The regulations require:
A single, self-venting opening for filling and pouring with no separate vents or openings.
A permeation-resistant container that permits no more than 0.3 grams per gallon per day of hydrocarbon emissions.
Automatic closure, such as a nozzle that automatically springs to the closed position when the user is not pouring from the container
Childproof features as outlined by the Children’s Gasoline Burn Prevention Act
Translation:The regulations require:
A single opening that's a pain in the rear to open for filling.
A complex nozzle design to encourage spillage.
No air vent to make dispensing from the container as slow as possible.
Flimsy nozzle construction to ensure limited lifetime.