Liquid Chalk works as an antiseptic against COVID

Many gyms have made the use of liquid chalk mandatory since the high alcohol content was expected to be an effective weapon against COVID. This decision was based on a “common sense” line of reasoning but now the hard science is in:


Liquid Chalk Is an Antiseptic against SARS-CoV-2 and Influenza A Respiratory Viruses

Liquid chalk essentially is antibacterial gel and magnesium carbonate mixed together, so the scientific finding confirms what we expected all along.

The CDC recommends an alcohol content of 60% for antibacterial gels and since the “sweet spot” for alcohol content in high-quality liquid chalk is between 60 and 70% most liquid chalks are expected to be effective against the SARS-CoV-2 virus. Ours is 70% alcohol.

This post is part of a series where we highlight the existing research around chalk.

Abstract, emphasis ours: The COVID-19 pandemic has impacted and enforced significant restrictions within our societies, including the attendance of public and professional athletes in gyms. Liquid chalk is a commonly used accessory in gyms and is comprised of magnesium carbonate and alcohol that quickly evaporates on the hands to leave a layer of dry chalk. We investigated whether liquid chalk is an antiseptic against highly pathogenic human viruses, including SARS-CoV-2, influenza virus, and noroviruses. Chalk was applied before or after virus, inoculum and recovery of infectious virus was determined to mimic the use in the gym. We observed that addition of chalk before or after virus contact led to a significant reduction in recovery of infectious SARS-CoV-2 and influenza virus but had little impact on norovirus. These observations suggest that the use and application of liquid chalk can be an effective and suitable antiseptic for major sporting events, such as the Olympic Games. IMPORTANCE To restrict the potential transmission and infectivity of SARS-CoV-2, the use of liquid chalk has been a requirement in an active gym setting. However, its effectiveness has not been scientifically proven. Here, we show that the application of liquid chalk before or after virus inoculum significantly impacts recovery of infectious SARS-CoV-2 and influenza viruses but not noroviruses. Thus, our study has shown that the implementation and application of liquid chalk in communal social gym settings is effective in reducing the infectivity of respiratory viruses, and this supports the use of liquid chalk in major sporting events to restrict the impact of COVID-19 on our communities.

PubMed Link Photo by CDC