nitrous in tanks australia (not a source/avail discussion)

[Goingtotherealside]

well unless a medical grade nitrous tank is stolen it is pretty hard to get nitrous in a tank pure, and car nitrous has impurities which are said to be toxic. how toxic are they exactly.

I have huffed worse than nitrous impurities.

All I want to know if I did get nitrous tanks meant for cars which you can get without a license, if i used a filter mask (and had a sober trip sitter to make sure i dont have it for more than 2 minutes.............) will i be able to hold in the car nitrous tank contents or does it have something like CO2 so you are forced to expell it from your lungs?

thanks