Particle detectors for high-energy physics applications can contain billions of MOS transistors, each of them prone to possible radiation-induced failures. The Future Circular Collider represents an unprecedented challenge to the radiation hardness of CMOS technology, with an estimated total ionizing dose (TID) from 10 to 500 times higher than the already very high TID expected to be reached by the HL-LHC. CMOS technologies currently used for design of particle detectors cannot withstand such extreme radiation levels and first investigations of the radiation response of near-future technologies are not showing substantial improvements. Furthermore, the unprecedented particle flux levels expected for FCC-hh (two orders of magnitude higher than for HL-HLC) may lead to additional failure mechanisms. Therefore, if innovative solutions are not developed and introduced, radiation-induced degradation of MOS transistor performance may represent a limit to the physics exploitation of the FCC.