Qualitative Assessment of Different Face Masks using Povidone-Iodine in Comparison to Standard Saccharin Method
DC58-DC63
Correspondence
Dr. Sapna Malik,
C 1201, Jal Vayu Vihar, ADS Marg, Near Hiranandani Gardens, Powai, Mumbai-400076, Maharshtra, India.
E-mail: sapna@somaiya.edu
Introduction: The World Health Organisation (WHO) recommends that N95 masks should be used by healthcare workers and patients. Given the shortage, extended use and reuse of masks, it becomes imperative to test the filtration efficacy. Surgical masks and cloth covers should also be assessed for their protection factor, since their use is more prevalent among the general population, and these masks are not certified by National Institute for Occupational Safety and Health (NIOSH). Occupational Safety and Health Administration (OSHA) is the authority for the standard testing and certification of Filtering Face Pieces (FFPs) in the USA; its equivalent in India is the Bureau of Indian Standards (BIS). The BIS recently relaxed the certification guidelines for both N95 and Surgical Masks; thus, even certified masks may prove to be inefficient.
Aim: To assess different face masks using povidone-iodine in comparison to standard saccharin method.
Materials and Methods: A cross-sectional study was carried out in a tertiary care hospital in western India from August 2021 to October 2021. A novel, qualitative (and semi-quantitative) function test using an aerosol of iodine solution and detector strips of starch-iodide paper was studied to prove for efficacy of masks by 15 volunteers and various masks of different types (surgical, N95, cloth) over three months. This method provides a rapid, simple and cost-effective assessment of respirator efficacy.
Results: Thirty five masks (N95, Surgical, Cloth and Silver nanoparticle) were tested, of which N95 - 90% pass the test. A 2 out of 5 trials of the double layered cloth mask + surgical mask combination passed both the iodine and saccharin tests. The sensitivity and specificity of proposed iodine test in comparison to standard saccharin test were (10/10, 100%) and (22/25, 88%).
Conclusion: Povidone-iodine method is a qualitative assessment which is a crude indicator of mask function as the masks that fail both tests will provide some degree of protection from airborne particles, and concentrations of many respiratory organisms. The N95 masks along with the double masks (surgical and cloth) passed the tests proving their efficacy.