The sensitivity of diploid and heteroploid cell lines for detection of cytotoxicity using the agar diffusion method on cell culture, was tested with ascorbic acid solution of different concentrations. A total of 562 samples of 21 various materials were tested. The heteroploid cell line, RC-IAL, showed in relation to the MRC-5 and HeLa cell lines, greater sensitivity because it showed the presence of cytotoxic effect with the lowest concentration used (10 and 25ug/ml) of ascorbic acid and showed greater diameter of cytotoxic halo in 15 samples and equal diameter in 16 of the 43 positive samples (7.6%). Out of 43 positive samples, the MRC-5 line did not show cytotoxicity in 3 sponge samples and 1 of acrylic resin. The PVC (polyvinylchloride) and polyethylene rarely showed positivity, while, the plastic, cotton and acrylic resin demonstrated cytotoxicity in about 5% of samples. We thus suggest the use of the RC-IAL and HeLa cell lines for continuation of this type of analysis at Adolfo Lutz Institute