Methylisothiazolinone, Benzisothiazolinone

This synergistic blend combines methylisothiazolinone (MIT) and benzisothiazolinone (BIT), two isothiazolinone-based biocides that work by disrupting microbial cell membranes and inhibiting enzymatic processes. The combination provides broad-spectrum antimicrobial protection at lower individual concentrations than either preservative alone, offering effective preservation against bacteria, yeast, and mold in rinse-off formulations. Formulators historically chose this blend for its potency and cost-effectiveness, though regulatory restrictions have significantly limited MIT use in leave-on products due to sensitization concerns, making it now primarily suitable for rinse-off applications only.