Assessing human exposure to semivolatile organic compounds (SVOCs) emitted from materials and products is difficult because methods are not available to easily measure the key emission parameters. A simple method based on a passive sampling technique was thus developed to measure the gas-phase SVOC concentration (y0) immediately adjacent to the material surface in a consumer product. The method employs standard stainless steel thermal desorption tubes, with values of y0 and an additional unknown parameter, K, the tube surface/air partition coefficient inside the desorption tube, obtained by fitting a diffusion model to the sampling data. Phthalates in two types of polyvinyl chloride flooring were selected to test the method. The values of y0 and K agree well with those measured in independent chamber tests. The y0 measurement method is shown to be applicable to chemicals with a wide range of vapor pressures. This novel method should be useful for assessing potential exposure to SVOCs in consumer products as well as for exposure-based prioritization of chemicals and their associated products in indoor environments.