[jnbiggs]

Hey guys,
First off... I'm not a chemist.  When my college told me to take 2 sciences I chose "rocks for jocks" ... geology.

I have a practical question for all of you.

I am building a composter to use in my vegetable garden.  I bought a 55 gallon plastic barrel that once contained windshield washer concentrate... the only chemical that I know was in this concentrate is methyl alcohol (barrel is still labeled with the cautions and hazard rating). 

Can I possibly render this container safe for composting?  Keeping in mind that the compost will feed the vegetables that my family eats.  Through my little bit of research I've learned that methyl alcohol/ methanol is toxic, but very miscible in water.  Obviously I can rinse out the small residual liquid still remaining in the container, but I'm unsure if the porous nature of the plastic would have absorbed some trace chemicals that would be leached out by the compost.  The rational side of me concludes that any possible amount that is absorbed by the compost would be so trace by the time it reaches my garden it would be insignificant.  But knowing my families health hangs in the balance I want to be 100% sure on this.  Thank you all so much for the help.

John

[curiouscat]

I think you'll be fine.

[Enthalpy]

I didn't grasp what the barrel shall serve to... Because (unless I misunderstood some English or your intention) a composting place must let the rainwater flow in and out, and some air pass through as well.

Typical compost places are made of wood planks, widely spaced on purpose - like the one working well in my father's garden. If you close the walls and the bottom, you get a rotten juice, not compost.

[billnotgatez]

2@Enthalpy
I assume the original posting involved a homemade device like this
http://www.homedepot.com/p/Good-Ideas-7-cu-ft-Compost-Tumbler-with-47-gal-Rain-Barrel-Base-in-Black-EZWH-BLK/203079110?cm_mmc=shopping-_-bingpa-_-28-_-203079110&ci_src=328768002&ci_sku=203079110
But, maybe I assume too much

@jnbiggs
I tend to agree with @curiouscat as far as methanol, but I wonder about the other chemicals that might be in your windshield washer concentrate - Do you have a brand name?

[Borek]

Methanol is definitely not a problem. Even if it is still there it is present in minute quantities, and it is always present in minute quantities in the fermented organic matter. But even if there will be much more, it will have plenty of time to vaporize, if not in the container, then once the content is used as a fertilizer.

I wouldn't be so sure about other chemicals, especially not knowing what they are.

[jnbiggs]

Thanks all.  Unfortunately, there isn't much more info I can derive from the labeling that might indicate what other chemicals were in the solution. It's called "Magic Bright" manufactured by Carsco, Inc. I can't find much info on the company or the product online. Methyl Alcohol is the only substance identified on any of the warning labels.

Hypothetically, if there were other dangerous chemicals in there, does anyone have any recommendations for cleaning it out aside from rinsing with tap water?

@billnotgatez you make a good assumption. Here's the exact design I'm aiming for http://lifehacker.com/5931882/build-a-tumbling-composter

[Arkcon]

Its just not a good idea to reuse a drum that last contained chemicals, I'm afraid.  We're all working under the premise that a trace of methanol won't badly affect food quality if it briefly contaminates compost.  But when you add as many "I don't know" chemicals as you can, I really default to the knee jerk response -- its inappropriate to re-use industrial chemical drums.

c.f. this former posting: http://www.chemicalforums.com/index.php?topic=22030.msg84242#msg84242

[curiouscat]

its inappropriate to re-use industrial chemical drums.

I'd agree if this was a direct food / beverage use. e.g. Should I wash this MeOH drum & use it to store milk / drinking water etc? No.

But in this case the specific use seems indirect enough. He will compost trash. That compost will fertilize plants. Plants will grow. There will be rain or some other water. He'll wash the final product & then consume it.

Seems a chain long enough seperated from direct food storage that it ought to be ok.

If you look at what they spray on crops on industrial farms that's some pretty nasty stuff. Way nastier than methanol.

The fear about trace ingredients that might be nastier is valid. But knowing that the original end use was windshield-washer fluid I doubt they would add something really really nasty anyways. This is fluid that will end up in sewers and groundsoil and I'm sure EPA would throw a huge fit if it had any real potent stuff in it.