Killing SARS-CoV-2 is relatively easier compared to many other virus say of noro viruses types and other common viruses that have a way more robust protein shell. Corona viruses are enveloped viruses with a protective fat layer. Disinfectants tear apart that fat layer which makes corona viruses “fairly wimpy”. The Environmental Protection Agency has a list of disinfectants that have shown to be effective in fighting corona viruses. Below is a better diagrammatic and technical way to explain –
“Ethanol (78-95%), 2-Propanol (70-100%) readily inactivated corona virus infectivity by approximately 4 log 10 or more. Sodium Hypochlorite required a minimal concentration of at least 0.21% to be effective. Hydrogen peroxide was effective with a concentration of 0.5% and an incubation time of 1 min.
On inanimate surface human coronaviruses can remain infectious for up to 9 days. A surface disinfection with 0.1% sodium hypochlorite, 0.5% hydrogen peroxide or 62%–71% ethanol can be regarded as effective against corona viruses within 1 min. A similar effect can be expected against the SARS-CoV-2.
Why Sodium Hypochlorite is farly safe to be used?
It is one of the most commonly used chemical for Food cleaning and disinfection, or for cleaning the root canal in a dentist shop or for similar other uses, and have been is use for many centuries.
If Sodium Hypochlorite as disinfectant is effective with Organic Load?
Indeed there will be impact and difference in efficacy, but this disinfectant itself happens to be a “Cleaning Agent” as well. Below research shows the result –
This disinfectant have additional capability to do cleaning as well. It’s efficacy increases because of this dual proficiency –
Another research below, in continuation of the above, suggest the usage of Sodium Hypochlorite as a good cleaning agent as well, apart from being a very effective killer of 100 of microbes
Sodium Hypochlorite is widely used in hospitals as well, as one of the primary disinfectant. Below snapshot shows the contact time and the strength needed for different “categories” of disinfections.
Why Sodium Hypochlorite still happens to be the best choice recommended for Covid19 control – be it our MoHFW or WHO or CDC or worldwide. It kills pathogens “better and faster”, compared to others in similar category.
What are the properties of an ideal disinfectant?
Any environmental adverse effects of Sodium Hypochlorite usage ?https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html#chlorine
How long Corona virus can stay “live” on different objects and strength of various disinfectant, and time respectively to kill the virus
Time needed by various Disinfectants to kill various strains of Corona virus
What is the ‘bulk’ of microbes or ‘viral load’(if microbe is a virus) which comes out while human engages in various activities like sneezing, talking etc
What is the size of Corona virus? And how it compares to other day to day Aerosols?
The COVID-19 virus is approximately 0.125 Micron or 125 nanometers in diameter. (Source: National Library of Medicine). However, it often travels in biological aerosols from coughing and sneezing which range in size from 0.5-3 Micron.
Why fogging is a better way to contain Virus spread?
Fogging causes no dripping losses or spraying stains. Thanks to the long persistence of the fog, insects are exposed for a longer time than with a conventional spray. The fog also achieves optimal penetration, distribution, coverage and adhesion on the surface of the leaves.
What are spores? If Virus also forms spores?
Some bacteria, fungi, protists transform into spore cells when external conditions are unfavorable; the result is reduced metabolic activity, higher ‘cidal’ resistance, and immunity from disinfectants. Spores lie dormant, and once conditions become favourable again, the microbe converts back to a vegetative state and grows actively. Viruses on the other hand cannot produce spores because virus are non-living and has to invade a living organisms and make use of the host’s genetic material (DNA) to multiply itself – a function which it cannot perform outside of a living cell.
Does higher contact time of disinfectant always increases the efficiency?
Depends. Every disinfectant has different contact time need for efficient killing of the microbes. For example in below example – there is hardly any “killing efficiency” difference between immediate and after 4 hours.
If the disinfectant you are using is having any skin irritation/ effect?
Desks were found to have 400X more bacteria than a toilet seat. • Tests have proved that in just a few hours, viruses can spread to 60% of a building’s occupants from a single doorknob.