The importance of sanitizing environments has always been crucial to guarantee the safety and health of the people who frequent them. With the advent of the COVID-19 pandemic, cleaning and disinfection have become even more crucial to preventing the spread of the virus. Among the various products used for sanitization, hydrogen peroxide is one of the most effective and used. Hydrogen peroxide is a chemical substance composed of two hydrogen atoms and two oxygen atoms used in sanitizing environments for its ability to kill bacteria, viruses, and fungi.  

In this article we will delve into what hydrogen peroxide is, how it works, and why it is important for sanitizing environments, useful notions for all professionals who wish to learn more about the topics mentioned, from hygiene managers in industries to health care workers and clinical engineers. 

Hydrogen peroxide and Covid-19

In 2020, the explosion of the Covid-19 pandemic highlighted the importance of environmental sanitization to prevent health problems. 

With circular no. 5443 of 02/22/2020, the Ministry of Health has indicated the tools and substances recommended for the sanitization of healthcare and non-medical working environments. 

As regards health facilities, which require particular attention, the Ministry reports that Coronaviruses, including the viruses responsible for SARS and MERS, “are effectively inactivated by adequate sanitization procedures which include the use of commonly used disinfectants treatment, such as sodium hypochlorite (0.1% -0.5%), ethanol (62-71%) or hydrogen peroxide (0.5%), for an adequate contact time”. 

Threrefore, Hydrogen peroxide in the indicated percentage, ranks among the currently most reliable compounds for the environmental sanitization of healthcare facilities, including that specifically aimed at the neutralization of Sars-Cov-2. 

The intervention areas of a professional sanitization process are common areas such as reception rooms (e.g., waiting rooms, reception) and other public places (e.g., operating theaters, clinics, toilets). 

A correct sanitization process is divided into the following phases, in this order: cleansing and disinfection. 

Detersion (or cleaning) is mandatory before disinfection because it decreases the microbial load, allowing the active ingredient to act: in fact, the removal of dirt removes the development medium for the microorganisms. 

Subsequently, disinfection brings into circulation molecules that can significantly reduce pathogenic microorganisms on surfaces and equipment. It is at this stage that hydrogen peroxide, if present in the disinfectant used, intervenes. 

Hydrogen peroxide: how it works

What is Hydrogen Peroxide? Commonly known with the chemical formula H2O2, it is a compound containing peroxide ions (O22-) that has a high oxidative and biocidal efficiency. 

In fact, it is widely used for disinfection, sterilization, and antisepsis, and is considered bactericidal, virucidal, sporicidal, and fungicidal depending on the concentrations of use. The 3% solution is the most commonly used and is stable over time if stored in opaque containers. [Return to the new line of text] It is also considered not very toxic to the environment, as it rapidly degrades into oxygen and water. 

Especially effective is the combination of hydrogen peroxide and silver. The two active ingredients act synergistically in order to penetrate the biofilm: peroxide for its oxidizing action and silver thanks to the electrostatic bond to the bacterial membrane where it causes cell death in addition to its bacteriostatic activity. 

How does sanitization with hydrogen peroxide and silver work?

In a closed environment with no people present, specialized personnel (equipped with correct PPE) such as AMIL Care personnel install a machine that nebulizes hydrogen peroxide with silver ions, saturating the environment and killing the microorganisms present (bacteria, mites, viruses, fungi, spores…). 

At the end of the process and with appropriate ventilation, it is possible to return to the sanitized environment in safety. 

Other methods of environmental sanitization

In addition to hydrogen peroxide, other more or less effective substances are used by companies for professional sanitization treatments. Let’s see the main ones. 

  • Ozone. It is a molecule made up of three oxygen atoms, which makes it an effective product in disinfection thanks to its marked oxidizing capacity. Also, regarding ozone, disinfection must be carried out by specialized personnel, in a closed environment and with no people present, since in high concentrations it is a toxic substance for humans. The operator installs an automatic machine that works starting from the oxygen naturally present in the air, transforming it into ozone, saturating the environment, and reducing present microorganisms by 99.9%. At the end of the process, the same machine destroys the ozone and, after a cycle that can last from 30 to 60 minutes, you can return to the sanitized environment. The Ministry of Health has declared that there is currently no evidence that ozone performs a sterilizing function against the new Coronavirus. 
  • Alcohol. in the form of sodium hypochlorite or hydroalcoholic solution (ethanol). The specialized personnel nebulize a solution of sodium hypochlorite (concentration 0.1% -0.5%) or ethanol (concentration 62-71%) with special dispensers. In the sanitization and decontamination operations of RSAs with Covid-19 sick residents, specialized decontamination personnel of the Italian Army follow this practice. 
  • Photocatalysis. Automated systems using reactive oxygen compounds would reduce the microbial load present in an environment by 99% (viruses, bacteria, molds). These systems can be used in the presence of people in the areas to be sanitized. However, to date, the Ministry of Health has not given any provisions on the use of Photocatalysis Systems as an authorized or recommended method to sanitize environments from the Sars-Cov-2 virus. 
  • Steam 160°/180°. Industrial Steam Machines generate steam and mix it with disinfectants in order to break down the microbial load present in an environment (viruses, bacteria, molds.). These systems can be used in the presence of people, but even in this case, there are no studies on their effectiveness against the Coronavirus. 
  • Cold plasma. Non-thermal plasma (NTP) is a physical phenomenon generated at room temperature, which uses the air as a gaseous mixture, transforming it into an ionized gas made up of various electrically charged particles both + and –: electrons, ions, atoms, and molecules which, colliding between them, they produce oxidizing species. The reactivity of the particles then causes oxidation phenomena capable of disaggregating the volatile organic compounds, bacteria, microorganisms, and odors. The sanitization carried out would include the air, but not the surfaces. Even this for now, is not an authorized or recommended method to sanitize from Sars-Cov-2 virus. 

Hydrogen peroxide in action with Medisystem

The combination of hydrogen peroxide and silver ions is therefore the most effective method for environmental sanitation. 

AMIL Care’s automated Medisystem disinfection system is based precisely on this combination. 

How Medisystem works: the Medibios dispensing machines – differentiated according to the environment to be treated – use a turbine to dispense Evolyse, a ready-to-use solution based on hydrogen peroxide and silver sulfate (10 ppm). 

The particles that are emitted (with dimensions from <1 to 5 µm) are carried by air and reach any free surface, remaining in suspension until their natural decay instead of precipitating as in common aerosolization systems. 

The saturation of the environment and the effectiveness of the Evolyse disinfectant guarantee complete disinfection even where the traditional method does not achieve the results required by the standard. 

The automated device with no-touch technology allows high-level disinfection cycles, based on certified decontamination protocols. For sanitizing environments effectively and in total safety.