Health Benefits of Biodiesel 

Biodiesel is a significantly cleaner-burning fuel than petroleum diesel. Using biodiesel reduces the amount of harmful emissions released into the air, including polycyclic aromatic hydrocarbons, sulfur dioxide, carbon monoxide, and a variety of toxic and carcinogenic compounds found in diesel exhaust. Although biodiesel can be blended with petroleum diesel at any ratio, meaningful air quality and health benefits can be realized with blends of 20% biodiesel (B20) or more.

Biodiesel promotes better health for drivers, mechanics, construction workers, and others working around diesel equipment by improving their workplace air quality. Emissions from diesel fueled engines include more than 40 air toxics, creating a serious health threat that has been linked to lung cancer, upper respiratory illnesses, allergies, asthma attacks and death from heart and respiratory disorders. Along with workers, members in the community also benefit from the reduction in these air pollutants.

Smoke (particulate material) and soot (unburned fuel and carbon residues) are of increasing concern to urban air quality problems that are causing a wide range of adverse health effects for their citizens, especially in terms of respiratory impairment and related illnesses.

Biodiesel is the first and only alternative fuel to have a complete evaluation of emission results and potential health effects submitted to the U.S. Environmental Protection Agency under the Clean Air Act Section 211(b). These programs include the most stringent emissions testing protocols ever required by EPA for certification of fuels or fuel additives.

Average biodiesel emission reduction compared to conventional diesel:

                                       B99                              B20

Total unburned hydrocarbons

                                       -67%                          -20%

Carbon Monoxide 

                                       -48%                       -12.6%

Carbon Dioxide*  

                                       -78%                        -15%*

Particulate Matter

                                      -47.4%                       -12%

Air Toxics             

                           -60% to -90%           -12% to -20%

Sulfates

                                     -100%                     -20%**

PAH(Polycyclic Aromatic Hydrocarbons)*** 

                                    -80%                            -13%

nPAH (nitrated PAH’s)***

                                    -90%                     -50%****

Ozone potential of speciated hydrocarbons                 

                                    -50%                             -10%

Mutagenicity      

                                    -89%                             -20%

*Lifecycle (when made from soybeans)

**Estimated from B100 result

***Average reduction across all compounds measured

****2-nitroflourine results were within test methods variability

Sulfur.  Biodiesel does not contain sulfur other than by trace contamination, so sulfur emissions are essentially eliminated by using pure biodiesel.  The absence of sulfur means a reduction in the formation of smog and acid rain by sulfate emissions which generate sulfuric acid in our atmosphere. 

Nitrogen Oxides. Nitrogen Oxides (NOx) is a class of gaseous chemicals that are formed by high temperature reactions of nitrogen and oxygen. It includes nitric oxide (NO), nitrogen dioxide (NO2), and a few other less prevalent compounds such as nitrous oxide (N2O). The primary concern with NOx is its contribution in smog formation.  

Research has varied regarding NOx emissions from biodiesel. Initial studies showed that depending on what source the biodiesel is made from, NOx emissions can either increase by 4-13% or be eliminated entirely.  NOx emissions also increase or decrease depending on the engine family and testing procedures. Research into biodiesel and NOx emissions is ongoing. At this time, however, researchers note that there are insufficient data to draw any conclusions, even directionally. If NOx emissions are a concern, they can be reduced with additives or oxidative converters.

How much carbon is saved by using biodiesel?

Biodiesel has a closed carbon cycle, typically creating a 78% lower lifecycle carbon dioxide emissions than petroleum diesel (when made with soybean oil).  A closed carbon cycle means that the plants grown for biodiesel take carbon dioxide from the air as a nutrient.  The oil is then extracted from the plant and is converted into biodiesel.  When the biodiesel is burned, it produces carbon dioxide which returns to the atmosphere.  This cycle does not add to an overall increase in carbon dioxide because the next crop will reuse the carbon dioxide in order to grow.  It can be argued that biodiesel is 100% carbon neutral because of this closed carbon cycle.  However, because some fossil fuels are often used in the production and transportation of biodiesel, the recycling of carbon dioxide is typically reduced from 100% to 78%.  When biodiesel is made from canola or used cooking oil and produced and consumed locally, the carbon dioxide savings are closer to 90-95% because very little fossil fuels are used in the process.

Want more information on biodiesel?

(Click on the subjects below. Downloadable PDFs coming soon!)

Biodiesel Basics

Marine Use

Your Car or Truck

Heating Your Home

Sustainability

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