The aim of this work was the development of materials to be used in the field of gas sensing for the detection of organic vapors. Conductive sensors were prepared with carbon black filled blends of poly(vinyl chloride) and diol-terminated poly(epsilon-caprolactone), an oligomeric plasticizer. For comparison, blends with di(2-ethylhexyl)phthalate, a traditional low-molecular-weight plasticizer, were also prepared. All sensors were tested upon exposure to different organic vapors. In general, the plasticizer content affected the response rates of the sensors, and a linear variation of the relative resistance with the analyte concentration was observed. (C) 2003 Wiley Periodicals, Inc.