Recently in the Ukraine, some 100,000 tons of sunflower oil were contaminated with mineral oil at high concentrations.Although much of the contaminated oil was withdrawn, there are products on the market that were produced before this contamination was detected, the editorial said.

To protect consumers, the European Commission decided to apply a legal limit of 50 mg/kg to the mineral paraffins in Ukrainian sunflower oil.

However, Dr. Koni Grob, of the Official Food Control Authority of the Canton of Zurich, Switzerland, wrote in the editorial that in many foods more than 50 mg/kg mineral oil components from other sources will be found.

Certain edible oils, but also certain other foods, like canned fish, frequently contain more than 50 mg/kg mineral oil components, some products as much as 1,000 mg/kg, the editorial said. No measures have been taken to stop the potentially harmful oils from reaching consumers, Grob said.

"Presently there is insufficient knowledge about potential negative effects of mineral oil on human health," Grob said.