Hexamethylenetetramine

[Boustrophedon]

Hexamethylenetetramine AKA hexamine or just hex was widely used as a fuel in camping stoves and for use in small steam engines, the Government has just (Oct 2023.) banned it, adding it to a long list of proscribed substances under REACH legislation. The rationale for this is that it is a precursor for the manufacture of explosives.

I smell b.llsh.t.

The only explosives you can make from hexamine are RDX and HMX, both requiring the use of concentrated nitric and sulphuric acid, both of which are on the restricted list anyway. The synthesis of RDX is not simple and certainly beyond the scope of the home chemist, thermal runaway and rapid unscheduled disassembly of the operative come to mind. Doing that in bulk quantities to make a terrorist bomb is quite unfeasible, given that there are way easier explosives to make.

Elsewhere someone suggested that hexamine might give false positives on sniffer type bomb detectors and those (neutron activation?) that detect things containing large amounts of nitrogen, can anyone comment or have anyone got any information on this?

[IvanV]

I think hexamine is rather polluting. And whilst the excuse for banning it may be silly, I think it is probably a good thing it gets banned, as apparently less polluting alternatives are available. The military like solid fuel, because it is much easier to transport and use in the field, so such alternatives are manufactured and available.

I have looked up some alternatives and tried to read their "technical literature", which was completely useless. Firedragon, one of the brands, claims it is a biofuel, but without saying what, or even what the energy content is. But Amazon disclose that Firedragon contains ethanol. So I imagine it is some kind of a solid matrix that holds a high proportion of ethanol, in the same way that traditional firelighters are some kind of solid matrix that holds a high proportion of kerosene.

[jimbob]

I think hexamine is rather polluting. And whilst the excuse for banning it may be silly, I think it is probably a good thing it gets banned, as apparently less polluting alternatives are available. The military like solid fuel, because it is much easier to transport and use in the field, so such alternatives are manufactured and available.

I have looked up some alternatives and tried to read their "technical literature", which was completely useless. Firedragon, one of the brands, claims it is a biofuel, but without saying what, or even what the energy content is. But Amazon disclose that Firedragon contains ethanol. So I imagine it is some kind of a solid matrix that holds a high proportion of ethanol, in the same way that traditional firelighters are some kind of solid matrix that holds a high proportion of kerosene.

Yup. Lots of discussion about this on backpacking forums. And they do tend to be heavier, and more bulky per brew than the hexi tablets.

Not something I have used for 30 years. Too unpleasant a smell.

[Boustrophedon]

I am unconcerned by the ban, except to check whether I have some tucked away. I like many others had hex to fire model steam engines made by Mamod, Wilesco and the like. As you can imagine Mamod was not consulted before the ban, nor even warned, the first they knew was a warning in the following January that they faced prosecution for continuing to supply hex with steam engines. This left Mamod with months of orders backing up that they couldn't sell and customers with models they couldn't fire. Lost custom and tooling up for alternative alcohol gel burners left Mamod with a £50k deficit that took them close to closing altogether. The lack of consultation is typical of government practice.

As it happens I never actually used Hexamine, the residue is highly corrosive causing pitting corrosion right through the brass boilers and corrosion of the steelwork, instead I used the old meths burners or small gas burners.
Both smell nicer.

But I am still highly suspicious of the motives for the ban.

[Woodchopper]

You can read the impact assessment here: https://www.legislation.gov.uk/uksi/2023/63/impacts

It mentions public consultations with business associations, chemical industry associations and hobbyist associations. It got over a hundred written responses.

Hexamine has also been on the list of controlled substances since a 2013 EU regulation - at that point there was no prohibition but a requirement to report suspicious sales.

Of course individual hobbyists couldn't be expected to keep up with legislation. But it seems to me that a company involved in supplying hexamine should have been paying attention.

[nekomatic]

Thanks for finding the source, Woodchopper.

But I am still highly suspicious of the motives for the ban.

What do you think the motives might be? I can understand if you think it’s security theatre that will have little practical impact on the risk of terrorism, but I’m having trouble imagining anything more sinister. Why would the Home Office have a covert anti-steam-modelling agenda?

I am going to agree that it’s possible the consultation was inadequately publicised though, in spite of the claim to have included hobbyist groups. I was completely unaware of the new legal requirement to microchip cats for example, until it was on the news the other day.

[Grumble]

You can read the impact assessment here: https://www.legislation.gov.uk/uksi/2023/63/impacts

It mentions public consultations with business associations, chemical industry associations and hobbyist associations. It got over a hundred written responses.

Hexamine has also been on the list of controlled substances since a 2013 EU regulation - at that point there was no prohibition but a requirement to report suspicious sales.

Of course individual hobbyists couldn't be expected to keep up with legislation. But it seems to me that a company involved in supplying hexamine should have been paying attention.

It’s a requirement of the HSaW act 1974 that you keep a current knowledge of best practice, which includes legislation. I have little sympathy for companies who fail to do this, it’s verging on or possibly actually criminal.

[Woodchopper]

Thanks for finding the source, Woodchopper.

But I am still highly suspicious of the motives for the ban.

What do you think the motives might be? I can understand if you think it’s security theatre that will have little practical impact on the risk of terrorism, but I’m having trouble imagining anything more sinister. Why would the Home Office have a covert anti-steam-modelling agenda?

It doesn't seem to be a good candidate for 'something must be seen to be done' legislation. Outside of some hobbyists few people will have heard of Hexamine. If the regulations are unnecessary then old fashioned incompetence would seem to be a likely explanation.

I am going to agree that it’s possible the consultation was inadequately publicised though, in spite of the claim to have included hobbyist groups. I was completely unaware of the new legal requirement to microchip cats for example, until it was on the news the other day.

Its difficult to know how much it was publicized. Normally, a trade association would fulfill that role and contact all the members and organize a response that represents the views of the membership. Its possible that the government didn't contact all the relevant associations, or that the associations didn't contact all their members. On the other hand, if the company wasn't a member then it has to take some of the responsibility.

[nekomatic]

It doesn't seem to be a good candidate for 'something must be seen to be done' legislation. Outside of some hobbyists few people will have heard of Hexamine.

I guess few people know about hexamine, but it would enable the government to say ‘look how tough on terrorism we are, we regulated another five explosive precursors just last Wednesday’.

[Boustrophedon]

As a result of the losses incurred over the bad handling of the Hex ban and later action by their landlord, Mamod ceased trading on Aug 4th and has closed down. This is a sad end for a British company with an 88 year history.
Many of us will have had a Mamod steam engine as a child, either a stationary engine or a loco or traction engine, which will have inspired an interest in science and engineering.