ASTM D6448-16(2022)

Standard Specification for Industrial Burner Fuels from Used Lubricating Oils

ABSTRACT
This specification covers four grades of fuel oil made in whole or in part with hydrocarbon-based used or reprocessed lubricating oil or functional fluids, such as preservative and hydraulic fluids. Grades RFO4, RFO5L, RFO5H, and RFO6 are of increasing viscosity and are intended for use in various types of fuel-oil-burning industrial equipment under various climatic and operating conditions, and are not intended for use in residential heaters, small commercial boilers, combustion engines, or marine applications. Detailed requirements for each grade of lubricating oil shall be tested accordingly, and are as follows: viscosity; flash point; water and sediment content; pour point; density; ash content; sulphur content; extracted pH; and gross heating value.
SCOPE
1.1 This specification covers four grades of fuel oil made in whole or in part with hydrocarbon-based used or reprocessed lubricating oil or functional fluids, such as preservative and hydraulic fluids. The four grades of fuel are intended for use in various types of fuel-oil-burning industrial equipment under various climatic and operating conditions. These fuels are not intended for use in residential heaters, small commercial boilers, combustion engines, or marine applications,  
1.1.1 Grades RFO4, RFO5L, RFO5H, and RFO6 are used lubricating oil blends, with or without distillate or residual fuel oil, or both, of increasing viscosity and are intended for use in industrial burners equipped to handle these types of recycled fuels.
Note 1: For information on the significance of the terminology and test methods used in this specification, see Appendix X1.  
1.2 This specification is for use in contracts for the purchase of fuel oils derived from used lubricating oil and for the guidance of consumers of such fuels. This specification does not address the frequency with which any particular test must be run.  
1.3 Nothing in this specification shall preclude observance of national or local regulations, which can be more restrictive. In some jurisdictions, used oil is considered a hazardous waste and fuels from used oil are required to meet certain criteria before use as a fuel.
Note 2: For United States federal requirements imposed on used oil generators, transporters and transfer facilities, reprocessors, marketers, and burners, see 40 CFR 279.
Note 3: The generation and dissipation of static electricity can create problems in the handling of distillate burner fuel oils. For more information on the subject, see Guide D4865.  
1.4 The values stated in SI units are to be regarded as standard; non-SI units, when given, are for information only.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 27.060.10 - Liquid and solid fuel burners
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.P0 - Recycled Products

Relations

• Refers: ASTM D445-24 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Apr-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D7094-23 - Standard Test Method for Flash Point by Modified Continuously Closed Cup (MCCCFP) Tester
• Effective Date: 01-Dec-2023
• Refers: ASTM D6822-23 - Standard Test Method for Density, Relative Density, and API Gravity of Crude Petroleum and Liquid Petroleum Products by Thermohydrometer Method
• Effective Date: 01-Dec-2023
• Refers: ASTM D4865-23 - Standard Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems
• Effective Date: 01-Nov-2023
• Refers: ASTM D2983-23 - Standard Test Method for Low-Temperature Viscosity of Automatic Transmission Fluids, Hydraulic Fluids, and Lubricants using a Rotational Viscometer
• Effective Date: 01-Nov-2023
• Refers: ASTM D445-23 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Nov-2023
• Refers: ASTM D95-23 - Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation
• Effective Date: 01-Oct-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D93-20 - Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
• Effective Date: 01-Aug-2020
• Refers: ASTM D1217-20 - Standard Test Method for Density and Relative Density (Specific Gravity) of Liquids by Bingham Pycnometer
• Effective Date: 01-May-2020
• Refers: ASTM D396-19a - Standard Specification for Fuel Oils
• Effective Date: 15-Dec-2019
• Refers: ASTM D1250-19e1 - Standard Guide for the Use of the Joint API and ASTM Adjunct for Temperature and Pressure Volume Correction Factors for Generalized Crude Oils, Refined Products, and Lubricating Oils: API MPMS Chapter 11.1
• Effective Date: 01-May-2019
• Refers: ASTM D396-19 - Standard Specification for Fuel Oils
• Effective Date: 01-May-2019
• Refers: ASTM D396-18a - Standard Specification for Fuel Oils
• Effective Date: 01-Oct-2018

Overview

ASTM D6448-16(2022): Standard Specification for Industrial Burner Fuels from Used Lubricating Oils defines requirements for four grades of fuel oil produced from hydrocarbon-based used or reprocessed lubricating oils and functional fluids, such as hydraulic or preservative fluids. This international standard ensures consistency and safety for industrial users who utilize recycled oil-based burner fuels in industrial heating processes. The specification promotes the efficient and safe use of alternative fuels while addressing environmental and operational considerations.

Key Topics

• Four Grades of Fuel: RFO4, RFO5L, RFO5H, and RFO6, which differ primarily by viscosity and composition. Each grade is tailored for specific types of industrial burners and intended operating conditions.
• Source Materials: Fuels may be made wholly or partially from used or reprocessed lubricating oils or functional fluids, which are blended with distillate or residual fuel oil as required.
• Intended Use: These industrial burner fuels are appropriate for industrial equipment and processes that can handle the properties of recycled oil-based fuels. They are not intended for residential heaters, small commercial boilers, combustion engines, or marine applications.
• Quality and Safety Requirements: The standard specifies test methods and limiting values for key properties, including:
  • Viscosity
  • Flash point
  • Water and sediment content
  • Pour point
  • Density
  • Ash and sulphur content
  • Extracted pH
  • Gross heating value (energy content)
• Regulatory Compliance: Observance of national or local regulations is required, as used oil can be classified as hazardous waste in some jurisdictions. Compliance with additional federal or local standards, such as US EPA regulations (40 CFR 279), may be required.
• Sampling and Testing: Guidance is provided on sampling procedures and the selection of appropriate ASTM test methods for product verification.

Applications

Industrial burner fuels from used lubricating oils play a significant role in:

• Industrial Furnaces: Used for direct process heating in applications such as aggregate, cement, lime, or phosphate kilns, coke ovens, and smelting or drying ovens.
• Large Industrial Boilers: Used for indirect heating in manufacturing and process industries where large volumes of heat are required.
• Sustainable Operations: Enables recycling and reuse of used lubricating oils, reducing reliance on virgin fossil fuels and supporting environmentally responsible waste management.

Important Considerations:

• Equipment Compatibility: Only industrial burners designed to process higher viscosity and higher ash/metal content fuels as specified by the grade should be used.
• Storage and Handling: Proper storage is required to prevent separation, maintain homogeneity, and avoid contaminants such as water, acids, or particulates which can affect performance and safety.
• Environmental Compliance: Fuel suppliers and users must ensure fuels meet both ASTM D6448 requirements and any additional environmental regulations applicable in the country or locality of use.

Related Standards

Users of ASTM D6448-16(2022) should also consult related ASTM standards and regulatory documents for sampling, testing, and regulatory compliance, such as:

• ASTM D396: Standard Specification for Fuel Oils
• ASTM D445: Kinematic Viscosity of Transparent and Opaque Liquids
• ASTM D93: Flash Point by Pensky-Martens Closed Cup Tester
• ASTM D1298/D4052: Density, Relative Density, or API Gravity of Petroleum Products
• ASTM D482: Ash Content in Petroleum Products
• ASTM D240: Heat of Combustion of Liquid Hydrocarbon Fuels
• US 40 CFR 279: Standards for the Management of Used Oil (for US users)
• ASTM D4865: Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems

Practical Value

Adopting ASTM D6448 helps industrial burner operators and recycled oil suppliers standardize product quality and safety, comply with environmental laws, and contribute to resource conservation by promoting the reuse of lubricating oils as valuable fuel. This specification is essential for procurement and operational best practices in facilities seeking both cost-effective and sustainable fuel solutions for industrial heating applications.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D6448 −16 (Reapproved 2022)
Standard Specification for
Industrial Burner Fuels from Used Lubricating Oils
This standard is issued under the fixed designation D6448; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This specification covers four grades of fuel oil made in
mendations issued by the World Trade Organization Technical
whole or in part with hydrocarbon-based used or reprocessed
Barriers to Trade (TBT) Committee.
lubricating oil or functional fluids, such as preservative and
hydraulic fluids.The four grades of fuel are intended for use in
2. Referenced Documents
various types of fuel-oil-burning industrial equipment under
2.1 ASTM Standards:
various climatic and operating conditions. These fuels are not
intended for use in residential heaters, small commercial D56 Test Method for Flash Point by Tag Closed Cup Tester
D93 Test Methods for Flash Point by Pensky-Martens
boilers, combustion engines, or marine applications,
1.1.1 Grades RFO4, RFO5L, RFO5H, and RFO6 are used Closed Cup Tester
D95 Test Method for Water in Petroleum Products and
lubricating oil blends, with or without distillate or residual fuel
oil, or both, of increasing viscosity and are intended for use in Bituminous Materials by Distillation
D96 Test Method for Water and Sediment in Crude Oil by
industrial burners equipped to handle these types of recycled
fuels. Centrifuge Method (Field Procedure) (Withdrawn 2000)
D97 Test Method for Pour Point of Petroleum Products
NOTE 1—For information on the significance of the terminology and
D129 Test Method for Sulfur in Petroleum Products (Gen-
test methods used in this specification, see Appendix X1.
eral High Pressure Decomposition Device Method)
1.2 This specification is for use in contracts for the purchase
D240 Test Method for Heat of Combustion of Liquid Hy-
of fuel oils derived from used lubricating oil and for the
drocarbon Fuels by Bomb Calorimeter
guidance of consumers of such fuels. This specification does
D396 Specification for Fuel Oils
not address the frequency with which any particular test must
D445 Test Method for Kinematic Viscosity of Transparent
be run.
and Opaque Liquids (and Calculation of Dynamic Viscos-
1.3 Nothing in this specification shall preclude observance
ity)
of national or local regulations, which can be more restrictive.
D473 Test Method for Sediment in Crude Oils and Fuel Oils
In some jurisdictions, used oil is considered a hazardous waste
by the Extraction Method
and fuels from used oil are required to meet certain criteria
D482 Test Method for Ash from Petroleum Products
before use as a fuel.
D1217 Test Method for Density and Relative Density (Spe-
cific Gravity) of Liquids by Bingham Pycnometer
NOTE 2—For United States federal requirements imposed on used oil
D1250 Guide for the Use of the Joint API and ASTM
generators, transporters and transfer facilities, reprocessors, marketers,
and burners, see 40 CFR 279. Adjunct for Temperature and Pressure Volume Correction
NOTE 3—The generation and dissipation of static electricity can create
Factors for Generalized Crude Oils, Refined Products, and
problems in the handling of distillate burner fuel oils. For more informa-
Lubricating Oils: API MPMS Chapter 11.1
tion on the subject, see Guide D4865.
D1266 Test Method for Sulfur in Petroleum Products (Lamp
1.4 The values stated in SI units are to be regarded as
Method)
standard; non-SI units, when given, are for information only.
D1298 Test Method for Density, Relative Density, or API
1.5 This international standard was developed in accor- Gravity of Crude Petroleum and Liquid Petroleum Prod-
dance with internationally recognized principles on standard- ucts by Hydrometer Method
1 2
This specification is under the jurisdiction of ASTM Committee D02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee D02.P0 on Recycled Products. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2022. Published October 2022. Originally the ASTM website.
approved in 1999. Last previous edition approved in 2016 as D6448 – 16. DOI: The last approved version of this historical standard is referenced on
10.1520/D6448-16R22. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6448−16 (2022)
D1480 Test Method for Density and Relative Density (Spe- D7094 Test Method for Flash Point by Modified Continu-
cific Gravity) of Viscous Materials by Bingham Pycnom- ously Closed Cup (MCCCFP) Tester
eter
2.2 U.S. Environmental Protection Agency Standards:
D1481 Test Method for Density and Relative Density (Spe-
EPA 600/4-79-020 Determination of Inorganic Anions by
cific Gravity) of Viscous Materials by Lipkin Bicapillary
Ion Chromatography
Pycnometer EPASW-846 Method 9000 Determination ofWater inWaste
D1552 Test Method for Sulfur in Petroleum Products by
Materials by Karl Fisher Titration
High Temperature Combustion and Infrared (IR) Detec- EPASW-846 Method 9001 Determination ofWater inWaste
tion or Thermal Conductivity Detection (TCD) Lubricants by Quantitative Calcium Hydride Reaction
D1796 Test Method for Water and Sediment in Fuel Oils by EPA SW-846 Method 9056 Determination of Inorganic An-
ions by Ion Chromatography
the Centrifuge Method (Laboratory Procedure)
D2622 Test Method for Sulfur in Petroleum Products by 2.3 Federal Code of Regulations Standards:
Wavelength Dispersive X-ray Fluorescence Spectrometry
40 CFR 279 Standards for the Management of Used Oil
D2709 Test Method for Water and Sediment in Middle
3. Terminology
Distillate Fuels by Centrifuge
D2983 Test Method for Low-Temperature Viscosity of Au-
3.1 Definitions:
tomaticTransmission Fluids, Hydraulic Fluids, and Lubri-
3.1.1 burner fuel oil, n—any petroleum liquid suitable for
cants using a Rotational Viscometer
the generation of heat by combustion in a furnace or firebox as
D3245 Test Method for Pumpability of Industrial Fuel Oils
a vapor or a spray, or a combination of both.
(Withdrawn 2010)
3.1.1.1 Discussion—Different grades are characterized pri-
D3828 Test Methods for Flash Point by Small Scale Closed
marily by viscosity ranges.
Cup Tester
3.1.2 reclaiming, n—the use of cleaning methods during
D4052 Test Method for Density, Relative Density, and API
recycling primarily to remove insoluble contaminants, thus
Gravity of Liquids by Digital Density Meter
making the oil suitable for further use. The methods may
D4057 Practice for Manual Sampling of Petroleum and
include settling, heating, dehydration, filtration, and centrifug-
Petroleum Products
ing.
D4175 Terminology Relating to Petroleum Products, Liquid
3.1.3 recycling, n—in petroleum technology, the acquisition
Fuels, and Lubricants
of oil that has become unsuitable for its intended use, and
D4177 Practice for Automatic Sampling of Petroleum and
processing it to regain useful materials.
Petroleum Products
3.1.4 re-refining, n—the use of refining processes during
D4294 Test Method for Sulfur in Petroleum and Petroleum
recycling to produce high quality base stocks for lubricants or
Products by Energy Dispersive X-ray Fluorescence Spec-
otherpetroleumproducts.Re-refiningmayincludeoneormore
trometry
of the following: distillation, hydrotreating, or treatments
D4377 Test Method forWater in Crude Oils by Potentiomet-
3 employing acid, caustic, solvent, clay, or other chemicals, or
ric Karl Fischer Titration (Withdrawn 2020)
combination thereof.
D4865 Guide for Generation and Dissipation of Static Elec-
3.1.5 used oil, n—in petroleum product recycling, oil whose
tricity in Petroleum Fuel Systems
characteristics have changed since being originally
D4868 Test Method for Estimation of Net and Gross Heat of
manufactured, and that is suitable for recycling.
Combustion of Hydrocarbon Burner and Diesel Fuels
D4980 Test Methods for Screening of pH in Waste (With- 3.1.6 waste oil, n—in petroleum technology, oil having
drawn 2009)
characteristics making it unsuitable either for further use or for
D5185 Test Method for Multielement Determination of economic recycling.
Used and Unused Lubricating Oils and Base Oils by
3.2 For definitions of other terms used in this specification,
Inductively Coupled Plasma Atomic Emission Spectrom-
refer to Terminology D4175.
etry (ICP-AES)
3.3 Definitions of Terms Specific to This Standard:
D5854 Practice for Mixing and Handling of Liquid Samples
3.3.1 industrial burner, n—a device that produces heat for
of Petroleum and Petroleum Products
industrial use through the combustion of liquid hydrocarbon
D6304 Test Method for Determination of Water in Petro-
fuels.
leum Products, Lubricating Oils, and Additives by Cou-
3.3.1.1 Discussion—Industrial burners are typically de-
lometric Karl Fischer Titration
signed for one of two applications:
D6450 Test Method for Flash Point by Continuously Closed
Cup (CCCFP) Tester
D6822 Test Method for Density, Relative Density, and API
Available from United States Environmental Protection Agency (US-EPA),
Gravity of Crude Petroleum and Liquid Petroleum Prod-
Ariel Rios Bldg., PennsylvaniaAve., NW, Washington D.C. 20460. (www.epa.gov/
epaoswer/hazwaste/test/main.htm.
ucts by Thermohydrometer Method
National Archives and Records Administration, Code of Federal Regulations
D7042 Test Method for Dynamic Viscosity and Density of
(CFR), Available from U.S. Government Printing Office Superintendent of
Liquids by Stabinger Viscometer (and the Calculation of
Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.
Kinematic Viscosity) www.gpoaccess.gov/cfr/index.html.
D6448−16 (2022)
(a) industrial furnaces—integral components of manufac- 5.2 The fuel oils shall be homogeneous fluids consisting
turing processes that provide direct heating, for example, in primarily of hydrocarbons. Fuel oils containing residual com-
aggregate, cement, lime, or phosphate kilns; coke ovens; or ponents shall remain uniform in storage and shall not separate
blast, smelting, melting, refining, or drying ovens. by gravity or aging into layers in normal operating conditions.
(b) industrial boilers—large indirect heating units that
NOTE 4—Prolonged storage or equipment down time may necessitate
transfer thermal energy to water or other fluids or gases for use
circulation of the fuel oil in-tank to prevent such separation.
in heating in industrial settings and in manufacturing pro-
5.3 The fuel oil shall not contain excessive amounts of
cesses.
organic or inorganic acids, or both, and shall be free of solid or
3.3.2 reprocessing, n—in petroleum product recycling, the
fibrousmatterthatcouldcausesystemhandlingormaintenance
preparation of used oil to be suitable as a fuel.
problems. The buyer and seller should agree on any require-
3.3.2.1 Discussion—Reprocessing includes procedures such
ments for particle size.
as settling, filtration, blending, distillation, and chemical treat-
NOTE5—Thefuelsdefinedbythisspecificationareappropriateonlyfor
ment.
burners capable of handling and combusting fuels with potentially higher
metals and ash content.
4. Classification
4.1 There are four grades of industrial burner fuel contain-
6. Detailed Requirements
ing recycled lubricating oils covered by this specification.
6.1 Grade RFO4—Therequirementsforthistypeoffuelare
These grades may or may not correlate directly with similar
presented in Table 1 and include fuels in the viscosity range
grades in other ASTM standards. The RFO designation iden-
below5mm /s(cSt)at100 °CinaccordancewithTestMethod
tifies them as Reprocessed Fuel Oils.The usage descriptions of
D445.
each grade may not describe all the uses, but are included as
6.2 Grade RFO5L—The requirements for this type of fuel
general information. The four grades are described as follows:
arepresentedinTable1andincludefuelsintheviscosityrange
4.1.1 Grade RFO4—Primarily a blend of used lubricating
2 2
5.0 mm /sto8.9mm /s(cSt)at100 °CinaccordancewithTest
oils and distillate or a reprocessed distillate product derived
Method D445.
from used oil. It is intended for use in pressure atomizing
industrial burners with no preheating. This grade of recycled
6.3 Grade RFO5H—The requirements for this type of fuel
oil fuel is used in many medium capacity industrial burners
arepresentedinTable1andincludefuelsintheviscosityrange
2 2
whereeaseofhandlingjustifiesthehighercostovertheheavier
9.0 mm /s to 14.9 mm /s (cSt) at 100 °C in accordance with
used oil fuels.
Test Method D445.
4.1.2 Grade RFO5L—A straight (100 %) used lubricating
6.4 Grade RFO6—Therequirementsforthistypeoffuelare
oil blend or a used lubricating oil and distillate blend fuel of
presented in Table 1 and include fuels in the viscosity range
intermediate viscosity, heavier than Grade RFO4. It is intended
2 2
15.0 mm /s to 50.0 mm /s (cSt) at 100 °C in accordance with
for use both in pressure-atomizing industrial burners not
Test Method D445.
requiring higher cost distillates and in burners equipped to
atomize oils of higher viscosity with or without pre-heating. Its NO
...