The toxic oil syndrome: 20 years on.

With hindsight, it is easy to criticise the standards of food regulation of two decades ago. Nevertheless, when the Spanish toxic oil syndrome (TOS) appeared in 1981, there were many who asked why aniline was permitted as an official adulterant for imported French rape seed oil, and why such adulterated oils were often illegally refined in Spain and marketed without difficulty. This review brings up to date a comprehensive survey of the ensuing research published in 1995 and concentrates on recent significant findings. These include the identification of the refinery that produced the toxic oil, and the detection of oil contaminants with possible aetiological significance. Possible chemical links have been found between oil contaminants and those detected in L-tryptophan implicated in the eosinophilia-myalgia syndrome (EMS). There is good evidence that the initial pathogenetic mechanism is immunological. On metabolic evidence, it is suggested that not one, but a group of, toxic agents was responsible for TOS.