SALEM, Ore. -- A law passed by Oregon legislators went into effect Wednesday, making it illegal to have gas station attendants top off fuel tanks.

The Legislature passed the measure to try to reduce the risk from gasoline vapors. The law is targeting Benzene, a carcinogenic chemical present in crude oil that is sometimes used as an additive in gasoline.

According to the Department of Environmental Quality, overfilling a gas tank can expose attendants and drivers to higher levels of Benzene and other vapors emitted while putting fuel into your tank.

"I think it's a great idea 'cause a lot of people get irritated when you top off their vehicle 'cause they feel the gas is going to sit around near the tube of the gas tank and get on the fender of the car also," Josh Wilson a driver from Aloha said.

A DEQ representative said he doesn't expect the agency or police to try to discover gas stations that might be ignoring the law. But gas station attendants said most customers pay with a credit card so filling to the nearest dollar amount isn't often a factor.

Legislation Outlaws Topping Off Cars