# Metal drum, toluene storage, for cooking



## Noseoil (Oct 24, 2020)

Is there a chemist in the forum who knows about the residual impurities left behind (on or in the metal) from storing toluene in a barrel or drum? 

I'm making a smoker with a 55 gallon drum which was used once to store toluene (new from the factory) and then discarded. I would like to hear from someone with a background in chemistry, who knows about the effects of using a barrel like this for smoking. What would the purging process be, what contaminates are left after evaporation & several months of sitting in the sun with openings for airflow allowing oxygen to interact with the interior surface. 

Please note, I asked for a chemist for an answer to this question (a scientist with the right background would be helpful also). Hear-say, opinions, & uninformed guesses about this question aren't really what I'm looking for & won't be helpful. I have a call into a manufacturer already, but haven't heard back yet so I'm wondering about someone from the forum who has a background in chemistry who can help.


----------



## Bytor (Oct 24, 2020)

My back ground is in Industrial Hygiene.  I do a lot of work with hazardous materials.  If the drum is still intact, you definitely want to be sure there are no remaing vapors that could ignite upon cutting it.  If it's been left empty for some time with the bungs off, it should be good.  Toluene has a pretty moderate evaporation rate, so any concern for remaining impurities would be minimal.  The chemical also has a pretty low odor threshold, so if there's any remaining, you should detect it.  If it's not cut yet, I would suggest adding several gallons of water to it maybe with some baking soda, swish it around and drain.  If it's been dry that long, there really shouldn't be any environmental concern with the water.  Then you should be able to cut it, as needed.

Odds are with it being the way you describe, there's nothing left, other than some possible odor if that.  Once cut and assembled, a good empty cook to get things up to temp will remove any potential lingering leftovers of it..  If I were in your situation, that's what I would do.  I know of a couple folks that have done similar to a couple of old Acetone drums and they continue to use them without issue.

Hope that helps.


----------



## Noseoil (Oct 24, 2020)

Bytor, many thanks for your input. It's already cut at this point, but I did let it sit for quite a while this summer with it open to the air & hot sun (drum is black, so absolutely no solvent left prior to cutting). I'm thinking it will still need a scrubbing for the steel grills I made (residual oil from the rolling mill on expanded metal), then a torch to dry it off, followed by several bouts of smoke & heat before I attempt any actual cooking. At that point, it should be well enough seasoned to start it's real work as an oven. 

Again, thank you kind sir for your input.


----------



## daveomak.fs (Oct 25, 2020)

https://www.pure-chemical.com/msds/Toluene.pdf


----------



## Bytor (Oct 25, 2020)

Wow, that sure does look nice.


----------



## Noseoil (Oct 25, 2020)

daveomak.fs, thanks for posting this pdf. I has seen a similar one, but it didn't address the issue with an empty, purged vessel. Disposal of a container containing some residual liquid would have been interesting to cut apart, as it would have flashed & exploded at the first spark from the grinder. That's why I let it sit open for a couple of months in the sun prior to working on it. Still waiting for a call from the manufacturer's agent...


----------



## Noseoil (Oct 29, 2020)

Finally spoke with a chemistry guy at a large chemical supplier. He said what I figured, don't use the drum for a smoker (liability issues if he had said otherwise). That having been said, he saiid they use steam to purge large tanker trucks to clean the interior of residual solvents with organic vapors & it works pretty well. So the answer is, NO, you can't use a solvent drum for a smoker, but it can be steam cleaned to use for storage.

I'm going to steam clean mine...


----------

