In the Spring of 1981 a pulmonary disease broke out in Spain. Cases were household related but on the contrary no other natural clusters were encountered.

The course of the disease did not improve with antibiotic administration and its geographic occurrence was found to be more frequent in a particular route.

A month and half after the first case was reported it was officially announced that an industrial and fraudulent oil sold as edible oil was the vehicle of this illness.

In 1983 the WHO considered this entity as a new disease that came to be called Toxic Oil Syndrome (TOS)

Grandjean P, Tarkowsky S. Review of investigations and findings. In: World Health Organization, editor. Toxic Oil Syndrome: Mass food poisoning in Spain. 1 ed. Copenhagen: World Health Organization, Regional Office for Europe; 1984. p 3-16.

Tabuenca JM. Toxic-allergic syndrome caused by ingestion of rapeseed oil denatured with aniline. Lancet 1981;2(8246):567-8.