Dose222™ Far UV-C Indicator Cards
Dose222™ Far UV-C Indicator Cards
Dose222™ indicator cards are an easy, cost-effective way to visually verify that areas exposed to far UV-C are within the regulated dosage range. Calibrated to react to filtered far UV-C light at a wavelength of 222 nanometres, the cards facilitate regular dosage checks on emitters intended for the disinfection of occupied spaces, such as Ushio’s Care222® far UV-C disinfection light sources, without special training or expensive equipment.
The Dose222 indicator technology uses a specially-formulated, photo-chromatic ink at the centre of the card. The ink is highly-sensitive to 222 nm far UV-C light. As the centre dot receives far UV-C exposure, it will change colour in accordance with the level of dosage received. The colour is then matched to the visual key on the outer ring to determine the radiant energy density. A check mark will also appear in the centre dot after the card has received 4 mJ/cm2 of filtered far UV-C light.
Dose222 should be used on a regular basis, or at least once per week, in areas operating filtered far UV-C devices. Dose222 indicators are designed to provide a visual indication of applied far UV-C dosage within a treatment cycle and are not intended to be used as a substitute for microbiological disinfection verification. Dose222 cards must be stored at room temperature, away from direct sunlight and must not be reused.
| Species | Reported dose for 3-Log Reduction (mJ/cm2) |
|---|---|
| Bacteria | |
| E. coli [Escherichia. Coli O 157] | 9 |
| Salmonella [Salmonella enterica subsp. Enterica serovar Typhimurium] | 10 |
| MRSA Staphylococcus aureus [methicillin-resistant S. aureus] | 15 |
| Viruses | |
| SARS-CoV-2 [Original strain and N5021Y variant] | 3* |
| Influenza [Influenza A H1N1] | 6 |
| Feline Calicivirus [Feline calicivirus (FCV) strain F4] | 24 |
* SARS-CoV-2 dose reported to 97.7% reduction
References
1. Narita K, Asano K, Morimoto Y, Igarashi T, Hamblin MR, Dai T, Nakane A. Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds. J Photochem Photobiol B: Biol 178:10–18. 2018. https://pubmed.ncbi.nlm.nih.gov/29101868/ .
2. Narita K, Asano K, Morimoto Y, Igarashi T, Nakane A. Chronic irradiation with 222-nm UVC light induces neither DNA damage nor epidermal lesions in mouse skin, even at high doses. PLoS One 13:e0201259. 2018. https://pubmed.ncbi.nlm.nih.gov/30044862/.
3. Narita K, Asano K, Naito K, Ohashi H, Sasaki M, Morimoto Y, Igarashi T, Nakane A. 22-nm UVC inactivates a wide spectrum of microbial pathogens. J Hosp Infect. 2020 Mar 31. pii: S0195-6701(20)30129-8. doi: 10.1016/j.jhin.2020.03.030. 2020. https://www.sciencedirect.com/science/article/pii/S0195670120301298 .
4. Willie Taylor, Emily Camilleri, D. Levi Craft, George Korza, Maria Rocha Granados,Wendy W.K. Mok, Peter Setlow. DNA damage Kills Bacterial Spores and Cells Exposed to 222 nm UV Radiation. Appl. Environ. Microbiol. 2020. https://aem.asm.org/content/86/8/e03039-19.
5. Report_2019_0032, KRCS. Performance test for virus inactivation efficacy by virus inactivation. s.l. : Kisato Center for Environmental Science, 2019.
6. Welch D, Buonanno M, Grilj V, Shuryak I, Crickmore C, Bigelow AW, Randers-Pehrson G, Johnson GW, Brenner DJ. Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases. Sci Rep 8:2752. https://www.nature.com/articles/s41598-018-21058-w.
7. Buonanno, M., Welch, D., Shuryak, I. et al. Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses. Sci Rep 10, 10285 (2020. 2020. https://doi.org/10.1038/s41598-020-67211-2.
8. Hiroki Kitagawa MD, Toshihito Nomura MD, PhD , Tanuza Nazmul MBBS , Omori Keitaro MD, PhD , Norifumi Shigemoto MD, PhD , Takemasa Sakaguchi MD, PhD , Hiroki Ohge MD, PhD. Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination. AJIC: American Journal of Infection Control (2020). 2020. https://doi.org/10.1016/j.ajic.2020.08.022.
9. Welch D, Buonanno M, Shuryak I, Randers-Pehrson G, Spotnitz HM, Brenner DJ. Effect of far ultraviolet light emitted from an optical diffuser on methicillin-resistant Staphylococcus aureus in vitro. PLOS One 13:e0202275. 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6086454/ .
10. Sachiko Kaidzu, Kazunobu Sugihara, Masahiro Sasaki, Aiko Nishiaki, Tatsushi. Evaluation of acute corneal damage induced by 222-nm and. Free Radical Research, 53:6, 611-617. 2019. https://doi.org/10.1080/10715762.2019.1603378.
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