Deformed relativistic kinematics, expected to emerge in a flat-spacetime limit of quantum grav-
ity, predicts violation of discrete symmetries at energy scale in the vicinity of the Planck mass.
Momentum-dependent deformations of the C, P and T invariance are derived from the κ-deformed
Poincaré algebra. Deformation of the CPT symmetry leads to a subtle violation of Lorentz sym-
metry. This entails some small but measurable phenomenological consequences, as corrections
to characteristics of time evolution: particle lifetimes or frequency of flavour oscillations in two-
particle states at high energy. We argue here that using current experimental precisions on the
muon lifetime one can bound the deformation parameter κ > 10 14 GeV at LHC energy and move
this limit even to 10 16 GeV at Future Circular Collider, planned at CERN. Weaker limits on de-
formation can be also obtained from interference of neutral mesons. In case of B 0 s from Υ decay
it amounts to κ > 10 8 GeV at confidence level 99%.