Identifying asbestos

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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rs6000
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Identifying asbestos

#1 Post by rs6000 » Mon Nov 04, 2019 7:30 pm

How do I differentiate asbestos from other items in sample I.e sand grains pollen etc I live in NV and am concerned of airborne contamination that has been documented in the news recently as being very high :shock:
I have a zeiss std 18 with a monocular polo head with swing in pol and have placed a linear pol on top of field lens,
anything else I may need.

Cheers
Jeff

MicroBob
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Re: Identifying asbestos

#2 Post by MicroBob » Mon Nov 04, 2019 9:06 pm

Hi Jeff,
to separate objects from other suff it is good to know the properties in thich the object differs from the other stuff. For asbestos this it temperature resistance in the first place. After burning organic matter the choice will be narrowed down considerably. Next come polarisation properties and refractive index.

Bob

MichaelG.
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Re: Identifying asbestos

#3 Post by MichaelG. » Tue Nov 05, 2019 12:27 am

Jeff

This is an excellent document from the UK Health and Safety Executive:
http://www.hse.gov.uk/pubns/priced/hsg248.pdf

... Pick from it what’s useful to you.

MichaelG.
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Wes
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Re: Identifying asbestos

#4 Post by Wes » Tue Nov 05, 2019 8:12 pm

Zeiss Photomicroscope III BF/DF/Pol/Ph/DIC/FL/Jamin-Lebedeff
Youtube channel

rs6000
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Re: Identifying asbestos

#5 Post by rs6000 » Wed Nov 06, 2019 4:51 am

Thank you all very much for your input and the sources of Documentation I have another question on something I don't have
do I really need a red slider like the ones described they seem quite expensive for such a vintage item.

cheers

Bryan
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Re: Identifying asbestos

#6 Post by Bryan » Wed Nov 06, 2019 5:42 am

My first job out of college was a microscopist I an asbestos lab. It’s been almost 30 years since I left that job but I remember a few things. I did two different types of analysis, the main one was PLM identification using a petrographic microscope. This was for identifying asbestos in bulk samples like popcorn ceiling or asbestos insulation. I would pulverize a sample and look at it under polarized light using different refractive oils. There are several different types of asbestos and they all have different refractive indices. Once I identified fibers that looked like asbestos I would identify the type with the proper oils. I would also determine the concentration for reporting purposes, any thing over 1% is considered asbestos containing.

It sounds like you are concerned with airborne asbestos. What I did was analyze filter cassettes that collected airborne dust for a work shift. I used a phase contrast microscope to count fibers, anything over a certain ratio of length and width. There was a method we had to follow counting fibers to determine the concentration. This didn’t specifically identify asbestos fibers, it gave a concentration of potential airborne asbestos. If we wanted to know if there was really asbestos in the sample it was sent to another lab that used an electron microscope.

Unless you are in thick dust and can get a concentrated sample to view It would be very difficult to identify airborne asbestos. Bulk samples have nice large fibers to identify, airborne asbestos will be much smaller, especially if it traveled some distance to reach you. I don’t know what concentrations you have in the air but it can be a problem. Look at what happened in Libby, Montana or Asbest, Russia, two extremely bad cases.

https://www.asbestos.com/jobsites/libby/

https://www.nytimes.com/2013/07/14/bus ... habit.html

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Re: Identifying asbestos

#7 Post by MichaelG. » Wed Nov 06, 2019 6:01 pm

rs6000 wrote:
Wed Nov 06, 2019 4:51 am
[…] do I really need a red slider like the ones described they seem quite expensive for such a vintage item.
The specification for the slider doesn’t seem too onerous
■ a removable first order red compensator (of retardation approximately 530 nm);

I suspect that a DIY approach would suffice.

Note: The text below Fig. 7 here is helpful:
https://www.microscopyu.com/techniques/ ... microscopy

MichaelG.
.
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Edit: Also worth a look:
https://www.microscopyu.com/techniques/ ... efringence
The area between zero and 550 nanometers is known as the first order of polarization colors, and the magenta color that occurs in the 550 nanometer region is often termed first-order red.
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rs6000
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Re: Identifying asbestos

#8 Post by rs6000 » Fri Nov 08, 2019 7:13 pm

seems like the general consensus is quartz ,mica etc sliders are not as important as differing refraction oils
my question now becomes I did not know of anything other then the immersion oil I use for 63x and 100x objectives where do I obtain such a wide variance of oils

Hobbyst46
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Re: Identifying asbestos

#9 Post by Hobbyst46 » Fri Nov 08, 2019 7:59 pm

rs6000 wrote:
Fri Nov 08, 2019 7:13 pm
seems like the general consensus is quartz ,mica etc sliders are not as important as differing refraction oils
my question now becomes I did not know of anything other then the immersion oil I use for 63x and 100x objectives where do I obtain such a wide variance of oils
I do not know if they fit asbestos analysis, but one of the best sources for defined nD oils is Cargille (USA). Their oils are also distributed by Amazon and specific laboratory suppliers, (Sigma etc); and are priced accordingly (not for inexpensive hobby use).

rs6000
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Re: Identifying asbestos

#10 Post by rs6000 » Fri Nov 08, 2019 9:51 pm

WOW :o

692$ to 2K$ for 7ML :shock:
AND I thought the sliders were expensive did I go on the wrong page?

https://cargille.com/refractive-index-l ... 10b42-bb01

Scarodactyl
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Re: Identifying asbestos

#11 Post by Scarodactyl » Fri Nov 08, 2019 10:41 pm

That's for a set of over 100 ri fluid bottles with 0.02 increments. I suspect you can get by with a few of the 1/4 oz bottles for your use, though I could be wrong as I haven't done asbestos analysis before.

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Re: Identifying asbestos

#12 Post by Bryan » Sun Nov 10, 2019 3:18 am

You don’t need anywhere near 100 different RI oils, I think I had a set of less than a dozen and there were a few out of that set that got the most use. I wish I could remember what ones we used.

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Re: Identifying asbestos

#13 Post by Bryan » Sun Nov 10, 2019 3:29 am

Here’s some information on bulk asbestos identification. It sounds a lot like the method I used and it lists the oils that you need

https://www.cdc.gov/niosh/docs/2003-154/pdfs/9002.pdf

rs6000
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Re: Identifying asbestos

#14 Post by rs6000 » Mon Nov 18, 2019 2:59 am

Thank you VERY much I sure have my work cut out for me looks like ill have to procure 6 differing RI oils according to that document and maybe a red slider
sure wish you could borrow or rent equipment like that would make a beginner Micropisist life much easier
but no scope shop in this town!!

rs6000
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Re: Identifying asbestos

#15 Post by rs6000 » Wed Nov 20, 2019 11:15 pm

Extreme confusion
I thought I new everything about differing types of Objectives Phase,Polo Strain Free, Dark F built in Iris, TIRF specific, DIC between all but Phase maybe a slight different glass Flourite ETC but other then that most objectives all seem the same optically

well after reading through those docs I have been provided I found a confusing line or two sounded like I need a special staining RI oil
here is quoted TEXt:

Dispersion staining
A2.39 Dispersion is a term used to describe the variation in RI with the wavelength of light. Differences in dispersion between particles and liquids mean that even though the RIs match at one wavelength, they may be quite different at others. This leads to colour effects when fibres are observed in matching RI liquids using white light. It is easiest to observe small bright particles against a black background; hence a central stop in the back focal plane of the objective is used


looks like I as well need a specialized Dispersion Staining objective DS type objective one that I have never seen on any website :shock:
MY new understanding is that POLO Scopes are not for faint of heart centering nosepiece turret, quartz wedges, analyzer,First order compensator, lambda plate ;;geesh the list goes on might as well buy a DIC setup does not seem much different and you save a lot of money on all those accessories
maybe I should go to school to learn this stuff I really don't know what to do now

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wporter
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Re: Identifying asbestos

#16 Post by wporter » Thu Nov 21, 2019 10:43 pm

Another possible reference, from the esteemed McCrone Research Institute:

http://www.mccroneinstitute.org/v/90/as ... tification

Hobbyst46
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Re: Identifying asbestos

#17 Post by Hobbyst46 » Fri Nov 22, 2019 9:31 am

Here is another good reference on asbestos and dispersion, from the late R. Pavlis
http://www.microscopy-uk.org.uk/mag/ind ... rsion.html

Regardless of asbestos analysis, it seems that dispersion staining can be fun, must find time to play with it!

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75RR
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Re: Identifying asbestos

#18 Post by 75RR » Fri Nov 22, 2019 12:39 pm

... maybe I should go to school to learn this stuff I really don't know what to do now
Is this something that you want to do yourself or need to do yourself or is it just something that you want done, as in it does not really matter who does it?

I ask because it seems to be getting overly complicated and potentially expensive.

Perhaps if you can provide a little more background someone can suggest a more practical solution ... as in you collect the samples and send them to a Lab
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

rs6000
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Re: Identifying asbestos

#19 Post by rs6000 » Mon Nov 25, 2019 1:20 am

Yes I wish to do this myself as 1. outside labs Will be expensive AND 2. I am a avid Cat 3 Cyclist in road Biking discipline and find myself outdoors majority of the time breathing heavily the norm as mountain passes and road races get your cardiovascular system going full TILT
jeff TTs.jpg
jeff TTs.jpg (59.78 KiB) Viewed 15233 times
so when I saw this news it frightens me most certainly :shock:
https://www.8newsnow.com/news/deadly-du ... -backyard/

I already have pretty good amount of prerequisites I thought :o Zeiss 18 scope with polarizing monocle head incl Bertrand/ Dia lens with port for slider, rotatable stage one 10x Zeiss strain free obj.
I was not prepared to find I still need additional equipment I did have plans to someday get a red first order slider but I never heard of DS objectives their description sounds like Phase COntrast optics but are decidedly different

the current setup works well for most of my specimens Below my setup and a sample of cellulose in glycerin medium with full crossed polos
but morphology of Asbestos is a whole other animal it seems :(
POLO Z18.jpg
POLO Z18.jpg (61.88 KiB) Viewed 15233 times
PaperNAP.jpg
PaperNAP.jpg (115.81 KiB) Viewed 15233 times

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75RR
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Re: Identifying asbestos

#20 Post by 75RR » Mon Nov 25, 2019 5:51 am

For those members in Europe who are unable to access the 8newsnow link, here it is on youtube:

Perhaps someone with a scientific background can comment on it.

https://www.youtube.com/watch?v=4BYDDLuZMSk
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MichaelG.
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Re: Identifying asbestos

#21 Post by MichaelG. » Mon Nov 25, 2019 5:53 am

rs6000 wrote:
Wed Nov 20, 2019 11:15 pm
looks like I as well need a specialized Dispersion Staining objective DS type objective one that I have never seen on any website :shock:
I noticed reference to this DIY project in John Gustav Delly’s recent book:
http://www.mccroneinstitute.org/uploads ... -84932.pdf

MichaelG.
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rs6000
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Re: Identifying asbestos

#22 Post by rs6000 » Mon Nov 25, 2019 10:35 pm

Some food for thought on the dangers of LIbby Mt and southern NV main contaminantes are actinolite: see link below
I just got off phone with Brenda Buck of UNLV and she mentioned in our discussion when its windy esp from the south there is a lot of airborne danger.

https://www.unlv.edu/sites/default/file ... 6-2192.pdf

Biological mechanism of induced disease
https://thorax.bmj.com/content/54/7/638

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Re: Identifying asbestos

#23 Post by Chris__R » Sat Nov 30, 2019 7:14 pm

Some time ago I bought a Lomo portable microscope, which is equipped for polarization work. It came in a fitted wood lined metal carry case, with the wedge and wave plates missing but I have managed to find the right ones, to fit their slots. It has the Bertrand lens in the upper part. They appear on ebay now and then.

I wondered why anyone would want a portable geological microscopy - one can hardly prepare 30 micron rock sections in the field! Then I realized, it was likely made with asbestos analysis in mind.
As "pol" microscopes go , it doesn't give any other special features, so what you already have should suit.

My first degree was metallurgy and materials science, so I always intended to use it for inspecting the asbestos-cement roof of my side shed, but never did get around to it. I have a set of refractive index liquids, but I also have not seen the type of objective referred to in the article. The objectives in the Lomo set are slightly unusual magnifications, but not otherwise remarkable.
Last edited by Chris__R on Sat Nov 30, 2019 9:02 pm, edited 1 time in total.

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Re: Identifying asbestos

#24 Post by Bryan » Sat Nov 30, 2019 8:51 pm

Chris__R wrote:
Sat Nov 30, 2019 7:14 pm
Some time ago I boiought a Lomo portable microscope, which is equipped for polarization work. It came in a fitted wood lined metal carry case, with the wedge and wave plates missing but I have managed to find the right ones, to fit their slots. It has the Bertrand lens in the upper part. They appear on ebay now and then.

I wondered why anyone would want a portable geological microscopy - one can hardly prepare 30 micron rock sections in the field! Then I realized, it was likely made with asbestos analysis in mind.
As "pol" microscopes go , it doesn't give any other special features, so what you already have should suit.

My first degree was metallurgy and materials science, so I always intended to use it for inspecting the asbestos-cement roof of my side shed, but never did get around to it! I have a set of refractive index liquids, but I also have not seen the type of objective referred to in the article. The objectives in the Lomo set are slightly unusual magnifications, but not otherwise remarkable.
I wonder if there is a way that they made thin sections in the field. I could see a geologist doing that on remote exploration work where a portable Petrographic microscope would be needed. I work in the environmental industry, it’s not unusual to have a microscopist on site to analyze air samples which is done with a phase contrast microscope. I have rarely seen anyone analyzing bulk asbestos samples in the field. Those are usually sent to a lab prior to doing site work since there is usually some remediation design done before starting a project. On a very large project you may have someone that can do both in which case they would have both microscopes onsite.

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Re: Identifying asbestos

#25 Post by MichaelG. » Sat Nov 30, 2019 9:43 pm

Field microscopes can be very useful in biological work, and probably this petrographic scope could also be used for mineral samples such as soil and crushed grains. In the olden days, we would scrape off rock particles into a drop of immersion oil on a slide, and attempt identification via birefringence and relief characteristics. A rock section is much better, but it would be a real trick to make a 30 micron thin section of a rock while living in a field tent, far off the grid!
Source: J. Gregory McHone, Canada
http://www.microscopy-uk.org.uk/mag/ind ... -Lomo.html

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Re: Identifying asbestos

#26 Post by Chris__R » Sat Nov 30, 2019 11:24 pm

I can't think what equipment to slice up, grind and polish rocks wouldn't be very large compared with this microscope. Also, it's a time-consuming business.
The case is about 24 x 20 x 10 cm.
Perhaps it would be for looking at insulation materials, etc. Otherwise why make it portable?

It could be useful for sand, etc, but are there enough people looking at that to make a special scope for it?

The scope I have is the MIN - 1, download/file.php?id=9260

rs6000
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Re: Identifying asbestos

#27 Post by rs6000 » Mon Aug 17, 2020 10:19 pm

I think I have found some samples identified as Blue Crocidolite and White Asbestos or Chrysotile
these images were produced using a Zeiss POL image crossed and Red compensator
and Darkfield

I was using a filter paper Disc taped to a Glass funnel amber latex hose to a battery operated blower
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chrokdiolite.jpg
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