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mikesorr68@googlemail.com  
#1 Posted : 06 August 2020 13:45:37(UTC)
Rank: New forum user
mikesorr68@googlemail.com

Has anyone come across any reliable research to assess the risks of vacuuming SARS-CoV-2 virus? There is lots of marketing inforation indicating that vacuums with HEPA or ULPA filters are effective etc and these are based on research that indicates that although the filter mesh size (0.3 microns and 0.12 microns respectrively) is signifiantly bigger than the size of the SARS-Cov-2 virus (0.005 to 0.2 microns), the filters are effective due to the actions of impact, impedence and brownian motion together with the fact that in the air the virus is carried on much larger saliva / mucus hosts, and largely it is these particles that are captured.

However what is not clear is that the virus settles out of the air onto floor surfaces, and that within less than 10 minutes, most of the moisture of the host mucus or saliva at room temperatures has evapourated. It is unclear what the virus is then attached to if anything, leading to concern that what is left is the smalled sized virus particles which potentially could pass through the filter mesh. Equally it is clear that by the nature of mechanics of how a standard dry suction vacuum works, the finer mesh filters require a higher powered motor to force the same amount of air through, and so the potential for disturbance is of the settled virus is quite high.

There a limited number of direct studies into how long the virus survives on differing surfaces - (although there are many reviews and reviews of reviews all based on the same original studies). What these appear to indicate is that the virus has a low sustainability on materials such as cottons (in the order of est 5 hours depending on the study read), but that on plastics it has a life expectancy of up to around 4 days (more or less). In many workplaces, hard wearing modern carpets are mostly polyester based - does this weight more towards the plastic than cotton?

So if employers want to comply with duties under the Workplace (Health Safety and Welfare) Regs to ensure the workplace is kept in good order, an efficient state and a state of cleanliness, can / should employers be asking staff to use vacuums, and if so, how?  I put the question in writing to HSE since the use of vacuums is conspicuous by its absence in both HSE and Central Govt guidance relating to cleaning. Indeed the only reference I have found is from the CDC which indicates that the answer is not known and there is an absence of research, therefore the recommended approach is to wet clean and disfect carpets before attempting to vacuum them https://www.cdc.gov/coronavirus/2019-ncov/faq.html#Cleaning-and-Disinfection.

Any help or knowledge would be greatly appreciated.   

A Kurdziel  
#2 Posted : 06 August 2020 15:07:04(UTC)
Rank: Super forum user
A Kurdziel

I don’t know but I suspect that based on what we know about the viability of viruses and the fact that you have to breath in the virus for it to effect you, I suspect that it is not an issue. And of course the virus is not everywhere only in those settings where there is someone who has the infection and is shedding the virus.

As to HEPA filters, I can assure that they work with viruses as they use them in biological safety cabinets working at upto Containment Level 4 (Ebola etc). They do not rely on a sieve effect ie the virus is blocked by the filtering material but rather the particle enters the matrix of the filter and basically gets lost and gives up try to find its way out of the maze( this can be described more accurately  by applying thermodynamics but as simple model it works)

thanks 2 users thanked A Kurdziel for this useful post.
stevedm on 06/08/2020(UTC), mikesorr68@googlemail.com on 06/08/2020(UTC)
stevedm  
#3 Posted : 06 August 2020 17:30:53(UTC)
Rank: Super forum user
stevedm

we learned a few things from the SARs epidemic in 2009 about transmission routes...Patient 0 from the Honk Kong hotel basically transmitted the virus to 112 others through fecal transfer into the HVAC system..which is why we are so interested in HVAC systems for COVID...and HEPA filters are as AK say doing the job..we now know that it actually stays in the porcelin for days and continues to get airated every time you flush the loo...not sure why I was telling you that.....the link below gives the only research I know at present on how long it lasts..

https://pubmed.ncbi.nlm.nih.gov/32511427/

Below is also an indoor air quality tool that is supposed to help model the same thing...haven't used it yet...

https://www.nist.gov/services-resources/software/fatima 

thanks 1 user thanked stevedm for this useful post.
mikesorr68@googlemail.com on 06/08/2020(UTC)
Roundtuit  
#4 Posted : 06 August 2020 21:27:11(UTC)
Rank: Super forum user
Roundtuit

http://forum.iosh.co.uk/posts/t127956-HSE-improvement-notice-for-general-housekeeping--and-legal-duty-to-report Why would a "former" HSE inspector be asking the great unwashed - surely your former colleagues would have the answer?

https://www.iosh.co.uk/forumrules.aspx Rule 11

Roundtuit  
#5 Posted : 06 August 2020 21:27:11(UTC)
Rank: Super forum user
Roundtuit

http://forum.iosh.co.uk/posts/t127956-HSE-improvement-notice-for-general-housekeeping--and-legal-duty-to-report Why would a "former" HSE inspector be asking the great unwashed - surely your former colleagues would have the answer?

https://www.iosh.co.uk/forumrules.aspx Rule 11

mikesorr68@googlemail.com  
#6 Posted : 07 August 2020 13:49:37(UTC)
Rank: New forum user
mikesorr68@googlemail.com

Thanks for this - yes former HSE, and whereas those individuals contacted have acknowledged questions and concerns and may have personal opinions that there is something to be explored. However at present no centralised response available and so as an organisation they are not answering. For clarity acknowledge that HEPA works fine for airborne units and my question was not to challenge use of these for removal of these the air where associated with a host moisture expelled form respiratory tract, rather the settled stuff where the moisture host has dried up and may not be present.

re Reg 11 - thanks for pointing out - this is my second foray into forum and have now picked up on this and had confirmation from IOSH admin team they have now changed what is displayed -  will know if it has worked when I press the submit button.  

Kindest regards  M

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