# $\rm SO(10)$ grand unified model restores the parity symmetry lost in $\rm SU(5)$ model

It is said in Lie Algebras in Particle Physics 2ed - From Isospin to Unified Theories (Georgi, 1999) p.285, Georgi said that

$$\rm SO(10)$$ grand unified model restores the parity symmetry that was lost completely in $$\rm SU(5)$$ model.

However, it seems to me that the spinor representation 16 alone in $$\rm SO(10)$$ model breaks the parity symmetry. Can experts clarify the conflict?