Charcoal Canister

It is a well-known fact that gasoline evaporates quickly when exposed to oxygen. Before the 1970’s the vast majority of cars allowed a great deal of gasoline to vent into the atmosphere, releasing dangerous chemicals and gasses. Vented gas caps allowed fuel vapors to be released directly into the atmospehere. Legislation was passed in 1970 to prevent this, and out of these new laws came charcoal canisters. Much like charcoal is used in drinking water applications, the canister traps fuel vapors emitted from the gas tank until the engine is started again and can draw the vapors in for combustion. Sealed gas caps allow vapors only one place to go, which is towards the charcoal canister. This simple design prevents any excess fuel vapors to vent into the atmosphere and in turn leads to a much cleaner vehicle.