Radiation treatment of fat-containing foods generates 2-alkylcyclobutanones (2-ACBs).
The 2-ACBs can be considered as “Unique Radiolytic Products” (URPs) – that is, compounds that are formed only through treatment with ionizing radiation.
Detection of 2-ACBs constitutes unambiguous evidence that the food has been treated with ionizing radiation. If no 2-ACB's are detected, the foos has not been treated by ionizing radiation.

Detecting irradiated foods by the method based on 2-ACB's, or more precisely 2-dodecyl- and
2-tetradecyl-cyclobutanones was standardized by the European Committee for Standardization (EN 1785). This method was also accepted as a method of detection of irradiated food by the Codex Alimentarius.

Irradiated food detection tests (Physical chemistry and nutrition lab)