A 10-year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re-evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave-on products.
Wilkinson, J. D., Shaw, S., Andersen, K. E., Brandao, F. M., Bruynzeel, D. P., Bruze, M., Camarasa, J. M. G., Diepgen, T. L., Ducombs, G., Frosch, P. J., Goossens, A., Lachapelle, J.-M., Lahti, A., Menné, T., Seidenari, S., Tosti, A., & Wahlberg, J. E. (2002). Monitoring levels of preservative sensitivity in Europe. A 10-year overview (1991-2000). Contact dermatitis, 46(4), 207-210. https://doi.org/10.1034/j.1600-0536.2002.460404.x (Original work published 2002)