Materials Characterization Paper 

In Support of the 

Proposed Rulemaking: 

Identification of Nonhazardous Secondary Materials That Are Solid Waste – Scrap Tires

April 6, 2010

===================================================================== 

1. Definition of Scrap Tires 

Scrap tires are used tires that can no longer be utilized as tires. 

2. Annual Quantities of Scrap Tires Generated and Used 

(1) Sectors that generate scrap tires: Scrap tires are generated from the replacement of 

tires on passenger and commercial vehicles. 

• The majority of scrap tires, 85 percent, come from passenger vehicles and light 

duty trucks. The remaining 15 percent comes from larger vehicles such as heavy 

duty trucks and buses (RMA 2009). 

• Many scrap tires are sent to processors where they are shredded and then sent to 

end users such as: plants using tire-derived fuel; civil engineering projects (e.g., 

construction sites for landfills, septic tank leach fields, or roads); and crumb 

rubber plants where they may be recycled into other products (Virginia 

Department of Environmental Quality 2008). Other tires are used whole, either in 

civil engineering or similar projects, or as a fuel. 

(2) Quantities of Scrap Tires Generated: Consumers and industry in the United States 

generated 4.6 million tons of tires in 2007, or an estimated 303.2 million scrap tires 

(RMA 2009). Of these tires, roughly 13 percent were landfilled. These landfilled 

tires are “wasted,” with their resource value being lost to society. Exhibit 1 provides 

a brief overview of the generation and use of scrap tires in 2005 and 2007 (except for 

the total annual quantity generated, 2007 figures are available only in terms of 

weight). Exhibit 2 provides more detailed information on the uses of scrap tires from 

1990 through 2007. 
Scrap Tires 

2

Exhibit 1: Overview of Generation and Use for 2005 and 2007 

Commodity 

Annual 

Quantity 

Generated 

Annual Quantity 

Used as Fuel 

Annual Quantity 

Land Disposed 

Annual Quantity 

Diverted to Other 

Uses1

Total Quantity 

Stockpiled as 

 of 2005/2007 

Scrap Tires 

(2005)2

299.6 million tires 

4.4 million tons 

155.1 million tires 

2.1 million tons 

177 facilities 

42.42 million tires 

0.6 million tons 

104.1 million tires 

1.5 million tons 

188.0 million tires 

2.9 million tons 

Scrap Tires 

(2007)3

4.6 million tons 

303.2 million tires 2.5 million tons 0.6 million tons 1.5 million tons 128.4 million tires 

Sources:

Data for 2005 are from RMA 2006, and data for 2007 are from RMA 2009. 

Notes:

1. The quantity diverted to other uses includes roughly 0.1 million tons of exported tires in both 2005 and 2007.. 

2. Of the 4.4 million tons of tires generated in 2005, the Rubber Manufacturers Association (RMA) has accounted for how 4.2 

million tons were managed. RMA was unable to determine how the remaining 0.2 million tons were managed. 

3. In its 2009 report, RMA states that, henceforth, it will include only weight-based figures in its published market data. This 

reflects the evolution of data reporting within the industry. Historically, RMA presented scrap tire data in units, consistent

with the first major report on scrap tire management completed by EPA. However, some governments and tire industry 

organizations present data in terms of weight, and the EPA Resource Conservation Challenge Tire Workgroup has 

recommended use of weight-based data. RMA states that this full conversion is necessary for consistency and precision of 

data, though it will make comparisons to previous years challenging. However, RMA still reports the quantity stockpiled in 

numbers of tires, because stockpile estimates continue to be given in units. 

Exhibit 2: Summary of Scrap Tire Uses from 1990 to 2007 

Millions of Tires Used 

Scrap Tire Use 1990 1992 1994 1996 1998 2001 2003 2005 20071

Tires Used as fuel (whole and 

shredded) 24.5 57.0 101.0 115.0 114.0 115.0 129.7 155.1 179.6 

Cement Kilns 6.0 7.0 37.0 34.0 38.0 53.0 53.0 58.0 48.4 

Pulp/paper Mills 13.0 14.0 27.0 26.0 20.0 19.0 26.0 39.0 77.1 

Industrial Boilers 0.0 6.0 10.0 16.0 15.0 11.0 17.0 21.0 14.5 

Utility Boilers 1.0 15.0 12.0 23.0 25.0 18.0 23.7 27.0 24.9 

Non-Fuel Uses 0.0 11.0 37.5 49.5 63.5 103.0 103.6 104.0 94.9 

Civil Engineering N/A 5.0 9.0 10.0 20.0 40.0 56.4 49.2 43.1 

Ground Rubber 0.0 5.0 1.5 7.5 7.0 21.0 18.2 30.1 43.0 

Export 0.0 0.0 12.5 15.0 15.0 15.0 9 6.9 6.3 

Cut/Punched/Stamped N/A N/A 8.0 8.0 8.0 8.0 6.5 6.1 0.1 

Miscellaneous/Agriculture N/A 1.0 3.5 4.0 5.5 7.0 3.0 3.0 0.5 

Electric Arc Furnaces N/A N/A N/A N/A N/A N/A 0.5 1.3 1.9 

Rubber Modified Asphalt2 N/A N/A 3.0 5.0 8.0 12.0 10.0 7.4 - 

Scrap Tires in Stockpiles 1000.0 1,000.0 800.0 500.0 400.0 300.0 275.0 188.0 128.4 

Sources:

Data for 1990 through 2005 are from RMA 2006, and data for 2007 are from RMA 2009. 

Notes:

1.RMA 2009 includes figures only in weight for 2005 and 2007, as well as percent change between 2005 and 2007. To 

approximate 2007 figures in terms of the quantity of tires, in order to demonstrate how various uses have changed over 

time, we applied the percent change in weight between 2005 and 2007 to the 2005 quantity figures. However, the 2007 

stockpile figure was given in quantity of tires. 

2.Rubber modified asphalt was not separated out as a category in RMA 2009. 

3.The tire derived fuel (TDF) total includes dedicated tires to energy. 
Scrap Tires 

3

 

(3) Trends in Generation: 

• Scrap tire generation increased by 36 percent from 1990 to 2007, while the 

amount reused or recycled increased from 11 percent in 1990 to 89 percent in 

2007 (RMA 2009). This reflects a major accomplishment in effective materials 

management. 

• During this same period, the number of tires in stockpiles declined by more than 

87 percent, from 1 billion to 128 million (RMA 2009). 

• The use of tires for fuel has increased from 24.5 million tires in 1990 to roughly 

179.6 million tires in 2007 (RMA 2009).1

 The Rubber Manufacturers 

Association (RMA) suggests that the use of tires as a fuel source will likely 

continue and may increase as the cost of conventional fossil fuels increases (RMA 

2006).

• The combustor survey database developed by EPA for the 2009 proposal of the 

Commercial and Industrial Solid Waste Incinerator (CISWI) standards and the 

Industrial Boilers Maximum Achievable Control Technology (MACT) standards 

indicates that the sources surveyed for these rules annually combust 599,000 tons 

of scrap tires2

 (EPA 2009). 

• States have contributed to the increased use of scrap tires as a fuel and for other 

purposes by regulating scrap tires and by working with the public and private 

sectors to improve the management of scrap tires to minimize landfilling, 

stockpiling, and illegal dumping (EPA 2007). Exhibit 3 demonstrates that 

stockpiles have been depleted despite increased generation, while Exhibit 4 

illustrates the increasing rate of reuse/recycling of scrap tires.

1 We approximated this 2007 figure of numbers of tires used as fuel by applying the percent change in 

weight of tires used for fuel between 2005 and 2007 (RMA 2009) to the 2005 quantity figure. 

2

 Although we report scrap tire data from the combustion database as a tonnage, the database includes 

material quantities expressed in terms of heating values (Btu). To express this information as a tonnage, we 

assumed that scrap tires have a heating value of 14,000 Btu per pound, which is the midpoint of the 12,000 to 16,000 

Btu/lb range referenced below from the North Carolina Division of Pollution Prevention and Environmental 

Assistance. 
Scrap Tires 

Exhibit 3: Changes in Scrap Tire Generation and Stockpile Depletion

Scrap Tire Generation Compared to the Number of Scrap 

Tires in Stockpiles

0

100

200

300

400

500

600

700

800

900

1000

1100

1990 1992 1994 1996 1998 2001 2003 2005 2007

Year

# of Tires (Millions)

Scrap Tire

Generation

Scrap Tires in

Stockpiles

Data from RMA 2009

Exhibit 4: Changes in Scrap Tire Generation and Reuse/Recycling

Scrap Tire Generation Compared to the Number of Scrap 

Tires Recycled or Recovered

350

0

50

100

150

200

250

300

1990 1992 1994 1996 1998 2001 2003 2005 2007

Year

# of Tires (Millions)

Scrap Tire

Generation

Scrap Tires

Recycled or

Recovered

Data from RMA 2009. We approximated the number of scrap tires recycled or 

recovered in 2007 by applying the reported percentage recycled or recovered in 2007 to 

the reported generation of scrap tires for 2007. 

3. Uses of Scrap Tires 

(1) Combustion Uses of Scrap Tires: 

A major use of scrap tires is as fuel, either in whole form or as tire-derived fuel 

(TDF). The southeast is currently the strongest market for use of scrap tires as fuel 

(Blumenthal 2009a). Whole tires are frequently used as fuel in cement kilns, and the 

reinforcing steel within tires provides an additional benefit (Gray 2009). Otherwise, 

use of whole tires is limited by whether they are compatible with the combustion and 

4
Scrap Tires 

5

handling characteristics of individual combustion units (EPA 2008c, Gray 2009). 

TDF is defined by ASTM as scrap tires that have been shredded and processed into 

rubber chips according to product standards. The use of TDF in combustion units is 

typically limited to blends of less than 30 percent of total energy input due to the high 

rates of heat release and the low moisture content of TDF. Thus, TDF is often used 

as a supplementary fuel in combustors to complement other fuel sources such as coal 

and biomass (ASTM 2006). 

• Pulp and paper manufacturers accounted for 43 percent of the fuel use of TDF, by 

weight, in the United States in 2007. Other users include cement manufacturers 

(27 percent of fuel use), electric utilities (14 percent of fuel use), industrial boilers 

(8 percent of fuel use), and dedicated tire-to-energy facilities (8 percent of fuel 

use). These figures represent a shift since 2005, when cement manufacturers 

accounted for 37 percent of use and pulp and paper manufacturers accounted for 

25 percent. From 2005 to 2007, use of TDF by pulp and paper manufacturers 

increased by 98 percent (RMA 2009). 

• Currently, a total of 66 cement kilns (at 43 cement production facilities) burn tires 

as fuel in the United States. Only ten of these kilns burn shredded tires; the 

remaining 56 kilns burn whole tires (Blumenthal 2009a). 

• Data on the precise breakdown between shredded tires and whole scrap tires in 

the scrap tire fuel market are not readily available. However, based on data from 

RMA (2009) and Blumenthal (2009a), EPA estimates that shredded tires make up 

69 percent of the market and whole tires make up 31 percent.  As indicated in Exhibit 2, RMA (2009) divides the scrap tire fuel market across different 

user industries. The RMA (2009) document also suggests that cement kilns and 

dedicated tire-to-energy plants are the main consumers of whole tires. To estimate the 

segmentation of the market, EPA therefore assumed that all other facilities burn shredded 

tires. In addition, based on RMA (2009), EPA assumed that dedicated tire-to-energy 

facilities burn whole tires exclusively and that cement kilns burn both whole tires and 

shredded tires. To distribute cement kiln tire use between whole tires and shredded tires, 

EPA relied upon data provided by Blumenthal (2009a) on the number of cement kilns 

that burn whole tires and the number that burn shredded tires. EPA assumed that the 

breakdown between whole tires and shredded tires among cement kilns is proportional to 

the percentage of kilns that burn whole tires and the percentage that burn shredded tires. 

• As of the end of 2007, there were 123 facilities permitted to use tire-derived fuel 

in the U.S. (RMA 2009). Exhibit 5 presents the 3-digit NAICS codes for these 

facilities. Appendix 1 includes basic identifying information for each facility in 

the U.S. known to be utilizing TDF. 

• The use of scrap tires as fuel accounts for roughly 53 percent of the beneficial use 

of scrap tires, as indicated in Exhibit 6. 

• As shown in Exhibit 7, the use of tires as fuel has increased significantly since 

1990. RMA indicates that the increased use of tires as fuel is likely due to 

increased energy prices for conventional fossil fuels and improvements in tire 

processing (RMA 2006). 

Comment [A1]: Information on 

shredded v. whole tires developed and 

provided in response to OMB comment. 
Scrap Tires 

Exhibit 5: NAICS Codes for Facilities Using Tire-Derived Fuel 

NAICS NAICS Title Count1

327 Nonmetallic Mineral Product Manufacturing2 44 

221 Utilities 22 

322 Paper Manufacturing 32 

562 Waste Management and Remediation Services 8 

Various Other Industrial Boilers 17 

Source:

RMA 2009 

U.S. Census Bureau 2007 

Note:

1. The values presented here are based on information in Chapter 3 of RMA 2009. 

Appendix C of RMA 2009, however, includes slightly different values. 

2. This sector includes cement kilns, a major user of TDF discussed throughout 

this paper. 

(2) Non-Combustion Scrap Tire Uses: Although energy recovery is the most common 

use of scrap tires, there are many non-fuel uses for scrap tires including the following:

• Agriculture/Miscellaneous (i.e., erosion control) 

• Civil Engineering (i.e., construction of landfills and roads)

• Cut/Punched/Stamped into other products (e.g., floor mats) 

• Electric Arc Furnaces (i.e., these units combust tires to utilize energy value and to 

incorporate carbon and steel into new steel products) 

• Ground Rubber (e.g., synthetic sports field turf)

• Rubber Modified Asphalt (RMA 2006)

Exhibit 6: Use of Scrap Tires in 2007

 Source: RMA 2009. 

6
Scrap Tires 

• Similar to the increased use of scrap tires as a fuel source, the beneficial use of 

scrap tires in non-combustion applications has increased significantly between 

1990 and 2001, and currently, a high percentage of truck tires are diverted into 

ground rubber applications (Blumenthal 2009a). Since 2001, however, the 

amount of scrap tires used for non-combustion applications has been fairly 

constant, whereas the amount used as fuel has continued to increase. This trend 

reflects the high fuel value of tires. The increased acceptance of tires as a 

legitimate fuel led to success in reduction of tire piles. With the increase in fuel 

prices since 2001, beneficial use of tires as fuel has become a more attractive 

management option than other beneficial use applications.

• Cooperation from state agencies is crucial to the growth and development of noncombustion applications of scrap tires. For example, despite Rubber Modified 

Asphalt’s potential to absorb large amounts of scrap tires (one highway lane 

absorbs approximately 1,000 scrap tires), reluctance on the part of state 

transportation agencies due to cost and performance concerns has hindered its 

growth as a market (Frye 2009; RMA 2009; Gray 2009). 

Exhibit 7: Trends in the use of Scrap Tires from 1990 – 2007 

0

50

100

150

200

1990 1992 1994 1996 1998 2001 2003 2005 2007

Year

# of Tires (Millions)

250

300

Rubber Modified Asphalt

Electric Arc Furnaces

Miscellaneous/Agriculture

Cut/Punched/Stamped

Export

Ground Rubber

Civil Engineering

Tires Used for Tire Derived

Fuel

Data from RMA 2009. We approximated 2007 figures in terms of the quantity of tires, 

in order to demonstrate how various uses have changed over time, by applying the percent 

change in weight between 2005 and 2007 to the 2005 quantity figures 

(3) Quantities of Scrap Tires Landfilled: The number of tires landfilled has slowly 

declined as the use of TDF and other applications for tires has increased. This trend 

reflects an important environmental accomplishment. Despite efforts to minimize the 

number of tires sent to landfills, tires are still landfilled because of the high cost of 

hauling tires to a processing facility in some areas (i.e., landfilling is often the least 

costly management option), or if they are in too poor of condition to be suitable for 

7
Scrap Tires 

8

beneficial use applications. This reflects a significant waste of resources. In general, 

the placement of whole tires in above-ground landfills is discouraged due to their 

large size, flammability, and potential to harbor mosquitoes. As an alternative, scrap 

tires may be placed in an underground monofill (RMA 2006). While EPA considers 

monofill disposal preferable to traditional above-ground tire piles, these are also a 

clear waste of valuable resources (EPA 2007).

(4) Quantities of Scrap Tires Stockpiled/Stored: Stockpiles of tires have been steadily 

decreasing as a result of state efforts to eliminate “tire piles.” States are typically 

responsible for regulating scrap tires, and each state, with the exceptions of Alaska 

and Delaware, has developed laws and requirements to address scrap tire concerns. 

While some states focus mostly on the management of scrap tires as they are 

generated, others have also developed programs to address existing tire stockpiles 

(EPA 2007). The majority of current stockpiles are located in seven states: Alabama, 

Arizona, Colorado, Massachusetts, Michigan, New York, and Texas (RMA 2009). 

As indicated in Exhibit 2, the number of tires in stockpiles has fallen by over 87 

percent since 1990. Most states, like EPA, encourage the use of tires as fuel. Some 

states have formally determined, under state law, that combustion of tires is not 

related to waste management, but is actually a beneficial use of resources.

4. Management and Combustion Processes for Tire-Derived Fuel 

(1) Types of Units Combusting Tires as Fuel: Tires are combusted as fuel in a variety 

of applications, including in boilers and kilns (RMA 2006). They can be used to 

supplement and/or replace a wide range of fuels including coal, coke, fuel oil, natural 

gas, and wood. Although many combustion units were not designed to burn tires, 

many are able to use tires as a supplement to conventional fuels (ASTM 2006). 

(2) Supply/Processing Chain for Tires Used as Fuel: While scrap tires are generated 

from many different sources, they are generally consolidated at key collection points 

(e.g., tire retailers, automotive repair shops, and fleets) through well-established 

channels before being shipped to processing facilities and end users. Exhibit 8 

summarizes the processing chain for scrap tires used as TDF. An additional source 

for scrap tires is historical tire piles. Furthermore, some tire processors send TDF to 

end-users indirectly, through brokerage firms (Sorcher 2009).
Scrap Tires 

Exhibit 8: Typical Process for Recovering Tires for Tire-Derived Fuel 

Scrap tires are removed from passenger vehicles and trucks. 

Tires that are no longer usable are collected at retailers, 

fleets, etc. until they are ready for transport. 

Tires are transported to processing facilities. 

Tires are chipped/shredded.1

Sent to TDF facility for combustion. 

Source: Texas Commission on Environmental Quality 2008 

Note: 1

. In some cases, combustion devices accept whole tires, which can provide environmental advantages over 

chipped tires (e.g., energy savings from avoided chipping). 

(3) Processing Scrap Tires for Fuel Applications: 

 Scrap tires are often processed through two physical processing steps: chipping/ 

shredding and metal removal. Shredded tires used as fuel consist of chipped tires 

ranging in size from 1 to 4 inches; the amount of metal in this material varies 

depending on how much the tires have been processed. This processing step is 

beneficial for many combustion units because it minimizes the metals content of the 

tires and improves heating efficiency. However, shredding tires to the smaller 

particle size required to remove metals increases processing costs (Gray 2009). The 

price of TDF therefore increases with smaller particle sizes conducive to metal 

removal (ASTM 2006, Gray 2009).3

 Tire processors can sort their material by metal 

content and charge higher prices for material with 90 percent of the metal wire 

removed (Gray 2004). 

Some units such as cement kilns do not require the removal of wire because their 

processes are hot enough to oxidize the wire. Also, the metals provide a positive 

value in the process as a substitute for raw materials, and considerable energy is 

saved by not chipping tires. Furthermore, some argue that the combustion 

characteristics of tires (and the emissions produced) are improved when combusted 

whole in certain combustion devices (e.g., cement kilns). Currently, there are at least 

 3

 The extraction of metals from tires can also cause deterioration of shredding equipment, which adds 

further to processing costs (Grantham 2009). 

9
Scrap Tires 

10

 

five states whose scrap tire programs divert whole tires for use as fuel in cement 

kilns: Alabama, California, Oklahoma, Pennsylvania, and Texas (Blumenthal 2009a). 

 In addition to chipping/shredding and metal removal, some TDF producers are 

experimenting with pyrolysis, but it has not become commercially successful due to 

high capital costs associated with processing equipment and the relatively low value 

of the outputs produced, especially the solid char product (CIWMB 1992, Gray 

2009).4

 

Because the specifications for TDF are somewhat user specific, the ASTM has not 

issued recommended specifications for TDF or the processing of scrap tires for use as 

TDF. 

While newly generated scrap tires can typically be processed for TDF applications, 

many tires in tire piles are in such poor condition that they cannot be processed and 

used as TDF. When tires from large stockpiles are processed, it is usually onsite at 

the stockpile itself; to avoid the degradation of processors’ primary equipment, 

stockpile tires are not shipped to processors’ main facilities (Blumenthal 2009b). 

Besides landfill or monofill disposal, the only other notable potential uses of these 

tires are in cement kilns and civil engineering applications (Gray 2009, RMA 2006). 

(4) Recognition of Value in Using this Alternate Fuel – by Regional, State, and 

Academic Parties:

The Resource Conservation Challenge (RCC) Scrap Tire Workgroup5

 has two goals 

related to scrap tires: (1) to manage 85 percent of scrap tires through reuse, recycling, 

and energy recovery and (2) to reduce the number of stockpiled tires by 55 percent 

from 2001 to 2008. To help meet these goals, the RCC workgroup has developed 

subcommittees to target different applications in order to make progress, one of 

which is the Tire-Derived Fuel Subcommittee, which is striving to support the 

expanded and appropriate use of scrap tires as a supplemental energy resource in 

properly permitted industrial facilities (RMA 2006). 

 

(5) State Status of Scrap Tire Used as Fuel: 

According to state responses to a 2006 survey by the Association of State and 

Territorial Solid Waste Management Officials (ASTSWMO), the following states 

have approved the use of scrap tires as fuel on at least one occasion: Maryland, 

Pennsylvania, Kentucky, Maine, and North Dakota. This use does not appear to have 

pre-approved status, however, suggesting that a case-by-case approval process for 

4

 To a lesser extent, there has been some experimentation with the use of cryogenics to shatter scrap tires 

into TDF chips, but an established industry for the use of cryogenics in the production of TDF has not yet developed 

(CIWMB 1992; Sorcher 2009). 5

 The Scrap Tire Workgroup contributes to the overall goals of Resource Conservation Challenge (RCC), a 

multi faceted initiative implemented by USEPA with three overarching goals: 1. to prevent pollution and promote 

recycling and reuse of materials; 2. to reduce the use of toxic chemicals; and 3. to conserve energy and materials. 

The Scrap Tire Workgroup of the RCC works on various issues related to scrap tire management and markets. The 

workgroup consists of over 50 representatives from various state environmental agencies, industry, trade groups, 

EPA and academia with expertise in scrap tire management, market development, and application technologies. 
Scrap Tires 

11

designation of beneficial use is in place in these states (ASTSWMO 2007). 

According to ASTSWMO, the following states have given pre-approved beneficial 

use determinations to the use of scrap tires as fuel: Indiana, Iowa, North Carolina, 

and Virginia. In addition, RMA data indicate that TDF has been approved for use in 

facilities in 34 states (RMA 2009). 

5. Scrap Tire and TDF Composition and Impacts 

(1) Composition of Tires Used as Fuel:

Tires have a high energy content ranging from 12,000 – 16,000 Btus per pound. This 

is higher than many conventional fossil fuels (e.g., coal). Tires that have been 

processed to remove steel reinforcing wire will have higher heating values per pound 

than tires that have not been processed to minimize wire metals. However, cement 

kilns report that the savings are greater overall when energy is not expended to shred 

tires. Also, the steel in tires is an important raw material in cement manufacturing. 

The Btu Values of tires and a number of other fuels are as follows: 

• Tires: 12,000 – 16,000 Btu/pound (North Carolina Division of Pollution 

Prevention and Environmental Assistance (NCDPPEA)) 

• Coal: 11,000 - 13,000 Btu/pound (NCDPPEA and EIA 2005) 

• Wood 5,000 Btu/pound (NCDPPEA) 

• Gas 21,000 – 24,000 Btu/pound (ASTM 2006) 

• Oil 17,000 – 19,000 Btu/pound (ASTM 2006) 

Exhibit 9 summarizes the metals content of tire-derived fuel and two fuels that it may 

displace: fuel oil and coal.

Exhibit 9: Metals Content of TDF, Fuel Oil, and Coal 

Metals Concentrations (Parts Per Million by Weight) 

TDF Fuel Oil Coal 

Barium Non-detect 0.3 200 

Cadmium 6 0.5 0.5 

Chromium 97 0.5 20 

Lead 65 - 40 

Manganese <100 - 70 

Mercury - <0.1 0.1 

Zinc 15,200 - 100 

Sources:

Fuel oil and coal estimates (excluding zinc) are from EPA 1998. 

TDF estimates and zinc estimate for coal are from Gray 2004. 

(2) Impact Information

• Cost Savings of Beneficial Use Applications: The net cost savings associated 

with the beneficial use of scrap tires (i.e., the cost savings realized less the costs 

associated with beneficial use) are a function of (1) avoided disposal costs, (2) 

fuel (or other input) savings associated with the beneficial use of this material, 

and (3) processing (e.g., shredding) and other costs associated with beneficial 
Scrap Tires 

12

use.6 Exhibit 10 summarizes readily available information on these variables. 

Based on this information, it is not possible to generate a single estimate of the net 

cost savings or benefits associated with the beneficial use of scrap tires. As 

suggested by the exhibit, avoided disposal costs depend on the location of 

disposal. In addition, cost savings can vary depending on the whether tires are 

shredded or whole. For example, a limited number of state programs pay cement 

kilns to receive whole tires at their facilities; one source estimates that kilns are 

paid between five and fifteen cents per tire (Blumenthal 2009), while another 

source estimates that kilns are paid up to twenty-five cents per tire (Gray 2009). 

However, some kilns take whole tires for free, and all kilns pay for shredded tires 

(Blumenthal 2009a). Information is not readily available on the costs of 

processing tires for beneficial use applications. 

Exhibit 10: Summary Economic Savings and Costs of Scrap Tire Beneficial Use 

Savings 

Avoided Disposal Costs 

Tip fees associated with landfill disposal vary by location and depend on the size of the tire. Example tip 

fees reported by local waste management authorities in California, Pennsylvania, and Virginia are as 

follows: 

California: $68 per ton (California Integrated Waste Management Board) 

Centre County, Pennsylvania: $66 per ton (Centre County Solid Waste Authority, 2003) 

Page County, Virginia: $155 per ton (Page County, 2008) 

Fuel or Material Cost Savings 

The fuel and material costs savings associated with beneficial use depend on the value of the fuel or input 

for which scrap tires serve as a substitute. The average cost of various fuels for which scrap tires are a 

substitute are as follows (2007 prices unless otherwise noted):1

• Natural Gas (Industrial): $7.35 / MMBtu (EIA 2008a, Table 20) 

• No. 2 Distillate (Industrial): $16.80 / MMBtu (EIA 2008b, Table 36) 

• Residual Fuel Oil Average: $9.19 / MMBtu (EIA 2008b, Table 38) 

• Coal – Average Delivered Price in 2006: $2.23 / MMBtu (EIA 2007, Table ES1) 

Costs 

Processing and Other Costs of Beneficial Use

Information on the costs of scrap tire beneficial use applications is not readily available. 

Notes:

1. To express these values as dollars per MMBtu, the following thermal conversion factors were used: 

1,031 Btu per cubic foot of natural gas, 138,690 Btu per gallon of Number 2 distillate, 149,690 Btu 

per gallon of residual fuel oil, and 22,473,000 Btu per short ton of coal (EIA 2005, Tables A1, A4, 

and A5). 

 6 With respect to the costs associated with beneficial use, cement kiln operators are generally required to 

enact performance testing and air permit modifications prior to using scrap tires and other alternative fuels. In 

addition, kilns may be required to install continuous emissions monitoring systems if they chose to burn scrap tires 

(EPA 2008a).
Scrap Tires 

13

 

• End-users running different combustion units will be willing to pay different 

prices based on the kind of fuel that is being replaced by TDF. For example, 

cement kilns often substitute TDF for low-grade coals, which are a relatively lowcost fuel. This translates into a lower willingness to pay. End-users substituting 

TDF for high-grade coal, oil or natural gas are more likely to pay higher prices for 

TDF. However, the relationship between metal content, operational efficiency, 

and willingness to pay of an end-user also depends on the specific combustion 

unit and cannot be generalized across an industry (Sorcher 2009). 

• Greenhouse Gas Emissions: Data compiled by the Greenhouse Gas Protocol, 

suggests that the greenhouse gas emissions rate associated with the combustion of 

scrap tires is approximately 0.081 metric tons of carbon dioxide equivalents 

(MTCO2E) per million Btu (MMBtu) of scrap tires combusted (GHG Protocol, 

2005). By comparison, based on emissions and energy data compiled by EPA, 

the GHG emissions rates for coal, natural gas, distillate oil, and residual oil are 

approximately 0.094 MTCO2E per MMBtu, 0.053 MTCO2E per MMBtu, 0.073 

MTCO2E per MMBtu, and 0.079, MTCO2E per MMBtu, respectively (EPA 

2008b). These estimates do not include upstream emissions impacts (e.g., from 

the extraction and transport of virgin materials), which are presented below in 

Exhibit 12. 

• Criteria Pollutants and Hazardous Air Pollutants: Although numerous studies 

have been conducted on the criteria pollutant and hazardous air pollutant (HAP) 

emissions associated with tire-derived fuel, most of these studies examine fuels 

that are a combination of scrap tires and conventional fuels. Therefore, these 

studies do not isolate the criteria pollutant or HAP emissions associated with 

scrap tires alone. 

Although existing studies do not include sufficient data to isolate the emissions 

associated with scrap tires alone, it is possible to reach a few general conclusions 

based on the results of these studies. For example, emissions test data compiled 

by EPA in 1997 suggest that substituting scrap tires for coal in electric utility 

boilers may lead to reductions in NOx and particulate matter emissions but show 

no clear pattern for SOx emissions (EPA 1997). The same study also examined 

the emissions impacts associated with tire combustion at several other types of 

facilities (e.g., pulp and paper mills, cement kilns, and industrial boilers) that use 

a variety of different fuels. In addition, a 2004 paper by Gray includes 

information on the emissions impact of TDF at six sample facilities. Based on 

this paper and the 1997 EPA study, Exhibit 11 indicates whether the use of tires 

as a fuel at each facility type may lead to a reduction or an increase in emissions. 

The available studies on emissions related to tires as fuel examine only a limited 

number of emissions sources, and it is unclear whether these sources are 

representative of the combustion units that may use tires. Note that at wellcontrolled facilities, emissions will not change significantly when tires are used.7

 

7

 EPA notes that its 1997 study was a laboratory test program (not full-scale) that assessed controlled 

burning of TDF in a Rotary Kiln Incinerator Simulator (RKIS). While the study concluded that, with the exception 
Scrap Tires 

14

We further note that variation in emissions could be attributable to factors other 

than the use of tires itself (such as variations in air pollution control device 

efficiency). 

Exhibit 11: Emissions Impact of Using Tires as a Substitute for Conventional Fuels, by 

Pollutant and Combustor Type 

NOx PM SO2 Zinc 

Utility boilers Reduction Reduction Data inconclusive Data inconclusive 

Industrial boilers Reduction Reduction Data inconclusive Increase 

Pulp & paper mills Reduction or similar Increase Increase Increase 

Cement kilns Data inconclusive Reduction Reduction Data inconclusive 

Sources: 

The information presented in this exhibit is based on emissions data in EPA 1997 and Gray 2004. 

Notes: 

1. “Reduction” indicates that emissions test data suggest that the use of TDF as a fuel will reduce 

emissions. “Increase” indicates that emissions may increase, and “similar” indicates that emissions 

are unlikely to change. “Data inconclusive” indicates that the available emissions data show no clear 

pattern with respect to the emission impact of using TDF as a substitute for conventional fuel. 

• Upstream Emissions Impacts: Use of tires as a replacement for fossil fuels may 

eliminate the environmental impacts associated with extraction and processing of 

the traditional fuels. Exhibit 12 lists the quantities of cradle-to-gate emissions for 

these fuels based on typical processes in the United States in the late 1990s. The 

generation of scrap tires generally creates minimal emissions. Of course, there 

are impacts associated with the shredding of scrap tires into TDF, and these are 

not accounted for in Exhibit 12. 

• Other Impacts: In addition to the impacts outlined above, the beneficial use of 

scrap tires limits, and in some cases prevents, the growth of scrap tire stockpiles. 

This could result in improvements to human health and the environment because 

such stockpiles provide habitat for disease vectors (such as mosquitoes and 

rodents), and because they can catch fire, creating large amounts of toxic smoke 

and hazardous liquids that can contaminate air, water and soils.

 

of zinc emissions, potential emissions from TDF are not expected to be very much different than from other 

conventional fossil fuels, it noted “as long as combustion occurs in a well-designed, well-operated, and wellmaintained combustion device." The study also clarified “Very little data exist for devices that are not welldesigned and use scrap tires for fuel. These sources include fireplaces, wood stoves, small kilns, small incinerators, 

or any device with poor combustion characteristics. Air emissions from these types of devices are likely between 

that of open burning and a combustor. There is serious concern that emissions would be more like those of an open 

tire fire than a well-designed combustor; however, emissions testing would have to be conducted to confirm this.” 
Scrap Tires 

15

Exhibit 12: Emissions from Extraction and Processing of Traditional Fuels 

Coal 

Distillate 

Fuel Oil 

Residual 

Fuel Oil Wood 

Natural 

Pollutant Gas 

---------------------------- Lb./MMBtu ----------------------

Criteria Pollutants 

PM2.5 - - - - -

PM10 - - - - -

PM, unspecified 0.246 0.012 0.012 6.67x10-4 0.004

NOx 0.022 0.061 0.062 0.08 0.117

VOCs 0.008 0.361 0.365 - 0.515

SOx 0.022 0.186 0.187 0.003 1.913

CO 0.017 0.046 0.046 0.022 0.223

Pb 2.60x10-7 1.01x10-6 1.00x10-6 - 2.72x10-7

Hg 8.17x10-8 1.87x10-7 1.87x10-7 - 7.18x10-8

Greenhouse Gases 

CO2 3.9 19 19.1 - 15.3

CH4 0.451 0.029 0.029 - 0.369

N2O 1.63x10-5 2.01x10-5 2.07x10-5 - 1.17x10-5

MTCO2E/MMBtu 0.006 0.009 0.009 - 0.01

Source:

Franklin Associates 1998. 

Note:

“-” signifies data not available; may equal zero. 

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 resource inputs, energy 

requirements, and releases to the air, water, and land for each step in the manufacture of a product 

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 consistent 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. 
Scrap Tires 

16

References 

ASTM International. 2006, “Standard Practice for Use of Scrap Tire-Derived Fuel”. 

Blumenthal, Michael. 2009a, Personal Communication with Lyn Luben, U.S. EPA, July 9, 2009. 

Blumenthal, Michael. 2009b, Personal Communication with Jason Price, Industrial Economics, July 21, 2009. 

Association of State and Territorial Solid Waste Management Officials (ASTSWMO), 2006 Beneficial Use Study 

Report, November 2007. 

California Integrated Waste Management Board, “Solid Waste Facility Tipping Fees: 1998 to 2000 Summaries of 

Special Waste Tipping Fee Surveys”, accessed August 28, 2008 at: 

http://www.ciwmb.ca.gov/landfills/TipFees/SumSW.htm

California Integrated Waste Management Board, “Tires as a Fuel Supplement: Feasibility Study”, January 1992, 

accessed June 18, 2009 at: http://www.ciwmb.ca.gov/Publications/default.asp?pubid=90

Centre County Solid Waste Authority. 2003, “Tipping Fees”, accessed August 27, 2008 at: 

http://www.centrecountyrecycles.com/Recycle/RefuseTippingFees/RefuseTippingFees.html. 

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

Frye, Neal. 2009, Entech, Incorporated. Personal Communication. July 3, 2009. 

GHG Protocol (the Greenhouse Gas Protocol Initiative). 2005, “CO2 Emissions from the Production of Cement 

(CSI)”, accessed on August 21, 2008 at: http://www.ghgprotocol.org/calculation-tools/cement-sector. 

Gray, Terry. 2004, “Tired Derived Fuel: Environmental Characteristics and Performance”. 

Gray, Terry. 2009, TAG Resource Recovery. Personal Communication. August 24, 2009. 

Grantham, Dewey. 2009, Liberty Tire Recycling, Inc. Personal Communication. May 26, 2009. 

North Carolina Division of Pollution Prevention and Environmental Assistance, “Tire Derived Fuel”, accessed 

August 20, 2008 at: http://www.p2pays.org/ref/11/10504/html/usa/tdf.htm. 

Page County, “Landfill, Compactor, & Recycling Sites”, accessed August 27, 2008 at 

http://pagecounty.virginia.gov/index.php?option=content&task=view&id=163. 

Rubber Manufacturers Association, “Scrap Tire Characteristics”, accessed August 21, 2008 at: 

http://www.rma.org/scrap_tires/scrap_tire_markets/scrap_tire_characteristics/ 

Rubber Manufacturers Association. 2006, “Scrap Tire Markets in the United States”. 2005 Edition. 

Rubber Manufacturers Association. 2009, “Scrap Tire Markets in the United States”. 9th Biennial Report. 

Sorcher, Michael. 2009, M.A. Associates, Inc. Personal Communication. May 27, 2009. 

Texas Commission on Environmental Quality. 2008, “Scrap Tires”, accessed August 21, 2008 at: 

http://www.tceq.state.tx.us/compliance/tires/index.html#gen. 

United States Census Bureau, “2007 NAICS Codes and Titles”, accessed August 21, 2008 at: 

http://www.census.gov/naics/2007/NAICOD07.HTM U.S. 
Scrap Tires 

17

United States Energy Information Administration (EIA). 2007, Annual Coal Report 2006. 

United States Energy Information Administration (EIA). 2005, Annual Energy Review 2004.

United States Energy Information Administration (EIA). July 2008a, “Natural Gas Monthly”. 

United States Energy Information Administration (EIA). June 2008b, Preliminary Petroleum Marketing Annual 

2007. 

United States Environmental Protection Agency (EPA). 1997, “Air Emissions from Scrap Tire Combustion”. 

United States Environmental Protection Agency (EPA). 1998, “Development of Comparable Fuels Specifications”. 

United States Environmental Protection Agency (EPA). 2007, “Basic Information”, accessed August 20, 2008 at: 

http://www.epa.gov/epaoswer/non-hw/muncpl/tires/basic.htm. 

United States Environmental Protection Agency (EPA). 2008a, Cement Sector Trends in Beneficial Use of 

Alternative Fuels and Raw Materials, October 2008. 

United States Environmental Protection Agency (EPA). 2008b, Inventory of U.S. Greenhouse Gas Emissions and 

Sinks: 1990-2006: Annex 2 Methodology and Data for Estimating CO2 Emissions from Fossil Fuel 

Combustion. 

United States Environmental Protection Agency (EPA). 2008c, “Tire Derived Fuel”, accessed August 20, 2008 at: 

http://www.epa.gov/epaoswer/non-hw/muncpl/tires/tdf.htm. 

United States Environmental Protection Agency (EPA). 2008d, “Updated 2006 Kiln List_Received 8_25_2008”, 

internal EPA document provided by EPA on August 25, 2008. 

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. 

Virginia Department of Environmental Quality. 2008, “Regional Collection and Processing Projects”, accessed 

August 21, 2008 at: http://www.deq.virginia.gov/wastetires/progsummary2.html. 
Scrap Tires 

18

Appendix 1: Summary of Facilities Using Tires as Fuel

State Location Company Type of Facility 

Alabama Calera Lafarge North America Cement kiln 

Alabama Courtland International Paper Corp. Pulp & paper mill 

Alabama Theodore Holcim Inc. Cement kiln 

Alabama Leeds Lehigh Cement Company Cement Kiln 

Alabama Ragland National Cement Cement kiln 

Alabama Stevenson Smurfit-Stone Pulp & paper mill 

Alabama Demopolis CEMEX Cement kiln 

Arkansas Foreman Ash Grove Cement Company Cement kiln 

Arkansas Crossett Georgia Pacific Pulp & paper mill 

Arkansas Ashdown Domtar, Inc. Pulp & paper mill 

Arkansas Pine Bluff International Paper Pulp & paper mill 

California Colton California Portland Cement Cement kiln 

California Victorville CEMEX Cement kiln 

California Redding Lehigh Southwest Cement kiln 

California Stockton Stockton Co-generation Industrial boiler 

California Lucerne Valley Mitsubishi Cement Cement kiln 

California Lebec National Cement Co. of CA Cement kiln 

California Kern County Mt. Posco Cogeneration Industrial boiler 

Colorado Florence Holcim, Inc. Cement kiln 

Connecticut Sterling Exeter Energy Dedicated tire-to-energy 

Florida Auburndale Wheelabrator Ridge Generating Station Utility boiler 

Florida Brooksville CEMEX Cement kiln 

Florida Brooksville Rinker Materials Cement kiln 

Florida Gainesville Florida Rock Cement kiln 

Florida Across the state Names not supplied Waste-to-energy (8) 

Florida Confidential Pulp & paper mill 

Georgia Clinchfield CEMEX Cement kiln 

Georgia Brunswick Georgia Pacific Pulp & paper mill 

Georgia Rome Temple Inland-Rome Pulp & paper mill 

Georgia Riceborough Interstate Paper Pulp & paper mill 

Georgia Dublin SP Newsprint Pulp & paper mill 

Georgia Cedar Springs Georgia Pacific Pulp & paper mill 

Hawaii Oahu AES Hawaii, Inc. Industrial boiler 

Idaho Inkom Ash Grove Cement Company Cement kiln 

Idaho Boise Boise P&N LLC (Boise Cascade) Pulp & paper mill 

Illinois Decatur Archer Daniels Midland (ADM) Industrial boiler 

Illinois Oglesby Buzzi Unichem USA Cement kiln 

Illinois Grand 

Chain/Joppa 

Lafarge North America Cement kiln 

Kansas Humboldt Monarch Cement Cement kiln 

Kansas Chanute Ash Grove Cement Company Cement kiln 

Kentucky Owensboro Owensboro Municipal Utilities Utility boiler 

Kentucky Wickliffe NewPage Corporation Pulp & paper mill 
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19

State Location Company Type of Facility 

Louisiana Mansfield International Paper Pulp & paper mill 

Louisiana Bastrop International Paper Pulp & paper mill 

Louisiana Monroe International Paper Pulp & paper mill 

Louisiana Deridder Boise Pulp & paper mill 

Maryland Fredrick Fort Detrick Industrial boiler 

Maryland Baltimore Wheelabrator Baltimore LP Utility boiler 

Maryland Joppa Harford Waste-to-Energy Utility boiler 

Maine Rumford NewPage Corporation Pulp & paper mill 

Maine Bucksport International Paper Pulp & paper mill 

Maine Skowhegan SD Warren Pulp & paper mill 

Michigan Hillman Hillman Power Utility boiler 

Michigan McBain Viking Energy Utility boiler 

Michigan Lincoln Viking Energy Utility boiler 

Michigan Dundee Holcim, Inc. Cement kiln 

Michigan Wyandotte Wyandotte Power Utility boiler 

Michigan Filer City Tondu Energy Utility boiler 

Michigan Grayling Grayling Generating Station Industrial boiler 

Michigan Escanaba New Page Pulp & paper mill 

Michigan Quinasec Mananany Paper Pulp & paper mill 

Minnesota Satell Versa Paper Pulp & paper mill 

Mississippi Montecello Georgia Pacific Pulp & paper mill 

Mississippi Jackson Nucor Steel Electric arc furnace 

Mississippi Vicksburg (International Paper) Pulp & paper mill 

Missouri Columbia University of Missouri-Columbia Industrial boiler 

Missouri Kansas City Aquila/ Sibley Generating Station Utility boiler 

Missouri Cape Girardeau Buzzi Unichem USA Cement kiln 

Missouri Joplin Empire District Electric Co. Asbury 

Power Plant 

Utility boiler 

Missouri St. Joseph Aquila, Inc. - Utility boiler 

Nebraska Lincoln Ashgrove Cement kiln 

New York Auburn Nucor Steel Auburn Electric arc furnace 

New York Fort Drum Black River Electric Utility boiler 

New York Niagara Falls Niagara Generation Industrial boiler 

North 

Carolina 

Roxboro Primary Energy Industrial boiler 

North 

Carolina 

Southport Primary Energy Industrial boiler 

North 

Carolina 

Lumberton Cogentrix Industrial boiler 

North Dakota Mandan MDU Heskett Station Utility boiler 

Ohio Akron Akron Thermal, LLP Utility boiler 

Ohio Chillicothe PH Glatfelter Pulp & paper mill 

Oklahoma Ada Holcim, Inc. Cement kiln 

Oklahoma Tulsa Lafarge North America Cement kiln 

Oklahoma Pryor Lone Star Industries Inc. dba Buzzi 

Unicem 

Cement kiln 
Scrap Tires 

20

State Location Company Type of Facility 

Oregon Durkee Ash Grove Cement Company Cement kiln 

Pennsylvania Wampum Cemex Cement kiln 

Pennsylvania Whitehall Lafarge North America Cement kiln 

Pennsylvania Allentown Lehigh Cement Cement kiln 

Pennsylvania Meadville ESSROC Materials Cement kiln 

Pennsylvania Northampton Northampton Generation (2008 start up) Industrial boiler 

South 

Carolina 

Hodges Trigen Biopower Industrial boiler 

South 

Carolina 

Harleyville Lafarge North America Cement kiln 

South 

Carolina 

Catawba Bowater Pulp & paper mill 

South 

Carolina 

Hartsville Sonoco Products Company Pulp & paper mill 

South 

Carolina 

Eastover International Paper Pulp & paper mill 

South 

Carolina 

Georgetown International Paper Pulp & paper mill 

South Dakota Ottertail Power Company Utility Boiler 

Tennessee Calhoun Bowater Incorporated Pulp & paper mill 

Tennessee Memphis TVA Allen Steam Plant Utility boiler 

Tennessee Knoxville CEMEX Cement Kiln 

Tennessee Jackson Gerdau Ameristeel Electric arc furnace 

Texas Midlothian Ash Grove Cement, Texas L.P. (f/k/a 

North Texas Cement) 

Cement kiln 

Texas New Braunfels Cemex of Texas, L.P. Cement kiln 

Texas Midlothian Holcim Texas L.P. Cement kiln 

Texas Mary Neal Lone Star Cement Cement kiln 

Texas Hunter Texas Industries Cement kiln 

Texas Midlothian Texas Industries Cement Cement kiln 

Utah Leamington Ashgrove Cement kiln 

Utah Morgan Holcim Inc. Cement kiln 

Utah Grantsville Chemical Lime Company Lime kiln 

Virginia Richmond Cogentrix Industrial boiler 

Virginia Portsmouth Southeastern Public Service Authority Industrial boiler 

Virginia Martinsville Tire Energy Corp (TEC) Industrial boiler 

Washington Seattle Ashgrove Cement Cement kiln 

West Virginia Parkersburg Allegeny Power Utility boiler 

Wisconsin Cassville Alliant Energy Utility boiler 

Wisconsin Sheboygan Alliant Energy Edgewater Generating 

Station 

Utility boiler 

Wisconsin Ashland Xcel Energy Bayfront Plant Utility boiler 

Wisconsin Madison University of Wisconsin Charter Street 

Plant 

Industrial boiler 

Wisconsin Kaukauna Thilmany Paper Pulp & paper mill 

Source: RMA 2009