At first glance, a gas can doesn't look like much is going on with it. If you try to pour one made within the last couple years, however, you might end up having a tougher time than before thanks to regulations set in place within the past five years.
Older gas cans recognized that the pressure created inside the container needed to be released in order for the user to pour the liquid out in a steady manner, and so all manufacturers designed them this way. Government regulations, however, were worried about the vapors escaping from the back vents and gas spillage that would leak into the atmosphere, and now require that every gas can made be made without a back vent and a "self-closing lid." Unfortunately, this has made gas cans of the modern day a handful to work. Between fidgeting with the top and cracking it open like a vault, by the time you're ready to pour, you're blindsided by the pressurized gas pouring out every which-way, causing steady pouring to be a fond memory. In typical fashion, government regulations which aim to make things better by using force causes the problem it's trying to solve to be exacerbated by extra spilled gasoline when attempting to pour.
Markets empower and provide solutions, but they can only do so much when the heavy hand of force comes from the government. Unintended consequences of regulation are slow to change and adapt rather than the quick response of the market to address consumer needs. Fee.org writes:
Who would make a can without a vent unless it was done under duress? After all, everyone knows to vent anything that pours. Otherwise, it doesn’t pour right and is likely to spill.
The government never said “no vents.” It abolished them de facto with new standards that every state had to adopt by 2009. So for the last three years, you have not been able to buy gas cans that work properly. They are not permitted to have a separate vent. The top has to close automatically. There are other silly things now, too, but the biggest problem is that they do not do well what cans are supposed to do.
