An interlaboratory study of the short time exposure (STE) test using SIRC cells for predicting eye irritation potential.

We have developed the short time exposure (STE) test using a rabbit corneal cell line (SIRC cells) as an alternative eye irritation test. The STE test uses relative viability as the endpoint after cells are exposed to the test material at 5%, 0.5%, and 0.05% concentrations for 5 minutes. In this interlaboratory study, 2 laboratories conducted the test using 70 raw materials in order to evaluate transferability, between-laboratory reproducibility, and predictive capacity of the STE test as an alternative eye irritation test. Transferability was assessed using saline as a negative control and 0.01% sodium lauryl sulfate as a positive control. The relative viabilities obtained for the 2 laboratories were almost the same. Therefore, transferability was considered to be excellent. The 2 laboratories showed similar relative viabilities for all 70 raw materials at each test concentration. The correspondence rates of the eye irritation categories (irritants and nonirritants) were over 97% for each concentration tested, exhibiting high between-laboratory reproducibility. The correspondence rates for predicting eye irritation potential of undiluted raw materials and a diluted solution (10%) were over 85% at each laboratory for the 5% and 0.05% test concentrations in the STE. Lastly, the correspondence rate for the rank classification by the STE test prediction model at each laboratory was over 72%, and the correspondence rate became almost 90% when acids, amines, and alcohols were excluded from the analysis. From the above data, excellent transferability, high between-laboratory reproducibility, and high predictive capacity of the STE test were observed in the interlaboratory study by 2 laboratories.