“As of 2021, the most frequent type of adulteration of olive oil is that oil of lower quality is mixed into it.[24] Adulterated oil is usually no more serious than passing off inferior, but safe, products as superior olive oil, however in 1981 almost 700 people died, it is believed, as a consequence of consuming rapeseed (canola) oil adulterated with aniline intended for use as an industrial lubricant, but sold as olive oil in Spain (see toxic oil syndrome).”

https://en.wikipedia.org/wiki/Olive_oil_regulation_and_adult...