The 28 nm CMOS technology was selected as a promising candidate for upgrade of the electronics of particle detectors at CERN. Despite the robustness of this node to ultrahigh levels of total ionizing dose has been proven, the capability to withstand 1016 1 MeV neq/cm2 fluences is still unknown. Displacement damage effects on two 28 nm CMOS technology processes were therefore investigated through proton and neutron irradiation up to the fluences of interest for high energy physics applications. N-type and p-type core and I/O transistors with different sizes were studied. The results of the extensive irradiation campaign revealed that the 28 nm CMOS node was indeed affected by either proton or neutron. However, through X-ray irradiation was possible to determine that the observed radiation-induced degradation was caused by the amount of total ionizing dose deposited during neutron and proton exposure rather than displacement damage. These results prove that 28 nm CMOS technology is suitable for applications in CERN's particle detectors.