Are Disinfectants for the Prevention and Control of COVID-19 Safe?

Cleaning products: Their chemistry, effects on indoor air quality, and implications for human health

The use of cleaning and disinfecting products both at work and at home increased during the COVID-19 pandemic. Those products often include surfactants, acids/bases, carcinogens such as chloroform, and endocrine-disrupting chemicals, such as cyclosiloxanes, phthalates, and synthetic fragrances, which may cause harmful health effects among professional cleaners as well as among people exposed at home or in their workplaces. The aim of this study was to synthesize the effects of the commonly used chemical, surface cleaning and disinfecting products on indoor air quality, focusing on chemical and particulate matter pollutants, exposure, and human health in residential and public buildings. We also provide a summary of recommendations to avoid harmful exposure and suggest future research directions. PubMed, Google Scholar, Scopus, and Web of Science (WoS) were used to search the literature. Analysis of the literature revealed that the use of cleaning products and disinfectants increase occupants' exposure to a variety of harmful chemical air contaminants and to particulate matter. Occupational exposure to cleaning and disinfectant products has been linked to an increased risk of asthma and rhinitis. Residential exposure to cleaning products has been shown to have an adverse effect on respiratory health, particularly on asthma onset, and on the occurrence of asthma(-like) symptoms among children and adults. Efforts to reduce occupants' exposure to cleaning chemicals will require lowering the content of hazardous substances in cleaning products and improving ventilation during and after cleaning. Experimentally examined, best cleaning practices as well as careful selection of cleaning products can minimize the burden of harmful air pollutant exposure indoors. In addition, indirect ways to reduce exposure include increasing people's awareness of the harmfulness of cleaning chemicals and of safe cleaning practices, as well as clear labelling of cleaning and disinfecting products.

Electrolyzed Hypochlorous Acid (HOCl) Aqueous Solution as Low-Impact and Eco-Friendly Agent for Floor Cleaning and Sanitation

Recently, the use of disinfectants has been becoming a diffused and sometimes indiscriminate practice of paramount importance to limit the spreading of infections. The control of microbial contamination has now been concentrated on the use of traditional agents (i.e., hypochlorite, ozone). However, their prolonged use can cause potential treats, for both human health and environment. Currently, low-impact but effective biocides that are prepared in a way that avoids waste, with a very low toxicity, and safe and easy to handle and store are strongly needed. In this study, produced electrochemically activated hypochlorous (HOCl) acid solutions are investigated and proposed, integrated in a scrubbing machine for floor cleaning treatment. Such an innovative machine has been used for floor cleaning and sanitation in order to evaluate the microbial charge and organic dirt removal capacity of HOCl in comparison with a machine charged with traditional Ecolabel standard detergent. The potential damage on floor materials has also been investigated by means of Scanning Electron Microscope (SEM). A comparative Life Cycle Assessment (LCA) analysis has been carried out for evaluating the sustainability of the use of the HOCl-based and detergent-based machine.

Evaluation of public awareness and performance toward the safe use of household disinfectants-cleaners to prevent COVID-19 in the Emirate of Abu Dhabi

Introduction

Disinfection is one of the most effective hygienic practices that would limit the spread of the Coronavirus Disease (COVID-19) through deactivating the coronavirus on contaminated skin, supplies, and surfaces. However, the type and concentration of disinfectants should be carefully selected to avoid damaging surfaces and to limit the side effects of these chemicals on household members and users. The aim of this study is to assess the public levels of awareness and performance concerning the safe use of household cleaning products and disinfectants during the spread of COVID-19 in the Emirate of Abu Dhabi.

Methods

The cross-sectional study was conducted between October and December 2021 among 750 residents of Abu Dhabi, Al Dhafrah, and Al-Ain regions. A google survey was distributed electronically for the online recruitment of the general population. Mann-Whitney and Kruskal-Wallis tests were used to determine whether significant differences exist in the levels of awareness and performance with regard to gender, region, education level, and diagnosis with COVID-19. Spearman correlation was used to test if any correlation existed between levels of awareness and performance. Kruskal-Wallis test was also used to check if significant differences exist in the mean score of performance with respect to irritation-to-poisoning symptoms.

Results

The study population recorded a lower mean score of awareness (5.37 out of 12) than performance (11.75 out of 16). The majority of the study population claimed a minimum of one irritation-to-poisoning symptom during the handling of household cleaners and disinfectants. Significant differences exist in the awareness and performance mean scores among various educational levels (P < 0.001). The level of awareness was statistically significant with regard to infection with SARS-CoV-2 (P < 0.05). Also, the level of performance was significantly different between males and females (P < 0.001). Kruskal-Wallis test showed that the mean score of performance is statistically significant with all the studied irritation-to poisoning symptoms (P < 0.05).

Conclusions

Awareness campaigns and training programs are recommended to address the safe use of household cleaning products and disinfectants in the United Arab Emirates (UAE).

Development of chlorine dioxide sustained-release device using carboxymethyl cellulose-polyvinyl alcohol-β-cyclodextrin ternary hydrogel and a new sustained-release kinetic model

Owing to unique physiochemical and biological properties as well as the ability to be combined with a wide variety of materials for both biocompatibility and hydrophilia, carboxymethyl cellulose (CMC) is an excellent choice as a carrier. Loading Chlorine dioxide (ClO₂) into biodegradable carrier for its good disinfection performance and high safety factors has attracted significantattention. Therefore, in this study, we used ClO₂ as a model drug, and a sustained-ClO₂-gas-release gel was developed from degradable materials, such as carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and β-cyclodextrin (βCD), through a simple and benign crosslinking strategy. Notably, the gel had sustained-release property in a wide temperature range of 4-35 ℃ and released ClO₂ gas effectively for more than 30 days. Furthermore, a loss factor was proposed based on the incomplete release of the drug in the sustained release process to a chieve a good fit with the gas diffusion process. A new diffusion model was designed based on the Korsmeyer-Peppas model, and an excellent fit was obtained. This sustained-ClO₂-gas-release gel provides theoretical and technical guidance for the development of sustained-disinfectant-release agents for use in space and offers new insights into the sustained release model of skeleton-soluble hydrogels.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10570-023-05070-6.

Calcium bicarbonate as an antimicrobial, antiviral, and prion‑inhibiting agent (Review)

Calcium bicarbonate does not act as a disinfectant at neutral pH; however, it exerts strong antimicrobial activity after it is placed in a high-voltage electric field, whereby it assumes an alkaline pH (12.4). Moreover, the microbicidal activity of the resulting solution (named CAC-717) is not influenced by the presence of organic material or resistance of the agent to inactivation. When sprayed on the skin surface, the pH of CAC-717 decreases rapidly to 8.84. CAC-717 comprises fine particles of 50-500 nm. When these mesoscopic crystals are dissolved in water, they destroy the genomes of bacteria or viruses and neutralize the infectious properties of abnormal prion proteins produced in ScN2a cells. The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic has resulted in unprecedented international demand for disinfectants. A small titer of SARS-CoV-2 remains infectious even after 30 sec in growth medium at pH 12.4. CAC-717 has exhibited a strong virucidal effect (3.6 to 4.4 log₁₀ decrease) against all examined SARS-CoV-2 isolates, including mutant forms. Similarly, human noroviruses also remain intact at pH 12.4; however, CAC-717 has been shown to cause a 3.25 log₁₀ reduction in norovirus genomic RNA compared to untreated samples. Existing evidence suggests that an unidentified mechanism controls the virucidal activity of CAC-717.

Nanoscale copper and silver thin film systems display differences in antiviral and antibacterial properties

The current Coronavirus Disease 19 (COVID-19) pandemic has exemplified the need for simple and efficient prevention strategies that can be rapidly implemented to mitigate infection risks. Various surfaces have a long history of antimicrobial properties and are well described for the prevention of bacterial infections. However, their effect on many viruses has not been studied in depth. In the context of COVID-19, several surfaces, including copper (Cu) and silver (Ag) coatings have been described as efficient antiviral measures that can easily be implemented to slow viral transmission. In this study, we detected antiviral properties against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) on surfaces, which were coated with Cu by magnetron sputtering as thin Cu films or as Cu/Ag ultrathin bimetallic nanopatches. However, no effect of Ag on viral titers was observed, in clear contrast to its well-known antibacterial properties. Further enhancement of Ag ion release kinetics based on an electrochemical sacrificial anode mechanism did not increase antiviral activity. These results clearly demonstrate that Cu and Ag thin film systems display significant differences in antiviral and antibacterial properties which need to be considered upon implementation.

Evaluating the Impacts of COVID-19 on Operations and Management of Community Centres: An Auckland, New Zealand Case Study

This study evaluates the impact of COVID-19 on the operations and management of Community Centres (CCs) in Auckland. This Coronavirus posed unprecedented challenges to the communities and public facilities here and in many other countries. To mitigate the pandemic outbreak, the New Zealand government adopted the so-called “go hard, go early” strategy, which put all of the country to strict self-isolation for 52 days [Baker et al. (2020). The Medical Journal of Australia, 213(5), 198–200.e1]. This research aims to explore what challenges some of Auckland’s CCs faced during COVID-19 lockdown and what management decisions were taken to operate the CCs during these periods effectively. The study was based principally on primary data collected from the managers and visitors of eight CCs across Auckland via semi-structured interviews and anonymous online surveys. With all the information gathered and generated through thematic, correlation and deductive analysis, the study produced a “road map” for management actions. This framework should enable CCs to better articulate decisions for more effective and safer operating during future pandemic outbreaks.

Chemical Exposures Affect Innate Immune Response to SARS-CoV-2

Severe outcomes of COVID-19 are associated with pathological response of the immune system to the SARS-CoV-2 infection. Emerging evidence suggests that an interaction may exist between COVID-19 pathogenesis and a broad range of xenobiotics, resulting in significant increases in death rates in highly exposed populations. Therefore, a better understanding of the molecular basis of the interaction between SARS-CoV-2 infection and chemical exposures may open opportunities for better preventive and therapeutic interventions. We attempted to gain mechanistic knowledge on the interaction between SARS-CoV-2 infection and chemical exposures using an in silico approach, where we identified genes and molecular pathways affected by both chemical exposures and SARS-CoV-2 in human immune cells (T-cells, B-cells, NK-cells, dendritic, and monocyte cells). Our findings demonstrate for the first time that overlapping molecular mechanisms affected by a broad range of chemical exposures and COVID-19 are linked to IFN type I/II signaling pathways and the process of antigen presentation. Based on our data, we also predict that exposures to various chemical compounds will predominantly impact the population of monocytes during the response against COVID-19.

Virucidal Effect of the Mesoscopic Structure of CAC-717 on Severe Acute Respiratory Syndrome Coronavirus-2

Here, the virucidal effect of calcium bicarbonate with a mesoscopic structure (CAC-717) on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was determined. Assays showed that CAC-717 had a strong virucidal effect on all examined SARS-CoV-2 isolates, including variant strains. The viral infectivity decreased within 15 s, and the virucidal activity of CAC-717 at a 1:49 ratio was similar to that of ethanol disinfectant. CAC-717 neutralization eliminated this virucidal effect, indicating that the alkaline condition of CAC-717 is important for virus inactivation and is an indicator of its mesoscopic structure and virucidal activity. The virucidal effect was observed in the presence of organic matter (bovine serum albumin). CAC-717 is a non-invasive and non-flammable substance with a low environmental burden, and its usefulness as a novel disinfectant has been confirmed.

Impact of the COVID-19 pandemic on household disinfectant consumption behaviors and related environmental concerns: A questionnaire-based survey in China

Considering the potential hazardous effects of disinfectant residues on environment, organisms and biodiversity, the sharp rise in use of disinfectants during COVID-19 pandemic has been considered highly likely to cause worldwide secondary disasters in ecosystems and human health. This questionnaire-based survey investigated the impact of COVID-19 outbreak on household disinfectant product consumption levels and behavior of 3667 Chinese residents. In particular, in the context that no strategy is currently available to minimize the disinfectant pollution, based on the similarities between disinfectants and pharmaceuticals, we proposed a perspective of ecopharmacovigilance (EPV), which is an effective measure to minimize the environmental risks posed by pharmaceuticals using drug administration protocols, for disinfectant environmental risk management. The public's environmental perceptions, attitudes and the related practices regarding household disinfectant consumption from an EPV perspective were also included in the study. The results showed that the COVID-19 outbreak caused a tremendous rise in the public's household disinfectant consumption and usage levels in China. After the COVID-19 outbreak, the chlorine-based and alcohol-based disinfectants were considered as the most preferred products for household disinfection and hand sanitization, respectively. Importantly, the Chinese public's environmental perceptions and practice on disinfectants were poor. Less than half respondents had positive attitudes toward the source control of disinfectant pollution. The population groups including females, the middle aged adults, those having healthcare professional background, as well as the higher-educated could be focused on to develop targeted efforts for the future control of disinfectant pollution in environment.

Tackling Airborne Virus Threats in the Food Industry: A Proactive Approach

The current SARS-COVID-19 crisis has demonstrated the dangers that airborne virus (AV) pandemics pose to the health of all workers (particularly in the meat processing industry), the economic health of the food industry, and food security. The impact that the current pandemic has had on the food industry points to the need for a proactive rather than reactive approach towards preventing future AV outbreaks. Such a proactive approach should be based on empirical assessments of current AV food safety practices and the development of more robust practices tailored to the culture and needs of the food industry. Moreover, a proactive approach is necessary in order to better prepare the food industry for future AV outbreaks, protect the health of workers, reduce disparities in AV occupational health risks, and enhance the safety of the food supply chain. The aim of this review is to make the case for a new food safety research paradigm that incorporates the intensive study of airborne viruses under conditions that simulate food industry work environments.

Direct Potentiometric Study of Cationic and Nonionic Surfactants in Disinfectants and Personal Care Products by New Surfactant Sensor Based on 1,3-Dihexadecyl-1H-benzo[d]imidazol-3-ium

A novel, simple, low-cost, and user-friendly potentiometric surfactant sensor based on the new 1,3-dihexadecyl-1H-benzo[d]imidazol-3-ium-tetraphenylborate (DHBI-TPB) ion-pair for the detection of cationic surfactants in personal care products and disinfectants is presented here. The new cationic surfactant DHBI-Br was successfully synthesized and characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectrometry, liquid chromatography-mass spectrometry (LC-MS) and elemental analysis and was further employed for DHBI-TPB ion-pair preparation. The sensor gave excellent response characteristics for CTAB, CPC and Hyamine with a Nernstian slope (57.1 to 59.1 mV/decade) whereas the lowest limit of detection (LOD) value was measured for CTAB (0.3 × 10-6 M). The sensor exhibited a fast dynamic response to dodecyl sulfate (DDS) and TPB. High sensor performances stayed intact regardless of the employment of inorganic and organic cations and in a broad pH range (2-11). Titration of cationic and etoxylated (EO)-nonionic surfactant (NSs) (in Ba2+) mixtures with TPB revealed the first inflexion point for a cationic surfactant and the second for an EO-nonionic surfactant. The increased concentration of EO-nonionic surfactants and the number of EO groups had a negative influence on titration curves and signal change. The sensor was successfully applied for the quantification of technical-grade cationic surfactants and in 12 personal care products and disinfectants. The results showed good agreement with the measurements obtained by a commercial surfactant sensor and by a two-phase titration. A good recovery for the standard addition method (98-102%) was observed.

New Clinical Applications of Electrolyzed Water: A Review

As the situation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is still deteriorating, there has been a huge increase in the demand and use of disinfectants. Electrolyzed water (EW), as a novel broad-spectrum disinfectant and cleaner, has been widely used for several years. EW can be produced in an electrolysis chamber which contains dilute salt and tap water. It is an effective antimicrobial and antibiofilm agent, with several advantages such as on-the-spot, cheap, environmentally friendly and safe for human beings. Therefore, EW holds potential significance for high-risk settings in hospitals and other clinical facilities. EW can also be applied for wound healing, advanced tissue care, and dental clinics. The present review article highlights the latest developments and new perspectives of EW, especially in clinical fields. Furthermore, the main action modes of antibiofilm and antimicrobial will be summarized.

Methods to disinfect and decontaminate SARS-CoV-2: a systematic review of in vitro studies

BACKGROUND

Cleaning is a major control component for outbreaks of infection. However, for the SARS-CoV-2 pandemic, there is limited specific guidance regarding the proper disinfection methods that should be used.

METHODS

We conducted a systematic review of the literature on cleaning, disinfection or decontamination methods in the prevention of SARS-CoV-2.

RESULTS

A total of 27 studies were included, reporting a variety of methods with which the effectiveness of interventions were assessed. Virus was inoculated onto different types of material including masks, nasopharyngeal swabs, serum, laboratory plates and simulated saliva, tears or nasal fluid and then interventions were applied in an attempt to eliminate the virus including chemical, ultraviolet (UV) light irradiation, and heat and humidity. At body temperature (37°C) there is evidence that the virus will not be detectable after 2 days but this can be reduced to non-detection at 30 min at 56°C, 15 min at 65°C and 2 min at 98°C. Different experimental methods testing UV light have shown that it can inactivate the virus. Light of 254-365 nm has been used, including simulated sunlight. Many chemical agents including bleach, hand sanitiser, hand wash, soap, ethanol, isopropanol, guandinium thiocynate/t-octylphenoxypolyethoxyethanol, formaldehyde, povidone-iodine, 0.05% chlorhexidine, 0.1% benzalkonium chloride, acidic electrolysed water, Clyraguard copper iodine complex and hydrogen peroxide vapour have been shown to disinfect SARS-CoV-2.

CONCLUSIONS

Heating, UV light irradiation and chemicals can be used to inactivate SARS-CoV-2 but there is insufficient evidence to support one measure over others in clinical practice.

Safe Use and Storage of Cleaners, Disinfectants, and Hand Sanitizers: Knowledge, Attitudes, and Practices among U.S. Adults during the COVID-19 Pandemic, May 2020

Cleaning and disinfection of frequently touched surfaces and frequent hand hygiene are recommended measures to prevent transmission of SARS-CoV-2, the virus that causes COVID-19. Since the onset of the COVID-19 pandemic, poison center calls regarding exposures to cleaners, disinfectants, and hand sanitizers have increased as compared with prior years, indicating a need to evaluate household safety precautions. An opt-in Internet panel survey of 502 U.S. adults was conducted in May 2020. Survey items evaluated knowledge regarding use and storage of cleaners, disinfectants, and hand sanitizers; attitudes about household cleaning and disinfection; and safety precautions practiced during the prior month. We assigned a knowledge score to each respondent to quantify knowledge of safety precautions and calculated median scores by demographic characteristics and attitudes. We identified gaps in knowledge regarding safe use and storage of cleaners, disinfectants, and hand sanitizers; the overall median knowledge score was 5.17 (95% CI: 4.85-5.50; maximum 9.00). Knowledge scores were lower among younger than older age-groups and among black non-Hispanic and Hispanic respondents compared with white non-Hispanic respondents. A greater proportion of respondents expressed knowledge of safety precautions than the proportion who engaged in these precautions. Tailored communication strategies should be used to reach populations with lower knowledge of cleaning and disinfection safety. In addition, as knowledge alone did not shape individual engagement in safety precautions, health promotion campaigns may specifically emphasize the health risks of unsafe use and storage of cleaners, disinfectants, and hand sanitizers to address risk perception.