Benzene in butane

For those of you who haven’t heard some Bay area butane process got contaminated and a bunch of gas has gone out with benzene in it. This is a PSA. I’m down in San Diego and my new shipment of supposedly clean n-butane arrived has benzene in it. Or at least I suspect that after the first runs I did with it failed for benzene. Called my testing lab and they said they are seeing way more benzene fails last few days than ever before. I advise everyone to test their gas or at least your first run tested before you run a ton of material, can’t imagine how much bad gas went to the traditional market where people will have no idea it’s in the product they made. Luckily I caught it relatively early hopefully some people will see this and figure out they got contaminated gas too before they run too much material.


Should be pretty easy to just boil off the butane if it’s contaminated with benzene.


Is there a way to test the gas prior to use? Ive asked our gas suppliers for coa’s multiple times and its always some bs excuse or a coa that doesn’t match the lot numbers for the tanks. Still waiting for a gas company to actually have some traceable supply chain.


Who was the supplier? The hydrocarbon company

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There’s no reason for people not to provide COAs - these gasses are all tracked.

You can totally have your gas tested at most testing labs that can do residual solvent testing too. There’s a special sampling port/container that you’ll need for your tank but other than that its like submitting a normal sample.

And really - if someone isn’t giving COAs - you can just tell the regulators, cause all of these hydrocarbons get tested for taxes and other crap and not having that stuff is not supposed to happen. Even the propane exchange tanks should have lot numbers associated with product batch and testing. -shrug-


I dont want to name drop my suppliers but both dont supply coa’s and ive asked regularly. They are used by many in this industry.


Shouldn’t @SolventDirect be able to handle this with all their bold claims


I have had tanks with benzene in it dating back to 2015

I think they clean old tanks with it


what does that tell us? they’re not making information available to you that you’re entitled to… is this the next THCP shitstorm thread?


i heard some background how this might even be possible. Seems like benzene is in most butane in minuscule amounts…not enough to trigger a test or fail… well if the tanks arent cleaned every fill these heavier hydrocarbons can collect in the tanks and eventually trigger a fail…

i think benzene is the higher c6-c10 hydrocarbons… i think its a good time to ask your supplier if they test for the heavier hydrocarbons or if you purify them out…

i know one gas supplier that reached out and say they do not sell any gas with any c6-c10 hydrocarbons at all


probably not neat benzene but maybe a rather raw and cheap distillation fraction that contains benzene.


Can u use benzene to make a novel synth? Lol

It’s like Lego, you can make the Millennium Falcon from 4x4 blocks. It’s not elegant, but it’s possible.


I hate to tell you pure solvent is never really pure

Even the food grade 200 ethanol I get contains some isopropyl and acetone somehow

No idea how

I bet most hydrocarbons will pop on an MS for benzene

Toxicity is in the dosage


H2S and heavier hydrocarbons were endemic in OK for the first year roll out… it was a massive flub, and frankly, really s****y to have to navigate that.


never said it was pure…just said they remove the c6-c10 hydrocarbons…

i also hear some companies chain of custody is fucked…and the reason you might not see a COA

ever notice how some companies show super old COAs


This is the exact issue ive been facing. We have been working towards getting gmp compliant and one of the big things is supply chain traceability. The only coa’s ive ever seen are 1-2 years old and not matching lot numbers.


Piece of info for y’all, we recently had a sample come back from GCMS OVI testing that reflected >500ppm benzene. Obviously we lost our shit about it and under substantial retesting, we found the “benzene” to be a heptane isomer. Definitely not saying this to be the case here, and this is why even with a good library match with MS we use standards to confirm, but I figured it was worth mentioning.

Edit: I should probably mention that this was during a (very) failed process change that had ~3000 ppm residual heptane


My results are about 2 ppm in badder and 8 ppm in HTE. None in the sugar. Still would have failed an otherwise fine batch of badder had I not randomly decided to do a residual solvent test on this batch prior to packaging.

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Every lot should be tested by a reputable 3rd party company like amspec. They should also be taking random tank within that lot and testing in-house.

I’ve been talking with a distributor about some of this.

Some suppliers don’t want their gas vendors to know they are playing the field sometimes with cheaper prices. Which is why some gas don’t have coas