Your browser doesn't support javascript.
Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination.
Su, Alison; Grist, Samantha M; Geldert, Alisha; Gopal, Anjali; Herr, Amy E.
  • Su A; Department of Bioengineering, University of California, Berkeley, Berkeley, California, United States of America.
  • Grist SM; University of California, Berkeley-University of California, San Francisco Graduate Program in Bioengineering, Berkeley, California, United States of America.
  • Geldert A; N95DECON.org.
  • Gopal A; Department of Bioengineering, University of California, Berkeley, Berkeley, California, United States of America.
  • Herr AE; N95DECON.org.
PLoS One ; 16(1): e0243554, 2021.
Article in English | MEDLINE | ID: covidwho-1067394
ABSTRACT
With COVID-19 N95 shortages, frontline medical personnel are forced to reuse this disposable-but sophisticated-multilayer respirator. Widely used to decontaminate nonporous surfaces, UV-C light has demonstrated germicidal efficacy on porous, non-planar N95 respirators when all surfaces receive ≥1.0 J/cm2 dose. Of utmost importance across disciplines, translation of empirical evidence to implementation relies upon UV-C measurements frequently confounded by radiometer complexities. To enable rigorous on-respirator measurements, we introduce a photochromic indicator dose quantification technique for (1) UV-C treatment design and (2) in-process UV-C dose validation. While addressing outstanding indicator limitations of qualitative readout and insufficient dynamic range, our methodology establishes that color-changing dosimetry can achieve the necessary accuracy (>90%), uncertainty (<10%), and UV-C specificity (>95%) required for UV-C dose measurements. In a measurement infeasible with radiometers, we observe a striking ~20× dose variation over N95s within one decontamination system. Furthermore, we adapt consumer electronics for accessible quantitative readout and use optical attenuators to extend indicator dynamic range >10× to quantify doses relevant for N95 decontamination. By transforming photochromic indicators into quantitative dosimeters, we illuminate critical considerations for both photochromic indicators themselves and UV-C decontamination processes.
Subject(s)

Full text: Available Collection: International databases Database: MEDLINE Main subject: Respiratory Protective Devices / Decontamination / N95 Respirators Type of study: Diagnostic study / Prognostic study / Qualitative research Limits: Humans Language: English Journal: PLoS One Journal subject: Science / Medicine Year: 2021 Document Type: Article Affiliation country: Journal.pone.0243554

Similar

MEDLINE

...
LILACS

LIS


Full text: Available Collection: International databases Database: MEDLINE Main subject: Respiratory Protective Devices / Decontamination / N95 Respirators Type of study: Diagnostic study / Prognostic study / Qualitative research Limits: Humans Language: English Journal: PLoS One Journal subject: Science / Medicine Year: 2021 Document Type: Article Affiliation country: Journal.pone.0243554