Methylchloroisothiazolinone (MCI) is an isothiazolinone-derived biocide used for controlling microbial growth in industrial and household products, often in a mixture with methylisothiazolinone .1,2 It is effective against Gram-positive and Gram-negative bacteria, as well as fungi when used in combination with MI with MIC values of 0.0002, 0.0002, 0.00005, and 0.00005% (w/w) for S. aureus, P. aeruginosa, A. niger, and C. albicans, respectively.2 MCI, alone and as a mixture with MI, can elicit contact sensitization.3
1.Frenzel, E., Schmidt, S., Niederweis, M., et al.Importance of porins for biocide efficacy against Mycobacterium smegmatisAppl. Environ. Microbiol.77(9)3068-3073(2011) 2.Lundov, M.D., Johansen, J.D., Zachariae, C., et al.Low-level efficacy of cosmetic preservativesInt. J. Cosmet. Sci.33(2)190-196(2011) 3.Scherrer, M.A.R., and Rocha, V.B.Increasing trend of sensitization to methylchloroisothiazolinone/methylisothiazolinone (MCI/MI)An. Bras. Dermatol.89(3)527-528(2014)