There is an increasing concern for health risks from exposure to chemical emissions in indoor environments where we spend a lot of time. A chain of complex relationships connects emission sources, exposure, and health effects. For some indoor contaminants, we know a lot about the separate relationships. However, linking specific sources and environmental exposure pathways to hazardous effects is challenging, with a lack of evidence that is needed for risk assessment as a result. This chapter presents the full chain model that follows chemicals and maps the relationships from sources to potential health effects. It is a tool to establish relevant scientific knowledge regarding chemical exposure. The model consists of three overlapping sections: environmental exposure, human exposure, and health effects, and includes relationships between emission sources, environmental pathways, human uptake, and effects on health and development. As a demonstration, results from the Swedish Environmental Longitudinal Mother and child Asthma and allergy (SELMA) study were applied to the full chain model. Phthalates, a group of abundant indoor contaminants, and airway disorders were used as an example. Starting with polyvinyl chloride (PVC) flooring as an emission source, connections were made between indoor dust levels, exposure and uptake among pregnant women, and airway symptoms in young children. By using the full chain model, not only separate relationships were identified. Butylbenzyl phthalate could be followed from a source to elevated environmental exposure and human uptake to associations with a higher risk for airway outcomes in children.