The question gains importance, when considering the numbers of adverse effects due to inaccurate preservation. First, the increasing number of cosmetics notified or withdrawn from the market because of microbial spoilage. Second, all reported cases, characterized by various degree of gravity, of problematic reactions to the end users; from eye and skin recoverable diseases to, in extreme cases, humans’ death, all them caused by the use of contaminated products. Finally, overexposure: it is quite common, but totally no-sense, to overdose preservatives into the formula; at the same time, it is globally recognized that a limited number of molecules are used to preserve a much bigger variety of finished products. In this way, it is possible that non-dangerous preservatives can become problematic because of overexposure.
To avoid these adverse effects, some simple suggestions for the selection of a safe, effective and economically sustainable preservative system can make the difference: quality of the molecules and synergistic effects to achieve broad spectrum protection by lowering the dosage, and focus on the dose-dependent preservative efficacy…quantity counts! These recommendations are basics steps to develop a stable and safe formula, which can be added with innovative active and functional ingredients, to achieve successful cosmetics.