CBRN plasma decontamination
The powers of plasma are not limited to the sterilization of medical devices. They are also useful for decontaminating surfaces soiled by chemical or biological agents. Such a situation can be caused by an industrial accident, by a terror attack act or in the context of an armed conflict.
What is CBRN contamination ?
Contamination is theunwanted existence of toxins on an object, surface, or part of the human body. The contaminated object or person therefore presents a health or use risk for themselves or for their environment.
The CBRN domain is concerned with the prevention or treatment of Nuclear, Radiological, Biological and Chemical threats. Let’s say it right away: plasma can do nothing against contamination of nuclear or radiological origin. But it is very interesting for treating biological or chemical contamination.
The action of plasma to decontaminate
Plasma is a dry decontaminant. It is composed of reactive, oxidizing or reducing species (i.e.: they swap electrons). However, what makes a compound dangerous for human health is precisely its ability to react by oxidation or reduction with the molecules that make up the cells of the human body.
The biocidal power of plasma is fully exploited in sterilization. It is even more easily applied to decontaminate, i.e., to eliminate the threat of a biological agent on an object or surface.
We think less of plasma to deactivate a chemical agent. And yet it has all the capabilities, through its reactive power. It has already been shown to remove pesticides on the surface of foods or fight toxins.
Plasma qualities for CBRN decontamination
The low action temperature of plasma, as well as its gaseous form, give it notable qualities.
For example, the current common forms of CBRN decontamination require large quantities of water to remove the contaminants from the surfaces to be treated or the products that were used to capture the contaminants (powders, liquids). The treatment of these effluents poses significant logistical, health and environmental difficulties. The treatment of these effluents poses significant logistical, health and environmental difficulties.
In the case of a plasma treatment, there is no need for water to evacuate the toxins. Contaminants are inactivated by the plasma and transformed into less dangerous or harmless compounds. They are evacuated in the ambient air, by an additional filtration if necessary.
For CBRN decontamination, Aurora can implement two types of devices: a low-pressure plasma or an atmospheric plasma.
Low pressure plasma decontamination
The low-pressure plasma is obtained inside a vacuum chamber. This application is recommended for small to medium sized objects. It allows to treat objects that would not support humidity.
The object to be decontaminated is placed in the decontamination chamber. A vacuum is created, then one or more air gases are injected. An electromagnetic source (radiofrequency) is then applied to the volume to be treated, which transforms the gas from the air into plasma. The object to be decontaminated then bathes in the plasma. The contaminants react with the plasma, which inactivates the biological agents or breaks down the chemical agents present. The duration of the process varies with the volume to be treated, between 1 and 4 hours.
When it leaves the enclosure, the object no longer presents a risk to health or the environment. It can be reused, stored, or disposed of.
This device can take sizes varying from the small oven (microwave type) to the container. It is particularly suitable for the preventive treatment of parcels or mail in strategic decision-making centers, to prevent an attack such as that of the anthrax bacillus.
Atmospheric plasma decontamination
The other Aurora plasma decontamination process is done at atmospheric pressure. It consists of applying a cold plasma torch (about 40°C) to the surface to be decontaminated.
The main advantage of Aurora atmospheric plasma is its ability to dry decontaminate the skin, without damaging it. The plasma precursor is the ambient air, which is ionized between electrodes, then injected into a tip of shape and size adaptable to the support: plasma blade, plasma jet, plasma disc, etc.
For large areas, such as a public place, an Aurora plasma torch ramp is mounted on an autonomous or remote-controlled vehicle. The plasma ramp is thus brought into contact with the surfaces: floors, walls, stairs, ramps, seats, etc.
The same principle can be applied to a plasma shower that is applied around the body of an infected person, rotating around it.
Plasma CBRN decontamination can be applied in emergency decontamination, as in immediate decontamination or in-depth decontamination.