Toxicity Of Picric Acid

[Blaine]

Hey i'm new to this forum and have a few questions about Picric acid;

I want to try to make some picric acid and I heard that this stuff is very toxic and was wondering what extra precautions I could take to avoid being poisoned from it.

Also what type of aspirin did you people use to make it, I've found a few kinds of aspirin on the shelve. Also I have never made anything that produces the Nitrogen Dioxide gas what are some extra safety steps I could take for that problem.

What are the chances of it exploding when I make it, Is it fairly safe?

And when it ask's for it to heat up the alcohol could i use a Bunsen burner?

Thanks in advance!
(sorry for such the newbie questions)

[ALENGOSVIG1]

Make sure to use gloves when handeling the picric acid. Buy the cheapest kind of aspirin. just make sure it contains acetylsalicylic acid. To avoid being poisined by the fumes when making it, do it outside. I dont really think theres much of a chance of it exploding. well, ofcourse theres always a small chance but its quite safe.

I wouldnt heat alcohol on a bunsen burner. Use a hotplate or a water bath to heat it up.

<small>[ July 06, 2002, 03:45 PM: Message edited by: ALENGOSVIG1 ]</small>

[Yi]

Common sense really. Don't eat it. Wash the containers that you use well. Avoid contact between cooking surfaces/food/utensils etc.

Any type of aspirin is ok. Aspirin is chemical compound and is the same whatever the brand. The only difference may be the binders.

Perform the experiment in a well ventilated area or outside.

Rather than using a bunsen straight onto the beaker. Use a water bath.

[Madog555]

avoid contact with it and solutions of it

[Anthony]

In addition, a respirator may be useful if handling the dry powder.

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"The Toxicity of our city"

[DBSP]

Just a note about the asprins. There are many who think asprin is asprin but it isn't, there are a large number of painkillers that don't contain ASA. I only know of two brand that actually contain ASA so make shure they caontain ASA before you buy them.

[Mr Cool]

Yes, there are painkillers with no ASA, but if it says "Aspirin" on it then it will contain ASA, since that is the commercial name for it.

[Anthony]

If you're in the UK look for ones with "BP" (British pharmaceutical) on them, they are cheaper and don't contain other crap that brands like Anadin do.

[vulture]

Picric acid "puffs" (that is, it will say "puff" and leave carbon behind and decompose into gas) above 225C or when struck.
Severe poisoning occurs after intakes of 1-2g.
It is absorbed by the skin and irritates eyes, skin and respiratory system.
It destroys red blood particles and damages the kidneys.
MAC 0,1mg/m^3

Do not heat it in metal containers, not even in solution as it is a strong acid, this will cause the formation of highly sensitive picrate salts.

[Dhzugasvili]

Picric Acid is an explosive which i have made many times and have reasonably good experience with it. It is a very amazing explosive to make before progressing into such kings as RDX and HMX, which i have also made successfully and in good yields thanx to information found here and on mega's site. I started out pretty novice, starting from blackpowder then progressing on to much more fun stuff...:-) SO anyways back to the topic at hand, the picric acid i have made i have always made with Phenol route, instead of going through the problems and hassels of the aspirin route, the more complicated one. However, i suggest if you do not have access to phenol, then this is better than the other route involving mercuric nitrate(if i remember correctly). SO i would definitely suggest getting ur hands on some Phenol Analytical Crystals/aka Carbolic Acid. The yield is very much incredible. However, after all my reactions, i wonder, if i have been using too much nitric hence wasting it...would i get an optimal yield if i used 12ml h2s04 (density 1.8) and 13ml nitric (density 1.4), instead of 12.5ml sulphuric and 38ml nitric to every 9.5 grams of Phenol? Oh and one last thing on Picric acid...After production i kept it in a PLASTIC container always... and ground it up into a fine powder in smaaalll amounts to make easier to load it into required density.to be safe, make sure that the product does not have residual nitric or sulphuric acids (very dangerous) by proper washing. I always conducted my reactions outdoors AND with a Russian Red Army issue gas mask that still works (hihi)!

[nbk2000]

Buy the cheapest aspirin you can find. Something like 300 pills for a dollar.

Not only does this make PA into an economically affordable explosive to make, but it also means that you're not going to have a lot of the fillers, buffers, and coatings to deal with that the fancier aspirins have.

[dave]

I have found a source of very cheap asprin. One website selling pet supplies they sell asprin powder in 5 pound containers for $19.99. The acetylsalicylic acid content is 50% per ounce. The cool part about this is that its already in powder for so there is no crushing required.

[Anthony]

"50% per ounce" is a bit of a misnomer.

But assuming they meant it's 50% pure, then you are going to need to purfiy it.

Can't really beat the price though :)

[Al Koholic]

Yeah thats not a bad price at all even though 50% by ounce seems to imply you're only getting 2.5 punds ASA. I get 2000 pills for 4 bucks...2 bucks for a thousand from BJ's....a great wholesale store in the eastern US if you wanna know. Need membership to buy from them though...650g ASA aint bad for 4 bucks expecially when that equates to 650 grams TNP after its all said and done. Since my KNO3 is virtually free and unlimited and the H2SO4 is about 10$ per 2 litres...not bad.

By the way, picric is so toxic because it uncouples the proton gradient between the matrix and the intermembrane space in your mitochondria from its normal function of oxidative phosphorylation...not good. Funny that DNP used to be marketed as a diet drug till a bunch of people died from it because it lingers in tissue to to hydrophobicity...

[drednort]

Picric acid turns your skin yellow on contact. But, I have seen something very unusual with this compound. It concerns one of the very senior lab boffins who burnt his hand on some very hot glass. He then went to get some picric acid, whilst his hand had gone red and started throbbing. He dissolved the picric acid in some ethanol and then put his burnt hand in it. He said that all the pain went away within minutes, no blisters either, just that the burnt skin fell away after a few weeks to give his normal hand back. Would have been a hospital trip.
But hey, it's not wise to dip anything into chemicals. Just something interesting to ponder on.

[vulture]

The effect that you describe seems possible, as nitrophenols make the cellmembrane permeable for ions like H⁺. This way, concentration gradients are nullified and thus osmosis is not possibly any longer. As a result the formation of blisters is greatly reduced.

However, there is a severe risk of blood poisoning when doing this!

BTW, the yellow color is the nitration of tyrosin in your skin.

<small>[ April 07, 2003, 04:48 PM: Message edited by: vulture ]</small>

[Al Koholic]

Couple of things:
The only ion capable of being nullified is H+ like you said. Judging from the fact that interstitial fluid and plasma have pH's around an average of 7.3, the H+ concentration would be low. I'd imagine Na+ to be largely responsible for any solvent drag. Interesting theory though and who knows...there may be something to it.

Also...are you sure its nitration of tyrosine?! If so, would you be obtaining a mono or dinitro tyrosine and for what reason would the NO2 group "want" to jump off of it's nice cozy existing phenol to another phenol with a carboxy amine on the end? I was always under the impression that the TNP simply had a very high affinity for the amino acids which make up the alpha keratin in the outter layer of skin. Those AA's being for the most part ones with hydrophobic R groups...ie met, ala, val, leu, ile, gly making them aliphatic like TNP and hence have high affinity. Slowly as the outter layer of skin is sloughed off, the color goes byebye.

[Einsteinium]

Here's a link to picric acid's MSDS:
<a href="http://www.jtbaker.com/msds/englishhtml/p4556.htm" target="_blank">http://www.jtbaker.com/msds/englishhtml/p4556.htm</a>

As all MSDS, this one is quite freaky (I'm wondering if NaCl MSDS is freaky too) but hey, picric acid was present in most chemistry lab of the last century. Just don't eat, rub your skin or sniff the stuff and everything should be fine.

I don't think picric acid nitrates tyrosine, nitrobenzenes aren't good nitrating agents at all. I simply think that some picric acid (strong acid) reacts with amine (and maybe amide) groups that are present in the proteins (as amino-acids and peptides...) of your skin forming new yellow picrate-protein salt.

[drednort]

That's not a bad MSDS at all. A little while ago I looked up the MSDS of water (too much time lounging about) using Aldrich's CD and it says that if you get it in your eye then you must wash it away with copious amounts of water. Some of those generic ones are pretty rubbish.