The possibility of revitalizing and reusing areas contaminated by hazardous substances has emerged as a great alternative in urban centers. The decontamination of these sites, among which some known as Brownfields, and its rehabilitation for reuse, besides presenting itself as an option to the creation of space in the great centers, stands out as a solution in the protection of public safety, the health of the population and the environment by the risks offered by the substances present therein. However, in the time elapsed between the identification of contaminated area and its revitalization, there is a probability of accidents caused by the leakage of hazardous waste deposited therein, causing harmful effects to the population and the environment, which implies immediate action by the public power. Based on a case study involving deactivated industry used as an area for clandestine storage of drums containing hazardous waste, the work proposes the creation of an action protocol aiming to guide the intervening actors in the accidental scenarios involving Brownfields. The objective is to offer a tool to help reduce the environmental damage caused by this type of occurrence, in addition to contributing to the discussion of public policies that allow programming the strategic management of Brownfields, changing the way of identifying, treating and managing contaminated areas.