29 Apr Killing Germs with Chemicals
COVID-19 reminded us all that germs can live on surfaces for a number of days. The current strain of coronavirus (COVID-19 or SARS-CoV-2) that is wreaking havoc around the world has seen scientists rush to find ways to kill it.
As it is a new strain, most cleaning methods have not been tested against this particular strain, but we can draw comparisons from similar viruses to help inform which products effectively kill these.
An analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days.
These viruses can be efficiently inactivated within one minute by surface disinfection procedures with:
- 62-71% ethanol, OR
- 0.5% hydrogen peroxide, OR
- 0.1% sodium hypochlorite.
As no specific therapies are available for SARS-CoV-2, early containment and prevention of further spread will be crucial to stop the ongoing outbreak and to control this novel infectious thread.
The science of destroying germs
Quaternary ammonium compounds are commonly found in disinfectant wipes, sprays and cleaners. They kill germs by denaturing the proteins of the bacterial or fungal cell, affecting the metabolic reactions of the cell and causing vital substances to leak out of the cell, causing death.
This alone can kill germs after 10 seconds of contact, and is highly effective as both a disinfectant and sanitiser when left on surfaces for one minute.
Hydrogen peroxide is also effective at killing germs. Even at a dilution of 0.5% concentration, it works to destroy germs through oxidation. This process occurs when the reactive oxygen atoms interfere with the electrons of other cells, causing the walls of the cells forming bacteria to break down.
When these two chemicals are combined, and when left on surfaces for one minute, they effectively kill coronaviruses and leave surfaces in a state difficult to support germ life.
A&S have released a product called A&S Spray Fresh Disinfectant that contains both quaternary ammonium compounds and hydrogen peroxide. Find out more about this product, and DIY cleaning kits here.