The EPA has stuck their nose into marine fuel tanks now too. It's a darn complicated mess, and if anything I think they have made things worse. They no longer have passive venting. There are two types of tanks now:
1) Tanks that breath through a charcoal canister which traps hydrocarbons from escaping. Unfortunately this restricts breathing when fueling up the tank, making it very hard / slow to fuel up, and resulting in overfills and spills.
2) Tanks that allow a couple psi of pressure or vacuum before venting, to try and contain most of the daily temperature changes without constantly breathing. Unfortunately this is leading to more leaks. We had a 60 degree temperature drop in January followed by severe cold, and I ended up with fuel in my bilge because an aluminum fitting didn't adjust to temperature fast enough, and leaked under pressure.
So basically, to minimize venting of gas fumes, we've now got tanks that are creating more leaks and spills. Not sure how that is better. Many of these technologies came from cars, but they have none of the complicated installation/motion/attitude/storage issues of boats.