COVID-19 & Recycled Clay

[HDudz]

I am a high school teacher and the thought of going back to school in the fall has presented a lot of questions.  The clay in my classroom is touched by SO MANY throughout the day.  I am wondering how to "disinfect" the clay so that we can keep everyone safe while preserving all of the amazing properties that clay has.  Is adding bleach safe for the clay?  Lysol?  Isopropyl Alcohol?  Do I allow clay to dry completely (allowing the virus to die) and then recycle?  I want to be prepared when Risk Management starts making suggestions to my classroom practices.

[Chilly]

Whatever you put in it also has to be safe for skin.  I can handle clay, but need to wear gloves when glazing as it dries my hands too much.  I wear gloves for general domestic stuff - washing up, cleaning bathroom etc,.  I would not touch clay if i thought bleach had been added to it.

No other suggestions, sorry, but it's something we might all have to consider in community studios - including me.   Arrrgh, will it ever end!

[Rae Reich]

I think adding a bit of soap to throwing/mixer water should take care of the clay - never tried it, though, might be too bubbly? 

And of course wiping down counter and wheel areas after working. 

Be sure students stay in their own demarcated work areas and wear masks.

Sounds like this  would be a question for Dr Faucci, or a science teacher. 

[ronfire]

Wonder how long the virus will live in clay or water? Might not be very long.

 

[Mark C.]

1 hour ago, ronfire said:

Wonder how long the virus will live in clay or water? Might not be very long.

 

I think this may be the case as clay does not hold other things for long as well. Never heard of someone getting a cold or pneumonia from clay. Good question that needs more research. If you do add anything make it the least nasty as possible -a little soap will be ok-vinegar is a better additive as it helps clay as well.Its a bit acidic as well which may be enough-it helps with the clay aging as well

welcome to the forum

[jrgpots]

An  Ultraviolet light (UVc) for 30 minutes burts in the sutdio should kill SARs CoV2 virus.  turn the light on at night.  Air out the studio in the AM to get rid of the ozone smell.  The light costs $35 -$75 depending on strength and ozone production. 

Jed

[Babs]

Fire it:-/

[Bill Kielb]

16 hours ago, HDudz said:

Is adding bleach safe for the clay?  Lysol?  Isopropyl Alcohol?  Do I allow clay to dry completely (allowing the virus to die) and then recycle?  I want to be prepared when Risk Management starts making suggestions to my classroom practices.

 

3 hours ago, jrgpots said:

minutes burts in the sutdio should kill SARs CoV2 virus.  turn the light on at night.  Air out the studio in the AM to get rid of the ozone smell.  The light costs $35 -$75 depending on strength and ozone production. 

Jed

You will  likely need to rely on current and future research as UV probably will become an important recent finding. Not to be confused with ozone producing UV which in itself is an active oxidant but also can be a significant irritant to people.

The case for UV: The UV protocol would likely have a very specific intensity and time to expose all sides of the clay if it becomes acceptable.  Old refrigerators used to  come with a very low intensity UV lamp. My how advanced we have become!

The case for the use of ozone: you could end up with an ozone chamber that all clay must be placed in for a period of time to ensure it is reasonably free from virus.

This is really something that needs testing to be valid. Really, really good question!

Adding things to the clay, likely not gonna be acceptable.

 

[liambesaw]

Using hydrogen peroxide (standard pharmacy 3% stuff) will kill coronavirus (as well as pretty much everything) and has only two byproducts.  Oxygen gas and liquid water.  Surely those two things will be fine in reclaim!

[Bill Kielb]

12 minutes ago, liambesaw said:

Using hydrogen peroxide (standard pharmacy 3% stuff) will kill coronavirus (as well as pretty much everything) and has only two byproducts.  Oxygen gas and liquid water.  Surely those two things will be fine in reclaim!

 

Maybe, problem with ensured contact and total time of contact. Gonna need some solid thinking and testing. I would never just say it is ok without testing 

[liambesaw]

Just now, Bill Kielb said:

Maybe, problem with ensured contact and total time of contact. Gonna need some solid thinking and testing. I would never just say it ok without testing 

Sure, just saying its an option that you can add to clay where the byproducts are benign.  Unlike soap, and Lysol, and bleach.  Can get even coverage in a pugmill, unlike with ozone or UV which can only address the surface.  

Test test test!  Works great to defunk my slip bucket, which is why i mentioned it

[Babs]

So where iz the clay becoming infected? At point of production or after students work with it?

If students swab down on entering classroom as required in food handling part of their studies, wear masks  not gloves as they are found to be dirtier than hands...dont tend to be washed as much during  the course of working..does this not suffice?

Wash basins with elbow operated taps

Adult classes..scraps of clay go into personalised buckets and are reclaimed and used by that student....

Not sure if that would not suffice....

Surfaces washed down with the bleach meths etc as part of the end of class clean up...

Can go ott on this BUT I am not making light of it....

Kids with sniffles not allowed in food handling areas...same in clay classes?

 

[Bill Kielb]

32 minutes ago, Babs said:

So where iz the clay becoming infected? At point of production or after students work with it?

If students swab down on entering classroom as required in food handling part of their studies, wear masks  not gloves as they are found to be dirtier than hands...dont tend to be washed as much during  the course of working..does this not suffice?

Wash basins with elbow operated taps

Adult classes..scraps of clay go into personalised buckets and are reclaimed and used by that student....

Not sure if that would not suffice....

Surfaces washed down with the bleach meths etc as part of the end of class clean up...

Can go ott on this BUT I am not making light of it....

Kids with sniffles not allowed in food handling areas...same in clay classes?

 

I think you would begin to assume at any point it could get contaminated. Washing things down with bleach might be great but if bleach or peroxide needs 20 minute contact time at a specific percentage concentration then it is hard to develop a goof resistant protocol that can easily be implemented by ordinary people. Remember it’s half lives and probability so very hard to say 10 minutes at three percent ........ etc

The interim saving grace would be effective treatments, right now it appears super contagious with an unknown level of true severity. No treatment and no real mortality data means err on the side of super cautious. This may change significantly as we get real data over the next months though.

[Rae Reich]

If it doesn't like high humidity, as I'm hearing, the virus wouldn't like to live in wet clay, tools, hands. A drop of detergent acts as a (oops, lost the word) emollient?

6' apart. Really, at least.

Hands should not touch faces and should be washed before and after  working in dry areas. Standard area mop-up between users.

Heavy breathing and exertion, even while masked, are more likely to expose you to stray airborne particles. Do such work far from other breathers. Breathe far away from such exertion.

Pay attention. Be intentional.

Fortunately, except for the greater separation, this is stuff that potters do or need to do anyway.

[Rae Reich]

W.H.O. Recipe for hand sanitizer:

Mix in well-ventilated area.

8.5 liters ethanol, 417 ml hydrogen peroxide, 145 ml glycerol and enough distilled or boiled water to make 10 liters. Mix by gently rocking the lidded glass or plastic container. Pour into smaller units. Let sit 72 hrs to kill microorganisms. Use within a few days. 

Says mixture won't smell pretty. A little essential oil?

[Min]

I haven't found anything that points to how long the novel coronavirus can live in moist clay for. The closest I could find are some studies done with other RNA viruses and soils. I think the solution to the problem might hinge on how much recycled clay there is to deal with. Research showing temperatures of 56C have been published as being able to kill the virus. If manageable then heating the clay and holding the temp there to ensure the entire mass is heated through should take of it. 

If it's a large amount of reclaim then I would be inclined to just put it aside until more data is available. 

[jrgpots]

UV lamps that emit 256 nm light have been used for years to sterilize empty surgical rooms.  This wavelength penetrates  a few mm into surfaces.  The room must be vacant when using the light.  However,  the newer 222 nm UV light does not penetrate the skin and has been shown to be sake to animals and humans.  Thus it can be used safely during regular business hours to kill surface and aerosolized particles.

UV light can be used in 2 ways:  

1.  a nightly UV 254 light exposure should clean and kill most surface and aerosolized  viruses.  

2.  a 222 nm UV light system can be run throughout the day when people are in the room without fear of damage or harm to humans.

The article below gives info on exposure rates and LD95 rate of the 222 nm light sources.  For those interested in looking into this, the linked article might be a starting point.  One would need to figure out his/her needed wattage for the studio.  

It looks very promising to me.   Someone may want to write a scholarly article about the use of this light in the studio setting.  It would be a great academic research project! 

https://www.nature.com/articles/s41598-018-21058-w

 

Jed

 

 

 

[jrgpots]

I found an interesting and a bit disturbing article in Vet Microbiol. 1998 Oct; 63(2-4):137-146. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7117430/

The article states that caronavirus  can live and thrive  in clay and that the clay can be infectious.  The article talks about clay particles can clear contaminated water, but the residual clay particles can carry an increased virus load because the filtration effect concentrates viral particles in the clay.  So, suggestions might be:

1.   Don't eat the clay.

2.   Wash hands before touching the face.

3.   Consider wearing Nitrile gloves while working with "community clay,"

 such as recycled clay.

4.   Like Min stated, consider heating the clay slurry above 56 degree C  if you recycle it.  Or delay the recycling of clay.

 

Jed

[Magnolia Mud Research]

23 minutes ago, jrgpots said:

I found an interesting and a bit disturbing article in Vet Microbiol. 1998 Oct; 63(2-4):137-146.

The article states that caronavirus  can live and thrive  in clay and that the clay can be infectious.  The article talks about clay particles can clear contaminated water, but the residual clay particles can carry an increased virus load because the filtration effect concentrates viral particles in the clay.  So, suggestions might be:

1.   Don't eat the clay.

2.   Wash hands before touching the face.

3.   Consider wearing Nitrile gloves while working with "community clay,"

 such as recycled clay.

4.   Like Min stated, consider heating the clay slurry above 56 degree C  if you recycle it.  Or delay the recycling of clay.

 

Jed

for those who want to read the article: 

Vet Microbiol. 1998 Oct; 63(2-4):137-146.
https://www.sciencedirect.com/science/article/pii/S0378113598002417 
 

Veterinary Microbiology
Volume 63, Issues 2–4, 1 October 1998, Pages 137-146
Veterinary Microbiology
In vitro studies on the use of clay, clay minerals and charcoal to adsorb bovine rotavirus and bovine coronavirus
Author  K.J. Clark (a), A.B. Sarr (b), P.G. Grant (b), T.D. Phillips(b), G.N. Woode (a)
(a)  Department of Veterinary Pathobiology and Public Health, College of Veterinary Medicine, Texas A&M UniversityCollege Station, TX 77845USA
(b)  Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station, TX 77845 USA
Received 26 January 1998, Accepted 6 July 1998, Available online 3 December 1998.

 

[Bill Kielb]

29 minutes ago, Magnolia Mud Research said:

for those who want to read the article: 

Vet Microbiol. 1998 Oct; 63(2-4):137-146.
https://www.sciencedirect.com/science/article/pii/S0378113598002417 
 

Veterinary Microbiology
Volume 63, Issues 2–4, 1 October 1998, Pages 137-146
Veterinary Microbiology
In vitro studies on the use of clay, clay minerals and charcoal to adsorb bovine rotavirus and bovine coronavirus
Author  K.J. Clark (a), A.B. Sarr (b), P.G. Grant (b), T.D. Phillips(b), G.N. Woode (a)
(a)  Department of Veterinary Pathobiology and Public Health, College of Veterinary Medicine, Texas A&M UniversityCollege Station, TX 77845USA
(b)  Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station, TX 77845 USA
Received 26 January 1998, Accepted 6 July 1998, Available online 3 December 1998.

 

I like the heating idea. 140 degrees (f) , kind of like cooking. Might be able to use a decent cooking style thermometer or probe. Just like cooking chicken. Think I will start producing a microwave with a probe that allows gradual heating and the option to hold the piece at 140 degrees for a period of time. Just need an idea to cool the clay without removing moisture. Heck break the clay into 1-2# balls, this might be doable.

[jrgpots]

12 minutes ago, Bill Kielb said:

I like the heating idea. 140 degrees (f) , kind of like cooking. Might be able to use a decent cooking style thermometer or probe. Just like cooking chicken. Think I will start producing a microwave with a probe that allows gradual heating and the option to hold the piece at 140 degrees for a period of time. Just need an idea to cool the clay without removing moisture. Heck break the clay into 1-2# balls, this might be doable.

Put the 1 -2 lb clay balls into plastic bags for the heating process to seal in moisture???

Jed

[Bill Kielb]

1 minute ago, jrgpots said:

Put the 1 -2 lb clay balls into plastic bags for the heating process to seal in moisture???

Jed

One thing for sure, It might be a simple way to get clay prepared for next day class work.

[Babs]

So perhaps ceramics in high schools and tertiary inst. cannot be delivered in the near future until such time as more solid facts are known about this virus.

Unlike the bovine, ovine and other such species we can wash purselves thoroughly and often . Ditto our work places, decide who comes near us and into our homes and areas and in some lucky places on the planet, we've overrun and over populated, still drink clean water.

Spread of virus and disease in livestock still depends on best practices of behaviour, hygiene and animal/ sq metre. 

Folk still bring meatstuffs into other countries in their suitcases for goodness sake!

[neilestrick]

I don't think there's any practical method to ensure that clay is sterile. You can't go mixing most things into the clay without messing up the workability of the clay, and those things that won't mess it up would have to be mixed in a slurry in order to get it to every particle. Not practical. Heating up all of the clay every day isn't practical either. There's no way to make sure everything in a public building is sterile. Even if you sterilize every table, chair, railing, etc several times every day, they're going to get touched hundreds of times in between cleanings. So you have to follow the good hygiene practices we've been told about for the last 2 months- wash your hands and don't touch your face. We'll probably also still be wearing masks until we get a vaccine, so that will help, too.

[Bill Kielb]

3 minutes ago, neilestrick said:

I don't think there's any practical method to ensure that clay is sterile. You can't go mixing most things into the clay without messing up the workability of the clay, and those things that won't mess it up would have to be mixed in a slurry in order to get it to every particle. Not practical. Heating up all of the clay every day isn't practical either. There's no way to make sure everything in a public building is sterile. Even if you sterilize every table, chair, railing, etc several times every day, they're going to get touched hundreds of times in between cleanings. So you have to follow the good hygiene practices we've been told about for the last 2 months- wash your hands and don't touch your face. We'll probably also still be wearing masks until we get a vaccine, so that will help, too.

Probably so, or always good practice anyway. Heating seems to be something doable for classes and I could see the possibility of it being best practice in a school environment. . Having read the 222nm UV stuff I am actually encouraged that it will become more popular everywhere. We put lots of 254nm UV in ductwork and indirect illumination in hospitals over the years, a proven performer. Problem is exposure to skin and eyes at that wavelength is a problem. Of all the bad that this has brought, using the 222nm UV  in public places could reduce the occurrences of flu as well. I find it a bit encouraging actually. Good hygiene always a good idea though.