Trichloroethylene (TCE) contamination has been detected near former industrial sites in the Île-de-France region. The concentrations measured in the air inside residents’ homes were up to 90 times higher than the Rapid Action Value (10 μg/m³) recommended by the High Council for Public Health (HCSP) for triggering corrective actions within six months. In the absence of specific national health recommendations, the Île-de-France Regional Health Agency requested Santé publique France to assess TCE exposures and associated risks and to assist in deciding on health care measures and temporary relocation. The assessment of hazards and dose-response relationships was based on available toxicological reviews. Excess individual risks were calculated and the health impact was estimated. The relevance of biomonitoring for exposure was evaluated with toxicologists. To inform the relocation decision, situations leading to unacceptable risks were identified for various combinations (concentration × duration of exposure). At the measured concentrations, the effects from which residents must be protected are carcinogenic. Individual exposure can theoretically be monitored via blood TCE levels, but the sensitivity of the assay methods is still insufficient to allow for biomonitoring. The very low excess cancer risk associated with exposure and the absence of biomarkers of early effects do not support the implementation of specific screening. However, for the most exposed families, remaining in their homes during decontamination work (3 years on average) would lead to unacceptable excess risks. Brought to the attention of national authorities, these results contributed to a response from the HCSP (February 11, 2016) specifying that at one of the contaminated sites, the relocation of the most exposed individuals should be considered without delay.