Those 6 gallon plastic gas containers are already designed for risk mitigation - enough gas to blow up, but probably burn no more than you and your garage. Also 6 gallons is about the top you can expect to hike up a road to a waiting car. If you need to economize, buy the $4.95 containers at Walmart, but watch for leaks eventually. Metal Type II containers provide an element of additional safety, both from sparks and combustion as well as longer term wear.

I recommend thinking different about gasoline before you store it: ask yourself, how much can I *safely* store where I'm at? I think any decision to store your gasoline indoors in your garage says that you have done the risk calculus and can accept the loss of that structure in a disaster, and you can live with an increased risk to you and your family of fire meantime. This gets more serious in attached versus detached garages, and the further away from fire reponse you live. Can you really store additional gas this way? There are local codes and regulations on how much you can actually store, but even in homes its a bad idea to store more than what you actually need and use in a *typical* season, feeding your lawn mower, chain saw etc. The best recommendation I've heard is a dedicated storage unit, with lots of air circulation, away from your house, garage or other structures. We don't always have such a thing, but sometimes we do - I ended up building a nice hut on a concrete pad that once housed a dog run, away from our house specifically for gas and other combustibles, such as excess paint and chemicals. I label the hut appropriately in case the fire dept has to approach it. By next summer I hope to expand on the pad and install a sheltered generator, although it may be exposed to crushing by falling trees so I have to ponder that some more. Meantime I think metal gas cans are a good long-term investment, and provide an important element of safety wherever you store your gasoline -keep an eye out for gas cans at yard and estate sales. I have two (empty) 10 gallon gas cans that are at least 40 years old and still bright and shiny on the inside - they wait for me to apply a new seal to make them whole again. I'm happy with my more modern Type II 5 gallon cans for long term storage though, and don't actually have room to safely store 2x10 more gallons even if I wanted it.