Sciencemadness Discussion Board

Canned Air - Hydrofluoric Acid

BobD1001 - 8-12-2014 at 23:12

Earlier tonight I was working with canned air dusting out my computer when some of it caught fire. The fire caused no damage and quickly extinguished however this was is a relatively enclosed room. Shortly after I noticed an acidic smell like vinegar or the like. I quickly opened both windows, turned on the ceiling fan, and aired out the room very well. After just researching the contents of the can a bit, it appears Difluoroethane is the main component of the duster, which according to data sheets produces Hydrofluoric Acid upon decomposition.

My question now is to safety: the exposure was very short and not even enough to make me sneeze or cough, just enough to notice some acidic smell. At this low level I'm assuming I should be okay as I'm not feeling any ill affects, but is there reason to believe otherwise?

woelen - 8-12-2014 at 23:55

If you just smelled something acidic it and experience no adverse effects, then you should not worry. HF indeed is very toxic, but you inhaled so little that you will not have any nasty effects.

BobD1001 - 9-12-2014 at 00:12

Thank you Woelen. My hastily performed research told me that I should be okay, but I wasn't quite sure of just how toxic it was. I believe what I smelled was right at or just above the odor threshold of 0.5-3ppm.

Quite scary however and in the future I will certainly stick to using compressed air rather than this "canned-air" Difluoroethane. Scary that the layperson would have not even known to research what fumes they were smelling.

CuReUS - 9-12-2014 at 01:07

Quote: Originally posted by BobD1001  

Quite scary however and in the future I will certainly stick to using compressed air rather than this "canned-air" Difluoroethane. Scary that the layperson would have not even known to research what fumes they were smelling.


most people think that canned air is actually "air" that has been compressed

but ,you would need a lot of pressure to be able to compress air and than put it in a can

so they use hydroflourocarbons which can be compressed easily

i once read about an incident in which someone's house had caught fire and although the person and been pulled out from the blaze,he had passed out due to smoke inhalation :(

one of his neighbours tried to give him CPR using a can of canned "air" ,thinking it was O2 or something :D

i doubt whether he survived

but look on the bright side
this could be used as a potential OTC source for HF


EDIT

i was under the impression that HF was OTC ,or atleast easily available as they liberally use it in "breaking bad" to dispose of men and machine ;)

also BOB,be careful while using compressed air for cleaning your computer
the air might come out with such force that your computer's cooling fan might come off its pivot :(

[Edited on 10-12-2014 by CuReUS]

woelen - 9-12-2014 at 03:37

I did an experiment some years ago. I burned some of the gas in excess air and kept a piece of glass above it. It became frosty, due to formation of HF.

C2H4F2 gives CO2, H2O and HF, when burnt completely.

subsecret - 9-12-2014 at 04:45

This could be a potential route to concentrated solutions of HF. One problem is that canned air is expensive IIRC.

Morgan - 9-12-2014 at 05:43

Hydrofluoric acid burn resulting from ignition of gas from a compressed air duster.
http://www.ncbi.nlm.nih.gov/pubmed/14501419

BobD1001 - 9-12-2014 at 16:49

Quote: Originally posted by Morgan  
Hydrofluoric acid burn resulting from ignition of gas from a compressed air duster.
http://www.ncbi.nlm.nih.gov/pubmed/14501419



That was one of the very few articles I was able to find similar to my experience, which needless to say scared me a bit more... hence leading to my original post. However I'm still alive and breathing well!

As to the other posts regarding the production of HF solutions utilizing the decomposition of Difluoroethane: it would certainly be a viable method in my opinion, as I can say the small amount which decomposed in this accidental experiment was able to make my room seem quite acidic. The only impurity I could foresee given that the decomposition products are CO2, H2O and HF would be the bitterant that they add to stop drug huffers.

Having said that it is something I would never try, far too much risk dealing with HF gas for my taste.

subsecret - 9-12-2014 at 16:52

If you got the gas stream hot enough, then the bitterant would decompose to CO2.

Fantasma4500 - 15-12-2014 at 04:31

not very clear acute effects, at least.. they would take long time and be practically impossible to notice, no matter how much people disagrees about fluorides toxic effects
vinegar.. thats really interesting.. i have actually wondered a whole lot about how HF smells, being fluorophobic that notation is .. gold!

actually i just came across this difluoroethane, and wanted to spread the word, apparently its not that unknown.. pretty interesting OTC source of fluor, no damn wonder they sell canned air that expensively haha.. now im just above happy that i chose to put together a smaller gas canon to clean my computer with, one shot gets all the dust out of the cooler for my CPU, very reccomended! half litre coca cola PET bottle and a 10mm ID plastic tube in the end and diesel start does it in one hit

about price:
http://www.ebay.de/itm/Ultra-Duster-Canned-Air-6-Cans-10-oz-...

but honestly, i cant believe they would allow such overly insanely nasty shit to get in the hands of innocent unknowing civilians, chemical hypocrisy is a reality, but difluoroethane meant to be dispersed in areas without ... very intense safety is just the dumbest thing i have ever heard, beyond my imagination! cant believe this

j_sum1 - 15-12-2014 at 14:32

Quote: Originally posted by Antiswat  

but honestly, i cant believe they would allow such overly insanely nasty shit to get in the hands of innocent unknowing civilians, chemical hypocrisy is a reality, but difluoroethane meant to be dispersed in areas without ... very intense safety is just the dumbest thing i have ever heard, beyond my imagination! cant believe this

I can't believe the stuff is labelled "air"! That is just irresponsible.

Bert - 15-12-2014 at 19:48

"Air dusters"

http://www.sisweb.com/referenc/msds/dustoff.pdf

Flammable limits: 3.9 - 16.9% by volume , ignition 454 C (849 F)

Sweet Jesus. DuPont put THIS out for the ignorant public to spray into (potentially powered up) electronic devices?!

Get a small air compressor, tank and "blow gun". Cheaper in the long run if you just want to blow dust out of equipment- And you can inflate tires or sports equipment with these as well.

[Edited on 16-12-2014 by Bert]

Morgan - 17-12-2014 at 13:17

I happened to notice a 10 ounce can of this Ultra Air Duster for $4.99 at a Harbor Freight store today and read the caution label just out of curiosity/because of this thread that was started. The label mentioned a bitterant to discourage inhalation as well as the flammable in certain circumstances caution.

http://www.harborfreight.com/10-oz-ultra-duster-industrial-s...

The Volatile Chemist - 17-12-2014 at 13:46

Sheesh. Interesting application.
I hope it has a stronger smell than vinegar, since I started in amateur chemistry, my ability to smell vinegar has decreased rapidly. I have no clue why.