Following the fire that occurred in Rouen on September 26, 2019, the Directorate General for Health asked Santé publique France to conduct an assessment of the fire’s impact on the health of the exposed population. Consequently, the Normandy Region’s Occupational Health Alert Group (GAST) was tasked with proposing a monitoring strategy for workers exposed to the fire in order to assess the event’s long-term health consequences. To do so, it described the different groups of workers, their potential routes of exposure, the identified pollutants, the medical monitoring initiated, and the health effects observed following the fire. Data were collected from various stakeholders, particularly those involved in medical monitoring by occupational health services. Workers were divided into four groups based on the spatiotemporal characteristics of their exposure: present at the fire site on the day of the fire; off-site on the day of the fire and within the plume; on-site after the day of the fire until the end of the remediation work; off-site within the plume’s impact zone and after the day of the fire until the end of the remediation work. The event affected many workers, ranging from 300 to 180,000 depending on the group. An analysis of the available environmental and health data indicates that some workers, particularly those on-site but also some workers present under the smoke plume, were exposed to pollution emitted by the fire. This exposure was short-lived on the day of the fire but may have persisted on-site afterward. The presence of volatile organic compounds (VOCs), particularly benzene, and polycyclic aromatic hydrocarbons (PAHs) was measured, but at low levels. However, due in particular to the complexity of the fire, uncertainties remain regarding the nature and levels of exposure. Furthermore, a quantitative health risk assessment (QHRA) was not yet available to complete this assessment. Medical follow-up was implemented by occupational health services and the medical department of the Seine-Maritime Departmental Fire and Rescue Service (SDIS-76) for certain workers present on—and off—the accident site on the day of the fire and the following 4 days. The acute effects observed were primarily of an irritative nature and similar to those identified in the general population. Based on these observations, the Gast proposes to document the fire exposure conditions in occupational health medical records for 3 of the 4 groups of workers (on and off-site on the day of the fire and on-site on the following days until the end of the remediation work). Given the duration of exposure, the pollutants emitted, and existing recommendations for good medical and occupational practices, no specific medical follow-up for workers is indicated; however, the risk of post-exposure anxiety must be considered during subsequent occupational health consultations. For firefighters, medical monitoring for conditions related to chemical exposure should be strengthened as part of the specific medical follow-up already in place for their profession. The GAST proposes that epidemiological surveillance be established for the four groups of workers (including subcontractors) in a manner similar to the surveillance that will be implemented for the general population using the national health data system. Healthcare for workers during an industrial accident must be improved in terms of, first, preparedness, response, and coordination among stakeholders; second, knowledge of exposures (with the rapid collection of biological samples for preservation); and finally, medical and epidemiological follow-up.