Materials Characterization Paper In Support of the Proposed Rulemaking: Identification of Nonhazardous Secondary Materials That Are Solid Waste – Used Oil

March 18, 2010

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1. Definition of Used Oil

EPA defines used oil as any oil that has been refine d from crude oil, or any synthetic oil, that has been used and as a result of such use is contaminated by physical or chemical impurities. 1

EPA’s criteria for used oil:

• Origin: Used oil must have been refined from cr ude oil or made from synthetic materials (i.e., derived from coal, shale, or polymers) . Examples of crude-oil derived oils and synthetic oils are motor oil, mineral oil, laminating surface agents, and metal working oils. Thus, animal and vegetable oils are not included. Bottom clean-out from virgin fuel oil storage tanks or virg in oil recovered from a spill, as well as products solely used as cleaning agents or for their solvent propertie s, and certain petroleum-derived products such as antifreeze and kerosene are also not included.

• Use: The oil must have been used as a lubrican t, coolant, heat ( non-contact) transfer fluid, hydraulic fluid, heat transf er fluid or for a similar use. Lubricants include, but are not limited to, used motor oil, metal working lubricants, and emulsions. An example of a hydraulic fluid is transmission fluid. Heat tr ansfer fluids can be materials such as coolants, heating media, refrigeration oils, and electrical insulation oils. Authorized states or regions determine what is consid ered a “similar use” on a site-specific basis according to whether the material is used a nd managed in a manner consistent with Part 279 (e.g., used as a buoyant).

• Contaminants: The used oil must be contaminated by physical (e.g., high water content, metal shavings, or dirt) or chemical (e.g., l ead, halogens, solvents or other hazardous constituents) impurities as a result of use.

2. Annual Quantities of Used Oil Generated and Used

(1) Sectors that Generate Used Oil:

• According to EPA, generators of used oil include “businesses that handle used oil through commercial or industrial operations or from the maintenance of vehicles and equipment.” Examples include: 2

1 See 40 CRF 279.1 for the specific definition.

2 EPA’s regulatory definition of used oil generators does not include 1) farmers who produce less than an average of 25 gallons of used oil per month and 2) individuals who generate used oil through the maintenance of their personal vehicles and equipment. Although EPA’s regulatory definition does not include these groups, the data included in this document reflect used oil generated by all entities that generate this material.Used Oil

o Automotive repair shops

o Vehicle service stations

o Fleets

o Grocery stores

o Metal working industries

o Energy industry

o Boat marinas (EPA 2008b)

• Exhibit 1 lists the NAICS codes of the ma jor sectors that generate used oil.

Exhibit 1: NAICS Codes for Used Oil Generators

NAICS NAICS Title

111 1 Crop production 221 2 Electric services 221 2 Electric and other services combined 324 2 Petroleum and coal products 332, 333 2 Special industry machinery 333 1 Metal working industries 333, 336 2 Construction machinery and equipment

421 2 Scrap and waste materials 445 1 Grocery stores 484, 488, 492, 493, 562 2 Motor freight transportation and warehousing 713 1 Boat marinas 811 1 Automotive repair shops 811 1 Fleets 811 1 Vehicle service stations 814 1 Private households 562 1 Waste Management and Remediation Services

Sources: 1. Description of sectors from EPA 2008b; NAICS identified from U.S. Census Bureau 2007. 2. EPA 2005b.

(2) Quantities of Used Oil Generated: Exhibit 2 summarizes the annual generati on and management of used oil. As indicated in the exhibit, an estimated 70 percent of used oil is either used as a fuel (i.e., burned for energy recovery) or re-ref ined into lubricating oil. However, depending upon the year, estimates indicate that as much as 90 percent of all collected used oil is burned for energy rec overy, leaving 10 percent or less to be rerefined into lubricat ing oil (Svizzero 2008).

(3) Trends in Generation: The data sources consulted for this document do not incl ude information on the trend in the generation of used oil. A 2006 report from the Depa rtment of Energy indicates,

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however, that the volume of oil changed by consumers themselves (e.g., households and owners/operators of commercial vehicles ) declined from 60 percent of total oil changes in 1997 to 45 percen t in 2005 (DOE 2006, p. 5-2). This shift in practice may have helped increase the recycling rate for used oil. During the 1997-2005 period, the recycling rate for used oil gene rated by service stati ons increased from 66 percent in 1997 to almost 100 percent (DOE 2006, p. 5-2).

Exhibit 2: Overview of Annual Generation and Use

Commodity Annual Quantity Generated Annual Quantity Used as Fuel Annual Quantity Disposed of in Landfills or Improper Locations Annual Quantity Re-refined Total Quantity Stockpiled

Used Oil 1.37 billion gallons 780 million gallons 426 million gallons 165 million gallons unknown

Sources: Data are from United States Department of Energy 2006, p.5-1.

3. Uses of Used Oil

(1) Combustion Uses:

• Use as feedstock at petroleum refinery

• Use as an alternative fuel (EPA 2008b)

For the purposes of regulating used oil burned for energy recovery, EPA makes a distinction between on-spec used oil and off-spec used oil based upon a finding that only certain contaminants in used oil pose a significant threat to human health or the environment. As a result, EPA has established maximum concentration limits for these constituents of concern, as summarized in Exhibit 3. 3 If the used oil is shown not to exceed any allowable level, it is on-spec and can be burned in any combustion device. Otherwise, it is c onsidered off-specification.

Published data on the distribution be tween on-spec and off-spec used oil nation-wide was not readily available, but an industry so urce estimates that roughly 20 percent of the used oil generated in the U.S. is off-spec (Harris 2009). In addition, data on used oil generated in Florida indicate that an estimated 110,308,107 gallons of used oil and oily waste were managed in Florida in 2005. Of this, 56,569,512 gallons (51.3 percent) were recycled as follows:

41,386,124 gallons (73.2 percent) were mark eted as an on-spec used oil fuel 1,775,815 gallons (3.1 percent) were burne d as an off-spec used oil fuel

3 The limits are set such that the emissions resulting from the burning of used oil containing these contaminants, at or below established “on-spec” limits, will pos e no more threat to human health or the environment than the emissions resulting from the burning of virgin oil or diesel (68 FR 44662, July 30, 2003).

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13,407,573 gallons (23.7 percent) were market ed for other industrial uses (e.g. phosphate beneficiation) (FL DEP 2006)

Averaging the industry source and the Florid a data, we estimate that approximately 77 percent of the used oil generated and used each year is on-spec and 23 percent is off-spec.

Exhibit 3: Criteria for On-Specification Used Oil Property Allowable Level

Arsenic 5 ppm maximum

Cadmium 2 ppm maximum

Chromium 10 ppm maximum

Lead 100 ppm maximum
Total Halogens 4,000 ppm maximum 1
Flashpoint 100° F minimum

Source: EPA 2001 Notes: 1. Used oil containing more than 1,000 ppm total halogens is presumed

to be a hazardous waste under the rebuttable presumption provided under §279.10(b)(1). Such used oil is subject to subpart H of part 266 rather than part 279 when burned for energy recovery unless the presumption of mixing can be successfully rebutted.

Although approximately 23 pe rcent of the used oil generated in the U.S. is off-spec, a lower portion of off-spec used oil burned as a fuel is off-spec because off-spec used oil is often blended into on-sp ec by used oil processors. Industry sources indicate that between 5 and 15 percent of the used oil sold or burned by used o il processors in the U.S. is off-spec. 4 In addition, the Florida data referenced above suggest that approximately 4 percent of the used oil ma rketed and burned in Florida is off-spec. 5 Averaging the available values, we estimat e that 8.2 percent of used oil sold or burned by used oil processors is off-spec. 6
, 7

4 Harris, 2009 estimates that off-spec used oil makes up approximately 15 percent of the used oil market, while Briggs, 2009 estimates that this figure is approximately 5 to 6 percent.

5 We derived this value by dividing the 1.7 million gallons of used oil burned as off-spec by the 43.1 million gallons of used oil burned as fuel (on-spec and off-spec combined).

6 This estimate is the average of the 15 percent value from Harris (2009), the midpoint of the 5 to 6 percent range provided by Briggs (2009), and the 4 percent value from Florida DEP (2006).

7 Briggs (2009) indicates thatused oil burners so metimes use off-spec used oil as a fuel.

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As shown in Exhibit 4, asphalt plants are the largest users of used oil as fuel, followed by space heaters and industrial boilers. It is likely that asphalt plants use on-spec used oil adhering to the criteria noted in Exhibit 3 above.

Exhibit 4: Users of Used Oil

Used Oil Burners

38%

14% 12% 10% 10% 4% 12%

Asphalt Plants Space Heaters
Industrial Boilers Utility Boilers
Steel Mills
Cement Kilns
Others

Source: DOE 2006, p. 5-2.

A portion of the used oil burned for energy recovery in the U.S. is reflected in the combustor survey database developed by EPA for the 2009 proposal of the Comme rcial and Industrial Solid Waste Incinerator (CISWI) standards a nd the Industrial Boilers Maximum Achievable Control Technology (MACT) standards. Accordi ng to this database, th e units surveyed by EPA for these standards annually combust 34 million gallons of used oil (EPA 2009). 8

(2) Non-Combustion Used Oil Uses: Used oil may be re-used if it is processed or regenerated (EPA 2008b).

(3) Quantities of Used Oil Landfilled: Approximately 426 millions gallons of used oil are landfilled or improperly disposed annually (DOE 2006).

(4) Quantities of Used Oil Stockpiled/stored: Readily available data sources on used oil do not suggest that this material is stoc kpiled or stored (for long periods of time)

8 Although we report used oil quantities from the combustor database in gallons, the database includes material quantities expressed in terms of heating values (Btu ). To express this information in terms of gallons, we assumed that used oil has a heating value of 140,000 Btu per gallon, consistent with the estimate in EPA 2008b. Also, we note that much of the used oil burned by combustion units included in the database may be reported as (virgin) fuel oil rather than as used oil. That is, the use of used oil may be underreported in the combustor database.

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in large quantities. This is because its value as a fuel or product leads to its prompt

use.

4. Management and Combustion Processes for Used Oil

(1) Types of Units Combusting Used Oil: Facilities burn both on-specification and off- specification used oil. However, offspec used oil may only be burned in sp ecified combustion devices (EPA 2008):

• Industrial furnaces as defined in 40 C ode of Federal Regulation (CFR) §260.10 and §279.61(a). Industrial boilers as defi ned in 40 CFR §260.20 that are located at facilities that are engaged in a ma nufacturing process where substances are transformed into new products.

• Utility boilers as defined in 40 CFR §260.20 that are used to produce electric power, steam, heated or cooled air, or other gases or fluids for sale.

• Used oil-fired space heaters provided th at the burner meets the provisions of 40 CFR §279.23.

• Hazardous waste incinerators subject to regulation under 40 CFR parts 264 and 265, subpart O.

(2) Supply/Processing Chain for Used Oil : The Standards for the Management of Used Oil in the Code of Federal Regulations define processing as “chemical or physical operations designed to produce from used oil, or to make used oil more amenable for production of, fuel oils, lubricants, or other used oil-derived product. Processing includes, but is not limited to: blending used oil with virgin petroleum products, blending used oils to meet the fuel specification, filtration, simp le distillation, chemical orphysical separation and rerefining” (40 CFR 279.50(a)).

(3) Processing Used Oil for Fuel Applications: Used oil is generated from many different sources and then consolidated at key collection points (e.g., commer cial and industrial operations , automotive repair shops, branch collection networks, and fleets) th rough well-established channels before being shipped to processing facilities and end users. Based on communications with used oil recyclers and marketers, the steps to process used oil for use as a fuel are as follows:

• Test the oil to determine whether it’s on-spec or off-spec. The recyclers and marketers who we contacted indicated th at nearly all used oil is on-spec (Blackburn 2009).

• Remove as much water and other liquids from the oil as possi ble by allowing the water to settle to the bottom, or also by using solvents to remove water (and sometimes antifreeze).

• Filter out metal scraps and other larger particles using screens. The filtering can be done when the oil is colle cted, or in the burner when the oil is added (Saunders 2008 and Blackburn 2008).

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The filtering and water extraction processes described above are standard practice in the industry. That is, most used oil goes through these processing steps prior to being used as a fuel.

In addition to the processing steps outlined above, processors typically store used oil in tanks, allowing oil to sepa rate from other liquids and se ttle to the bottom of the tank. These steps allow processors to provi de users with relativ ely high-quality used oils (Saunders 2008 and Blackburn 2008, 2009).

Estimated counts of the entities involved in the various stages of used oil processing and use include the following:

• 379 used oil transporters and transfer facilities

• 150 used oil processors and re-refiners

• 750 burners of off-specification used oil

• 340 used oil fuel marketers (Office of Management and Budget 2005, p. 52)

(4) State Status of Used Oil use as Fuel: Based on a review of information from the 2006 Beneficial Use Survey conducted by the Association of State and Territori al Solid Waste Management Officials (ASTSWMO), none of the 34 states responding to the survey reported that they had given used oil a beneficial use designation as a fuel (ASTSWMO 2007, p.B-38-39). States typically regulate used oil practi ces under federal used oil management standards (EPA 2008c). 9 This may include establis hing programs to encourage appropriate use of used oil. For example, DOE indicates that 24 states have enacted purchasing program preferences to stimulat e the demand for used oil (DOE 6-3 to 6- 4).

5. Used Oil Composition and Impacts

(1) Composition of Used Oil

• 140,000 Btu per gallon 10 (EPA 2008b)

• A 2003 study by Dominguez-Rosado and Pichte l indicates that used motor oil has the following metals concentrations:

o Zinc: 838 mg/kg

o Lead: 110 mg/kg

o Cadmium: 9.4 mg/kg

o Barium: 4,100 mg/kg

o Chromium: Not detected (Domi nguez-Rosada and Pichtel 2003)

9 As of September 30 2008, 31 stat es have received federal authorization for the Recycled Used Oil Management Standards and an additional 10 states have adopted the Standards.

10 The heat input of used oil on a Btu per pound basis depends on the density of the used oil. Assuming a density of 7 pounds per gallon (Mississippi DEQ, 2007), the 140,000 Btu per gallon estimates translates to 20,000 Btu per pound.

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• Used oil often contains approximately 2 to 5 percent additives (DOE 2006, p. 9- 14). Exhibit 5 summarizes the most comm on of these additives. In addition to these additives, used oil may include a number of physical and chemical contaminants, including metals, di rt, and solvents (EPA, 2008a).

Exhibit 5: Common Additives Found in Used Oil Purpose of Additive Additives Anticorrosion Zinc dithiophosphates, metal phenolates, fatty acids and amines Antifoamant Silicone polymers, organic copolymers Antiodorant Perfumes, essential oils Antioxidant Zinc dithiophosphates, hindered phenols. Aromatic amines, sulphurized phenols

Antiwear Additive Chlorinated waxes, alkyl phosphites and phosphates, lead napthenate, metal triborates, metal and as hless dithiophosphates Color Stabilizer Aromatic amine compounds

Corrosion Inhibitor Metal dithiophosphates, metal dithicarbamates, metal sulfonates, thiadiazoles, and sulfurized terpenes
Detergent Alkyl sulfonates, phosphonates, alkyl phenates, alkyl phenolates, alkyl carboxylates, and alkyl substituted salicylates Dispersant Alkylsuccinimides, alkylsuccinic esters Emulsifier Fatty acids, fatty amides, and fatty alcohols

Extreme Pressure Additives Alkyl sulfides, polysulfides, sulfurized fatty oils, alkyl phosphites and phosphates, metal and ashless dithiophosphates and ca rboxylates, metal d ithiocarbamates, and metal triborates Friction Modifier Organic fatty acids. Lard oil. Phosphorous based compounds

Metal Deactivator Metal Deactivator Organic complexes cont aining nitrogen and sulfur amines, sulphides and phosphates Pour point depressant Alkylated naphthalene and phenolic polymers, polymethacrylates

Rust Inhibitor Metal alkylsulfonates, alkylamines, alkyl amine phosphates, alkenylsuccinic acids, fatty acids, alkylphenol ethoxylates, and acid phosphate esters Seal Swell Agent Organic Organic phosphates aromatic hydrocarbons Tackiness Agent Polyacryl ates and polybutenes Viscosity Polymers of olefins, methacr ylates, di-enes or alkylated styrenes

Sources: DOE 2006, Table 9 and EPA 2005a, Appendix C-2.

(2) Impact Information

• Cost Impacts: The cost impact associated with consuming used oil as a fuel depends on both the value of the fuel that it displaces and the cost of processing used oil. The Department of Energy reports that the market value of used oil is approximately 65 to 75 percent of the pr ice of No. 6 fuel oil (DOE 2006, p. 4-4), but it is unclear whether this estimate applies to processed or unprocessed used oil. At October 2008 fuel prices, the 65 to 75 percent estimate suggests that the value of used oil is approximately $1.14 to $1.31 per gallon. 11 In addition, in terms of the economic benefit r ealized by facilities that se ll their used oil, a used oil recycler in Idaho indicates that the price paid by oil recyclers for unprocessed used oil varies depending on the quantity and frequency of sale (Blackburn 2008).

11 This is based on a price of $1.75 per gallon for No. 6 fuel oil (DOE 2008).

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At current oil prices, used oil recy clers pay between $0.60 and $1.07 per gallon for used oil (Blackburn 2008). Used oil ma rketers must also bear the costs of testing to determine whether oil is on- specification or off-specification. The results of an EPA survey of used oil ma rketers indicate an av erage facility annual cost of testing of $3,462 (EPA 1998).

• Emissions Impacts of Used Oil as a Fuel: To characterize the potential environmental impacts and benefits associ ated with the use of used oil as an alternative fuel, we identified comparativ e emissions information for used oil and for the fuels it typically repl aces: distillate fuel oil an d residual fuel oil. More specifically, we obtained information on the emissions associated with the combustion of each of these fuels andthe emissions associated with cradle-togate processing of the virgin fuel oil, impacts that would be avoided by burning used oil as an alternative. Exhibit 6 below summarizes this information. Note that this analysis does not include the emissions associated with the preparation of used oil for combustion, and may therefor e overstate the relative air emissions reductions associated with using this alte rnative fuel. However, the majority of the upstream impacts of used oil are the result of the generation of the primary product associated with the oil; the pro cessing required to prepare used oil for combustion is limited. Additionally, since not all contaminants in used oil cause health or environmental risk, maximum conc entration limits can be set such that used oil burned with concentrations at or below the limits will not create risk. These concentration limits define the difference between on-spec and off-spec used oil.

Exhibit 6 shows that the principal bene fits of combustion of used oil are associated with upstream production offsets and include substantial reductions of NO x , CO, and CO 2 emissions. In terms of combus tion-specific emissions, use of used oil results in notably lower NO x emissions, in particular when compared to residual fuel oil. On the other hand, part iculate matter and lead emissions may be substantially higher than virgin fuel oil, depending on the concentrations of those compounds in the used oil.

Note that other uses for used oil may be environmentally preferable to combustion (e.g., recovery and reuse as a lubrican t) but this analysis examines only combustion uses.

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Exhibit 6: Emission Factors for Used Oil an d Alternatives

Used Oil Distillate Fuel Oil Residual Fuel Oil

Combustion Combustion Combustion plus Upstream Combustion Combustion plus Upstream Pollutant

-------------------------------- Lb./MMBtu ---------------------------
Criteria Pollutants PM2.5 - - - - - PM10 0.162 – 0.190 0.011 0.011 0.093 0.093 PM, unspecified 0.203 – 0.238 - 0.012 - 0.012 NOx 0.131 0.173 0.234 0.367 0.428 VOCs - 0.001 0.363 0.002 0.367 SOx 0.051 – 1.014 0.209 0.394 1.593 1.781 CO 0.034 0.036 0.082 0.033 0.079 Pb 1.79x10 -3 – 2.16x10 -3 4.60x10 -6 5.61x10 -6 5.80x10 -5 5.90x10 -5 Hg - 1.58x10 -6 1.77x10 -6 8.67x10 -6 8.85x10 -6

Greenhouse Gases
CO 2 151.7 161.2 180.1 173.3 192.5 CH 4 - 3.7410 -4 0.030 0.007 0.036
N 2 O - - 2.01x10 -5

- 2.07x10 -5
MTCO 2 E/MMBtu 0.069 0.073 0.082 0.079 0.088

Sources: Distillate fuel oil and residual fuel oil emissions from Franklin Associates 1998. Used oil emissions from EPA 1995, Vermont Agency of Natural Resources 1996, and Colorado Department of Public Health and Environment. Notes: “-” signifies data not available; may equal zero. Heating value of used oil assumed to be 145 MMBtu/1000 gal.

The emission information presented in this table is derived from Life Cycle Inventory (LCI) data, as compiled by Franklin Associates. LCI data identifies and quantifies re source inputs, energy requir ements, and releases to the air, water, and land for each step in the manufacture of a pr oduct or process, from the extraction of the raw materials to ultimate disposal. The LCI can be used to identify those system components or life cycle steps that are the main contributors to environmental burdens such as energy use, solid waste, and atmospheric and waterborne emissions. Uncertainty in an LCI is due to the cumulative effects of input uncertainties and data variability.

There are several life cycle inventory databases available in the U.S. and Europe. For this paper, we applied the most readily available LCI database that was most consiste nt with the materials and uses examined. These LCI data rely on system boundaries as defined by Franklin Associates, as described in the documentation for this database, available at: http://www.pre.nl/download/manuals/DatabaseManualFranklinUS98.pdf

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References

40 CFR 279.50(a)

Association of State and Territorial Solid Wa ste Management Officials (ASTSWMO). 2007, 2006 Beneficial Use Study Report , November 2007.

Blackburn, Randy. 2008. Commercial Fuel Recycling, LLC, Idaho, personal communication, September 25, 2008 and November 20, 2008.

Blackburn, Randy. 2009. Commercial Fuel Recycling, LLC, Idaho, personal communication, April 24, 2009.

Briggs, William. 2009. ORRCO, personal communication, August 24, 2009.

Colorado Department of Public Health and Environment. 2008, “A Guide to Hazardous Waste and Air Requirements for Used Oil Space Heater s”, accessed on August 29, 2008 at http:// www.cdphe.state.co.us/ap/sbap/sbap_useoilheaters.pdf

. Dominguez-Rosado, Elena and John Pichtel. 2003, “Chemical Characterization of Fresh, Used, and Weathered Motor Oil Via GC/MS, NMR, and FTIR Techniques,” Proceedings of the Indiana Academy of Sciences, Vol. 12, No. 2, 2003, pages 109-116.

Florida Department of Environmental Protection. 2006, “Florida’s Used Oil Recycling Program: 21 st Annual Report,” March 2006.

Franklin Associates. 1998, “Franklin US LCI 98 Library”.

Harris, Christopher. 2009. Association of Responsible Recyclers, General Counsel, personal communication, August 21, 2009.

Mississippi Department of Environmental Quality. 2007. “Material Density and Volume Conversion,” http://www.deq.state.ms.us/MDEQ.nsf/page/Recycli ng_MaterialDensityandVolumeConversion?OpenDocu
ment.

Saunders, Brandon. 2008. Polar Refrigerant Technol ogies, New Hampshire, personal communication, September 25, 2008.

Svizzero, Michael. 2008. U. S. Environmental Protecti on Agency, personal communi cation, citing American Petroleum Institute data, October 22, 2008.

United States Census Bureau. 2007. “2007 NAICS Definitions”.

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United Stated Department of Energy (DOE). 2008, “Short-Term Energy Outlook,” November 12, 2008.

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United States Environmental Protection Agency (EPA). 1998, “Supporting Statement For Renewal of ICR (#1286); Used Oil Management Standards R ecord Keeping and Reporting Requi rements,” accessed April 27, 2009
at http://www.epa.gov/was te/conserve/materials/usedoil/support.htm

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United States Environmental Protectio n Agency (EPA). 2001, “RCRA, Superf und & EPCRA Call Center Training

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Module Introduction to Used Oil,” October 2001.

United States Environmental Protection Agency (EPA). 2005a, “G uidance and Summary of Information Regarding the RCRA Used Oil Rebuttal Assumption,” March 2005.

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United States Environmental Protection Agency (EPA). 2008a, “Code of Federal Regulations: Standards for the Management of Used Oil”, accessed August 28, 2008 at http://www.gpoaccess.gov/index.html

. United States Environmental Protection Agency (EPA). 2008b, “Managing Used Oil: Advice for Small Businesses”, accessed August 19, 2008 at http://www.epa.gov/epaoswer/hazwaste/usedoil/usedoil.htm

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United States Environmental Protection Agency (EPA). 2008c, “Authorization Status by Rule”, accessed December 2, 2008 at http://www.epa.gov/epawaste/laws-regs/state/stats/authall.pdf.

United States Environmental Protection Agency (EPA). 2009, Combustor survey database in support of the 2009 proposal of the Commercial and Industrial Solid Waste Incinerator (CISWI) standards and the Industrial Boilers Maximum Achievable Control Technology (MACT) standards, April 2009.

United States Office of Management an d Budget (OMB). 2005, “Supporting Statement for Information Collection Request Number 1286.07 Used Oil Management Standards Recordkeeping and Reporting Requirements”.

Vermont Agency of Natural Resources. 1996, “Vermont Used Oil Analysis and Waste Oil Furnace Emissions Study”, accessed on Au gust 29, 2008 at http://www.epa.gov/ttn/catc/dir1/w_oilacr.pdf

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