Sciencemadness Discussion Board

Handling Formic Acid? Strength compared to other acids?

FireLion3 - 26-9-2014 at 22:07

How does formic acid compare to the corrosive strength of other acids? To acetic? To sulfuric? To hydrochloric? For the sake of handling safety.

DraconicAcid - 26-9-2014 at 22:12

I believe that it's much more toxic than acetic acid, even if it's not much more corrosive (it's Ka is about 10^-4 as compared to acetic's 10^-5).

[Edited on 27-9-2014 by DraconicAcid]

FireLion3 - 26-9-2014 at 22:14

Toxic in terms of...inhaling... drinking....spilling on skin..? I take great care when handling any acids, but I like to know precisely what is going to happen if I spill some on myself and precisely how long I have to act. Sulfuric acid being the scariest that I've handled.... how does formic acid compare to it?

xfusion44 - 26-9-2014 at 22:31

I would say it's not so dangerous, when compared to H2SO4, but here you have probably all, you have to know: http://www.sciencelab.com/msds.php?msdsId=9924100

Mailinmypocket - 27-9-2014 at 08:42

I got burnt by formic acid last year and still have the scar. There is a picture of the burn at the bottom of this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=4311&a...



Texium - 27-9-2014 at 08:53

Formic acid can't be good to get on you considering it's a component of ant venom...

UnintentionalChaos - 27-9-2014 at 09:16

It's about 10x more acidic than acetic acid. Complicating handling are the fact that it's an inhibitor of mitochondrial cytochrome oxidases. It's not nearly as bad as cyanide, but I imagine that this causes much more significant tissue damage if not removed immediately.

Additionally, with strong acids (esp. sulfuric) it undergoes dehydration to carbon monoxide.

S.C. Wack - 27-9-2014 at 11:26

Quote: Originally posted by FireLion3  
How does formic acid compare to the corrosive strength of other acids? To acetic? To sulfuric? To hydrochloric? For the sake of handling safety.


People reply that it's not much different from acetic acid which most consider vinegar, and it's not clear that this is something that will inspire "safe" handling. If you instead put some on a stick and hold it up to your nose, safer handling is practically guaranteed. Especially if the stick touches your nose.

[Edited on 27-9-2014 by S.C. Wack]

Metacelsus - 27-9-2014 at 14:39

Yes, in my experience it has much stronger fumes than acetic acid.

Brain&Force - 27-9-2014 at 15:04

There is a wiki page which contains instructions for the safe handling of formic acid.

aga - 27-9-2014 at 15:08

Quote: Originally posted by zts16  
Formic acid can't be good to get on you considering it's a component of ant venom...

ISTR that Formic Acid was first discovered by some nutter Distilling a pot full of ants.

Edit

Hahaha. It's on wiki :
"The first person to describe the isolation of this substance (by the distillation of large numbers of ants) was the English naturalist John Ray, in 1671"

'Naturalist' meant something else 343 years ago i guess.

[Edited on 27-9-2014 by aga]

Texium - 27-9-2014 at 15:14

Quote: Originally posted by aga  
Quote: Originally posted by zts16  
Formic acid can't be good to get on you considering it's a component of ant venom...

ISTR that Formic Acid was first discovered by some nutter Distilling a pot full of ants.
Yep, and that's how it was produced until somebody found a way to efficiently synthesize it.

mnick12 - 27-9-2014 at 16:41

Well I don't think the pKa has a whole lot to do with how dangerous the acid is.

For example I have been burned dozens of times by drops of sulfuric, nitric, and hydrochloric acid. None were ever that bad, just a slight tingle sensations that could be washed away, and at worst a small wound. However formic acid was MUCH worse than any of those acid. I splashed just a drop or two on my wrist while pouring some from a cylinder. Quickly there was a strong tingling sensation, and before I could get my gloves off there was and overpowering stinging/burning sensation on my skin. Quickly I ran my wrist under cool water, but to no avail the burning continued for about another hour. Anyway after that the skin swelled significantly. After about three days the skin died and fell off, I was left with an oozing wound.

I would say formic acid is much much nastier than any mineral acid in terms of the caustic effect on tissue, despite being a much weaker acid.

unionised - 28-9-2014 at 10:14

Formic acid isn't a very strong acid, but it's quite a good protein solvent.
You don't want to get it on any proteins which you consider important- such as your skin or eyes.