In 2000 i worked for a firm where one of the drivers kept a big gas bottle in the footwell of a FL10. He didn’t know it was slightly leaking and next morning he woke up and lit a ■■■, he was blown clean out of the cab and ended up in a bad way in hospital. I left the firm soon after so I didn’t know if he recovered.
Maybe the bottles are safer now but I wouldn’t keep one in the cab.