Toxic and genetic effects of fuel oil photoproducts and three hydroperoxides in Saccharomyces cerevisiae.

Phototransformation of no. 2 fuel oil by UV irradiation at wavelengths designed to simulate sunlight resulted in the formation of products toxic to the yeast Saccharomyces cerevisiae. Increasing the time of irradiation of the fuel oil samples increased the toxicity. Fuel oil that had been irradiated for 12 or 24 h was convertagenic to the yeast strain D4. The toxicity and genetic activity of these samples could be removed by treatment with thiacyclohexane. It is thought that hydroperoxides are the primary photoproducts responsible for these biological effects. Of three hydroperoxides tested, tert-butyl was convertagenic and cumene and tetralin were not. However, all three hydroperoxides were toxic to yeast.