Objectives TTo investigate the genotoxic effect of different antiscalants on CHO cells with an in vitro comet assay and flow cytometry in vitro micronucleus test.

Methods The IC₅₀ value of three different antiscalants (modified potycarboxytic acid antiscanlant, polyacrylic acid antiscalant and maleic acid antiscalant) were 2.781, 2.401 and 1.347 mg/mL, respectively. The IC₅₀ value of each antiscalant was used as the high dose group. In comet assay, CHO-K1 cells were treated with each antiscalant in different concentrationsfor 3 h, and 1 μg/mL K₂Cr₂O₇ was used as a positive control; tail DNA% and tail moment were used to detect the damage of DNA. In the flow cytometry in vitro micronucleus test, a treatment with and without metabolic activation was included. For the treatment with metabolic activation, CHO cells were treated with each of three antiscalants in different concentrations, in the +S₉ treated group, using 0.1 μg/mL cyclophosphamide (CP) and 0.1 μg/mL colchicine as positive control; For the treatment without metabolic activation in the -S₉ treated group, using 0.1 μg/mL mitomycin C (MMC) and 0.1 μg/mL colchicine as positive control. A flow cytometric method was used for micronuclear rates of cells labeled by EMA and SYTOX Green.

Results In comparison with the negative control, the tail DNA% and tail moments in three dose group of three antiscalants were significantly different. In comparison with the negative control, the high dose of modified potycarboxytic acid antiscalant treated without metabolic activation showed a positive result and the high and middle dose of modified potycarboxytic acid antiscanlant and polyacrylic acid antiscalant treated with metabolic activation showed positive result.

Conclusions Under the present experimental condition, three antiscalants showed genotoxicity.