The so called "no-spill", no vent, EPA, CARB, Ralph Nader cans do NOT help. Resident RH and differential heating/cooling will develop moisture in your cans unless you have a very special place with a completely controlled environment to store your fuel.
I'm not a scientist, but have tested several methods with the crap, boutique fuel they sell here. The best cans for me have been old German surplus army gerry cans when I fill them as much as possible (less air space). The stupid plastic Blitz cans (even the CARB compliant) seem the worst. Store your gas through enough heating/cooling cycles and take note of the water in the bottom (even with fuel treatments like Stabil). I got a real shock last fall when I noticed 1-2ozs slug of water in the bottom of my favorite mix jug. The fuel was only a week or two old, but I had mixed into that same jug all summer. I think it accumulated over time as I never drop the very bottom slug of fuel into my saws and probably hadn't dumped it into my mower between fillings like I usually do. I have yet to harm one of my saws, but have been mixing smaller amounts and using it up more frequently. I also make sure I don't "mix over" anything left in the jug. It's a PITA always running low, but I guess that's the price I pay. I have also gotten more anal about running my equipment (not just saws) out of fuel when storing. I use too much for the fuel in a can and there is almost no source of good gas anyway around here.
Don't even get me started on how stupid the whole making fuel from your food source is. How less efficient it is so MORE fuel is burned into the environment to produce the same amount of work. Or how it burns much more energy and dollars to produce. But we're saving the planet......
I'm all for a new, better fuel source, but this crap is not it. :censored: It's not even a good stop gap IMHO.