Goldfinger:
Get this,
In last job, I was ‘told’ to carry a 2500litre site (bunded) fuel bowser (‘we’ know it was empty), then call past a gas products supplier and collect/add on 10 oxy and 10 acetalyne!! 
I think I’m gonna like this one… 
First, can I assume (from you saying “carry”) that the “2,500litre site (bunded) bowser” is the kind that looks like a big metal IBC?
If it was the kind that looks like a big metal IBC, it counts as a package. If it was a package and it was nominally (= said to be) empty, then it doesn’t count for anything towards load limit ‘freebies’ in ADR, because there’s no ‘freebie’ limit on most empty packages and so you could carry an unlimited number of such things if you wished to without worrying about ADR…
Goldfinger:
Gas supplier refused to sell and advised me it would be jail for me if anything happened! 
If the bowser counts as an empty package, then the gas supplier was completely wrong and went on to lose himself a sale for no good reason.
Goldfinger:
ie, whos to know the bowser in empty? (proof of cleaning + cert to say that) if not, it’s classed as ‘nominaly full’. Plus the gases, er, boom…
If the bowser is of the ‘trailer’ kind, ie it was a tank on a chassis on wheels and towed behind your vehicle, then you’re correct because ADR counts such a vehicle as a tank vehicle and you’d be fully in scope of ADR just for that reason alone, whether it was empty or full.
However, if it was a package, which from the info you gave is more likely, then you and the gas supplier were both wrong. (There’s no grey area here.
)
Goldfinger:
And as for the gas, I think he said I would be over my limit anyway before ADR, orange plates etc.
Until you tell me the sizes of the Acetylene and Oxygen cylinders, the jury is out cos it was quite possibly legal for you to have carried the (package) bowser, the oxygen and the acetylene all at once. ADR allows the bowser and the two kinds of gases to be carried on the same vehicle at the same time. Whether you were ‘in scope’ of ADR ( = needed an ADR licence and orange plates etc) depends on the quantity of the gases you’d been asked to carry.
Goldfinger:
One of the MANY reasons I jumped ship!
If nobody had a clue what they could or couldn’t do and made up rules as they went along, then I wouldn’t blame you for jumping ship.
