Semivolatile organic compounds (SVOCs) are widely used indoor as plasticizers, flame retardants, or pesticides. They are present in indoor environments both in air (as gas and suspended particles) and settled dust. Thus exposition to possibly harmful agents: (phthalates, polybromodiphenylethers, organophosphorous compounds.) occurs (Mitchell et al. 2007;Wu et al. 2007). Here is presented the framework of the ECOS project, which objective is to assess domestic cumulative exposure to these substances and associated health risks.