Table 3.

Test suitability and determination of results

Test conditions (test established if all conditions are met).

1. The frequency of cells with chromosomal aberrations in the negative control group must be within the control range of the historical control data and within 95% of the historical control data.

2. The frequency of cells with chromosomal aberrations in the positive control must be within the control range of the historical control data and show a statistically significant increase compared to the negative control.

3. Cell proliferation criteria must be met in the negative control.

4. All three test conditions must be tested unless one of the three test conditions (absence and presence of metabolic activation in the short-term treatment, absence and presence of metabolic activation in the continuous treatment) is positive.

5. There should be at least three readable doses in the test substance group and at least 300 mitotic divisions per dose should be observed in the control and test substance groups.

6. Criteria for selection of the highest concentration should be appropriate.

Determination of results (The frequency of cells with chromosomal aberrations is considered positive if all of the following conditions are met; otherwise it is negative).

1. A statistically significant increase in the frequency of cells with chromosomal aberrations compared with the negative control at one or more doses.

2. The increase is dose dependent.

3. The frequency of cells with chromosomal aberrations increases beyond the control range of the negative control historical control data.