Malondialdehyde, acrolein, 4-hydroxy-nonenal and 4-hydroxy-hexenal are generated during the oxidation of polyunsaturated fatty acids in foods. The current project deals with the development, implementation and validation of analytical methods, determination of the target aldehydes in foods available in the Belgian market and finally based on the obtained results, an exposure assessment to the target components taking into account the consumption data of the Belgian population.