COVID-19 is an infectious disease transmitted by animals caused by the coronavirus strain called SARS-CoV-2.
Contamination is manifested by a number of symptoms (fever, cough, etc.) and the disease can lead to the development of an acute respiratory distress syndrome. Sudden loss of smell (called anosmia) or taste (called ageusia) has also been observed.
SARS-CoV-2 has a variety of shapes from round to oval.
It has an average diameter of 67 nm (which makes it a large virus)
Its genome is made up of RNA (RiboNucleic Acid) of around 30,000 nucleotides (the building block of DNA or RNA). This virus is 50% identical to that of MERS-CoV, 79.5% identical to that of SARS-Cov, 91% identical to a coronavirus present in a species of pangolin and 96% identical to a coronavirus present in a horseshoe bat.
The infectious mechanism of the virus is not yet fully understood.
The action of pulsed light
The main role of pulsed light is to completely inactivate microorganisms.
Effet photochimique :
For many chemical and physical agents, DNA is an important target of bacterial cells.
The complex structure of the molecule shows that it can be modified in several ways.
The first cellular target of pulsed light is DNA.
Part of the UV-C spectrum is responsible for the destruction of germs.
Maximum inactivation occurs at 270 nm and no lethal effect is observed for wavelengths above 300 nm.
The maximum absorption of DNA nucleotide bases in ultraviolet light is 260 nm. This absorption has the effect of generating DNA breaks. In fact, UV-C induces a photochemical modification, such as the formation of thymine dimer. These changes affect microbial reproduction or protein synthesis, which leads to cell death.
Continuous UV treatment affects DNA by reversible mechanisms under certain experimental conditions. It appears that this reversibility does not occur in the case of pulsed light treatment, which may be due to severe inactivation of the DNA repair system.
Photothermal effect :
The mechanisms of disinfection by pulsed light include the bactericidal effect of the UV-C part of the light (including the lethal formation of thymine dimer on bacterial DNA) and the photothermal effect.
When the temperature increases temporarily due to the absorption of ultraviolet energy from the lamp by microorganisms, inactivation takes place for high energy levels.
The increase in temperature comes from the difference in absorption of ultraviolet energy between bacteria and the environment. Part of the water in the microorganisms is vaporized, producing a thin flow of vapor which alters the membrane and causes it to rupture.
Despite the low water content, this phenomenon also affects spores. Obviously, this photothermal effect is proportional to the energy of the treatment, and as the energy increases, it will become more effective. Therefore, after exposure to low doses of pulsed light, the protein retains its activity while this activity disappears when a higher dose is induced.
Therefore, it is very likely that both effects are involved in the inactivation of microorganisms by pulsed light. The relative ratio depends on the energy delivered and the characteristics of the treatment.
The LP.Box is a compact and ergonomic machine, in “office” format.
It allows disinfection of surfaces, liquids or products by eliminating the pathogens present.
The LP.Box has been tested on several strains such as Escherichia Coli, Bacillus subtilis or Aspergillus niger and also on the human coronavirus.
It also makes it possible to degrade phytotoxins, mycotoxins, alkaloids, phytosanitary and medicinal residues.
As mentioned above, the principle of pulsed light is based on the emission of polychromatic light covering a wide spectrum (200 to 1200 nm) by light flashes (between 1 μs and 100 ms per flash). Our expertise allows us to make the right adjustment depending on the products (wavelength, light intensity, pulse impact time, number of passes).
Thus, with the selection of particular wavelengths, pulsed light is used for the purpose of destroying pathogenic microorganisms.
Our LP.Box has been certified effective against human coronavirus by an independent laboratory.
The operation of the LP.Box is simple. Just place the product to be treated in the enclosure provided for this purpose. Then close the door and start the treatment cycle. During the cycle, the door is locked and the user cannot access the content. Once the cycle is finished, a signal warns the user who can remove the disinfected products.
The abatement rate
When talking about disinfection, it is important to clarify what it is.
It is the ability of a system to remove a pathogen from an environment.
Bacterial or viral abatement depends in particular on the technology used, the exposure distance and the exposure time.
Bacterial abatement is characterized by a LOG (base log 10).
This very simply means that at 1 LOG, the number of bacteria is divided by 10, so the efficiency is 90%.
At 2 LOG, the number of bacteria is divided by 100, the efficiency is 99%.
At 3 LOG, the number of bacteria is divided by 1000, the efficiency is therefore 99.9%.
For a reduction from 2 LOG to 3 LOG, we speak of decontamination.
At 4 LOG, the number of bacteria is divided by 10,000, the efficiency is therefore 99.99%.
At 5 LOG, the number of bacteria is divided by 100,000, the efficiency is therefore 99,999%.
For a reduction from 4 LOG to 5 LOG, we speak of disinfection.
At 6 LOG, the number of bacteria is divided by 1,000,000, the efficiency is therefore 99.9999%. We then speak of sterilization.
It is important to note that from 4 LOG, the subject treated no longer presents an infectious risk.
The LP.Box allows disinfection of more than 4 LOG (or even 5 LOG depending on the pathogens) in 5 seconds and at a distance of 50cm from the target to be treated.
We therefore offer a very effective and very rapid disinfection solution.