Research shows chalk could be a climber’s best friend

Posted by Emma Travers on 15/04/2021

Peer-reviewed research shows that the amount of infectious virus was reduced by around 99% immediately upon contact with the chalky surfaces.

READ: The fully peer-reviewed research article

At the start of the Coronavirus crisis The Warehouse Climbing Centre, Gloucester, The Lakeland Climbing Centre Kendal and the ABC (Association of British Climbing Walls) set up a working group to research the science behind the virus and climbing.

They wanted to understand the potential impact of chalk on the virus, as there were some concerns within the climbing community around how chalk on holds may act as a reservoir for the virus. The team at De Montfort University were commissioned to undertake the research to assess whether coronavirus can survive in climbing chalk and if it remains infectious to people.

Although COVID‐19 is predominantly transmitted by respiratory droplets, this research set out to investigate the effect of climbing chalk on the risk of fomite transmission (transmission through materials) via shared climbing holds that are not cleaned between users.

A model coronavirus for SARS-CoV-2, human coronavirus OC43, was used for the experiments. The presence of infectious virus on a plastic surface dusted with chalk was monitored over the course of one hour. The results indicated that the amount of infectious virus was reduced by around 99% immediately upon contact with the chalky surfaces. By comparison, the control test where no chalk dust was present, showed only a slight decline in infectious virus over these time periods.

Rich Emerson, Chair of the ABC said: “These results look fantastic and show chalk could once again be the climber’s best friend. We hope that it will provide comfort to our customers as they return to climbing at indoor walls. We will not lessen all our other COVID-safe measures such as regular hand sanitisation and social distancing but this extra factor should temper fears that chalky handholds could be vectors of the disease."

More on Methodology

The researchers dusted dry plastic surfaces with different chalks (magnesium carbonate, calcium carbonate, or a blend of the two) and added droplets of a model coronavirus called HCoV-OC43, which has a very similar structure and survival pattern to that of SARS-CoV2 (which causes COVID-19). Then, over the course of an hour, they recovered the virus from the surfaces at several intervals to inspect the number of infectious virus particles present.

Results

Within just one minute of the virus coming into contact with the chalk, the number of infectious particles in all of the samples was reduced by more than 99%.

Dr Shivkumar said: “Rather than just looking at whether the virus was still present in the chalk, we wanted to explore if any virus that comes into contact with chalk still posed a risk of infection. Our study suggests that chalk powder inactivates infectious virus and is therefore unlikely to harbour coronaviruses like SARS-CoV-2.