Nowadays, also in light of the recent pandemic, the sanitization of public and private spaces takes on a primary role in safeguarding the health of people who live and work in all environments, especially medical ones. However, the substances traditionally used for this purpose could now prove to be ineffective, since the bacteria themselves have developed a high resistance to these products. In this context, a valid ally can be an unusual material, namely silver. 

Silver as an antimicrobial

The antimicrobial activities of silver have been known for centuries, but it was in the second half of the last century that its functions became clearer to the scientific community. This noble metal can play a fundamental role for medical purposes, and even more in the sanitation and sanitation of environments and machinery. The material by its nature has germicidal biological characteristics. If used in the right way, silver lends itself to maximum sterilization of medical instruments and devices, an absolute advantage compared to other products and solutions. 

Sanitization with ionic silver: a precious practice

Disinfection with silver salts is a widespread practice today, but few know how the precious antimicrobial properties of this substance work. The silver ions produced by salts are used to ensure safety in water distribution systems, for air purification, or in the biomedical sector, even in wound care. 

The silver ions (Ag+) which are released from inorganic salts and other macromolecular complexes, have high levels of toxicity for bacteria (including Acinetobacter, Escherichia, Pseudomonas, Salmonella, Vibrio, Bacillus, Clostridium, Enterococcus, Listeria, Staphylococcus, Streptococcus). Furthermore, the ionic action of silver is also relevant for various pathogenic fungi and even viruses. 

Silver: the methods of action for sanitization

Let’s see in detail some of the modes of action of ionic silver: 

  • First of all, once the deposition on the cell walls of the bacteria has taken place, the ions damage their structure;
  • Subsequently, the main cellular functions of the bacteria in question are inhibited;
  • One of the cellular activities consists precisely in the duplication, which is inhibited by the silver nanoparticles;
  • In this way the proliferation of pathogenic microorganisms is therefore avoided, obtaining a high level of sterility and sanitation of the surface or environment.

There are numerous studies on silver and empirical demonstrations of this ‘technology’ for sanitation. In percentage terms, it has been estimated that the effective effectiveness of using silver ions can even reach 98%. Furthermore, long times are not foreseen for the complete sanitization of the surfaces or environments in which the product is used. The data report immediate and lasting results, as the ions are responsible not only for the elimination but also for the inhibition of the development of any pathogens and dangerous microorganisms. However, often ionic silver must be used with other solutions, or simply with water, which reactivates the nanoparticles of the substance to obtain greater sanitization effectiveness of environments or machinery. 

However, for the use of silver salts in the field of sanitization, it is necessary to follow the instructions of the various products. Far from being dangerous to human health, according to many studies, ionized silver has minimal levels of toxicity for the human body, just as the risks associated with its inhalation, ingestion or contact with the dermis are extremely low. 

Instead, one of the greatest risks lies precisely in the ineffectiveness of the product, if used in excessive quantities. In such cases, bacteria and microorganisms could develop a resistance that prevents the ions from acting on the elimination of any pathogens, as has happened over time for products traditionally used in the field of sanitization. Furthermore, it should be considered that some environments, due to their constitutive characteristics, are particularly suitable for treatment with silver ions. 

In addition to many studies, the application of silver ions in medical sanitization has been tested during the Covid-19 pandemic. To reduce the risk of viral contamination, a process of injecting silver ions into the structure of special laminates and medical materials has been adopted by some Italian companies. In this way, the bacterial or viral presence was reduced by as much as 99.9% in the coatings in which the process was implemented. 

The use of silver ions by AMIL Care

It should be noted that according to the provisions of Annex XXXVIII of Legislative Decree 9 April 2008, no. 81 of the Consolidated Law and in the annex to Directive 2006/15/EC, the maximum quantity of silver to be used to act in complete safety is 0.01 mg/m3. 

In this regard, the use of silver by AMIL Care takes place in its ionic form and at the highest level of oxidation, which is not repeated once released into the environment. In addition, a large part of its residual particles, based on what was stated above, are precisely absorbed by bacteria, fungi, and other pathogenic microorganisms. Consequently, any risk of exceeding the indicated maximum threshold or danger is averted, guaranteeing instead maximum efficacy in the various products. 

AMIL Care, safe with silver sulfate

Given the Silver Sulphate content in Evolyse of 10 mg/L of Ag (10 ppm corresponding to 10 mg/Kg), it follows that 1 ml of nebulized product contains 0.01 mg of Ag, even if the dispenser product never comes into contact with it. The analysis of the degradation of silver in the ionic form has reached its maximum oxidation number and therefore it does not oxidize further in the environment: a large part is absorbed by bacteria, spores, and fungi and disappears, and what remains (less than a quarter) is deposited. It is therefore not possible in the environment presence of silver residues such as to exceed the limit values ​​indicated in the Consolidated Law 81/2008. 

Even in treatments with higher dosages (3ml/m3 and 5ml/m3) the fact that at the end of the delivery, the first element that settles is the heavy metal is valid. The residual values ​​on the surfaces are not detectable at the reporting level to the point of being far below the threshold limits of 0.050 mg/Kg indicated in the Maximum limits for contact of substances with food (EFSA Journal 2006 “Opinion of the scientific panel on food additives, flavorings, processing aids, and materials in contact with food”).