Ultraviolet (UV) light is an electromagnetic radiation. Its wavelength spectrum falls in the region between visible light and X-Rays. It is invisible and ranges from 100 nm to 400 nm has been traditionally subdivided... More ...
Log Reduction is a mathematical term that is used to express the percentage or proportion of microorganisms deactivated in a disinfection process... More ...
THE EFFECTIVENESS OF UV-C
UV-C is an electromagnetic radiation that can destroy the ability of microorganisms to reproduce by causing photochemical changes in nucleic acids. Wavelengths in the UV-C range are especially damaging... More ...
Ultraviolet (UV) light is an electromagnetic radiation. Its wavelength spectrum falls in the region between visible light and X-Rays. It is invisible and ranges from 100 nm to 400 nm has been traditionally subdivided in 3 categories or regions.
Natural UV radiation is of course coming from the Sun. Around 10% of all that energy falls within the UV range, and only 4% is capable of crossing our atmosphere and reaching the Earth’s surface where we live. The rest is absorbed by the oxygen (O2) and ozone (O3) in stratosphere, blocking most of the UV-B and all the UV-C component of the UV light.
|UV-C||100 nm to 280 nm||Germicidal radiation - inactivates pathogens|
|UV-B||280 nm to 315 nm||Actinic radiation - causes photochemical reactions|
|UV-A||315 nm to 400 nm||Considered non-germicidal|
Yes, in fact UV is a well-known technology in this field. It is reported that Hart in 1937 used an array of UV lamps to sterilize supply air in a surgical operating room. Hart employed direct, high-intensity UV for the disinfection of hospital operating room air at the Duke University Hospital, after traditional methods had failed. Riley, in 1972, installed UV lamps in a school ventilation system dramatically reducing the incidence of measles, and subsequent applications enjoyed similar successes. Since then, UV-C has been successfully implemented in a number of appliances and devices to support inactivating microorganisms, such as bacteria, viruses and fungi.
The first UVC continuous disinfection robots were built ca. 15 years ago, mainly to decrease the number of HealthCare-Associated Infections (HAIs).
Exposure time to disinfect a room is a function of mainly 4 variables, these are:
Pathogen UV-C susceptibility (microbe-fluence)
Log Reduction Factor (LRF)
UV-C device radiation power (DRP)
Distance from UV-C device to the exposed microbial
Exposure Time = Φ (microbe-fluence, LRF, DPR, Distance)
COVID-19 is the respiratory disease caused by the SARS-CoV-2 virus that has generated outbreaks worldwide. Structurally, this virus is not unique and is similar to other coronaviruses such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). The SARS-CoV-2 has been identified as a new variant in the betacoronavirus family (Fisher 2020).
Every virus requires a certain dose of UV-C energy to disable their ability to perform vital cellular functions. The SARS-CoV-2 virus is now under ongoing ultraviolet susceptibility studies, but there is a common understanding that due to the fact that is a typical enveloped RNA virus, the dosage is expected to be similar to SARS-CoV-2 , but many other tests on related coronaviruses have been conducted over the years. Many tests on related virus have concluded that coronaviruses are highly susceptible to ultraviolet inactivation. This report reviews these studies and provides an estimate of the ultraviolet susceptibility.
|Virus type||Deactivation Dose (90%)||Source|
|Coronavirus||0,70 (mJ/cm2)||Walker 2007|
|Berne virus (coronaviridae)||0,70 (mJ/cm2)||Weiss 1986|
|Murine coronavirus (MHV)||1,50 (mJ/cm2)||Hirano 1978|
|Canine Coronavirus (CCV)||2,90 (mJ/cm2)||Saknimit 1988|
|Murine coronavirus (MHV)||2,90 (mJ/cm2)||Saknimit 1988|
|SARS Coronavirus CoV-P9||4,00 (mJ/cm2)||Duan 2003|
|Murine coronavirus (MHV)||10,30 (mJ/cm2)||Liu 2003|
|SARS Coronavirus (Hanoi)||13,40 (mJ/cm2)||Kariwa 2004|
|SARS Coronavirus (Urbani)||24,10 (mJ/cm2)||Darnell 2004|
As soon as SARS-CoV-2 virus deactivation dose is measured, SpeedyCare™ UV robot would incorporate that value into its database to recalculate the right timing. In the meantime, SpeedyCare™ UV robot would consider a dose of 50 mJ/cm2 for a deactivation rate of 99%.
This International Standard specifies minimum human safety requirements for the use of UVC lamp devices. It is applicable to in-duct UVC systems, upper-air in room UVC systems, portable in-room disinfection UVC devices, and any other UVC devices which may cause UVC exposure to humans. It is not applicable to UVC products used for water disinfection.
Maximum daily dose per person is set in 6 mJ/cm2. SpeedyCare UV robot includes a set of safety features, including motion sensors which ensure an immediate switch-off to prevent the operator from UV-C exposure. However, in case of direct exposure to UV-C and according this standard, any operator could be safely exposed every day to 1 min at a distance of 4 m from the device.
Despite of the evident low risk of exposure, we recommend the use protective clothing and goggles, typically used for occupational safety and health purposes.
Due to the high demand associated with the COVID 19 outbreak, we invite our customers to reach out us via this form. Our sales representatives will respond within the next 48 h. For any urgent enquiries please feel free to contact us on (+34) 917 676 505.