Lava Rock Packing Safety (scoria)

[bearriver]

Here is a place where you can discuss what you know and or think about the safety aspects of using lava rock (scoria). This conversation has grown contentious in the past, so I hope that we can all keep our big boy pants on for this one.

If you do or do not think lava rock is safe, please discuss it here where it will not disrupt any other conversations. Any information gleaned on either side of the fence is greatly appreciated. Thank you.

[S-Cackalacky]

I posted a link to an MSDS for scoria on that other thread -

Was doing some research and found this - http://www.rock-hill.k12.sc.us/UserFile ... Scoria.pdf" onclick="window.open(this.href);return false;" rel="nofollow . It's from a specific mining company in Iceland(?), so it's hard to say if this same MSDS holds true for other sources.

I don't know what any of the chemical compounds are in the report. Maybe someone could post up and let us know if any of them are unsafe.

Edited to repair the link in the "quoted" section.

[bearriver]

I broke that list down by their names


47.4% Silicon dioxide
14.5% aluminum oxide
1.7% titanium dioxide
13.6% Iron(III) oxide
12.2% Iron Oxide
10.4% calcium oxide
8.0% Magnesium oxide
2.2% Sodium Oxide
0.3% Potassium Oxide
0.2% Phosphorus pentoxide
0.2% Manganese(II) oxide

[S-Cackalacky]

Bear, appears that most are more interested in the pissing contest going on in the other thread. I posted up the link to the MSDS report and it has gone virtually ignored. I thought MSDS reports were considered fairly reliable resources related to safety - must have been mistaken. Anyway, thanks for the translation of the chemical compounds.

[bearriver]

You have pulled one of multiple MSDS spec sheets available, thus reconfirming that we know what comprises lava rock. Thanks Cack. That is a great way to start this thread.

With that information and data like it, we can determine if the substances present are safe or not in a still. You have a list of chemicals comprising the rocks and a list of chemicals comprising the vapor. It's then the researcher's responsibility to compare those substances for inadequate resistance. My research thus far, and the research of others more knowledgeable is in agreement (in no small part thanks to Mash Rookie). Two things can change that agreement. One: if someone presents scientific evidence that suggests generic lava rock inherently can have dangerous levels of a substance that we are not currently aware of. Two: evidence of low resistance between a chemical in the vapor, and a chemical in the rock, again leading to hazardous levels of a substance. The information is laid out there for anyone to look at.

Opinions are just that, but the scientific method currently has shown that lava rock is considered safe for use in a still. This is why I love the scientific method. It filters out all the human baggage and gets straight to the good stuff.

[S-Cackalacky]

With all the bickering going on in the other thread, I had to satisfy my own curiosity. That was the first MSDS document I stumbled upon and since it was an Icelandic mining company I figured it must mean something because the island is basically volcanic. I would imagine they are a major source for the stuff. Rad posted in the other thread that the chemical compounds in the list are inert. I don't know how deep Rad's knowledge of chemistry goes, but I know he has a broad knowledge of many subjects and I pretty much trust his opinions, but second opinions are welcomed and appreciated.

[pfshine]

From Wikipedia.

Phosphorus pentoxide is not flammable. It reacts vigorously with water and water-containing substances like wood or cotton, liberates much heat and may even cause fire. It is corrosive to metal and is very irritating – may cause severe burn to the eye, skin, mucous membrane, and respiratory tract even at concentrations as low as 1 mg/m3.

[pfshine]

Calcium oxide (quick lime) is a very caustic material. Has anyone that has been using lava rock noticed any corrosion in the column or boiler? Also with the large amount of iron oxide (rust) in the rock has anybody noticed any excess rust around penetrations (triclamps drains heating elements)?

[Jacksonbrown]

Iron oxide contaminated SS rusts very quickly.
Some machine shops that specialise in SS refuse to work with mild steel for this reason.

[FullySilenced]

I would prefer this thread not have any speculation.... ONLY THE FACTS that you find from a verified source...

Lets see if we can keep the BS out of this thread people...

Happy Stillin,

FS

[pfshine]

What speculation?

[FullySilenced]

I didn't say there was any speculation as of yet...

I just would prefer this thread only contain facts...

[bearriver]

Well said FS. (Edit: I'm not sure that he was implying someone was speculating, but just giving a fair early warning.)

To answer the question pfshine posed, no. I have used the same rocks for a year on the same boiler with no subsequent rust to the stainless below the column. I use a stainless boiler with stainless fittings below a copper LM, and inspect it frequently.

(Note: For those aware, my rusted elements documented here had another issue altogether that is not uncommon)

Edit again, posted the same time as FS.

[shadylane]

From Wikipedia.

Phosphorus pentoxide is not flammable. It reacts vigorously with water and water-containing substances like wood or cotton, liberates much heat and may even cause fire. It is corrosive to metal and is very irritating – may cause severe burn to the eye, skin, mucous membrane, and respiratory tract even at concentrations as low as 1 mg/m3.

I've boiled a pound or three of scoria and didn't notice any violent chemical reactions.
Nor have I seen any changes in the bag of scoria that's laying under the bench where the condenser water leaks

[pfshine]

Upon further review the Phosphorus pentoxide looks pretty bad at first in the hazard sections but it is used frequently in water treatment and other things. Here is a full bio on it.

http://pubchem.ncbi.nlm.nih.gov/compoun ... ection=Top" onclick="window.open(this.href);return false;" rel="nofollow

[thecroweater]

One thing to take into consideration is that scoria from Oz or the USA is more likely to be millions of yrs old where as from Iceland it may well have been hours old. The point I'm making is more logical than scientific but it stands to reason that anything solvent would have leached out of this very porous rock countless millennium ago

[Jacksonbrown]

I may have been thinking of galvanic potential see here.
Could still be an issue though.

[S-Cackalacky]

Would be nice to get some input here from a chemical engineer or scientist. With those compounds Pfshine pointed out as being of concern, do they transition to something else with the introduction of the reactive catalyst (water), or do they remain as they are and present a potential hazard - IDK. Also, would it be a fair assumption that the concern with those compounds would be somewhat mitigated by how they are dispersed in the stone - that is, if it's 0.2% total volume, would the concern be with the smaller percentage that's actually exposed on the surface area? And, what is an acceptable level?

With the presence of the phosphorus pentoxide and calcium oxide in the scoria, I wonder why the MSDS doesn't list them as a potential hazard. Do other MSDS sources similarly list them and likewise don't show any indications of potential hazards? Wonder what the reasoning is for that. Would seem that this all needs a lot more investigation to settle it one way or the other.

[thecroweater]

ok the reason it seems to be inert is because it is inert. In pyroclastic rock it will be found in a stable polymorphic solid glass phase due to the fact it has far exceeded the compounds melt point of 562'C forming an orthorhombic crystal system. I would hazard a guess if it wasn't made stable any compound so soluble in water should have leached out millions of years ago

[emptyglass]

Good thread Bear.

I'm no rock hound or geologist, but the scoria we have access to here in the south east of Australia is very old in geological terms. As crow said, its been rained on foe a long time. From what i'm told and was taught at school Australia is one of the oldest stable geological places in the world. Our rocks are old.

The scoria I have access to used to come from here https://en.wikipedia.org/wiki/Mount_Elephant" onclick="window.open(this.href);return false;" rel="nofollow but as the article says, there are some 200 similar deposits of it here.

I cant comment on "lava rock" from other counties, but the stuff here is pretty well inert. It works very well in the application of distillation packing, no apparent negatives have been noticed.
Like any material, it must be used in confidence. If in doubt, leave it out.

I appreciate the scientific approach to this thread, in respect to that I have no scientific evidence its completely safe, but I will throw the question of if any of the alternatives also pose any positive or negative effects that can be similarly backed up with scientific evidence?

So I guess its up to the user to decide on the safety of any local lava rock, or stuff supplied in bags from big box stores with no traceability to the source.
As "lava rock" is a compound, it will have natural variance in its composition from region to region, its really up to the user to decide if the benefits of clean neutral from a cheap as chips medium is something they are prepared to risk, or if they want to initiate their own toxicology reports.

The common alternatives are generally considered to be copper structured packing that is proven to work but is very costly, or spiral prismatic packing made from stainless, that has stuff like chromium, molibdomen, phosphorus and a host of other things in its composition.
I kinda trust a natural compound like lava rock, although it could scruff your ass should you try and wipe with it, but i digress....

[pfshine]

Good thread Bear.

From what i'm told and was taught at school Australia is one of the oldest stable geological places in the world. Our rocks are old.

Dang straight they're old. The oldest rock ever found was in Australia, 4.375 Billion years old +/- 6 million years. Anyhoo the page I linked to above states that Phosphorus pentoxide reacts with propanol which is in our foreshots. (Ok maybe a little speculation coming up) if the rocks are broken up you expose internals that have not been subjected to erosion and leaching. That being said I'm not bashing or saying it's gonna kill you. I plan to get some here in the near future and put it through a battery of cleaning and tests. I will break it down to the size I want wash it off give it a good boil then give it a good long soak in fores and one more rinse before using. If I had the the machines or time and money I would put samples of each bath before and after through a gas chomatograph and spectral analysis, but since I don't I will evaporate each and look for crystallized salts that could be harmful or explosive IF said reactions are even plausible in our current use and methods for distillation as packing material.

[S-Cackalacky]

Here's another MSDS - https://view.officeapps.live.com/op/vie ... a_rock.doc" onclick="window.open(this.href);return false;" rel="nofollow . It doesn't give a list of the chemical compounds, but, like the other one, it doesn't show any hazards - other than to avoid breathing the dust.

Posted while Pfshine was posting.

[bearriver]

Here are 7 MSDS reports on scoria from major producers and suppliers. I am happy to get more if anyone wants to see them.

I want to note that many of the worlds largest suppliers are based out of Australia.

https://www.menards.com/msds/100869_001.pdf" onclick="window.open(this.href);return false;" rel="nofollow
http://www.bpsaust.com/files/Scoria.pdf" onclick="window.open(this.href);return false;" rel="nofollow
https://www.google.com/url?sa=t&rct=j&q ... GU&cad=rja" onclick="window.open(this.href);return false;" rel="nofollow
http://www.hanson.com.au/LinkClick.aspx ... &tabid=136" onclick="window.open(this.href);return false;" rel="nofollow
http://www.winstoneaggregates.co.nz/wp- ... lt_web.pdf" onclick="window.open(this.href);return false;" rel="nofollow
http://www.bunnings.com.au/australian-b ... a_p0760155" onclick="window.open(this.href);return false;" rel="nofollow
http://www.eden.is/index.php/download_file/-/38/" onclick="window.open(this.href);return false;" rel="nofollow

[Jacksonbrown]

https://en.m.wikipedia.org/wiki/Frit

[Jacksonbrown]

I appreciate the scientific approach to this thread, in respect to that I have no scientific evidence its completely safe, but I will throw the question of if any of the alternatives also pose any positive or negative effects that can be similarly backed up with scientific evidence?

304 and 316 are actually food grade stainless and copper is the standard for potable water. I won't be wasting my time verifying those materials.

[pfshine]

Maybe I missed it but what does frit have to do with this? Please don't bring negativity to this thread.

[bearriver]

https://en.m.wikipedia.org/wiki/Frit

I had no idea what frit even was. Avoiding any speculation I will say that there is plenty of good stuff to research there. Thanks for that addition.

[rad14701]

The compounds listed are, in fact, in the lava rock, otherwise they wouldn't be listed... The surface may have been washed clean of these compounds many years ago but every new fracture would potentially expose more as it creates new surface area... During the testing process the lava rock is most likely pulverized, exposing extreme amounts of virgin surface area... Washing the lava rock would, theoretically, remove a majority of the newly exposed compounds... However, as stated earlier, amounts of what could be potentially hazardous compounds are relatively low compared to their presence in everyday life... I'd recommend boiling and rinsing before use, which I'm fairly sure most who use it have done as standard practice...

[Jacksonbrown]

Maybe I missed it but what does frit have to do with this? Please don't bring negativity to this thread.

Toxic compounds trapped in a vitreous matrix? It sounded kinda like what's being dug up here. I thought it was relevant, maybe it isn't.
It's mostly used as a way to make handling lead compounds much safer in glass and enamel production.

Another research angle at least.

http://digitalfire.com/4sight/hazards/c ... s_168.html

Someone will probably try to use it as packing material now. 'It's like lava rock and marbles got together and had kids"

[thecroweater]

Jacksonb your synthetic matrix has Jack to do with scoria and the reason those compounds are listed as non hazardous is not because they are trapped inside as a lot of the rock is broken down to a required grading size. The reason its not listed as hazardous is because in the form they are in and the amount they are present they are zero risk to health. If they were then the very many companies the deal with them would protect themselves by disclosing such.