Ventilation is not sufficient in refrigerated warehouses or arenas. Gas leaks associated with the use of Freon cooling systems can cause damages similar to carbon oxide. In addition, ammonia and CO2 can cause significant damage to health, such as breathing difficulties, and even death. Often in enclosed or covered areas, it is important to have CO2 or ammonia detectors in order to avoid gas buildups and ensure compliance with the standards of the MDDEFP, the MTQ, the MAPAQ, the CSST, and the MSP.