Sciencemadness Discussion Board

Has anyone smelled hydrazoic acid?How does it smell like?Is it worse than chlorine,ozone and nitrogen dioxide?

nagyepf - 9-12-2020 at 21:26

Almost all articles on the internet about hydrazoic acid or hydrogen azide mention what dreadful sharp pungent smell it has. Did anyone have experience with that? Can it be compared to anything else?

Pumukli - 10-12-2020 at 22:07


C'mon guys!

78 reads so far and not a single hint that "back in the days I heard about someone who really smelled this stuff".
I'm surprised because we have people here who actually was brave enough to intentionally smell HCN...

Anyways, I had the impression that HN3 is similar to HCN as they are both acute poisons and they either kill you on the spot or let you get away unharmed without long term consequences. But a few days ago I read somewhere that azides are mutagenic so I'm not so sure now regarding the "without long term consequences" part...

DraconicAcid - 10-12-2020 at 22:09

I've never worked with azides, so I can't help you.

B(a)P - 10-12-2020 at 23:45

Given how severe the symptoms are for a very low dose I have always been extremely cautious when working with hydrazoic acid. So much so that on the few occasions I have worked with it I have not caught a wiff. I think you will find most are the same. In terms, 'back in the days' it's toxicity has been well known for some time and it is quite inaccessible.

nezza - 11-12-2020 at 11:59

I've worked with azides, but never tried to prepare Hydrazoic acid. It is rumored to be extremely unstable and explosive.

itsallgoodjames - 11-12-2020 at 12:11

I've worked with hydrazoic acid before, though only very dilute (5%). I didn't smell it. Azides are generally terrifying to work with, so I made an effort to not breath any of it in.

Rhodanide - 2-1-2021 at 13:01

Yes, sort of. On accident. Here's the thing; in my experience, HN3 has a strange and extremely frightening effect on you in that it constricts the nasal passages almost completely. This, I've found, however alarming and possibly dangerous, may be an indicator to present amounts of HN3 at low concentrations and good indication to get the f*** out of Dodge. When I first encountered it, I attempted to make a roughly 5 mLs of a 5-10% solution of it via the reaction of the Barium salt with dilute Sulfuric acid, which would precipitate the sulfate salt and (hopefully) leave the acid in aq solution. Needless to say, it didn't seem to want to. Result: nasal passages nearly sealed for ~10 minutes, light headed, eyes bloodshot. Nose closed up within maybe 10-15 seconds, so I really couldn't lean in and get a good sniff (which wasn't my intention AT ALL, believe me. I didn't wanna off myself.), so I couldn't really work out any sort of odor besides maybe something acrid. The second time was interestingly in my 5-Atz synthesis. Iirc one of the intermediate compounds formed in solution is Guanyl Azide, and I happened to be short on time and ended the reflux about an hour or so early. Acidified, and immediately got a mild closing of my nose, just like with the HN3 before. It's such a specific feeling, I just think that had to have been it. If anyone is suicidal enough to get the odor down and the specific nuances of it, then go ahead. Because I'm not gonna.

mackolol - 3-1-2021 at 12:10

I wonder what would it do with one's lungs if it passed there. One could have big trouble breathing :0

And yessss my 420th post here, it's time to celebrate guys :cool:

[Edited on 3-1-2021 by mackolol]

karlosĀ³ - 3-1-2021 at 12:39

Quote: Originally posted by mackolol  

And yessss my 420th post here, it's time to celebrate guys :cool:
[Edited on 3-1-2021 by mackolol]

Damn reefer :P

draculic acid69 - 26-1-2021 at 06:52

Smoke a fatty to celebrate.

BauArf56 - 18-4-2021 at 07:46

What does nitrogen dioxide smell like? i read somewhere that it smells like sulfur dioxide... is it true?

Antigua - 18-4-2021 at 07:54

No, not at all. SO2 has a very "penetrating" and sort of sweet, but disgusting in larger concentrations smell. I assosciate NO2 with fume exhaust. It's easy to smell in very minor quantities and the smell doesn't change considerably with concentration.

DraconicAcid - 18-4-2021 at 08:28

NO2 smells like bleach to me.

paulll - 18-4-2021 at 09:18

Quote: Originally posted by DraconicAcid  
NO2 smells like bleach to me.

That's what I get from it; It is distinct but I think if you could separate out the physical sensation of having nitric acid boogers, the odours themselves are nigh-on identical to me.

Fyndium - 18-4-2021 at 09:48

NO2 has a bit chlorine-like, maybe more pungent and sort of sweetish nuance, difficult to explain, but you can differentiate between chlorine and NO2 if you meet them sometime. Pungent, at most, and threshold is extremely low: if there is some, you will smell it. NO2 is extremely toxic, and it can produce lung damage that takes several months to heal, and can leave permanent impaired breathing ability. Accidents involving some in silos and other places it has been and breathed in larger quantities, have required months of hospitalization. I studied this when I accidentally dosed myself due to a slight runaway & failed scrubbing.

SO2 has, on the other hand, pretty much the smell you would expect sulfuric acid to smell like. Sour, stingy, coughing odor, and if you work with it, for example doing bisulfite adducts, you will likely cough up half the time and have a sore throat afterwards. It's not toxic, though, except in large quantities and acutely, so it's mainly irritating to work with.

zed - 18-4-2021 at 13:27

Ummm. Just read something about that a few hours ago. Authors claimed the Azides kill by inducing extreme Hypotension. Might have compared Azides to Nitroglycerine, as a vasodilator.

Doesn't seem like it would be such a big deal, but I suppose when all of the blood vessels in your body dilate at once, you just don't have enough blood to maintain circulation.

Kinda like anaphylactic shock; you turn beet red and swell up. Without intervention, you are in trouble.

But, in the case of Azides.... There might not be an effective way to intervene.

Anyway, a later article doesn't quite agree about the why and how of Azide toxicity.

But, you can read about it for yourself.

[Edited on 18-4-2021 by zed]

karlosĀ³ - 18-4-2021 at 14:51

chemplayer said it smells similar to nitrite esters, but that he felt the incapacitating effects instantly too(which, according to him, also resembles nitrite esters in their effects).
The post is somewhere on here.