ChocolateStirBar - 4-11-2017 at 17:38
Hi guys.
I recently opened my (HDPE) container of 36% aqueous HCl. I wore gloves and vented eye glasses. I read the MSDS.
What I was not prepared for however was the unholy amount of vapour/smoke/fumes it gave off! I instantly stopped what I was doing and replaced the cap
so I could prevent an out of control level of vapour and a resulting injury or panic.
The smell is very characteristic and has ever so slightly burnt my nasal mucus membranes, they are not sore, I'm just "aware" of them if that makes
sense. The MSDS says it is not corrosive to lungs themselves so I do not have any health anxieties.
I am somewhat glad for the experience. It made me realise life is not a textbook nor first person youtube video which does not show how much safety
gear the video maker has on.
Now, I have a few questions:
1) Will the HDPE bottle and cap be good to hold the HCl over long periods of time? I've heard it's a bastard for escaping.
2) Would you guys recommend a respirator in future? I have no reason not to buy one regardless.
3) Are there gloves/clothes made of X material which resist HCl better than other materials?
4) What should I not store the HCl near? For example, not near metals. Not near oxidisers. Not near bla bla bla. Whatever you guys have advice on
storage wise is welcome!
Thanks!
j_sum1 - 4-11-2017 at 19:08
Your simplest solution is to dilute your 36% down to about 20. That will do most of what you want it to do for most experiments and you will nearly
eliminate vapour problems and your acid will last a lot longer. Even diluting to 30% will make an enormous difference.
A couple of other things:
I recommend doing a titration of your acid so that you know what you have.
If you think you might actually need 36% for anything you can always keep aside a few mL. Go for a small glass bottle with a narrow top and
fill it right up. You want to minimise the head space in the bottle. You also want to minimise the area of the liquid exposed to that head space.
Both of these will lessen the rate that the HCl escapes. And then of course choose something with a tight-sealing cap.
Alternatively, HCl gas is easy to make when needed: simply add concentrated H2SO4 to some sodium chloride and the gas will be evolved.
A fume cupboard is highly recommended for this kind of thing. Makes for easier breathing. As you note, HCl is an acute problem rather than a
chronic problem. It will be really unpleasant but if you are not feeling bad then there won't generally be long-term effects.
Storage of your concentrated HCl (even at 20-30%) will always have an effect on any iron or steel in the vicinity. Accelerated rusting will
occur to anything in the same room. Larger quantities are best stored in a ventilated area away from everything else.
JJay - 4-11-2017 at 20:45
I remember being surprised by the fumes the first time I ever handled 37% hydrochloric acid... I usually don't bother with a hood when I handle it,
but don't leave the bottle open any longer than necessary, and typically I don't handle large quantities. If you are pouring multiple liters between
containers, a fume hood is strongly advised. Most any gloves will resist it. You can store it in the bottle it came in for a few months, and if you
are concerned about corrosion, you could put the bottle in a sealed bag with some lime.
[Edited on 5-11-2017 by JJay]