Sciencemadness Discussion Board

Chemical anomalies in the public space.

froot - 30-10-2018 at 07:42

It would be interesting to see what bizarre chemicals people encounter from time to time in their daily routines so I thought I'd start a topic on it. If there is already one I obviously did not find it and forgive me and please merge this to the older one.

As a thread starter I thought I'd share this:
I went to a chemist in town last week and outside their shop they had a rather nice display of antique medicines. While looking through this collection I was shocked to find a bottle of picric. I have no idea how that could've been medically relevant or weather the collection owner was ignorant or just testing to see if anyone would notice it. I'm not expecting the latter, this is not a very intellectual town. The lady at the till acknowledged that it was their collection and why? In response I simply said I found it quite interesting and left.
I showed a few friends and family these photos but to my dismay they didn't seem to appreciate my find as much as some people here would so here it is.


IMG_9065.JPG - 2MB IMG_9066.JPG - 1.3MB IMG_9064.JPG - 1.5MB

fusso - 30-10-2018 at 07:48

Why didn't you ask whether you can buy it from them or not?

froot - 30-10-2018 at 10:55

I don't need any. If I did I'd much rather synthesize it.

morganbw - 30-10-2018 at 11:52

It is sad to me that the word picric raises eyebrows.

unionised - 30-10-2018 at 13:36

Picric acid was used as a burn medication.
It's probably real.
The interesting question is ; should someone warn the owner?
I think they should.

Assured Fish - 30-10-2018 at 18:06

Is the pircric acid stored under water?
Its hard to tell but its only sensitive if its dry if im not mistaken.

BromicAcid - 30-10-2018 at 18:54

Picric acid was used in a lot of formulations for its antibacterial properties. Storing under water is a fairly new introduction on storage, so is storing in plastic bottles. Picric acid itself isn't remarkably friction or shock sensitive. It was the metal picrates formed in the caps of some of these old bottles that were the real trouble makers.

VSEPR_VOID - 30-10-2018 at 19:10

I would be worried about it drying out

Herr Haber - 31-10-2018 at 03:55

Quote: Originally posted by Assured Fish  
Is the pircric acid stored under water?
Its hard to tell but its only sensitive if its dry if im not mistaken.


By the color I'd say no. Dry picric acid looks a bit like sulphur depending on cristal size.

I'm not too keen on crying wolf but in this case I think the owner should be warned. Just to avoid possible complications if someone else spots this and reacts... differently.

AJKOER - 4-11-2018 at 18:20

My recollection having once owned some picric acid (which was somewhat moist) was that I was surprised to learn how small a lethal dose is (highly poisonous if taken internally). In other words, proper disposal is a must, one cannot just throw it away.

Yes, it was used in the treatment of burns.
----------------------------------------------------

On a train trip I was surprised to see many chemical container railroad cars that have just numbers, and no indication of what industrial compound was being transported.

So, in the event of some accident, one may not know in a timely fashion as to exactly what chemical agent was spilled or was being heated in a fire.

Now, that may not be necessary if the chemical by itself is relatively safe, but a chemist knows that some chemicals just don't mix well with others forming potentially some very problematic products (like a NH4+ salt and an alkaline aqueous hypochlorite).

[Edited on 5-11-2018 by AJKOER]

j_sum1 - 4-11-2018 at 19:07

Quote: Originally posted by AJKOER  

Now, that may not be necessary if the chemical by itself is relatively safe, but a chemist knows that some chemicals just don't mix well with others forming potentially some very problematic products



coke and mentos.jpg - 29kB

[Edited on 5-11-2018 by j_sum1]

unionised - 5-11-2018 at 13:28

Quote: Originally posted by Assured Fish  
Is the pircric acid stored under water?
Its hard to tell but its only sensitive if its dry if im not mistaken.

Judging by the style of the bottle it's a good 50 years old.
As far as I can tell, it's sealed with a cork.
Even if it was wet once, it won't be now.

I'd say this was a bomb squad job unless someone in the store can assure you that they got an old empty bottle + filled it with yellow paint.

S.C. Wack - 5-11-2018 at 15:47

Services Textbook (1972): Picric acid (Chapter 6) is now unlikely to be met with in the British Service, although it was used as a pressed filling for shell from about 1890 until the 1914-18 War. Also known in the Service as Lyddite (after the site in Kent where early experimental work was done on shell filled with picric acid), it was considered very suitable for armour-piercing shell as it would withstand the shock on impact or penetration before being subsequently exploded by the fuze system.

Bretherick's (2007): The first high explosive shock-resistant enough to find use in shells. Most of its salts are more sensitive.
Alone, or Heavy metals, or Bases
1. Cooper-Key, A., Home Office Rept. 211, 9, HMSO, 1914
2. Kirk-Othmer, 1965, Vol. 8, 617
3. Urbanski, 1964, Vol. 1, 518
4. Garey, H. E., Chem. Eng. News, 1979, 57(41), 51
5. Ventrone, T. A., CHAS Notes, 1982, 1(3), 1—2; (4), 4
6. Mendenhall, G. D., Chem. Eng. News, 2005, 83(6), 5
Picric acid, in common with several other polynitrophenols, is an explosive material in its own right and is usually stored as a water-wet paste. Several dust explosions of dry material have been reported [1]. It forms salts with many metals, some of which (lead, mercury, copper or zinc) are rather sensitive to heat, friction or impact. The salts with ammonia and amines, and the molecular complexes with aromatic hydrocarbons, etc. are, in general, not so sensitive [2]. Contact of picric acid with concrete floors may form the friction-sensitive calcium salt [3]. Contact of molten picric acid with metallic zinc or lead forms the metal picrates which can detonate the acid. Picrates of lead, iron, zinc, nickel, copper, etc. should be considered dangerously sensitive. Dry picric acid has little effect on these metals at ambient temperature. Picric acid of sufficient purity is of the same order of stability as TNT, and is not considered unduly hazardous in regard to sensitivity [4]. Details of handling and disposal procedures have been collected and summarised [5]. Once a reagent found in most laboratories, it now excites undue fear; in reaction to an ill-informed safety officer’s demand for removal or destruction of a bottle of the wet solid, one chemist introduced synthesis and drop-weight detonation tests into a university teaching course. It seldom or never detonated, while dibenzoyl peroxide, sold to the public in concentrated form as a resin hardener, always did. (The safety officiouser was satisfied by a certificate alleging that the wet acid had been converted to perhaps more dangerous dry picryl chloride) [6]. Subsequent editions of the journal are loud with the protests of ‘Safety Professionals.’


...now say it a different way:

Laboratory Safety for Chemistry Students (2016): ...when picric acid reaches a dry state it has the same potential as TNT to be explosive. If a bottle if picric acid is found to be dry or to have dried crystals around the cap, it should not be handled...

...a rifle bullet will not detonate TNT.

[Edited on 6-11-2018 by S.C. Wack]

j_sum1 - 5-11-2018 at 16:34

Maybe this is off topic, but how many energetic materials also have a medical use?
There's picric acid and nitroglycerine. What else?

Expolsive/medical always seemed an odd combo.

Cezium - 7-11-2018 at 00:24

Not exactly an energetic but KClO4 (brand name "Chlorigen") to block thyroid and CNS Na/I symporter.
en.wikipedia.org/wiki/Potassium_perchlorate#Medicine_use

phlogiston - 7-11-2018 at 03:57

Potassium chlorate must also have a pharmaceutical use, because I used to be able to buy it (decades ago) from a very small local pharmacy. They would not keep an inventory of chemicals only for little boys interested in chemistry. Also, the staff only knew it by its Latin name 'kalii chloras'.

Not exactly medical use, but picric acid and dinitrophenylhydrazine are used in clinical diagnostic laboratories a lot, respectively to assay creatinine in urine, and for assaying various ketones and aldehydes

[Edited on 7-11-2018 by phlogiston]