Sciencemadness Discussion Board - Question about Ethyl Bromide

Question about Ethyl Bromide

EvlRenne - 2-3-2021 at 03:30

Hello everyone,

I already asked this question on Reddit, but I want to hear a second opinion.
Soon enough I will work with alkyl halides, and I want to be prepared.
I've been reading through a lot of SDSs, but those are not useful as there are no direct instructions like - what to do in case of XXX, rather than call the doctor, call the hazard center, and so on. In some SDSs I even saw - ask experts for help...

So, questions are:

1) What to do in case of minor spillage?

My proposal was to use sodium acetate.

As well I found that in labs commonly used Chemizorb®. I started to dig up into its MSDS, and found quite interesting and funny things. Some manufacturer's MSDS states - "A registration number is not available for this substance", the other's - "Chemizorb® is a coarse grained material based on chemically inert porous mineral or synthetic copolymers (grain size >1 mm (95%)."
Digging up a little bit further I found that Chemizorb® is 95-100% Celite...

I am not sure about Celite though, EtBr still will continue to evaporate out of it, on the other hand EtBr+C2H3NaO2 will form an ester.

2) How to proper decontaminate glassware before "regular" wash in the sink?

3) How to properly dispose wastes?

4) How to proper store Ethyl Bromide if you are paranoid?

I already aware that a proper amber container with a PTFE disk inside cap is enough, no heating / no UV / cool in the freezer before open.

What do you think, as an extra precaution measurement, is it useful to put a bottle into the jar filled with sodium acetate, the same way as storing mercury in sulfur?

[Edited on 2-3-2021 by EvlRenne]

njl - 2-3-2021 at 05:37

The reaction with sodium acetate won't be very fast without base and heat, I think sodium hydroxide would be better for cleaning since you're still left with inert products but the reaction will be much faster.

draculic acid69 - 4-3-2021 at 00:08

I'd say NaOH to treat etBr spills would be best

Fyndium - 4-3-2021 at 02:57

For spills, I'd absorb them with something suitable, and then neutralize the surfaces and equipment with NaOH. I usually seal all absorbents (like dirty paper towels) in ziploc bags and dispose. This will prevent then contaminating anything and it also keeps the odors in.

It'd be good to keep a bottle of absorbent near in case of such event. They use everything from diatomaceous earth to cotton to sawdust to absorb oil and other spills, and pretty much as long as it doesn't react with the spill and it absorbs it well, it works. In an emergency, even secondary measures work, because they restrict the spill and give you more time to do decontamination.

Preventive measures, such as handling chemicals in a fume hood with table that has edges high enough to contain any spills and is leakproof, are good to have. I've sealed my fume hood's table with polyethene foil and it has successfully contained a couple of spills, which were nothing more serious but water solutions, but it does work.

[Edited on 4-3-2021 by Fyndium]

dioxine - 5-5-2021 at 06:11

Hello. This is very interesting topic for me since im paranoid about it too.
Is it possible to poison myself while making ethyl bromide or something like that(isopropyl bromide for example) not with chemical itself but formation of BROMOPHOSGENE?
Im sure it generates COBr2 with fire, but what about sunlight or some other conditions?

Also i want to recommend this source - "Phosgene and related carbonyl halides". There are much info about chloroalkanes and bromoalkanes and how they form phosgene.

Any info will be helpful. Thanks.

[Edited on 5-5-2021 by dioxine]

[Edited on 5-5-2021 by dioxine]

njl - 5-5-2021 at 07:21

If you manage to make bromophosgene in this scenario you're either trying to make bromophosgene or shouldn't be messing with alkyl halides in the first place.

dioxine - 5-5-2021 at 13:41

njl, thanks for your answer!

Well im just trying to collect as much data as possible because i saw a lot of videos people making bromoethane and they dont use anything special - just fume hood enough maybe to reduce fumes of bromoethane itself, so it looks relatively safe.

But some books claims that phosgenes could be formed, at least with fire.
just these two examples:
"Phosgene and related carbonyl halides":

Russian source, "in flame forms bromophosgene"

I just trying to understand practical side of this - do i really need to be extremely prepared like im working with phosgene itself or basic safety steps will be enough? Any harmfull concetrations possible?

So sorry if im too much stupid for you - im not a chemist, just engineer who wants to make chemistry on amateur level.

[Edited on 5-5-2021 by dioxine]

Elemental Phosphorus - 6-5-2021 at 06:55

Quote: Originally posted by dioxine

njl, thanks for your answer!

Well im just trying to collect as much data as possible because i saw a lot of videos people making bromoethane and they dont use anything special - just fume hood enough maybe to reduce fumes of bromoethane itself, so it looks relatively safe.

But some books claims that phosgenes could be formed, at least with fire.
just these two examples:
"Phosgene and related carbonyl halides":

Russian source, "in flame forms bromophosgene"

I do not think this should be too much of an issue if you work in a good hood or with good ventilation. However, maybe avoid using an open flame to heat when you do your distillation.

The temperature required is not much, so it should be pretty easy to heat it with a hot plate or heating mantle. Generally, burning halocarbon compounds produces all kinds of nasty compounds, but if you avoid putting it in a flame or subjecting it to electrical discharge (which usually has a unique ability to rearrange compounds in strange ways) you should be fine.

Ethyl bromide itself is not extremely toxic. While you should minimize exposure and use good ventilation, the creation of much more toxic compounds like phosgene isn't going to occur under normal reaction conditions.

Jenks - 6-5-2021 at 07:13

The main risk you have is inhaling the vapor, which is easily formed given a boiling point of 38°C - about body temperature. So work with good ventilation, and don't worry about cleaning up spills. If there is a spill, go away and come back after it evaporates and the vapor has dissipated.

Texium - 6-5-2021 at 07:43

If you just want to experiment with alkyl halides in general, perhaps consider making a less volatile one for your first one. Ethyl bromide has the lowest boiling point of any alkyl halides that are liquids at room temperature. Butyl bromide, or even isopropyl bromide, would be easier and safer to handle, if you don’t need ethyl bromide specifically. You don’t need to worry about bromophosgene though, as long as you aren’t burning your product.

[Edited on 5-6-2021 by Texium]

clearly_not_atara - 6-5-2021 at 09:55

The production of toxic levels of carbonyl bromide in an EtBr flame is not very likely. Unlike phosgene, COBr2 <> CO + Br2 is a reversible reaction which favors the RHS at high temps. It likely appears because both CO and Br2 are combustion products of EtBr.

Even so, EtBr is not that flammable. In an EtBr fire, I'd be concerned primarily about exposure to Br2.

[Edited on 6-5-2021 by clearly_not_atara]

dioxine - 7-5-2021 at 05:36

Well i have to say thank you all for so much advices. Its really what will help me. Im thinking of starting with isopropyl bromide. Will be going to work on a small scale to prevent poisoning someone.

Is an open area and sunlight an issue in this case? Because i dont have fume hood but have access to well-ventilated open space(literally strong winds that makes even heavy things like glass rods fly). im more worried about sunlight with UV and other spectral components. Also some neighbors making barbecue sometimes. Im far enought not to hurt them, but can it be source of CO?

[Edited on 7-5-2021 by dioxine]

[Edited on 7-5-2021 by dioxine]

[Edited on 7-5-2021 by dioxine]

Elemental Phosphorus - 11-5-2021 at 18:19

I do not think that production of bromophosgene by sunlight should be an issue. If you are working outdoors with good ventilation, I also don’t think you should be too concerned about the vapors. Of course you should avoid inhaling them, but if you’re producing a plume of vapors something is probably not right. The vapors will be quickly dispersed anyhow. A mask is also always an option for added protection, although I’m not sure what filters you’d need. I use 3M filters that filter for acid gases, particulates, etc, but then again I’ve never made alkyl bromides, so I’m not sure if they work for that. Either way, the toxicity of bromides is not extreme, the production of bromophosgene or more toxic compounds is very unlikely unless you have a fire (or lightning strikes your setup

), and if you do have a spill you can simply walk away and let it dissipate, and a respirator probably isn’t needed.

Your neighbors grilling at a distance away will almost certainly not be an issue, although if they’re close by they might have some questions about what you’re doing.

Then again, maybe someone with more experience in these syntheses can correct me. I’ve never made alkyl bromides and the most formal education I have in chemistry is a high school class (haven’t been to college yet) so I may not be the right person to ask. That said, I have done a number of reactions that do produce fumes (chlorine reactions, bromine synthesis, nitric acid distillation, nitrations, etc.) and doing these outdoors, sometimes using a respirator has always worked fine for me.

Fyndium - 11-5-2021 at 23:03

If you produce enough CO to cause issues to your BBQ neighbors, I wonder what kind of scale you are actually doing.

Likelihood is by over 10-fold is that if they see you doing whatever sort of chemistry, they think you're running a meth lab.

Regarding to synthesis of ethyl bromide, I did some about a decade ago and I don't remember having any issues with it. I clearly remember the smell, too.

Oxy - 12-5-2021 at 11:50

Quote: Originally posted by Fyndium

I clearly remember the smell, too.

I would be really pleased if more chemicals would smell as nice as EtBr

Fyndium - 12-5-2021 at 12:26

I would be really pleased if more chemicals would smell of nothing. I mostly fight with a circus of all variations of our olfactory capacity. Because many chemicals smell of nice, but if you have even a little bit more than few grams of them, the smell will quickly become overwhelming. I actually went through some waste solvent canisters of my shed and I opened one which had residues of my phenylacetaldehyde tests, and my shed still smells again of mixture of flowers, honey and mouse shit(due to oxidation to PAA), and while it's a very pleasant smell at first, the second whiff just makes you mad of it.

At the beginning of summer, when flowers start to bloom, you can easily smell phenylacetaldehyde. Every time I do, good memories flash up. I might wanna do some more PAH just to enclose it in a small glass jar to whiff it sometimes.

At least it isn't as carcinogenic as EtBr to whiff for.