Risks and vulnerabilities are important aspects of the studies about environmental issues under the demographic point of view. They can be analyzed from populations and/or places exposed to certain risks and vulnerabilities. The current study examines how the socio-demographic characteristics of the population at situation of technological hazards in São Sebastião, North Coast of São Paulo, can help us deal with hazards related to Petrobras’ biggest waterway terminal (Tebar), located in the city’s central area. It analyses which population is at risk of technological hazards. From micro-demography, fieldwork and semi-structured interviews with dwellers at risk areas were carried out in the surroundings of Tebar (Vila Amélia, Topolândia and Porto Grande neighborhoods) with the intent to comprehend the risk perception they have and which are the mobilizations to face the hazards, elements that allow the analysis of the site vulnerability of place from the demographic point of view.