Acetic Acid - Update

[Tim Keenan & Rebecca Counts]

Robert and List:

Just got back from the PNW Convention in Banff, AB, so I am at the end of 
this thread.

99.5% Pure may mean that it is uncontaminated with anything but water, 
and not be a reference to concentration.  If it is labeled Glacial Acetic 
Acid, this means that it is anhydrous, that is CH3COOH and nothing else. 
If it is, it will produce really spectacular burns on skin, or in your 
lungs and pharynx on inhalation.  It is not toxic, particularly, and can 
be safely disposed of by dilution, BUT, do it either in a fume hood or 
out of doors, and do it by adding the acid slowly to a large volume of 
cold water.  It will produce heat rapidly.  If you add water to the acid, 
it will boil explosively, splashing everyone in the vicinity with 
boiling, almost pure acid. As with any concentrated acid, always dilute 
by adding acid to water, and not vice versa.

In my former life as a paleobotanist, I used glacial acetic acid mixed 
with concentrated sulfuric acid to dissolve all the cellulosic material 
out of lake sediment samples in order to isolate fossil pollen.  The 
combination of those two acids will turn a solid piece of wood into a 
solution of cellulose acetate.  Just as a matter of interest, that is 
what rayon is.  We disposed of the residue by diluting it a little at a 
time in a large volume of water and putting it down the drain of our fume 
hood.  WEAR GLOVES AND A FACE SHIELD.

Tim Keenan
Noteworthy Piano Service
Terrace, BC