I think the California EPA reference is to the CARB device found on alot of plastic gas cans, its a doohickey that controls the amount of gas vapor that can come out and along the way also makes it easlier to pour from the can - easier to fill a chainsaw without spilling. I haven't seen them on metal Type II gas cans though.

I have found three good gas cans at garage and estate sales for about $5 each, and I have a couple rough looking Jerry Cans I might touch up with some rust treatment and renew the gasket seals, then repaint. I don't consider the brand new metal gas cans from Gemplers or other places to be a bad deal, they are made in the USA and really well built - just an upfront cost, think of it as an investment of sorts in your family's safety. I just don't have a very good opinion on those Chinese $5 plastic gas cans, I'd go upmarket a bit and get a version with the CARB device on it, thicker plastic at least.