Guidance for Biodiesel Producers and 

Biodiesel Blenders/Users
EPA420-B-07-019

November 2007

Transportation and Regional Programs Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency

Guidance for Biodiesel Producers and 

Biodiesel Blenders/Users

NOTICE

This guidance does not necessarily represent final EPA decisions or 

positions. It is intended to present technical analysis of issues using data 

that are currently available. The purpose in the release of such guidance is 

to facilitate the exchange of technical information and to inform the public of 

technical developments.
Purpose 

The purpose of this document is to explain and clarify EPA’s regulatory 

requirements for biodiesel producers and biodiesel blenders/users. While the 

term biodiesel generally has a broad interpretation, as used in this guidance 

document, its meaning is directed specifically to biodiesel-ester. 

Background 

Use of renewable fuels, such as ethanol and biodiesel, in motor vehicle fuels has 

been growing rapidly for a variety of reasons. Biodiesel usage has been 

increasing particularly rapidly. This widespread increase in biodiesel usage has 

highlighted a need to promote adherence to the primary industry standard for 

biodiesel (B100 blendstock used to produce biodiesel blends), ASTM 

International (ASTM) D 6751, and consider new ASTM standards for blends of 

biodiesel and conventional petroleum-based diesel. EPA is also currently 

coordinating significant additional testing to resolve issues related to the effect of 

biodiesel on vehicle emissions performance. 

Biodiesel is a fuel made from plant or animal feedstocks, and may be used in 

conventional diesel engines. Biodiesel is comprised of specific chemical 

components defined by ASTM as "mono-alkyl esters of long chain fatty acids 

derived from vegetable oils or animal fats." In the United States, most biodiesel 

is made from soybean oil. However, canola oil, sunflower oil, recycled cooking 

oils, palm oil, animal fats, and other oils are also used as feedstocks. 

Biodiesel is typically manufactured through a process called "trans-esterification." 

This process uses an industrial alcohol (typically methanol, sometimes ethanol) 

and a catalyst (sodium methylate, can be sodium hydroxide) to convert the base 

plant oil or animal fat into a fatty-acid mono-alkyl ester fuel (biodiesel), with 

glycerin as a byproduct. Biodiesel in its pure form is known as B100, but it can 

be blended with conventional diesel fuel. The most common blends are B5 (5 

percent biodiesel and 95 percent conventional diesel) and B20 (20 percent 

biodiesel and 80 percent conventional diesel). 

Biodiesel is registered with the U.S. Environmental Protection Agency (EPA) as a 

motor vehicle diesel fuel and motor vehicle diesel fuel additive. It is registered for 

use at any blend level up to B100 in highway diesel vehicles. 

Biodiesel, as discussed in this document, does not include renewable diesel. 

Renewable diesel is a non-ester based diesel blend derived from non-petroleum 

resources, such as plant oil or animal fats or wastes. Because renewable diesel 

is processed in a refinery along with petroleum stocks, it becomes 

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indistinguishable from petroleum diesel, and does not need to be blended 

downstream of the refinery. 

Neat vegetable oils and recycled greases (also called waste cooking oil or yellow 

grease) that have not been processed into mono-alkyl esters are not biodiesel. 

These raw oils, used as fuel extenders or fuel substitutes, are not registered with 

EPA and are not legal to use as a motor vehicle fuel. Furthermore, cooking oil is 

physically and chemically different than diesel fuel and its use in conventional 

engines will generally cause negative effects on emissions and engine durability. 

Because of the potential for increased emissions, it is considered unlawful 

tampering to convert a vehicle designed for diesel fuel to operate on waste oil 

without EPA certification. To date, EPA has not certified any conversions for 

waste oils. Even with EPA certification, conversions may violate the terms of the 

vehicle warranty. For more information on the certification process, please visit 

EPA's Web site at: www.epa.gov/otaq/cert/dearmfr/cisd0602.pdf (22 pp, 152 K, 

About PDF) 

EPA Requirements for Biodiesel Producers under 40 CFR Part 79 and Part 

80 

Section 211 of the Clean Air Act provides EPA with the authority to regulate fuels 

and fuel additives in order to obtain information about emissions and health 

effects related to fuels and their additives, and where appropriate to reduce the 

risk to public health from exposure to their emissions. In part, regulations 

implementing this authority are codified in Part 79 of the Code of Federal 

Regulations (40 CFR Part 79), which requires that each manufacturer or importer 

of motor vehicle gasoline, motor vehicle diesel fuel, and their additives, have their 

product registered by EPA prior to its introduction into commerce. Registration 

involves providing a chemical description of the product and certain technical, 

marketing and health-effects information. This allows EPA to identify the likely 

combustion and evaporative emissions. In many cases, health-effects testing is 

required for a product to maintain its registration or before a new product can be 

registered. EPA uses this information to identify products whose emissions may 

pose an unreasonable risk to public health, warranting further investigation 

and/or regulation. 

Producers of biodiesel for highway use are manufacturers of motor vehicle fuel or 

fuel additive. As part of EPA’s registration process for fuel manufacturers, 

biodiesel producers must complete and submit EPA registration form 3520-12 

(Fuel Manufacturer Notification for Motor Vehicle Fuel, available at 

http://www.epa.gov/otaq/regs/fuels/ffarsfrms.htm), and also provide the following 

information: 

1. The feedstocks used to produce biodiesel. 

2. A description of the manufacturing process used to produce biodiesel. 

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3. Emissions and health effects testing on the manufacturer’s biodiesel, or 

alternatively proof of registration with the National Biodiesel Board (NBB) 

showing access to the Tier 1 and Tier 2 emissions and health effects 

testing data. 

4. Test results from a representative sample of the manufacturer’s biodiesel 

demonstrating compliance with the parameters specified in ASTM D 6751. 

Since emissions and health effects testing for biodiesel is very expensive, 

biodiesel producers normally arrange for access to “group data” on the testing of 

biodiesel which is representative of all products in that group. NBB has provided 

EPA with the required group data on biodiesel that met the nationally accepted 

biodiesel standard at the time of testing, which was 1998. This standard has 

since been adopted as ASTM D 6751, and continues to undergo refinements. 

Thus, a biodiesel producer may meet EPA’s emissions and health effects testing 

requirement for biodiesel by reaching an agreement with NBB for access to 

NBB’s registration data, and making a certification to EPA that the producer has 

notified NBB of the use of NBB’s data and reimbursed NBB for the use of their 

data. Any biodiesel producer who does not have access to NBB’s data must 

provide EPA with its own emissions and health effects test data as part of the 

registration process. 

In addition to registering with EPA under 40 CFR Part 79, biodiesel producers 

are also required to register under 40 CFR Part 80 as a refiner. This applies to 

both highway and nonroad biodiesel. Under 40 CFR Part 80, diesel fuel 

producers must complete and submit EPA registration forms 3520-20A (Fuels 

Programs Company/Entity Registration) and 3520-20B1 (Diesel Programs 

Facility Registration). Both of these forms are available at 

http://www.epa.gov/otaq/regs/fuels/rfgforms.htm. 

Highway and nonroad biodiesel producers must also comply with all of EPA’s 

regulatory requirements for diesel fuel producers in 40 CFR Part 80, Subpart I. 

The primary standard for diesel fuel producers in Subpart I is the 15 ppm sulfur 

standard, which will be phasing in for all diesel fuel from now through 2014. 

Although biodiesel typically contains less than 15 ppm sulfur, biodiesel producers 

are still required to test each of their biodiesel batches for sulfur and 

appropriately designate their product as required by Subpart I. Subpart I also 

contains diesel fuel standards for minimum cetane index (40), or a maximum 

aromatics content (35 volume percent), which biodiesel typically meets. Lastly, 

Subpart I contains reporting and recordkeeping requirements for diesel fuel 

manufacturers. 

EPA Guidance for Biodiesel Blenders/Users 

Although the Part 79 registration is for biodiesel use at any blend level up to 

B100 in highway diesel vehicles, ASTM D 6751 points out that a considerable 

amount of experience exists with blends containing 20 percent biodiesel and 80 

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percent conventional diesel (B20). Thus, ASTM D 6751 recommends that 

biodiesel blends containing more than 20 percent biodiesel should be evaluated 

on a case-by-case basis. ASTM D 6751 also recommends that biodiesel users 

consult the equipment manufacturer owner’s manual regarding the suitability of 

using biodiesel or biodiesel blends in a particular engine or application. Many 

engine manufacturers currently limit warranty coverage to diesel fuel containing 

no more than 5 percent biodiesel. 

Consumers should be careful only to buy biodiesel from a reputable dealer. 

Improperly processed biodiesel may contain unreacted or partially reacted oils or 

fats (measured by the total glycerin), which can cause the fuel to gel at higher 

than expected temperatures. ASTM D 6751 specifies maximum allowable 

concentrations of free glycerin and total glycerin. Also, consumers should be 

careful that they are not inadvertently purchasing straight vegetable oil instead of 

biodiesel. One method of ensuring quality biodiesel is to buy from producers or 

marketers that are certified in the voluntary national biodiesel accreditation BQ 

9000 program (see http://www.bq-9000.org/ for details). 

Requirements for handling and using biodiesel may differ from requirements for 

petroleum-based diesel. For example, biodiesel can gel at low temperatures and 

may require special handling in cold climates during winter. Other possible 

problems that may be caused by B100 use include degradation of some fuel 

lines and gaskets (e.g. those made from nitrile and natural rubber) and reduced 

power or fuel economy. Consumers should check with their vehicle 

manufacturers for recommendations about biodiesel use or consult the 

information available on the NBB web site at 

http://www.biodiesel.org/resources/fuelfactsheets/ under ‘Engine Manufacturers’. 

Engine manufacturers have expressed concern about degradation of biodiesel 

due to long storage times, which may cause biodiesel to exceed the limits in 

ASTM D 6751 for acid number, viscosity or sediment. For example, NBB 

recommends that B100 be stored for no more than 6 months before usage. The 

Department of Energy document “Biodiesel Handling and Use Guidelines” 

(available at http://www.nrel.gov/vehiclesandfuels/npbf/pdfs/40555.pdf.) contains 

a detailed discussion on the stability of B100 and B20 and is a good source of 

information on biodiesel in general. 

Current Activities Regarding Biodiesel 

Emissions Performance 

Having an accurate assessment of biodiesel effects on diesel engine emissions 

is critical to state, regional and national organizations for making informed 

decisions regarding biodiesel use. EPA’s 2002 review of then available test data 

entitled “A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions” 

concluded that biodiesel improves HC, CO and particulate emissions while 

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slightly increasing NOx. However, the magnitude of biodiesel NOx impact still 

remains controversial. EPA has recently shown experimentally that this impact is 

proportional to test cycle load. Using this information and working in cooperation 

with the stakeholders, EPA has developed a proposal for a Collaborative 

Biodiesel Emission Test Program to address the NOx issue. The funding for this 

test program is currently uncertain. However, we continue to believe that a welldesigned study such as this is necessary to accurately determine the effect of 

biodiesel on emissions. In addition, EPA is currently updating the 2002 biodiesel 

study using test data which have become available in recent years. 

Standards Harmonization 

EPA is also working with several standard-setting organizations, both nationally 

and internationally, and other government organizations in a general effort to 

harmonize standards for biofuels produced from a variety of feedstocks and 

blended in petroleum-based fuels at various concentrations. EPA’s regulations 

codifying the Renewable Fuel Standard Program established in the Energy 

Policy Act of 2005 (EPAct) were recently finalized in 40 CFR Part 80, Subpart K, 

and provide significant flexibility for biofuels producers, refiners and importers to 

properly account for the large volumes of renewable fuels that must be blended 

into gasoline or diesel fuel under EPAct. Since EPAct does not mandate where 

biofuels must be produced or blended into gasoline or diesel fuel, EPA 

encourages other standard-setting organizations, particularly state governments, 

to allow biofuels producers and biofuels blenders the flexibility to decide where 

biofuels can be most economically produced and blended into gasoline or diesel 

fuel. EPA is promoting standards that will result in nationally accepted, 

consistent, biodiesel quality levels and blend rates. 

EPA is also participating in several ongoing ASTM activities regarding biodiesel 

quality and standards. ASTM recently added a stability specification to ASTM D 

6751 and expanded the applicability of ASTM D 6751 to all diesel fuels (ASTM D 

6751 was previously applicable to just highway diesel fuel). EPA’s renewable 

fuels program regulations, recently finalized in 40 CFR Part 80, Subpart K, 

require biodiesel producers to meet all specifications in the most recent version 

of the standard (ASTM D 6751-07) for biodiesel to be considered a renewable 

fuel, and included in compliance calculations under Subpart K (see 40 CFR 

80.1101(h)(3) and 80.1115(b)). ASTM is also considering whether to expand 

their standard for petroleum-based diesel fuel (ASTM D 975) to include diesel 

blends that contain up to 5 volume percent biodiesel, and is developing a 

standard for B6 to B20. 

Enforcement Activities 

EPA also plans to increase enforcement efforts to ensure that biodiesel 

producers are complying with EPA’s standards, in particular ensuring that all 

biodiesel meets ASTM D 6751. Section 211(a) of the Clean Air Act gives the 

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Administrator of the EPA regulatory authority to “...designate any fuel or fuel 

additive...and...no manufacturer or processor of any such fuel or fuel additive 

may sell, offer for sale, or introduce into commerce such fuel or additive unless 

the Administrator has registered such fuel or additive....” This is codified in 

EPA’s regulations at 40 CFR 79.4(a)(1), which state that “no manufacturer of fuel 

designated under this part shall ... sell, offer for sale, or introduce into commerce 

such fuel unless the Administrator has registered such fuel.” 

ASTM D 6751 was first published in 2002 (ASTM D 6751-02). Since then it has 

been periodically revised and updated. EPA’s routine practice has been to 

register biodiesel that meets the version of ASTM D 6751 in effect at the time of 

registration. Because most biodiesel has been registered with EPA since 2002, 

EPA expects that most biodiesel will meet either ASTM D 6751-02, or later 

versions of ASTM D 6751. For biodiesel registered since 2002, any biodiesel 

that does not meet the version of ASTM D 6751 in effect at the time of 

registration will be considered an unregistered fuel subject to the penalty 

provisions in 40 CFR 79.8 (civil penalties of up to $32,500 per day per violation). 

Biodiesel registered prior to 2002 must meet the ASTM D 6751 specifications 

contained in its registration application, which are generally equivalent to ASTM 

D 6751-02. For biodiesel registered prior to 2002, any biodiesel that does not 

meet the ASTM D 6751 specifications contained in its registration application will 

be considered an unregistered fuel subject to the penalty provisions in 40 CFR 

79.8 (civil penalties of up to $32,500 per day per violation). 

In addition to the provisions covering violations under 40 CFR Part 79, violations 

of EPA’s diesel fuel standards in 40 CFR Part 80, Subpart I are covered in 40 

CFR 80.610 through 80.615. EPA regulations at 40 CFR 80.4 also provide 

authority to EPA inspectors, who present appropriate credentials, to enter the 

premises of any fuel manufacturer, importer, carrier or distributor and make 

inspections, take samples, obtain information and records, and conduct tests to 

determine compliance with all of EPA’s fuels regulatory requirements in 40 CFR 

Part 80. Any person who violates these regulations is liable to the United States 

for a civil penalty of up to $32,500 per day per violation (see 40 CFR 80.5). 

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