Hydrogen peroxide (H2O2) acts immediately as a disinfectant. There is no residual effect, as H2O2 rapidly breaks down into O2 (oxygen) and H2 (water). This is one of the positive benefits of H2O2 disinfection, as no residues or deposits left behind on disinfected surfaces. As cleaning must occur each day, long-term residual effects of disinfectants are often superfluous in hygiene settings. Moreover, if residues persist and product builds up on surfaces, over time such deposits may decrease the effectiveness of cleaning, and in particular the ability to remove microbial biofilms.
Hydrogen peroxide acts as an oxidizing agent, and its disinfection action is through the generation of reactive oxygen species such as the hydroxyl radical (OH), which have a lifespan of some picoseconds. When hydroxyl radicals come into contact with a cell they act by removing electrons from susceptible chemical groups, in the process destroying the cell wall and cell membranes. At higher concentrations cell damage can progress to the inside of the cell, destroying the nucleus also. As hydrogen peroxide acts on multiple cell targets, cells are unable to develop resistance strategies. Therefore, no alternation with other disinfectants is required.
For vegetative bacteria: hydrogen peroxide acts by oxidising susceptible chemical groups, such as sulfhydryl groups, and the double bonds of bacterial enzymes, resulting in modification of protein structure, with a loss of function and, ultimately, cell death.
For bacterial endospores: hydrogen peroxide’s oxidizing ability extends to the disorganization of dipicolinic acid, the molecule of central importance to the unique resistance properties of bacterial endospores.
For viruses: hydrogen peroxide’s ability to denature proteins extends to the virus’ protein shell, called the capsid, as well as on the genetic material of the virus.
Curative disinfection is required where microbial contamination, such as with MRSA, VRE, Aspergillus or C. difficile is already known. The device must be set in accordance with the volume of the room to be disinfected.
Preventive disinfection is sufficient where the aim is to reduce incidental contamination by environmental microbes. The device may be set in accordance with half of the volume of the room to be disinfected.
Hydrogen peroxide is safe to use at concentrations up to 10%. Airandé only uses hydrogen peroxide at concentrations up to this safe concentration. Above 10%, it is mandatory to observe the legislations[BC1] regarding the transport of dangerous goods and to introduce pictograms in the technical files and MSDS.
Given the rapid breakdown of hydrogen peroxide into water and oxygen, hydrogen peroxide is considered an eco-friendly disinfectant.
When hydrogen peroxide is used as a disinfectant manually applied, it is safe to remain in the room during application. However, when disinfection is undertaken using Airandé’s nebulizers (DF-1 Nebula or DF-2 Aridus) or the Hygien’Air, no humans or animals can remain in the room during disinfection. This is because application in vapour form increases the concentration of hydrogen peroxide in the air above safe levels. In Europe generally, a maximum limit of 1 ppm is permitted, in the Netherlands, 12 ppm. However, because of the rapid breakdown nature of hydrogen peroxide, air concentrations rapidly return to safe levels once active disinfection is halted.
There are two reasons for the need to wait for one to two hours before entering the room after active disinfection. The first reason is to allow sufficient contact time of remaining hydrogen peroxide vapour to settle on surfaces and interact with microbes to destroy them. The second reason is to allow time for any remaining hydrogen peroxide to break down into water and oxygen, thus returning room concentrations of hydrogen peroxide to safe limits. One to two hours is at the maximum end of the range to be set for re-entry. The minimum time before re-entry could be as little as 20 minutes.The actual timing will depend on a range of circumstances that will be assessed with you by our distributors at the time of installation.
No, it is not necessary to wipe disinfected surfaces. Disinfected surfaces are left dry, and no additional work is required.
Disinfection using hydrogen peroxide vapour is a surface treatment and does not penetrate sufficiently to decontaminate the fibres of hangings (curtains, drapes) or filters, including HEPA filters. Alternate methods of decontamination must be used for these. The Airandé range of air and surface purifiers (for example, the AP-13 or the Ventum) are an ideal choice for these extra decontamination steps.
To prepare the room for disinfection the room must first be cleaned as per your standard cleaning protocols. Before switching on the before switching on the Airandé Nebula, Aridus, or Hygien’Air appliance it is necessary to close the windows and to open all cabinets, drawers, etc. in the room. All surfaces to be disinfected must be exposed to the hydrogen peroxide vapour for disinfection to occur.
In order to achieve efficient disinfection the Hygien’ Air device should be placed in the corner of the room where the spray angle is as wide as possible.
The dual nozzle Nebula or Aridus should be placed in the middle of the room. The device can spray up to a 10 meter long distance. If a corridor of 30 meters is to be disinfected, two appliances in sequence should ideally be used.
If the room has an air renewal system, never place the appliance below it because it can alter the diffusion of the hydrogen peroxide vapour in the room. If the air renewal system cannot be switched off or set to a minimum, then to achieve disinfection it may be necessary to increase the volume of product that is dispersed into the room. Otherwise, additional product may need to be sprayed into the room, over and above the volume that would be otherwise expected to achieve disinfection.
The Hygien’Air requires only annual monitoring of the filter and well of the spraying pipe. The Airande Nebula and Aridus should be checked annually to ensure that its specially designed nozzles are functioning well. The filter on the Nebula and Aridus will require regular change. The timing of that change will depend upon the amount of use of either device. Your distributor will be able to provide more guidance to suit your particular circumstances, but we would recommend a filter change at least every 6 months.
There is no risk of corrosion of the electronic equipment in the room at the concentration used by Airandé. University studies have assessed exposure to hydrogen peroxide vapour of a variety of types of surfaces , and no corrosion or bleaching has been observed, in contrast to other, more aggressive disinfection agents, such as chlorine.