thermochromic - 12-10-2020 at 19:40
So obviously I know natural gas, propane, and whatnot has mercaptans added for safety but the cylinder of both industrial grade oxygen and industrial
grade 75%Ar/25%CO2 I have for welding have no noticeable smell. A few days ago I picked up a cylinder of 100% Argon from my local Matheson dealer for
some shielding gas on a couple LAH reductions I have coming up for safety. Problem is, the gas has a disagreeable smell to it. It not really the
mercaptan smell i'm used to but, first off, its hard to even smell because of an intense burn to the nostrils, akin to sticking your face over some
37% HCL and inhaling just enough to fill your nose (but not your lungs), you get when attempting to try and smell it. What i could pick up was like
maybe hints of ammonia mixed with pyridine with 'spicy' tones to it, pungent, almost like methyl isocyanate.
Just curious if anyone has any input on if this is a purposely added substance for safety reasons, or an impurity resulting from manufacture. It is
industrial grade. I am hesitant to think the ladder because it is supposed to come from distillation of air; however, Argon is about as harmless a gas
as you can get. Sure it can displace air but so can a lot of stuff, plus my older cylinder of ArCO2 mix had no such smell (I will say it has nit been
used a lot and was filled around 2008 so thing may of changed since then).
However going to their website and using the link they provide for the SDS on it, which my tank says 'UN1006' on it, which looks to be their part
number,
https://store.mathesongas.com/safety-data-sheets-sds/
After searching for 'Argon"
I find
https://www.chemadvisor.com/matheson/database/msds/002323490...
and it clearly states "argon 100%". So what gives? Bottle contamination? Since the substance is unknown I feel it would be foolish to ask if it will
interfere with my reaction. If I take it back up there and complain about the smell, they will probably reply with "shouldn't bother your TIG welding
any". Now while I do not necessarily mind informing them of my intended use of it, I feel, at the least it will be a headache and possibly a lot more
money to get higher grades (do they make food grade argon?). I suppose I could get food grade nitrogen or something, but again, not sure if they even
stock it. I know Matheson is pretty big in the gas world so I have no doubt they could probably order it. The reason I did not get nitrogen to begin
with was that I have a limited amount of money and space so I figured argon would be a "cover all" gas in case I do something in the future that
nitrogen wouldn't cut it on. Plus argon is heavier than air so it is good at blanketing the reaction inside the flask, or at least that is what I
read. Just wanted to opinions on what other people would do.
Thanks
[Edited on 13-10-2020 by thermochromic]
[Edited on 13-10-2020 by thermochromic]
bobm4360 - 12-10-2020 at 19:50
With that effect on you, it's not inert. Take it back!
B(a)P - 12-10-2020 at 21:04
I purchase argon on a semi regular basis (every few years).
The argon welding gas sold in Aus, at least from BOC where I get it, is sold as industrial grade and claims to be suitable for analytical and food
applications. It is 99.995% pure, the balance being O2, N2 and H2O.
It certainly does not have any odourant.
I wonder if a bottle that contained an argon mix with something else has been refilled and sold as argon, you would hope they had controls in place to
prevent this.
Edit
I would take it back. If it has such a terrible odour/effect I can't imagine welders being happy to use it.
Also UN numbers are dangerous goods classifications not product codes,
UN1006 is for compressed argon.
[Edited on 13-10-2020 by B(a)P]
[Edited on 13-10-2020 by B(a)P]
thermochromic - 13-10-2020 at 08:03
Ok, that is kind of what I was leaning towards. Thanks. I will say it is an older bottle by the looks of it. The only other markings I saw on it were
a removable, like a price sticker but larger, sticker that had "265 Q11 033" on it. Probably an internal batch number, filling location, and other
quality control numbers. Seems like they will need it on this one.
Fyndium - 13-10-2020 at 08:15
If it were intentional, it would be for the exit bag guys. Probably not quite suitable for any critical welding jobs or for chemistry, not even
speaking of food or medical grade. Good question would be, why bother if you ruin the inert gas with impurities?
Dr.Bob - 13-10-2020 at 16:44
I have never had an inert gas smell at all in my history. I would guess that someone (could have been a previous customer) screwed up, and either
contaminated the cylinder, or they reused oine from a different gas, or who knows what. I would call them and tell them the argon seems contaminated
based on the irritating small and see what they say. Offer to ask OSHA or the EPA about it if they are a pain. But they might just laugh, you
never know.
thermochromic - 14-10-2020 at 16:15
Well I sent their company customer service dept a nice email explaining what happened and they forwarded it to the store manager, who replied to me
and told me to bring it back up for a replacement. When I got there they said they did not have any 60 cubic foot cylinders left however they had some
80 cubic foot and would exchange that for it free of charge. They seemed to be taking the matter rather seriously and told me they were sending it off
to their lab to analyze. Seems in my case at least, Matheson had great customer service.
B(a)P - 14-10-2020 at 17:13
Excellent result! Glad to hear they were helpful.
It would be interesting to find out what it actually had in it, I doubt they will get back to you with that though.......