Medium to Large Explosions

I feel the plastic type now is quite up to the strength etc, although I have only carried diesel in my 20lt size drums . . . strength wise they would be on par with metal too I think (roto moulded one piece, tough), but less prone to long term rust, dents, etc.

The spout storage dilemma is one to consider.
Mine are stored inside, and especially with diesel they are a little messier to use when emptying, but travel externally a lot cleaner from dust / rain etc.

The external type are exposed to the elements, but can be stored inside the vehicle to ensure they are clean for use, and would air off quickly with petrol residue.

Metal ones have the pour spots separate, and I think sold separately ?

Plastic are a lot more stronger and safer then the old metal types.

Look at how many fuel tanks are plastic these days including the big capacity ones earthmoving contractors use in the back of their utes and in boats.

I understand what you concerns are for the two but in the real world having the issues you said is extremely rare and nearly non existent.

We probably need to discuss what actually causes an explosion? It's not full jerrycans.

Explosions are caused by vapour in a confined space. Therefore an empty volatile fuel container is the most dangerous thing around - as many an explosion victim has found when he attacked an empty drum with a gas axe or angle grinder.
I have personally known two of those victims. One was killed, the other was seriously maimed.

If you open a jerry can, regardless of the type, you are exposing vapours to the air.
These vapours are where the real danger lies - not so much, the liquid fuel.

These vapours will NOT explode, unless they are confined in a container.
Vapours in open air will burn - they will go WHOOOOMPH!! - as they light up.
Thus, people believe this is an explosion - but it's not. It's just a rapid advance of vapour ignition, of burning.

From vapours lighting up, you then have a fire you have to put out (I've been there and done that, and it isn't fun, believe me - particularly when the vapours have lit up in your face).

Thus, the greatest threats you face when opening any petrol container are:

1. Fuel sloshing out under pressure and spilling on you, or the ground around you.
2. A source of ignition that is not readily recognised, or immediately understood.

The sources of ignition for fuel vapours are many and subtle.
By far the most dangerous, believe it or not, is synthetic clothing or synthetic upholstery.
Friction on synthetic clothing or upholstery creates static electricity.
A buildup of static electricity releases frequently in a sharp spark - as we've nearly all experienced as we get "zapped" quite often, as we open a car door and get out, after a drive.

The next sources of ignition to be aware of are things such as gas fridge pilot lights.
Vapours travel on the wind like you wouldn't believe. They travel to sources of ignition and then the vapours light up at the source of ignition and travel back to the vapour source - the fuel.
Then the fuel lights up and commences to burn. At that point you automatically, as reflex action, throw the fuel container away, and the fuel spreads and makes the fire spread. It can get very nasty.

The best thing to do with a fuel fire is not throw the container away, but place it quickly, upright on the ground.
Use a dry powder extinguisher if its available, or smother the flames with a blanket or towel or tarp or some other heavy covering if one is ready to hand.
If nothing is ready to hand, move everything and everyone away and let it burn out. It won't explode if the container is open.

It doesn't matter in the least whether you have poly or metal fuel containers.
The level of risk of fuel ignition upon opening is generally low - but it still pays to take extreme care when opening, and take steps to ensure that sources of ignition are minimised and preferably eliminated.

Thus, you keep well away from, and upwind, of any open flames such as pilot lights, and campfires, candles, or anything similar.
You eliminate, as much as possible, other potential ignition sources - such as mobile phones, any other radio-frequency emitting devices, or potential sources of sparks.
You eliminate, as much as possible, the potential of a static electricity spark - by touching earthed metal objects before opening fuel containers, and by placing the container on the ground before opening.
You must be aware of the potential for fuel splash upon opening, so always tilt the container back away from the cap when opening - and crack the cap or lid slowly to release pressure.

Don't hold a fuel container between your legs when opening. My leading mechanic opened a jerry can of petrol this way, the fuel sloshed out and over his feet and legs - and it immediately ignited from an ignition source they never found - and he was badly burnt.

If you don't believe that fuel can ignite from a static electricity spark from buildup on synthetic clothing, you need to watch this actual CCTV footage from a service station fire.

Cheers, Ron.

I think that how you handle, store and carry fule and fuel containers is far more significant that the difference between plastic and metal

every single point that people raise favouring one over the other points to a failing in the handling storage or carrying of the container......and maybee the selection on the base of quality.....not that it is plastic or metal.

cheers

make sure you wear a helmet while walking just in case the sky falls.....
ive used both with no issues.
ive kept plastic ones in the vehicle for many years with no spontaneous combustion

Thanks everyone for your advice. It seems that quality plastic is the way to go and watch the pilot lights, static and leaks in the cans.