The marginal social cost (MSC) function is theIn risk characterization, the quantitative component can be presented as a probability. might include a reference dose (RfD) to communicate non-carcinogenic health risks. can be based on inferences instead of actual data. all of the abovesum of the following: market-level marginal abatement cost (MACmkt) + marginal cost of enforcement (MCE). marginal abatement cost (MAC) + marginal external cost (MEC). marginal abatement cost (MAC) + total social cost (TSC). market-level marginal abatement cost (MACmkt) + marginal external cost (MEC)