Greetings (3 years later).
Yes, MSDS exist. I don't think they are useful. They are written by lawyers, for lawyers. I believe the MSDS starts showing up at about 11% acetic acid. And yes, acids of any kind can burn skin. Highly concentrated acetic acids are flammable. The lower the concentration, the more water is present, and the less net heat can be produced. Explosion risk? If you were pumping acetic acid under high pressure, and a pinhole leak developed; such that a "cloud" of very fine droplets was produced, it might be an explosion hazard. There might be other odd situations which could generate explosion hazards. But yes, high concentrations of acetic acid will burn.
I am getting so tired of pricing for what the market will bear.
Vinegar comes from fermenting sugars. Acetic acid can come from other things. If you want to use acetic acid for a herbicide, it need not be "vinegar", unless you have a reason to distrust the other things that might be in the acetic acid.
I'm in Canada, and about the strongest vinegar I see on the shelves is 9%. This is meant for "pickling". They really don't want people to pickle the "proper" way, by using lactobacilii to convert sugars into lactic acid.
A couple of years ago, the cheapest food stores had 4 litre (about 1 gallon) of 5% vinegar for say $1.70. I see today, that they again have a bottle of 5% vinegar for $1.7 or so, except it is 2.5 litre. I have no doubt all these companies can justify things, but 60% increase in price over 2 years is just a little bit ridiculous. But this is vinegar, and not acetic acid.
I think I went through the calculations properly a few months ago, and I believe the world market price for 5% acetic acid (NOT VINEGAR) assuming water is free, is about $0.10 (CDN).
There is a quality issue in talking about vinegar versus acetic acid. Vinegar is food grade. Acetic acid isn't. They can have quite different impurity profiles.
I have a sister who works at a cleaning supply place. They have VINEGAR in their store, they do not have acetic acid. The prices they charge for vinegar are ridiculous. But, I live in an economy dominated by the "oil patch"; and the feeling is that everybody in the community has too much money; and so you can charge whatever you want and people will still buy it.
A few years ago, my
local Coop Agro store had 20% vinegar. The price was "okay". To use acetic acid (or vinegar) as a herbicide, you really need to know what it is you are going to be killing. There is no sense using 20% acetic acid for something which can be killed by15%. What using "over-concentrated" acetic acid gives you, is a faster kill. If there is a chance of rain later today, the stronger acetic acid solution may give better results if it does actually rain.
Acetic acid in the soil eventually turns into water and
carbon dioxide. Every organism in the soil comes across acetic acid at some point, and has some way of dealing with it.
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Using 5% acetic acid vinegar as a herbicide may work where you live, it no longer makes sense here. It probably didn't make sense when it was $1.7 for 4 litres. It does not make sense when you only get 2.5 litre for $1.7.
I would have thought a cleaning company would have the option of clients buying acetic acid, instead of buying vinegar. They don't. I've looked periodically into the possibility of buying things like a barrel of vinegar (food grade) or acetic acid; and there is no savings. One oil patch company sells 53% acetic acid for something or another; minimum order is something like 1300 kg.
High concentrations of acids (or bases) which need to be diluted are trivial in the lab, when you are making something like 100-1000 ml of solution. If you are working with multiple gallons; things are not so easy. Diluting concentrated acids or bases generates heat. If you do it wrong; you can get localized boiling. If the acid you are diluting is flammable and you do it wrong; you could start a fire. If you are using plastic vessels and you do it wrong, you could melt holes in the vessels. There are lots of ways to get into trouble.
It would really be best; if you could purchase the strength you need. But that doesn't seem to be what business is providing; unless you want to pay LOTS of money.
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If you make acetic acid (or vinegar) over the course of a year, and live someplace that gets significantly below 0C in the winter, you may be able to increase the strength of acetic acid by freezing it. You need to use a vessel design that won't break when things (involving water) freeze.
It seems likely (I haven't tried (yet)) that you can concentrate acetic acid by pouring your vinegar (or acetic acid) onto a tall column of activated charcoal. Activated means the carbon (charcoal) is amenable to adsorb things (adsorption is to become attached to a surface; absorption is to become attached to a volume).
Biochar (which includes burning
trees) is carbon. It may be activated out of the kiln, or you may need to do something else to it. But, if you pack a column with fine activated carbon; and start pouring acetic acid (or vinegar) onto it, it seems the acetic acid preferentially adsorbs onto the surface of the carbon, letting whatever else is in the acetic acid (or vinegar) to (possibly) pass on through the column.
Maybe there are components of the feedstock, which adsorb onto the carbon better than acetic acid.
But, absent that point, to deliver acetic acid (or vinegar) onto the top of such a column; the acetic acid adsorbs at the first opportunity it s presented with. Leaving the rest of the contents to travel down through the column; and eventually leave. Perhaps the pH of this first liquid is 7. If so, it means that all pH related things had adsorbed onto the charcoal in the column.
A person keeps adding more and more acetic acid (or vinegar) to the column. Adding more acetic acid, might mean that something adsorbed onto the column, desorbs and travels further down? Nominally suggesting that acetic acid is the preferred species to adsorb on the column
At some point the column will become "loaded". If we are monitoring pH at the bottom of the column, we are expecting the pH to drop when the column is filled.
https://www.sciencemadness.org/whisper/viewthread.php?tid=5528
https://www.sciencemadness.org/talk/viewthread.php?tid=10545
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The above is to be interpreted as a book report. It should not be considered expert opinion. The engineering society in Alberta, Canada decided it needed to make a diversity statement. It considered gender and ethnicity. It would not consider things such as autism. I told them where to stick their P.Eng.
