HEALTH AND ENVIRONMENT

In 2000, biodiesel became the only alternative fuel in the country to complete the EPA-required Tier I and Tier II health effects testing under the Clean Air Act.

These independent tests not only conclusively demonstrated that biodiesel significantly reduces virtually all regulated emissions but also showed biodiesel does not pose a threat to human health.

For instance, biodiesel emissions show decreased levels of polycyclic aromatic hydrocarbons (PAH) and nitrated polycyclic aromatic hydrocarbons (nPAH), which have been identified as potential cancer causing compounds. In Health Effects testing, PAH compounds were reduced by 75%–85%, with the exception of benzo(a)anthracene, which was reduced by roughly 50%. Targeted nPAH compounds were also reduced dramatically with biodiesel, with 2-nitrofluorene and 1-nitropyrene reduced by 90%, and the rest of the nPAH compounds reduced to only trace levels.

Typically, biodiesel is blended with petroleum diesel at levels up to 20% (B20). The presence of oxygen in the biodiesel reduces emissions of greenhouse gases, toxic compounds, and particulate matter (PM) when biodiesel blends are burned in diesel engines. These reductions are robust and have been observed in numerous engine and vehicle testing studies. A U.S. Department of Energy study showed that the production and use of biodiesel, compared to petroleum diesel, resulted in a 78.5% reduction in carbon dioxide emissions.

The ozone (smog) forming potential of biodiesel hydrocarbons is less than diesel fuel.

Sulfur emissions

These are essentially eliminated with pure biodiesel. The exhaust emissions of sulfur oxides and sulfates (major components of acid rain) from biodiesel are essentially eliminated compared to diesel.

Criteria pollutants

These are reduced with biodiesel use. Tests show the use of biodiesel in diesel engines results in substantial reductions of unburned hydrocarbons, carbon monoxide, and particulate matter. Further, a recent study by the National Renewable Energy Laboratory (NREL) concluded that “B20 has no net impact on NOx emissions.”

Carbon Monoxide

The exhaust emissions of carbon monoxide (a poisonous gas) from biodiesel are on average 48% lower than carbon monoxide emissions from diesel.

Particulate Matter

Breathing particulate has been shown to be a human health hazard. The exhaust emissions of particulate matter from biodiesel are about 47% lower than overall particulate matter emissions from diesel.

Hydrocarbons

The exhaust emissions of total hydrocarbons (a contributing factor in the localized formation of smog and ozone) are on average 67% lower for biodiesel than diesel fuel.