Ultraviolet Disinfection in the Healthcare Setting
Ultraviolet technology is not a new science .
In fact , it was discovered in 1845 by Arthur
Downes and T . P . Blunt , who observed that exposing test tubes with microbes to sunlight prevented growth of microorganisms .
By Mary Olivera , MHA , CRCST , CHL , FCS
• few weeks ago , I traveled to a healthcare
A facility in Kansas City to work on a performance
improvement project . I arrived at the airport early and went to the airline ’ s lounge to get some work done before my flight . To my surprise , the lounge was equipped with a UV-C disinfection box , which uses the power of ultraviolet light to disinfect electronic devices . This machine was similar to a toaster oven , both in appearance and ease of use . Next to it there was a set of instructions that travelers could follow to get their phones , tablets , and other small devices free of microorganisms .
As a sterile processing professional , I thought it would be amusing to observe how people interacted with the machine . Would they use it to disinfect their devices ? If so , would they follow the instructions for use ( IFU )? My observations revealed some amusing findings . Some people scrutinized the machine and walked away , while others used it with total confidence and ease . It ’ s likely those who used the machine already had some familiarity with it . Perhaps they were airline regulars or members of the medical community . But anyone outside of that group — mostly casual travelers — didn ’ t engage with the machine . Maybe the system was of no use to them , or they didn ’ t understand how to operate it .
Ultraviolet technology is not a new science . In fact , it was discovered in 1845 by Arthur Downes and T . P . Blunt , who observed that exposing test tubes with microbes to sunlight prevented growth of microorganisms . They also found that with increased light exposure times , test tubes remained free of bacteria . Since then , ultraviolet disinfection has been widely used in healthcare settings thanks to technological advancements . One example is the UV light in an adenosine triphosphate ( ATP ) reader , used to verify cleaning effectiveness . Another example is robotic UV-C equipment used to disinfect critical areas in hospital settings , such as the operating room .
What is ultraviolet germicidal radiation and how does it work ? A UV-C system emits an invisible light
that is shorter in wavelength than ordinary light . The ultraviolet germicidal irradiation ( UVGI ) spectrum consists of three parts : UV-C , the shortest wavelength ; UV-B , the next shortest ; and UV-A , which is closest to visible light . When applying ultraviolet radiation to a germicidal process , the UV-C has been found more effective than UV-B and UV-A radiation in inactivating some common viruses .
UV-C radiation penetrates the microbes to damage the cell ’ s deoxyribonucleic acid ( DNA ) and break apart the molecular bond , which prevents the microbiomes from duplicating . Ultraviolet germicidal irradiation can be effective when used in applications for disinfecting air , water , and hard surfaces . The most frequently used UVGI systems in hospital settings today are for surfaces , although air disinfection is gaining acceptance in areas where sterile air is needed , like the operating room .
How efficient are UVGI systems ? UV-C radiation is the most effective wavelength in destroying molecular bonds and rendering microbes incapable of survival and reproduction . However , its efficacy depends on distance , duration of exposure , and type of organism present .
●Distance : Manufacturers of UV-C germicidal disinfection equipment explain this concept using the Inverse Square Law principle ; the further the ultraviolet light has to travel ( distance from the lamp ), the less intense it becomes , thereby reducing its ability to penetrate and kill microbes . Therefore , the effectiveness of the UVGI depends on the intensity of the light and the distance from the object it is disinfecting .
●Duration : Most bacteria can be killed or destroyed in seconds using an UVGI ; however , there are many factors that influence the duration of the cycle . Each equipment manufacturer ’ s unique design and intended operation is defined in the IFU of the equipment and should be followed . Some factors that influence the duration of the cycle are the strength or wattage of the UV light bulb , distance from the