Four reference polymers studied by the International Union of Pure and Applied Chemistry working party on interactions of polymers with living systems were characterized by electron spectroscopy for chemical analysis. The surface of a polyethylene specimen was found to consist of only hydrocarbon (-CH2-) groups, as expected. Similarly, the surface of a poly(dimethyl siloxane) was found to be in close agreement with the expected stoichiometry of this polymer. The surface of the PVC sample showed a high surface concentration of hydrocarbon-rich plasticizer. Also, Si, O and Zn were detected. Cellulose coil specimens were heavily silicone contaminated. A 24 h rinse of this material in water reduced the Si level to 5%, and produced a surface spectrum closer to that expected for cellulose.