Covid-19 has sparked global panic. Central banks have cut interest rates to near zero, made billions available in liquidity, and urged markets to stay calm.

So how much will cash usage, and the wider banknote industry, be impacted by coronavirus? Are polymer notes safer or paper (cotton) ones?

In 2015, scientists from the Institute of Genomics and Integrative Biology in New Delhi researched what particles of dirt were evident on different Indian rupee banknotes. The banknotes were collected from street vendors, grocery stores, and money exchanges. Their analysis revealed fungi (70%), bacterial populations (9%), and viruses (<1%) were evident on the banknotes. These were cotton substrate banknotes – known to harbor more bacteria than their polymer counterpoints because they absorb a larger amount of water. While still only minimal, the water allows the bacteria to survive for long on a banknote.

Once withdrawn from the bank, a banknote can pick up bacteria or viruses from every party that it comes into contact with. This is similar to other common surfaces, such as elevator buttons and handrails.

Polymer banknotes also have the potential to transmit bacteria from one party to another but on a much smaller scale. According to scientists at the Harper Adams University, bacteria found on human hands are less capable of sticking to plastic banknotes compared with cotton substrates. In addition, bacteria found on human hands die off faster when on plastic banknotes.