ABSTRACT
The demand for face masks is increasing exponentially due to the coronavirus pandemic and the particulate matter (PM) in the atmosphere. As a result, an enormous number of disposable mask filters have been produced and discarded, contributing to plastic waste. Underprivileged people who cannot afford to purchase commercial face masks have started making fabric masks with waste clothing;however, this material does not effectively filter viruses or PM. Therefore, in this study, a chitosan coating was applied to clothing fabrics to increase their effectiveness as face masks. The improvement in the PM removal efficiency owing to the chitosan polymer was observed for stocking, innerwear, and bamboo materials, but not for cotton. Furthermore, chitosan prepared in the form of a nanowhisker (CsW) achieved a PM 2.5 removal efficiency of 96% in a five-layer cotton fabric. In addition, a commercial biodegradable poly(lactic acid) filter was coated with CsW, which increased the PM 2.5 removal efficiency from 67% to 83%. Additionally, microbial growth was significantly suppressed in the chitosan-coated fabrics, and the degree to which it was suppressed depended on the coating concentration. The study will aid in the utilization of face mask filters that are more sustainable, efficient, and widely accessible. © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.
ABSTRACT
Background: Demand for alcohol-based products, including gel- and aqueous-type hand sanitizers, room sprays, and mouthwashes, has rapidly increased during the ongoing COVID-19 pandemic because of their microbicidal properties. However, toxic methanol can be found from the intentional addition of methanol by manufacturers and invariable production during the manufacturing of alcohol (ethanol). Although the FDA has recommended that such products should contain less than 630 ppm of methanol, it is only a temporary measure established specifically to regulate such products during the current COVID-19 pandemic and hence is not strictly regulated. Objective: This study aims to detect and quantify the level of methanol in alcohol-based products. However, some manufacturers unethically add methanol to their products and promote them as methanol-free. Besides, they do not provide proficiency and toxicity test results. Therefore, these kinds of products need to be analyzed to determine if they are acceptable to use. Methods: This study qualitatively and quantitatively investigates the amount of methanol in commercial alcohol-based products using a newly developed headspace gas chromatography/mass spectrometry method. Moreover, alcoholic beverages which contain methanol are analyzed to be compared with the levels of methanol in alcohol-based products and determine if their methanol levels are acceptable. Results: Methanol concentrations in gel-type hand sanitizers (517 ppm) and mouthwashes (202 ppm) were similar to those in white wine (429 ppm) and beer (256 ppm), respectively, while that of aqueous-type hand sanitizers (1139 ppm) was 1.5 times more than that of red wine (751 ppm). Conclusion: Methanol levels in most of the alcohol-based products did not exceed the FDA-recommended limit.