Fig. 5.

Mixture toxicity of methylisothiazolinone (MIT) and 0.5% propylene glycol (PG) to cultured HaCaT cells. Cultured HaCaT cells were treated with a mixture of MIT and PG for 24 hr, and viability was measured by MTT assay. Cell viabilities did not decrease in the 0.5% PG-treated or negative control groups. MIT (A, 300 μM; C, 400 μM) showed cytotoxicity in a concentration-dependent manner. Its toxicity was not influenced by 0.5 % PG. A, 300 μM MIT; B, 300 μM MIT + 0.5% PG; C, 400 μM MIT; D, 400 μM MIT + 0.5% PG. There was no statistically significant (p > 0.05) difference between A and B, or between C and D.