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 . object being disinfected , location of the UVGI , and the type of microorganism ( s ).
●Exposure : As in steam sterilization or low-temperature sterilization processes , direct exposure to the UV light is required when using an UVGI . Surfaces must be cleaned because contaminants such as bodily fluids , soils , and dust can inactivate the effectiveness of the ultraviolet radiation . Also , the UV radiation light must not be blocked . This includes microshadows , which can limit the disinfection efficacy of the UVGIs . The size of the room as well as fixed equipment must also be taken into consideration .
Shortage of personal protection supplies and the increase in microbial contamination during the COVID-19 pandemic emphasized the need for quick and effective processes to help eradicate the spread of the virus . UVGI proved to be an effective methodology to reprocess and increase availability of N95 respirators and other personal protective equipment during the Food and Drug Administration ( FDA )’ s Emergency Use Authorization ( EUA ).
The use of handheld devices in the hospital settings has increased due to the need to quickly communicate with patient relatives and medical teams . A study addressing microbial contamination of mobile phones found that 72.6 percent of mobile phones revealed positive growth of one or more microorganisms . One hundred three mobile phones ( 39.8 percent ) were contaminated with one microbe , while 85 ( 32.8 percent ) were contaminated with more than one organism . Some of the organisms found on the mobile devices were coagulase-negative Staphylococci ( CoNS ), methicillin-resistant Staphylococcus aureus ( MRSA ), Pseudomonas aeruginosa , and Bacillus subtilis . These organisms are a major threat to patients who are vulnerable , immunocompromised , or elderly . Mobile device cross-contamination presents an infection control challenge to the hospital .
The infection preventionist realizes the practicality — or impracticality — of frequently wiping mobile devices to provide protection . To achieve required decontamination by wiping , each side of the device needs to be thoroughly wiped and left wet based on the contact time of the wipes , which can range from 1 to 3 minutes . The process of wiping both sides and waiting up to 6 minutes ( 3 minutes per side ) is long and not conducive to adherence .
Other uses for ultraviolet light are to disinfect-critical areas such as operating rooms and sterile processing departments . After the terminal cleaning is completed , robot-like UV disinfectors are placed in strategic locations of the surgical suite to perform the environmental disinfection process . Many healthcare facilities have expanded the use of these UVGIs to other areas of the hospital such as the sterile processing department ( SPD ), intensive care unit ( ICU ) and the emergency department ( ED ). It is essential to understand that the process is not effective if there is visible soil on the surfaces . Cleaning must always be the first step in the process .
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The air that is vented into critical areas such as a surgical procedure room can also be disinfected by using UVGI to prevent transmission of airborne infections . There are UVGI systems designed to disinfect the air as it flows through the ducts of the HVAC system ; there are also less complex systems that work independently of HVAC filtration status and are mounted in the ceiling to address the static air in the room , squams , floating bacteria , and viruses .
Are ultraviolet germicidal irradiation devices safe to use ? Are there any risks to humans ? Can the process cause damage to the medical equipment or surfaces ? Before purchasing any type of equipment , the user must take the following into consideration :
●Evaluate what the hospital needs and the intended use of the product . Consider if the UVGI can meet the specific requirements , such as disinfecting a large area or individual devices .
●What type of UV-C lamps does the equipment use ? Some devices use lamps that generate ozone that can irritate the respiratory system and others use UV-C lamps that contain mercury that may cause damage or discoloration of medical equipment and surfaces .
●Assess the types of construction material on fixed equipment , as UV-C can deteriorate some plastics , polymers , and textiles .
●Skin and eye injury may occur from direct exposure to UV radiation . Comprehensive training should be provided to all users and the staff in general when ultraviolet germicidal irradiation disinfectors are purchased . Staff must understand how to use these machines safely and they can be used when humans are in the space that is being disinfected .
●Ensure the manufacturer of the device provides comprehensive training , the equipment instructions for use , all the related material for the operation and safety risks of the equipment .
UV-C germinal disinfectors have been proven to be effective against COVID-19 virus and other bacteria resistant to antibiotics . There are many UVGI options for healthcare facilities , whether for air , water , or surface disinfection . It ’ s important to do your research to ensure the UVGI you select meets your specific needs . But no matter how effective the UVGIs are , we always must employ the basic steps of cleaning because anything that is not clean to begin with cannot be disinfected .
Mary Olivera , MHA , CRCST , CHL , FCS , has actively participated in the monitoring , surveying and training interdepartmental staff in the proper cleaning , decontamination and sterilization practices and has been highly committed to the standardization of interdepartmental processes . Currently , she is the president and CEO for OSPECS Consulting , LLC . a company dedicated to facilitating process re-engineering in healthcare organizations .
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