The invention consists in a preventive isolation system for chronic respiratory patients who are at risk after a catastrophe. These patients are one of the most affected with the particulate matter and the pollution that is generated after a natural disaster. Isolation is generated by positive environmental pressure, which is used to prevent the transmission of diseases from the outside to the inside to highly immunodepressed individuals or patients. In this case, as there is greater entry of filtered air prevents the entry of particulate matter and contaminants within a space. The advantages of the intervention are portability, rapidity in assembly and disassembly, use of technological materials and inclusivity. The invention could be used for other types of catastrophe in which particulate material (volcanic eruptions, tsunamis, forest fires) is generated for allergic persons, for immunosuppressed patients who have to avoid contact with outside air and / or virus surroundings.