In the Île-de-France region, individual boilers are often the cause of carbon monoxide (CO) poisoning incidents in homes. The characteristics of these poisoning incidents may vary depending on the type of housing and the department. The objectives of this study, conducted in homes equipped with individual boilers, were to describe the characteristics and compare the departmental incidence rates of CO poisoning incidents occurring in apartments on the one hand and in single-family homes on the other. Between 2007 and 2010, among the 200 incidents reported in apartments, the source was generally located in the kitchen (67.9%) or the bathroom (15.3%). Among the 235 incidents reported in single-family homes, the source was most often in the basement (30.4%); appliances other than the furnace could be implicated. The incidence rate was 7.4 incidents per 100,000 apartments and 6.3 incidents per 100,000 houses (p=0.07). The risk of a CO poisoning incident occurring was half as high in three departments in the outer suburbs compared to the reference department located in the inner suburbs. Although the characteristics of CO poisoning episodes in homes equipped with individual boilers vary by housing type, the frequency of these episodes is similar in apartments and single-family homes. (R.A.)