The Trad-SH has been successfully employed to qualify the environment air, which is contaminated by mutagens. So, this work is aimed at evaluating the mutagenic potential of the emission from incense indoors to the Tradescantia KU-20 clone. Experimentally, the inflorescence of the KU-20 clones was kept for 2, 4 and 6 hours the emission from the incenses (kind 1 and 2) in a closed room of 25.83 m3 of volume. The mutagenic effects of the atmosphere were analyzed by comparing a group of non-exposed inflorescence (group one, control) to inflorescences kept under polluted atmospheres, in a closed room, for 2, 4 and 6 hours (groups two, three and four). The experimental data were analyzed using statistical methods. The frequency of mutations observed in the inflorescences from group one was significantly lower than that exhibited by groups two, three and four. The results suggest that the emission from the incense plays an important role in the development of plant mutation and that the Trad-SH assay is a useful tool for routine indoor biomonitoring in environments where chemical substances are used.