The Emergency Situation Response Unit (CASU) Backed by the Ministry of Environment, Ineris equipped an Emergency Situation Response Unit in 2003 (CASU), which now operates 24 hours a day, 7 days a week. The unit provides public authorities with immediate decision-making support in the event of observed or imminent technological dangers to humans or the environment. Its multidisciplinary teams are on call and ready to mobilize the scientific and technical facilities and competencies required. The Experts at Ineris Ineris’ 24/7 on-call system relies on two permanent specialists who ensure technical contact with the requester, and a head of operations representing Ineris’ senior management. Backed by Ineris’ expertise potential, CASU can mobilize all or part of the Institute’s expert skill base, according to the needs of the intervention. Its role in decision-making support for public authorities was established by the inter-ministerial circular of July 15, 2005. Areas of Intervention Transmission of information on substances directly involved in or likely to be formed during an accident (smoke particles, products of decomposition, etc.). Transmission of information on accidents similar to the event in progress, and follow-up after the accident. Risk analysis according to the characteristics of the event. Identification of dangerous phenomena and modelling their effects. Assessment of risks from damage control devices, in collaboration with emergency services and those managing the accident. Examples of Interventions Identification of domino-effect risks following a vent fire in a refinery warehouse that stored flammable products. Expert consultation on the toxicity of substances formed by the incomplete combustion of residue from a fire in a large warehouse of hazardous products. Assessment of potential accident scenarios which might occur while lifting a freight car carrying hazardous products. Expert consultation on toxicity, explosive and environmental contamination risks for a range of scenarios developed to salvage a damaged barge carrying benzene on the river Rhône.