What size bottles are you all using? Butane or propane? Surely a diddy camping bottle of gas would be little risk compared to a big 47kg type? Although crap money wise.
There's very little risk when it comes to the actual bottles as long as they are closed and secure when driving, the risk comes
from leaks after the gas leaves the bottles.
In caravans and motorhomes all gas must be carried in a sealed container with a vent at the bottom, its basically to keep it
away from anything electrical that might spark and ignite leaking gas.
There's also a limit on how much gas you can carry in a car or van I think 47kg would be over the limit.