:) Thank you, Mr. Fuad and AMT. I am so grateful for your comment and I am sorry if I have violated any rules. That wasn't my point for sure. :) However, I see you both appreciate my input and that's more valuable to me than 4 ... no...than 4000 kudoz ps.

To neuneutek: Please submit your input in an answer to the question. Thank you.

The point is a liter of ammonium in a room is toxic while a 20 litres of ammonium spread in a big Opera hall may not be toxic at all. :) All depends on the concentration (BY VOLUME "for gases")

:) When it comes to gases and toxicity concentration BY VOLUME not by mass is important. For example 1 litre of ammonium gas diffused in a 2-litre volume box is 50%. THat's in contrast of mass concentration which is more important for solid and liquid tox