To support the African ChemObs project (the Integrated Health and Environment Observatories and Legal and Institutional Strengthening for the Sound Management of Chemicals in Africa), we provide a critical review of methodologies for valuing the health damages from policy inaction associated with chemical exposures. In particular, we discuss how disability-adjusted life years (DALYs) and IQ loss should be valued. We conclude by providing advice on communicating the costs of inaction and the benefits and costs of action to policymakers. By the social costs of inaction, we mean the private or market costs, as well as the external costs, from pollution exposures compared with no exposure. Knowledge of these damages can then lead to policies designed to force investment and operating decisions in the market to account for (internalize) such costs/damages. The costs of inaction can be distinguished from the benefits and costs of action. The benefits of action are the value of, for example, the health improvements from regulations or other forms of action. These actions usually come with a cost of resources to bring about such actions. The net benefits to society of an action are the benefits minus the costs of action. In general, as regulations of chemicals rarely eliminate all exposures, the costs of inaction generally exceed (in absolute terms) the benefits of action.The cost-of-illness (COI) approach to health valuation measures the direct medical expenditures associated with disability or illness, including hospital, physician, and medication costs, as well as long-term rehabilitation costs.