We are frequently asked how we estimate the UVC dosage needed to reduce pathogens in the environment. Scientists to date have established so called "k-values," which are disassociation constants that determine how much UVC energy will need to be applied to dissociate the DNA or RNA bonds in viruses, bacteria or fungal spores. Each potential pathogen has a specific k-value, which simply means that a specific amount of UVC dose (UVC Dose = UVC intensity x time) will break the DNA / RNA bonds of the DNA / RNA chain when a certain amount of UVC dose is applied. The pathogen will no longer be able to replicate; hence, is no longer capable of causing disease.
Example: Using the American Ultraviolet Pathogen Inactivation Chart for Coronavirus at 99.9% (3-log reduction) and the table on this page, which shows UVC dose (mJ/cm2) values, the following can be estimated:
Coronavirus (SARS): UVC dose 5.00 mJ/cm2 is the estimated UVC dose for a 3-log coronavirus reduction and referring to the dosage table and rounding this value the following can be estimated for the mobile room solution MRS45-12. The MRS45-12 at 10 feet distance takes less than 1 minute to inactivate coronavirus to 99.9%. If the object being disinfected is closer to the MRS45-12 it would require an even lower run time.
Additional examples are MRSA (estimated UVC dosage 25 mJ/cm2 for a 2 to 3-log reduction, 50 mJ/cm2 for 3+log reduction) or C. diff. (estimated UVC dosage 50 mJ/cm2 for 2 to 3 log and 100 mJ/cm2 for 3+ log reduction). Looking at the dosage table shown on each brochure for the respective mobile room solutions and dosage values near 25mJ/cm2, 50mJ/cm2 or 100mJ/cm2 at various distances allows to estimate the run time for these two pathogens.
None of the American Ultraviolet UVC products detailed above are certified, or approved under any applicable laws, as a medical device, and as such, American Ultraviolet, and its Representatives and Distributors, do not currently intend for them to be used as medical devices anywhere globally. Products have not been evaluated by the FDA.