Sciencemadness Discussion Board

UK: Hydrochloric acid, phosphoric acid, and hexamine now restricted/banned!

SplendidAcylation - 14-12-2023 at 02:49

I'm surprised there isn't already a thread on this topic, but there doesn't seem to be...

I was just checking the list of regulated explosive precursors and poisons on the UK government website, to see if barium compounds were there (they are!), and I came upon something that I could not quite believe.

As of 1st October 2023, the government have sneaked some new additions to the list of regulated chemicals, three of which in particular caught my attention:

Hydrochloric acid (10% w/w)
Phosphoric acid (30% w/w)
Hexamine

Here is the full list here:
https://www.gov.uk/government/publications/supplying-explosi...


Is this really happening, or am I hallucinating (perhaps I have inadvertently inhaled too much nickel vapours in my recent experiments)?


Most of the things on those lists are vaguely understandable, but hydrochloric acid, how on earth is this an explosive precursor?

Until now, i have taken it for granted that hydrochloric acid is the one strong mineral acid that is, and always would remain, freely accessible, due to the fact that it isn't involved with explosive production in any way that I am aware of.

Now, to be fair, it isn't a huge problem, because it is possible to distil hydrochloric acid, obtaining the azeotropic concentration of 20.2% w/w, but that is nowhere near the 35% concentration that was previously readily available.


As for phosphoric acid, I suppose it is possible to concentrate phosphoric acid by evaporating off the water somewhat, however i have a vague memory that it polymerizes or something, with prolonged boiling.

As for hexamine, this can of course be made from ammonia and formaldehyde.

So all in all, it isn't really a huge problem for me, at least, but I just find it totally shocking and quite scary, to be honest!

Apologies if I made some errors, this is really a rushed post, I look forward to discussing the chemistry by which we can circumvent these new restrictions in further posts.


I think it might be a good idea to go around various outdoor/camping stores to see if they have any hexamine tablets in stock, it is possible they might have not received the memo.

Hexamine is very useful in organic chemistry, for the Delepine reaction and the Sommelet, among others I'm sure.


There are also still some listings for hydroponic pH down on eBay, those are 81% phosphoric acid, so it might be worth buying some, before they realize they are committing a crime and remove their listings...

RU_KLO - 14-12-2023 at 04:17

I dont know how is it in UK, but in my country, buying, producing or storing is the same problem (I think that producing is harsher). So if they knock at your door....

unionised - 14-12-2023 at 05:29

Re. "
As for hexamine, this can of course be made from ammonia and formaldehyde."
Only if you can still get them
formaldehyde 5% w/w (CAS RN 50-00-0)
Is on that list.

SplendidAcylation - 14-12-2023 at 05:38

@unionised,

Formaldehyde is under the "Reportable poisons" category;

Anything under the "Reportable" headings are still available legally, however suspicious transactions must be reported.

Anything under the "Regulated" headings are illegal to sell/buy/possess without a licence...

unionised - 14-12-2023 at 05:50

If I was a shop, I'd think really hard about not stocking formaldehyde- just to save myself paperwork / hassle/ getting lumbered with a product I wouldn't be able to sell if they changed the rules.
Anyone feel like distilling acetal plastic shavings?

Sir_Gawain - 14-12-2023 at 07:54

Distilling acetal yields formaldehyde?

BJ68 - 15-12-2023 at 00:23

https://www.reddit.com/r/brexit/comments/b7dgsz/2000years_la...

bj68

SplendidAcylation - 15-12-2023 at 02:43

Quote: Originally posted by unionised  
If I was a shop, I'd think really hard about not stocking formaldehyde- just to save myself paperwork / hassle/ getting lumbered with a product I wouldn't be able to sell if they changed the rules.
Anyone feel like distilling acetal plastic shavings?


Well if they did change the rules they would probably limit the concentration rather than ban it completely, so you'd just have to dilute the stocks you had :D

Paraformaldehyde isn't listed there, so I'm not sure if that is even counted at all.

Anyway, there are still plenty of places where you can buy formaldehyde at the moment in the UK.

It can also be made, of course, by passing methanol vapour over a heated coil; Catalytic dehydrogenation.

@BJ68 :D:D:D

clearly_not_atara - 15-12-2023 at 10:47

Phosphoric acid can indeed be concentrated by heating. Its high affinity for water means that this requires high temperatures. At all concentrations above 85%, when in the liquid phase, phosphoric acid exists as a mixture of oligomers, eventually forming a negative azeotrope with bp ~860 C and a molar composition of roughly 1:1 H3P3O9:P2O5.

IIRC, if phosphoric acid is concentrated just the right amount, it will all crystallize as pure diphosphoric acid, H4P2O7, under standard conditions.

[edit by mod]
Removed accidental smilie.

[Edited on 14-4-2024 by j_sum1]

Alkoholvergiftung - 15-12-2023 at 23:02

clearly_not_atara what would be the best material for boiling phosphoric acid? copper? it attacks glas so its on the long term no option.

Keras - 16-12-2023 at 01:42

Really, I think the best way to ‘concentrate’ phosphoric acid is to add phosphorus oxide to it until you reach 100%. Phosphorus oxide is not easy to source, but it is not restricted, contrarily to phosphorus itself.

Conure - 24-1-2024 at 10:20

Damn, you brittish people are ahead of us in sweden. We can still order 30% HCl and 85% H3PO4. However in 2025 NaOH and KOH will be gone from the public. The motivation is that it causes too many accidents.

Belowzero - 24-1-2024 at 10:26

Quote: Originally posted by Conure  
Damn, you brittish people are ahead of us in sweden. We can still order 30% HCl and 85% H3PO4. However in 2025 NaOH and KOH will be gone from the public. The motivation is that it causes too many accidents.


Pretty sure more accidents happen with water, perhaps they should do that next.

clearly_not_atara - 25-1-2024 at 07:33

Quote: Originally posted by Alkoholvergiftung  
clearly_not_atara what would be the best material for boiling phosphoric acid? copper? it attacks glas so its on the long term no option.

I think you could use graphite but I would suggest trying a small amount first. But glass has decent resistance at the concentrations we're usually interested in. It's only when you get to very high temperatures and concentrations that the attack on glass becomes severe.

EDIT: in particular, decomposition of monoammonium phosphate in a graphite crucible might be a possibility

[Edited on 25-1-2024 by clearly_not_atara]

ManyInterests - 13-4-2024 at 17:27

This is just nuts. I bought a few packs of hexamine fuel tablets recently even though I have too much hexamine. It is stuff like this that really irks me. It's also why I stocked up on a lot of sulfuric acid and nitrates.

EF2000 - 14-4-2024 at 01:40

Quote: Originally posted by SplendidAcylation  


Most of the things on those lists are vaguely understandable, but hydrochloric acid, how on earth is this an explosive precursor?

Until now, i have taken it for granted that hydrochloric acid is the one strong mineral acid that is, and always would remain, freely accessible, due to the fact that it isn't involved with explosive production in any way that I am aware of.

Unfortunately, it really is an explosive precursor. TATP syntesis requires any relatively strong mineral acid: sulfuric, nitric, hydrochloric, phosphoric. Hydrochloric is said to give best results. Phosphoric acid can also be used to prepare HMTD, though usually it's done with citric acid. Sulfuric and nitric are already regulated, so now they came for hydrochloric and phosphoric. (One day they'll come for citric acid, and there would be no more lemons and oranges in the UK.)

LookingForAnswers - 17-4-2024 at 15:24

I've seen in Home Bargains "killrock" descaler ( black one ) and there is some small concentrations of H3PO4. i dont remember volume but maybe someone will be interested

LookingForAnswers - 15-5-2024 at 14:16

Im not sure how this ban is working but on ebay is still avaible ph down which is 81% phosphoric acid...

Precipitates - 15-5-2024 at 18:40

The worry is whose watching*

If you live on a farm you're probably okay, but large amounts of pH down for a residential address, probably a bit strange and law enforcement may want to check on you - and if they find any other "chemicals", that will raise their suspicions that you're not planning to use the pH down for it's intended use, so must be making a bomb.

If you've got a license for the "hobby" use of chemicals, you will probably be okay, but I'm not sure how easy it is to get that license from the home office.

*This could be just paranoia, but I'm sure there are not that many suppliers, so it wouldn't be too difficult for the police to check-up on who they are selling to. Additionally, I've had packages arrive in terrible condition and smelling really bad with leakage e.g., 880 ammonia, so there is a risk your neighbours are going to know what you've ordered i.e. "dangerous chemicals!!!". They will call the cops if they are super-scared of chemicals - as a lot of people seem to be - or/and don't get on well with you anyway.

[Edited on 16-5-2024 by Precipitates]

greggles - 7-3-2025 at 12:54

Has anyone come up with good ways to acquire these chemicals now?
I have seen phosphoric acid and hexamine mentioned earlier, but sulfuric and hydrochloric acids could be harder to obtain.
Hydrochloric acid can be made (very slowly) with electrolysis, or faster with sulfuric acid and salt.
Sulfuric acid can be obtained from some car batteries - can you use old, dead ones? I have a friend who has quite a collection - or does it have to be fully charged?
Any other solutions for obtaining any chemicals on the (rapidly growing) list would be good, as even getting low concentrations of these chemicals can be hard. The chemicals are expensive enough without licenses from the Home Office making everything more expensive.

chempyre235 - 7-3-2025 at 13:05

If you have sulfuric acid, you can react it with table salt to get HCl. I know spent batteries have several impurities, but I don't know what it would take to make the acid useable. There are several threads for the production of H2SO4. I'd start there.

Among the various routes to sulfuric acid are:



[Edited on 3/7/2025 by chempyre235]

woelen - 7-3-2025 at 14:04

Even with the chemical restrictions, you still can buy H2SO4 at 15% concentration as a private person. This acid then can be boiled down to make it more concentrated. Getting at 50% should be no issue, even getting to 75% can be done easily. Getting it highly concentrated above 90%, however, will be really hard (and dangerous!!). As a starter, however, acid at 50% or so concentration is quite interesting already, and even the acid of 15% can be used for many interesting chemistry experiments at home.

Hydrochloric acid still is available at 10%, most likely in hardware stores. You can fairly easily concentrate this to appr. 20% by slowly boiling off about half its volume of water vapor. You'll notice that if you boil off 10% HCl, then you get almost pure water vapor.

greggles - 8-3-2025 at 04:34

Quote: Originally posted by chempyre235  
I know spent batteries have several impurities, but I don't know what it would take to make the acid useable.

How do these batteries work? I know that the impurities can be removed enough for my usage, but is the acid concentration in dead or discharged batteries lower than in fully charged ones? This was my main concern with extraction from old batteries, as all the ones I can get my hands on are probably flat.

TmNhRhMgBrSe - 8-3-2025 at 20:37

ha~?! ban common chemicals?? freedom ha ma~~~ freedom? where fuck freedom a, DNLM! ONL99 rubbish uk government, no L need move to uk la! (ﾉꐦ`Д´)ﾉ彡┻━┻
really want big hand big hand slap down to those say want move to uk, hahahahahaha :0)

(tofu skin (negative review) is give uk government)

[Edited on 2025-3-9 by TmNhRhMgBrSe]

greggles - 10-3-2025 at 11:54

Quote: Originally posted by TmNhRhMgBrSe  
ha~?! ban common chemicals?? freedom ha ma~~~ freedom? where fuck freedom a, DNLM! ONL99 rubbish uk government, no L need move to uk la! (ﾉꐦ`Д´)ﾉ彡┻━┻
really want big hand big hand slap down to those say want move to uk, hahahahahaha :0)

(tofu skin (negative review) is give uk government)

[Edited on 2025-3-9 by TmNhRhMgBrSe]


It is a lot easier to understand you if you speak normally. If it is not your native language, fine, but you can do better than that.

Chemical Acquisition

MadHatter - 10-3-2025 at 16:30

Seems in Europe the worry is about explosives. Here in the U.S. the worry is about
illegal drugs. Always a function of where you reside. Sorry to hear about the
increasing restrictions in the U.K. !

MrDoctor - 10-3-2025 at 22:48

they are doing everything they can to prevent wallet-reductions. you have to make everything yourself now.