Simple models with both baryon and lepton number violation by two units

We construct simple renormalizable extensions of the standard model where the leading baryon number violating processes have $Delta B = pm Delta L = -2$. These models contain additional scalars. The simplest models contain a color singlet and a colored sextet. For such baryon number violation to be observed in experiments, the scalars cannot be much heavier than a few TeV. We find that such models are strongly constrained by LHC physics, LEP physics, and flavor physics.