The UV Light Deception

Comments – Figure 2:  The data shown above in Figure 2 is important, because it shows the Log Reduction data at four (4) feet after ten (10) minutes of UV-C exposure, for bacteria that were spread over different sized disks.  The Log Reduction data only ranged from about (0.6 - 2.0) for C. difficile spores.

Per Federal standards, when a test surface is contaminated with 1,000,000 bacteria spores, and a Log Reduction of about 0.6 Log to 2.0 Log is shown for C. difficile spores, between about 10,000 to 100,000+ C. difficile survivors will remain! This is NOT disinfection, decontamination, or sterilization.  OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Also in Figure 2, the Log Reduction data ranged from about (1.0 – 5.0) for the vegetative bacteria (non-spore) MRSA (Staphylococcus aureus), at four (4) feet after ten (10) minutes of UV-C exposure.

Per Federal standards, when a test surface is contaminated with 1,000,000 bacteria, and a Log Reduction of about 1.0 Log to 5.0 Log is obtained for MRSA (Staphylococcus aureus), that means there will still be between about 10 to 100,000 MRSA survivors remaining that can grow their population exponentially and infect people.  This is NOT disinfection, decontamination, or sterilization.  OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Comments – Figure 3:  As shown below in Figure 3, the test media is exposed at four (4) feet for ten (10) minutes at different orientations to the UV-C light including at: zero (0) degree horizontal orientation, forty-five (45) degree orientation, and ninety (90) degree vertical orientation.  The test results show Log Reduction data that ranged from only about (1.3 - 2.2) for C. difficile spores depending on the test orientation.  The test results also showed Log Reduction data that ranged from only about (3.3 – 4.8) for MRSA (Staphylococcus aureus) depending on the test orientation.

When a test surface is contaminated with 1,000,000 bacteria spores, and a Log Reduction of about 1.3 Log to 2.2 Log is shown for C. difficile spores, that means there will still be between about 1,000 to 10,000+ C. difficile survivors remaining. Pathogenic bio-burden is a health risk.  When a Log Reduction of about 3.3 Log to 4.8 Log is obtained for MRSA, that means there will still be between about 10 to 100+ MRSA survivors remaining that can exponentially increase their population.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g).  (2)(3)

Comments – Figure 1:  The data shown above in Figure 1 is important, because it shows the Log Reduction data at four (4) feet after ten (10) minutes, and also forty (40) minutes, of UV-C exposure, for the Tru-D UV-C product, and the Clorox Optimum UV-C product, for both MRSA bacteria and C. difficile spores.

The Log Reduction for C. difficile spores was about 1.7 Log for Tru-D UV-C, and 1.6 Log for Clorox UV-C, after ten (10) minutes of treatment.

Per Federal standards, when a test surface is contaminated with 1,000,000 bacteria spores, a Log Reduction of about 1.7 Log with Tru-D means there will be more than 10,000 C. difficile survivors remaining that can infect people, and a Log Reduction of about 1.6 Log with Clorox Optimum UV-C means there will also be more than 10,000 C. difficile spores remaining that can infect people.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

The Log Reduction for C. difficile spores was about 3.4 Log for Tru-D UV-C, and 3.2 Log for Clorox UV-C, after forty (40) minutes of treatment.

Per Federal standards, when a test surface is contaminated with 1,000,000 bacteria spores, a Log Reduction of about 3.4 Log with Tru-D means there will be more than 100+ C. difficile survivors remaining.  A Log Reduction of about 3.2 Log with Clorox Optimum UV-C means there will also be more than 100+ C. difficile spores remaining.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Conclusion:  First, this study demonstrates that even after 40 minutes, both Tru-D's UV-C product, and Clorox's Optimum UV-C product, were still NOT able to reach a 6.0 Log performance level for either C. difficile or MRSA, and neither of these products can claim disinfection, hospital disinfection, or sterilization, per Federal regulations. (2)(3)

This study also reinforces the previously reported research data that UV-C light surface treatment is adversely impacted by not only the exposure time to the UV-C light source, but also the orientation or angles of the surfaces to the UV light source.

More importantly, per the United States EPA, these independent data show that UV-C room treatment systems do NOT meet the legal definitions for disinfection, hospital disinfection, sterilization, or as a sporicidal against C. difficle, per Federal regulations. (2)(3)

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3)  William Rutala, PhD, MPH, and David Weber, MD, MPH et al.:  "Room Decontamination with UV Radiation", Infection Control & Hospital Epidemiology, October 2010, Vol. 31, No. 10. (7)

"The efficacy of UV irradiation is a function of many different location and operational factors, such as intensity, exposure time, lamp placement, and air movement patterns."

 

“In our test room, the effectiveness of UV-C radiation in reducing the counts of vegetative bacteria on surfaces was more than 99.9% in approximately 15 minutes, and the reduction in C. difficile spores was 99.8% within 50 minutes.”

Comment:  According to Federal regulations, this is NOT disinfection, decontamination, or sterilization, that requires a 6.0 Log reduction or Percent Reduction of 99.9999%, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)  The 99.8% and 99.9% reported percent reductions only equates to a Log Reduction of about 3.0 Log, leaving viable organisms.

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Comments – Table 1:  The C. difficile spore data in Table 1 above shows a Log Reduction range of (3.71 to 4.37) for direct UV-C light exposure, and (1.46 to 3.40) for indirect UV-C light exposure.

If a test surface is contaminated with 1,000,000 bacteria, per Federal standards, and a Log Reduction of about 3.71 Log to 4.37 Log is achieved for C. difficile spores with exposure to direct UV-C light, that means there will still be between about 10 to 100+ C. difficile spore survivors remaining on surfaces.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Also, if a test surface is contaminated with 1,000,000 bacteria, per Federal standards, and a Log Reduction of about 1.46 Log to 3.40 Log is achieved for C. difficile spores with exposure to indirect UV-C light, that means there will still be between about 100 to 10,000+ C. difficile spore survivors remaining on surfaces.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards:  OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

The MRSA (Staphylococcus aureus) data in Table 1 above shows a Log Reduction range of (3.13 to 5.50) for direct UV-C light exposure, and (2.44 to 5.25) for indirect UV-C light exposure.

If a test surface is contaminated with 1,000,000 bacteria, per Federal standards, and a Log Reduction of about 3.13 Log to 5.50 Log is achieved for MRSA with exposure to direct UV-C light, that means there will still be between about 1 to 100+ MRSA survivors remaining that can exponentially increase their population and infect a person.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

If a test surface is contaminated with 1,000,000 bacteria, per Federal standards, and a Log Reduction of about 2.44 Log to 5.25 Log is achieved for MRSA with exposure to indirect UV-C light, that means there will still be between about 1 to 1,000+ MRSA survivors remaining that can exponentially increase their population.  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Conclusion:  This study reinforces the current research data that UV-C light treatment process is adversely impacted by shadowed surfaces.  More important, per the United States EPA and Federal regulations, this data shows that UV-C room treatment system results and claims do NOT meet the legal definitions for disinfection, hospital disinfection, sterilization, or as a sporicidal against C. difficle. (2)(3)

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4)  John M. Boyce, MD, et al.: “Impact of Room Location on UV-C Irradiance and UV-C Dosage and Antimicrobial Effect Delivered By A Mobile UV-C Light Device”, Infection Control & Hospital Epidemiology, June 2016, Vol. 37, NO. 6. (5)

“UV-C irradiance, UV-C dosage, and antimicrobial effect achieved in patient rooms varied significantly, depending on the location and orientation of surfaces relative to the UV-C device.”

 

“With 15-minute cycles, counts of MRSA on disks were reduced by 3 to >4 log10 and VRE by 1–4 log10 at varying distances and orientations relative to the UV-C device (Table 2).  Log10 reductions of C. difficile were highest (2 to >4 log10 ) when disks were facing the device at a distance of 1.3 m and were lowest (0–1 log10 ) when disks were in a shaded area 3.3 m from the device (Table 2).”  (emphasis added)

Comments -  Referring below, to Table 2 and the data column for a 15 minute cycle (far right), the UV-C device was NOT able to achieve even close to a 6 Log Reduction for disinfection, in direct light at even 1.3 meters, for vegetative bacteria like MRSA, and VRE, as well as C. difficile spores.  Instead, the UV-C product achieved a maximum performance of only around a >4.0 Log Reduction.  This is NOT disinfection, decontamination, or sterilization, as defined by the EPA.  (2)(3)

However, more concerning was how the UV light performance was significantly degraded at even a short distance (1.3 meters) in situations where the MRSA, and VRE, as well as C. difficile spores, were exposed to the UV light at a zero (0) degree angle for a 15 minute cycle, providing a low Log Reduction range of only (3.0 – 4.0) for VRE, a low Log Reduction of only around >4.0 Log for MRSA, and a low Log Reduction range of only (2.0 – 4.0) for  C. difficile!

* NOTE:  The data in Table 2 represents the range of “Log Reduction” data for MRSA, VRE, and Clostridium difficile (C. Difficile) spores, where the innoculated disks were placed at six (6) different locations with respect to the UV-C device: direct light, angled light at zero (0) degrees, and shaded, at two (2) different distances:  1.3 meters (4 feet) and 3.3 meters (10 feet).

Even more alarming regarding Table 2 above, is how the UV light performance was significantly degraded at even a short distance (1.3 meters) in situations where the bacteria and spores were shaded from the UV light for a 15 minute cycle, providing an even lower Log Reduction range of only (2.0 – 3.0) for VRE,  a low Log Reduction of only around >4.0 Log for MRSA, and an extremely low Log Reduction range of only (1.0 – 2.0) for C. difficile.

Finally, the UV light performance was very degraded at ten (10) feet or (3.3 meters) in situations where the bacteria and spores were shaded from the UV light providing an extremely low Log Reduction range of only (1.0 – 2.0) for VRE, a low Log Reduction of only around 3.0 Log for MRSA, and a shockingly low Log Reduction range of only (0 – 1.0) for C. difficile!  When exposed to the UV light at a zero (0) degree angle, for a 15 minute cycle, only a shockingly low Log Reduction range of (0 – 2.0) was achieved for C. difficile.

However,  Cadnum and Dr. Donskey et al. (2016) (6), show that even a 40 minute exposure time in the most favorable exposure orientation of facing the UV-C light (sold by Tru-D and Clorox), at only 1.22 meters, only provides a best case Log Reduction of about 5.3 Log for the vegetative bacteria (non-spore) MRSA (Staphylococcus aureus), and an even worse best case Log Reduction of only 3.3 Log for C. difficle spores.  Obviously, after even 40 minutes of exposure, UV-C cannot meet the Federal standards for a 6.0 Log Reduction to claim Disinfection, and UV-C cannot meet the Federal Standards of “no growth” to claim efficacy for C. difficle spores.

Conclusion:  The various data shown above in Table 2 and provided by Dr. Boyce et al. (2016), show that a UV-C light room treatment system is adversely impacted by surface angles, shadowing, and distance from the UV light source, and does NOT meet the legal definitions for disinfection, hospital disinfection, sterilization, or as a sporicidal against C. difficle, per Federal laws. (2)(3)

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5)  Michelle Nerandzic, and Curtis Donskey, MD et al.:  "Evaluation of a Pulsed Xenon Ultraviolet Disinfection System for Reduction of Healthcare-Associated Pathogens in Hospital Rooms", Infection Control & Hospital Epidemiology, February 2015, Vol. 36 No 2. (4)

“As shown in Figure 3, the efficacy of PX-UV decreased as distance from the device increased. For each pathogen, significantly less reduction was achieved at 4 feet versus 6 inches and at 10 feet versus 4 feet (P < .05 for each comparison) .... At 10 feet from the device, the log 10 CFU reduction was less than 1 log 10 CFU/cm 2 for each pathogen."  (emphasis added)

 

“The efficacy of PX-UV was dramatically reduced as the distance from the device was increased.” (emphasis added)

* Important Note:  PX-UV = Pulsed UV product, sold by Xenex

Comments – Figure 3:  The data shown above in Figure 3 is important, because it shows the Log Reduction data after ten (10) minutes of PX-UV exposure, for MRSA and VRE bacteria, and C. difficile spores, at the following distances and conditions: four (4) feet, four (4) feet (and shaded), and ten (10) feet.  The Log Reductions are as follows:

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4 ft.      10 minutes                  C. difficile spores       0.5   Log Reduction (aprox.)

4 ft.      10 minutes (shaded)    C. difficile spores       0.6   Log Reduction (aprox.)

10 ft.    10 minutes                   C. difficile spores       0.2   Log Reduction (aprox.)

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4 ft.      10 minutes                  MRSA                        1.8   Log Reduction (aprox.)

4 ft.      10 minutes (shaded)    MRSA                        1.5   Log Reduction (aprox.)

10 ft.    10 minutes                   MRSA                        0.7   Log Reduction (aprox.)

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4 ft.      10 minutes                  VRE                            0.6   Log Reduction (aprox.)

4 ft.      10 minutes (shaded)    VRE                            0.4   Log Reduction (aprox.)

10 ft.    10 minutes                   VRE                            0.1   Log Reduction (aprox.)

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According to these data from Figure 3, the Xenex PX-UV light provided extremely low Log Reductions, and NONE of these Log Reduction values (C-diff. Spores and MRSA) are even close to meeting the Federal requirements to claim: disinfection, hospital disinfection, or sterilization, per the following EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)  The Xenex PX-UV light was NOT even able to achieve a Log Reduction anywhere close to the 5.0 Log amount of inoculum applied to the test slides.

Also, the Figure 3 data shows how drastically diminished the Log Reduction values were, when observed at a distance of ten (10) feet from the UV light source.  The highest Log Reduction recorded was for MRSA, with a Log Reduction of only 0.7 Log, which is no where even close to the 5.0 Log amount of inoculum applied to the test slides, and certainly does NOT meet the EPA standards.

Comments – Figure 4:  The data shown below in Figure 4 shows the low Log Reduction performance for both the Xenex PX-UV light product, and the continuous mercury UV-C light product.

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4 ft.      10 minutes                  C. difficile spores       1.0   Log Reduction (aprox.) - UV-C

4 ft.      10 minutes                   C. difficile spores       0.5   Log Reduction (aprox.) - Xenex, PX-UV

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4 ft.      10 minutes                  MRSA                        3.1   Log Reduction (aprox.) - UV-C

4 ft.      10 minutes                   MRSA                        1.8   Log Reduction (aprox.) - Xenex, PX-UV

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4 ft.      10 minutes                  VRE                            3.6   Log Reduction (aprox.) - UV-C

4 ft.      10 minutes                   VRE                            0.6   Log Reduction (aprox.) - Xenex, PX-UV

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According to the data above from Figure 4, both the Xenex PX-UV light and the continuous mercury UV-C light product, failed to produce Log Reduction values (C-diff. spores and MRSA) that can satisfy the Federal requirements to claim: disinfection, hospital disinfection, or sterilization. OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

The data shown above in Figure 4 is important, because it shows the poor Log Reduction data at four (4) feet after ten (10) minutes of PX-UV and UV-C light exposure.  The Log Reduction data was reported at an extremely low Log Reduction of 0.5 Log for C. difficile spores by the Xenex PX-UV product, and an extremely low Low Reduction of 1.0 Log for C. difficile spores by the continuous mercury UV-C light product.

If a test surface is contaminated with 1,000,000 bacteria spores, and a Log Reduction of only 0.5 Log is obtained by Xenex PX-UV for C. difficile spores, that means more than 100,000+ C. difficile spore survivors will remain on the treated surfaces!  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

In addition, the Figure 4 data shows that when a test surface is contaminated with 1,000,000 bacteria spores, and a Log Reduction of only 1.0 Log for UV-C light is achieved for C. difficile spores, that means 100,000 C. difficile spores will survive on the surface!  This is NOT disinfection, decontamination, or sterilization, per the EPA standards: OCSPP 810.2200 (3), OCSPP 810.2200 (5) & (6), and OCSPPP 810.2100 (d)(2) and (g). (2)(3)

Conclusion:  This study reinforces the previously reported research data that both the Xenex PX-UV light product, and the continuous mercury UV-C light product, are adversely impacted by the distance of the treated surfaces to the UV light source, and do NOT meet the EPA performance requirements for disinfection, hospital disinfection, sterilization, or as a sporicidal against C. difficle. (2)(3)  Any claim of being able to “disinfect an entire room” flies in the face of this data.

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6)  Louis Stokes VA Hospital, Cleveland, OH, 2017, FedBizOpps, Solicitation Number: VA250-17-Q-0774

“The number of C-Diff rooms has increased, despite current sanitation procedures …. The Louis Stokes Cleveland VA Medical Center currently utilizes the Tru-D Smart UVC Part Number: 0367AOLF, but we are still not getting the desired results and the level of disinfection expected to especially hard to reach areas.”  (emphasis added)  (1)

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7)  Irene Louh, MD, PhD, and Henry Ting, MD, et al.: “Clostridium Difficile Infection in Acute Care Hospitals: Systematic Review and Best Practices for Prevention”, Infection Control & Hospital Epidemiology, April 2017, Vol. 38, NO. 4.  (10)

“Terminal cleaning with UV light in addition to bleach cleaning had uncertain efficacy.” (emphasis added)

“Haas et. al. instituted pulsed UV treatment in addition to terminal bleach disinfection in a large urban hospital, with minimal incremental reduction in CDI rates.” (emphasis added)

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8)  U.S. CDC - Clinical Alert to U.S. Healthcare Facilities - June 2016, U.S. Centers For Disease Control & Prevention, “Global Emergence Of Invasive Infections Caused By The Multidrug-Resistant Yeast Candida auris”, June 24, 2016 (last updated: 2017). (9)

https://www.cdc.gov/fungal/diseases/candidiasis/candida-auris-alert.html

“The Centers for Disease Control and Prevention (CDC) has received reports from international healthcare facilities that Candida auris, an emerging multidrug-resistant (MDR) yeast, is causing invasive healthcare-associated infections with high mortality. Some strains of C. auris have elevated minimum inhibitory concentrations (MICs) to the three major classes of antifungals, severely limiting treatment options." (emphasis added)

 

"Environmental Cleaning – Anecdotal reports have suggested that C. auris may persist in the environment. Healthcare facilities who have patients with C. auris infection or colonization should ensure thorough daily and terminal cleaning and disinfection of these patient’s rooms using an EPA-registered hospital grade disinfectant with a fungal claim." (emphasis added)

Comment:  The situation with C. auris, is a serious threat to human safety, and very specific standards are currently specified by the CDC, to address C. auris.  UV-C and PX-UV are NOT mentioned by the CDC as an approved treatment to address the C. auris threat.  Only disinfectants that can meet the United States EPA standards for hospital disinfection (OCSPP 810.2200 (5) & (6)), and fungal claims (OCSPP 810.2200 (9)(e)), are approved by the CDC to counter C. auris.