[Cockney]

Hi there,
I tested two batches of hcl this evening to determine the stronger as a rough and readyguide, batch one was known to be 38% and just fuming and the second, unknown and sold as masonry cleaner. I used about 2mm in each test tube and dropped some aluminium foil into it and observed the reaction. Batch two was much weaker judging by the reaction speed. Shortly after there was a noticeable haze in the air, no smell and I only noticed it when I left the room and went back in. I ventilated the room straight away by throwing all the doors and windows open.
What happened to cause this, my only thoughts are that there is a cat litter tray in the same room, could the hcl fumes have reacted with a small amount of ammonia in the air ?
I was wandering in these fumes for a couple of minutes, I take it I have not put myself in any danger!

Any idea's ?

Cheers
Cockney

[Arkcon]

The haze in the air is likely HCl vapor, it very volatile, and very soluble in water in the air, and forms in the air a mist of HCl in water.  You'll also get the white smoky haze of ammonium chloride crystals in the air from ammonia and HCl, but you should have noticed the ammonia first.

Funny thing about aluminum and HCl, the product, aluminum chloride, isn't stable in water, so breaks down, releasing CL2 gas, which attacks free aluminum, and generates heat, which evaporates HCl vapor, which attacks free aluminum to make aluminum chloride, which breaks down in water, and so on.

None of this is good to breathe.  Your biggest problem from mild exposure is conjunctivitis, an inflammation of the cornea.  You'll know it when your eyeball won't fit under the eyelid anymore.  Massive inhalation of strong acid is likewise, pretty obvious once it's effects strike. You'll know if you can breathe, or not.  Try to use more ventilation next time.

Oh, P.S. masonry cleaner is roughly 35% HCl, that's about as strong as HCl in water can get, and be shipped and stored easily by the hardware store.  Only labs or industry can get stronger, and they usually don't bother.

[Cockney]

Cheers,
The fumes were not thick, I couldn't actually detect anything until I left the room and came back in and noticed it looked hazy, there was also no smell of ammonia, the cat litter tray does get emptied :-) I had just done a distillation experiment with a home made condenser so the atmosphere in the area my have had a lot of moisture.
Anyway I'm still here... Eyes are a little sore, maybe feeling a little dry. I have spoken to the local eye hospital as a precaution and they said it should settle down and didn't seem too concerned but advised to go down for a check if it got worse or does not go away. I would assume any irritation would only get better from now, eyes were fine when I went to bed last night, only started feeling strange over the past few hours which made me check with them.

Anyway, thanks for the response, clearly an error in my judgement and will now always ventilate regardless of the amounts used.

Cockney