The critical behavior of the entropy production rate is analyzed in dynamically irreversible models, chosen as being invariants under the operations satisfied by the C_3ν; symmetry group and defined on square lattices. A stochastic approach is followed, considering Markovian processes in continuous time; therefore, assuming a master equation representation for the time evolution of the probability distribution of states. Monte Carlo simulations were performed, revealing a divergent behavior in the derivative of the entropy production at the critical point, which is characterized by the exponent α=0.32(2), in close analogy with the critical behavior of the specific heat of the 3-state Potts model. This result supports the conjecture according to which the considered models are in the same universality class of the 3-state Potts model.