Allowed to take a full reserve can 'on' the vehicle?

We recently received an interesting question from one of our readers. The reader Michael H. asked us something about "Taking a 20 liter Reserve canister". The question: "I drive a Ford Ranger Wildtrak. The rear bumper is equipped with a swing arm and transports a reserve canister holder including a 20l steel reserve canister. Can you fill the 20l steel reserve canister with 20l diesel (or petrol) and transport it on the outside of the vehicle? Both the canister and the holder are approved for road use. In other words, the holder was removed from the TÜV on the vehicle and the canister corresponds to the applicable standard.

In addition, some information about the canister and the holder:

• Canister: UN approval for transport according to the dangerous goods ordinance (GGVS road/GGVE rail/ GGV sea)., 0 mm steel according to DIN 9, with fuel-resistant inner coating, outside with durable powder coating, bayonet lock, no limitation of the maximum period of use according to ADR, for all types of fuel suitable, coated sheet steel design with locking pin, UN approval, for the transport of dangerous goods according to GGVS
• canister mounts: Suitable for 20 liter metal cans, with rubber padding, lockable

Canister and holder may be installed at the rear of the vehicle and are approved and registered according to TÜV. The only thing that is unclear to me (and also to my TÜV inspector) is whether the canister can also be transported filled at the rear".

it depends on the type of mount

If the manufacturer of the vehicle with the canister on the outside has received an operating permit from the Federal Motor Transport Authority, i.e. the canister not afterwards has been attached, the TÜV inspector no longer has to ask himself any questions. Proper use is then also included with the operating license of the vehicle. Do you have the holder for the canister later grown yourself, you need one for this ABE. This also shows how and whether you can use the holder for the canister with an empty or filled canister.

This post is not legal advice! It only reflects our experience/assessment with this topic!

In other words, if the holder comes from the accessories and is approved for installation on the vehicle, then the enclosed documents must contain a corresponding note as to whether the canister may be transported full or only empty. If there are no documents, then legal use is not necessary in traffic.