Chelation of EDTA-2Na
EDTA-2Na is a white crystalline powder. It is slightly soluble in water and easily soluble in many organic solvents such as ethanol, ether and chloroform. When EDTA-2Na encounters free metal ions in the solution, it will hold the metal ions like a pair of large tongs of a crab, so that the metal ions cannot harm our skin.
Antibacterial effect of EDTA-2Na
EDTA-2Na can enhance the activity of fungicides to resist Gram-negative bacteria, such as Escherichia coli, Shigella, Pneumoniae, Vibrio cholerae, etc. EDTA-2Na can combine with the metal ions in the microbial cell wall to improve the permeability of the microbial cell wall, which is conducive to the penetration and function of antibacterial agents. Due to the lack of reliable antibacterial activity, EDTA-2Na is generally not used alone, but used with other preservatives.
The effect of EDTA-2Na in regulating pH
It can adjust the pH of cosmetics, that is, it can automatically adjust the pH of cosmetics within the range that we can fit, so as to protect our skin from strong irritation. In addition, it presents a gradual color from wine red to blue under different pH levels, so it is often used in cosmetics.
Other uses of EDTA-2Na
EDTA-2Na is also used in various other personal products, such as adding hair dye. The basic components of hair dyes are mostly oxidation dyes O- and P-aryl diamine dyes and their derivatives. In order to prevent these oxidation dyes from oxidative deterioration during storage and transportation, it is necessary to add reducing agents sodium sulfite or sodium bisulfite. These two reducing agents are easy to decompose in the presence of metal ions. The addition of EDTA can stabilize reducing agents such as sulfite, and make the dyes oxidize more uniformly during color development, and prevent "discoloration caused by impurity metal ions" ".
EDTA-2Na is used in soaps and shampoos to increase foam and enhance detergency. This is because it complexes with metal ions in the water to adjust the hardness of the water. At the same time, the addition of EDTA can inhibit the bacteria in the soap and delay the rancidity of fatty acids in the soap.
EDTA-2Na can also be used in deodorants, the role is to remove copper and iron that can cause bad odors.
EDTA-2Na can also stabilize vitamin preparations that are prone to oxidation in the presence of metal ions.
Is EDTA-2Na safe in cosmetics?
The disodium EDTA added in beauty and skin care products is very safe. A review published in the International Journal of Toxicity stated that EDTA does not cause cancer at a very high concentration (750mg/kg/day). The content of disodium EDTA in our beauty and skin care products is less than 0.02mg. So disodium EDTA is very safe to use in cosmetics. But don't eat it. Because food is the object of the digestive tract, not the skin!