Ok, hope no one got injured in that one, because the result is some kind of ilarius! But don't get me wrong, I'm a paramedic, so O know about the gravity of the potential injuries and drama if some thing like this.
Now about thos little green bottle, they are not made to be reusable, even is some kit are made just to do this. They have a tendancy to leek when brand new, so mess with that opening once to many time, and it is just a leek waiting to happen.
Now about that smell, some people might not be able to smell the odor, but some people are just carless and just used stuff without nowing that household good can be dangerous.
Remeber, it is gas. It also need to reach a certain concentration to explode. And he was asking how to carry a 20 bls propane tank to camp, not for en extendend period of time on an overland trip.
But the best thing you have to do, is follow youre local government regulation and ay attention to what you are doing. We saw a camper explosion in tje picture, but we also see hous explosion, and gas is still used in house everywhere.
Not always and especially if it is in the trunk.
Apparently some people are genetically unable to smell the odourant mercaptin so that is another reason to heed the commonsense suggestion to only transport propane tanks upright and in the open air or in an enclosure vented appropriately outside the passenger area. And of course it goes without saying that a propane alarm down at floor level isn't a bad idea
from
http://globalnews.ca/news/2006424/camper-explodes-in-kelowna-walmart-parking-lot/
(Tanks used in propane powered vehicles have a sealed shroud over the inlet and outlet and pressure relief valve and that shroud is vented to atmosphere via a pipe)