Silver as a human-compatible, skin-friendly, irritation-free preservative.
What started more than 10 years ago in the field of process fluid development has found its way into our natural cosmetics via various veterinary products. Silver is excellently suited, for example, to make water durable for a long time. This was already used in antiquity. Also our grandmothers knew how to help themselves with the silver coins of that time. Today, especially sailors and outdoor freaks use products containing silver ions (e.g. MicroPur) to conserve their drinking water.
The silver ions (Ag+) work according to the "oligodynamic principle" or the "oligodynamic effect" (►link).
What even has positive effects for humans prevents microorganisms from growing even in the ppm (parts per million) range.
We were able to prove that even in the lowest concentrations (<5ppm) the metabolic activity of microorganisms in complex process fluids is drastically reduced.
Microscopic images of coliform germs (1000-fold):
Left: Phase contrast image: All cells visible
Right: Superposition of fluorescence image with phase contrast: The living cells glow red.
Middle: Overlay of two fluorescence images. Yellow-lighting E.coli / Red-lighting Coliform germs
The fluorescent gene probe signals reflect the physiological state of the bacteria present. The more active a bacterium is, the more target sites (rRNA) there are in the cell and the more gene probes (fluorescence-labelled oligonucleotides) can bind in the cell. The detected cell appears all the brighter under the fluorescence microscope. The intensity of the detected signal allows conclusions to be drawn about the metabolic activity of the bacteria.
By using very small amounts of our silver we are in the fortunate position to be able to consistently omit all conventional preservatives such as potassium sorbate, benzyl benzoates, sodium and potassium benzoates, phenoxyethanol, phenoxypropanol or any parabens.
Silver ions act very efficiently against all microorganisms, whereby resistances are not known, since silver ions "attack" the microorganisms via various mechanisms of action. However, it is not sufficient to add pure silver ions, as these would react immediately with chlorides or oxygen to form poorly soluble, ineffective salts. This is exactly where we have a patented solution. We use silver in the form of silver ions, which are structurally embedded in a matrix. This matrix is of plant origin and protects the silver ions from oxidation.
However, silver ions have a small disadvantage. If our products are exposed to the sun for too long, a slight discoloration can be seen. This is because the silver ions are reduced to elementary silver and react with their matrix. However, this reaction is absolutely unproblematic and certainly acceptable if we can do without all preservatives.
Further information, Patent (US): ►United States Patent 8951574