it's encouraging to see it given a clean bill of health in this case." Mycotoxins are naturally occurring toxins produced by moulds, which can grow on materials used in animal feed. It is possible for some of these toxins to be metabolised and transferred into milk. Previous work has shown that low levels of aflatoxin M1 can occur in retail milk, with a 1996 survey finding four per cent of samples over the legal limit. Ochratoxin A has not been tested for previously. Both organically and conventionally produced milk were sampled in the survey (20 organic and 80 conventional samples). The three samples where mycotoxins were detected below the legal limit were all conventionally produced and taken from the farm gate.