Food irradiation is a proven technology that enhances food quality and safety by removing microorganisms and extending shelf life. Ultraviolet C radiation (UVC) has recently attracted interest due to its potential to inactivate foodborne pathogens. It relies on several advantages; however, there is limited research on its efficacy and safety particularly concerning food packaging materials such as polyethylene terephthalate (PET). This study reports on the effect of UVC radiation on commercial thermoluminescence dosimeters (namely, TLD-100, TLD-200, TLD-400 and GR-200) placed under PET films with different thicknesses (0.10, 0.42, and 0.60 mm). The results indicate the potential use of these materials for the detection of UVC radiation passing through the randomly selected PET samples. Fourier transform infrared spectroscopy assesses potential structural and chemical alterations in the PET induced by UVC exposure.