| Degree | CYTOTOXICITY | DESCRIPTION OF THE OF CYTOTOXICITY AREA |
| 0 | Absent | Absence of decolorization around or under the sample |
| 1 | Slight | Decolorization limited to the area under the sample |
| 2 | Mild | The size of the decolorized area from the sample is less than 0.45 cm |
| 3 | Moderate | The size of the decolorized area from the sample is between 0.45 cm and 1.0 cm |
| 4 | Severe | The size of the decolorized area from the sample is greater than 1.0 cm, but does not involve the entire plate |