California's Clean Gasoline Reduces Benzene Levels

07/08/96

The California Air Resources Board (ARB) announced that the introduction of cleaner burning gasoline in California has significantly reduced the airborne amount of the human carcinogen benzene.

Average benzene levels measured at 11 monitoring stations in Northern California dropped by more than 50% in Spring 1996 as compared to Spring 1995. Factors such as weather and the time of year can affect benzene levels, but the sharp drop measured between Spring 1995 and Spring 1996 is attributable to cleaner gasoline with about half as much benzene as conventional gasoline.

California's ARB required California's oil refineries to begin making the cleaner gas by March 1, 1996, at the latest, and the cleaner gas had largely replaced conventional gas at California pumps by late March. All gasoline sold in California must now meet the ARB's specs for cleaner gas.

The results in Northern California repeat what happened in Southern California when federally reformulated gas was introduced into the region a year earlier. That gasoline had the same low benzene levels as the new California gas, and Southern California saw benzene levels drop by more than half between Spring 1994 and Spring 1995. Southern California switched to the state's new cleaner gas at the same time Northern California did, and maintained their low benzene levels.

Benzene is a colorless gas, and one of the many chemicals that go into conventional gasoline. Exposure to benzene most commonly causes leukemia, and 90 percent of airborne benzene comes from gasoline: the gas contaminates the air through tail pipe emissions and evaporation, which happens during refueling.

California's ARB estimates that the use of cleaner burning gasoline will reduce human cancer risk from exposure to benzene and other toxic substances from motor vehicles by 30 to 40 percent.

The ARB's cleaner gasoline, in addition to reducing benzene levels, also reduces smog-forming emissions from motor vehicles by 15 percent, double the reduction afforded by the federally reformulated gasoline. That reduction is comparable to taking 3.5 million vehicles off of California's roads. The cleaner gas has added about 5 to 8 cents a gallon and reduced fuel economy by 1 to 3 percent.

California's ARB will begin testing the affect of the new cleaner burning gas on ground-level ozone this summer when ozone levels are at their highest.

Paul Dever -- The Auto Channel