Microorganism is a kind of tiny, simple structure and invisible to the naked eye. It must be observed by optical microscope or electron microscope. It is a necessary component of natural ecological balance. It is at least 100 thousand species. The main microorganisms in cosmetics are bacteria, molds and yeasts.
Cosmetics are spoiled by microbial contamination, and sometimes they can be seen in the appearance of products. For example, mould and yeast are more often in the edge of the packing cover, the liner and the surface of the product, producing mildew, and the product is generally cloudy, precipitated, color change, pH change, odor release, foaming and bloating, odor change, demulsification or block after microbial contamination. Some microbes can also produce toxic substances, which can cause skin allergies and cause serious harm to the human body.