Dept. of Environmental Quality graphic

Starting Wednesday, Oregon gas station attendants can no longer “top off” gas tanks because of new state environmental regulations.

The Oregon Department of Environmental Quality created the ban to reduce benzene and other toxic air pollutants from gas stations and other gasoline storage and dispensing facilities.

Topping off is when a gas station attendant continues to fill a gasoline tank after the nozzle clicks off.

However, according to a DEQ news release, topping off the tank does not equal more gas in the tank. Most modern pumps simply return the fuel pumped after the pump clicks off back to the pump, which means drivers are paying for gas that does not get into the vehicle’s fuel tank.

Moreover, topping off can cause gasoline to spill and release benzene, a known carcinogen, and other toxic air pollutants into the air, the DEQ said. And in some cases, overfilling a gas tank can cause a vehicle’s vapor control system to clog and stop working, which can require costly repairs.

The Environmental Quality Commission, DEQ’s rulemaking and policy advisory board, approved and adopted the no topping off regulations in December, 2008. The new rules also require all larger Oregon gasoline storage and distribution facilities that dispense an average of 40,000 gallons per month or more to use vapor capture controls similar to those the state requires to use in Portland, Medford and Salem areas.

The new prohibition on topping off involves an educational period for businesses and customers. The DEQ has a free poster and flyer about the ban available for printing at www.deq.state.or.us/aq/permit/vapor/vapor.htm.

DEQ’s regulations follow on the heels of an Environmental Protection Agency rulemaking last year that tightened air quality regulations for fuel dispensing facilities nationwide. The federal standard does not address topping off at the pump. The DEQ said Oregon’s tougher standards go beyond the federal rules to reduce benzene by an estimated 28 tons per year and volatile organic compounds by an estimated 1,610 tons per year.