EDTA generally refers to ethylenediamine tetraacetic acid or its sodium salt, which is an important artificial organic polybasic acid chelator and can form stable complexes with most metal ions. EDTA can generate four kinds of sodium salts. With the increase of the number of sodium atoms, the solubility in water will gradually increase.
When EDTA is first applied to cosmetics, it is added to soap or facial cleanser to soften hard water (the mechanism is that EDTA can chelate metal ions) and make soap based foam richer and more durable; Then, in the late 1950s, it was found that EDTA could improve the antibacterial properties of chemical preservatives, which attracted more attention in the cosmetics industry.
When there are metal ions in the solution, EDTA will hold the metal ions like a crab's tongs, making it difficult for the metal ions to react with normal valence, commonly known as chelation. Why should we chelate these metal ions? Take calcium, magnesium, iron, copper and manganese plasma as an example. They exist in the form of divalent cations in dilute solution. They react with anions to form salts and precipitate, such as the phenomenon of tea scaling on the inner wall of teapots often encountered in daily life.
Such metal ion pollutants will also appear in cosmetics. Production water, raw materials, manufacturing equipment, containers and packaging may introduce metal ions, which will lead to cosmetics discoloration, taste change, turbidity, accelerated corruption and other phenomena. Add 0.05% - 0.2% EDTA into the cosmetics formula, and then these EDTA will be firmly combined with metal ions when dissolved in water, so that they can no longer react with anions, thus preventing or reducing the occurrence of the above adverse phenomena.
2、 Synergistic corrosion protection.
The antibacterial ability of EDTA is mainly aimed at gram-negative bacteria, such as Escherichia coli, dysentery bacilli, pneumonia bacilli, Vibrio cholerae, etc., especially for Pseudomonas aeruginosa. Even if used alone, it can produce obvious bactericidal effect. The experiment showed that the use of EDTA with a concentration of 250 ppm alone without other chemical preservatives could kill 99.99% of Pseudomonas aeruginosa. When the concentration dropped to 100 ppm, the mortality rate of Pseudomonas aeruginosa was 57% - 99.5%.
In addition, EDTA also has good effects on some yeasts and molds, but it is generally not recommended to use it alone. It can play a better antibacterial role only when it is used together with other preservatives. Antibacterial mechanism: EDTA can combine with metal ions in microbial cell wall to improve the permeability of microbial cell wall, which is conducive to the penetration and function of antibacterial agents. If you have any questions or needs, please come to our website for consultation http://www.xhczhushu.com Come on!