Australia's Science Forum

Hi All,

Had a bit of a fright today. Was about to make up some dilute HCl but when I opened the bottle of concentrated HCl all this gas started erupting from under the lid as soon as I slightly twisted it (as in the lid was still basically on and not screwed all the way off). I fully admit I squeaked and jumped back, and was extradinarily grateful that I was wearing full PPE and doing it in the fume hood, but it was still super scary and there is a gap between my gloves and my lab coat sleeve, and my face isn't covered beyond my safety glasses... I eventually took the whole lid off and it continued to steam scarily so I've left it alone in the fumecupboard.

Anyone know why my bottle of concentrated HCl did this and how to prevent it?

Was a new one, or used before? It could have been the heat we have had lately? We placed ours on a china dish, bee hive dish think it was called. Has a hole at the bottom of the dish, never had the problem before, after 18 years we are all still learning. So glad you are ok scary and you had your PPE on, not every wears a lab coat. Well done Samantham

Old bottle only had about 400 mls left out of 2.5L. We keep ours in acid resistant plastic tubs that can hold 1.5 x the amount of liquids stored in it. Had to fight to get them (inspection year came around at the right time so I got them). My thought was perhaps the heat but its been cool today (we had rain yayayayayayayay). How long would it take for pressure due to heat to calm down?

Wow! I've never had that happen in the nearly 30 years I've been a lab tech. It sounds unstable and if you have eliminated contamination my guess is also heat. Unless there was a build up of condensation and you had the classic water/acid reaction which would have been a chlorine gas? Good warning to us all though.