Materials Characterization Paper In Support of the Final Rulemaking:

Identification of Nonhazardous Seco ndary Materials That Are Solid Waste Secondary Glass Material (used as ingredient in glass manufacture)

February 3, 2011

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1. Definition of Secondary Glass Material

Secondary glass material consists of both post-c onsumer glass (glass in municipal solid waste [MSW]) as well as post-industrial glass (i.e., glass scrap generated in the process of glass material manufacture). Glass in the MSW stream in cludes glass containers and packaging as well as glass used in durable goods, such as furnitu re, appliances, and consumer electronics. Postindustrial glass includes fiber scrap from fiber glass and fiberoptics ma nufacturing processes as well as internal container glass scrap.

2. Annual Quantities Generated and Used

(1) Sectors that generate secondary glass material:

• Secondary glass material is generated by NAICS sector 3272, Glass and Glass Product Manufacturing. Secondary glass materi al can also be collected as part of MSW, but the focus on this paper is on the industrial product.

(2) Quantities and prices of seco ndary glass material generated:

• EPA estimates that 13.6 million tons of glass packaging and other glass scrap material was generated in 2007 (EPA 2007).

• In addition, one report addr essing the glass industry es timates that more than 60,000 tons of “glass-manufacturing scra p” are generated annually (Argonne National Laboratory). It is unclear if ot her process steps in glass manufacturing generated additional quantities of scrap, and it is also unclear whether this scrap includes or excludes scrap th at is internally reused in manufacturing. This estimate does, however, exclude scrap fr om fiberglass manufacturing, and appears to exclude secondary glass from post-consumer sources.

• The report further estimates that an addi tional 200,000 tons of fi berglass scrap is annually generated during the manufactur ing of fiberglass products (Argonne National Laboratory).

• Glass pricing information is available in some cases for post-consumer MSW glass, but is not available specifically for industrial scra p. It is possible that industrial glass scrap has a different pric ing structure, due to differences in composition, quality, product consistency, and contamination.Secondary Glass Material

2 (3) Trends in generation of secondary glass material:

• Differences in trends between different t ypes of glass could not be identified at

this time.

3. Uses of Material/Commodity

(1) Ingredient uses of secondary glass material in combustion processes:

• Glass-to-glass processing is generally the most environmentally beneficial recycling option, other things being equal. Ninety per cent of recycled MSW glass is used to make new glass containers. Today, most glass manufacturers rely on a steady supply of recycled crushed gla ss, known as "cullet," to supplement raw materials. To make glass, manufact urers mix sand, soda ash, limestone, and cullet; heat the mixture to a temperature of 2,600 to 2,800 degrees F; and mold it into the desired shape. Sand is the only material used in greater volumes than cullet to manufacture glass.

• Attempts by the glass manufacturing indus try to recycle secondary glass fiber material back into fiber glass and fibe roptics production processes have failed in the past because they have resulted in an unacceptably high rate of filament breakage in the subsequent glass-manufactur ing processes. This breakage rate is due to the presence of impurities in the sec ondary glass fiber material. It is not clear, however, whether these problems prevent the use of this material in other types of products

(2) Other uses of secondary glass material:

• Other uses of high-quality cullet include use as abrasives, aggregate substitute, bead manufacturing, kitchen tiles, count er tops, wall insulation, frictionators (match tips), fluxes in metal foundr y work, and roadbed aggregate.

(3) Quantities of secondary glass material landfilled:

• The recycling rate of gla ss in the MSW stream in 2007 was 23.7 percent. Of the 13.6 million tons of MSW glass and p ackaging generated in 2007, 10.36 million

tons were landfilled and 3.22 million tons were recycled (EPA 2007).

• At this time, we have not determined landfill quantities of other glass types, such as fiberoptic material and glass manufact uring scrap that never enters the MSW stream. At most, according to the re port by Argonne National Laboratory, these quantities would be r oughly 260,000 tons for fiberglass and other glass manufacturing scrap.

(4) Quantities of secondary gla ss material stockpiled/stored:

• Estimates of the quantity of secondary gl ass material being stockpiled could not be identified at this time, but because disposal of these products is not restricted and the market for secondary materials ha s generally been strong, little incentive exists to create stockpiles.Secondary Glass Material

3 Exhibit 1: Overview of Generation and Use of Secondary Glass Material

Commodity Annual Quantity

Generated Annual Quantity Used as Ingredient Annual Quantity

Landfilled Annual Quantity in

Other Uses Total Quantity Stockpiled Glass

Furnaces Other
-------------------------------------- Short Tons per Year --------------------------------

MSW Glass 13.6 million 2.90 million* Undetermined 10.36 million 0.32 million Undetermined

Glass manufacturing

scrap 60,000 Undetermined Undetermined Unde termined Undetermined Undetermined Fiberglass manufacturing

scrap 200,000 Undetermined Undetermined Unde termined Undetermin ed Undetermined

* Calculated using EPA data (EPA, 2007) and the EPA estimate that 90% of MSW glass is used to make new glass containers (EPA, 2008). All other ingredient us es are included in the “Other Uses” category.

Sources : EPA 2007, 2008 Argonne National Laboratory

4. Management and Combustion processes

(1) Types of units using secondary glass material:

• Secondary glass material can be used in glass furnaces in place of virgin raw materials in glass manufacturing, though pa rticular types of scrap (e.g., from fiberglass) appear to be difficult to use in certain applications.

(2) Sourcing of secondary glass material:

• In terms of industrial glass production, typically the same glass manufacturing facility that produces secondary gla ss material reuses it in their glass manufacturing processes; it is not clear to what extent this feedstock is considered scrap. Glass manufacturers can also buy recovered glass (cullet) on the commodity market; much of this glass is recovered from MSW streams and traded by municipal recycling facilities or by brokers.

(3) Processing of secondary glass material:

• Although all glass is made of silica and soda , the type and quantity vary slightly with different types of glass. These di fferences frequently cause manufacturing problems due to different melting points and chemical incompatibility. In addition, since neither brown nor amber gla ss is used to manufacture clear glass, it is important to sort gla ss by color. After color sorti ng, glass is typically crushed and travels by conveyor belt through a seri es of refinements. Magnets pull out metal, and air currents remove lightwei ght material such as paper (EPA 2008).

• Some cullet suppliers use sophi sticated equipment such as lasers to sort colors of crushed glass and further remove small contaminants. Scientists continue to develop mechanisms to improve materials sorting, and, therefore, the quality of the cullet (EPA 2008).Secondary Glass Material

4 • Argonne National Laboratory is developing a technology that will enable the glass fiber industry to recycle its glass-fiber-forming and fiberglassmanufacturing scrap into new glass products without either adversely impacting its operations, or the qualit y of its products due to th e increasing glass-filament breakage rate (Argonne National Laboratory).

(4) State status of secondary glass material use as ingredient:

• At this stage we have not identified any states that have approved use of secondary glass material in glass manufact uring, but we have not performed an exhaustive investigation of state activities and regulations. The practice of glassto-glass recycling is commonplace, alt hough manufacturers of cathode ray tube (CRT) glass are now generally located outsi de of the United States. Under federal regulations, processed CRT glass sent to a glass manufacturer is not a solid waste, and it is unlikely states c onsider this a process that fa lls within their solid waste jurisdiction.

5. Commodity Composition and Impacts

(1) Composition of secondary glass material:

• More than 95 percent of all manufactur ed glass is made from sodium oxide, calcium oxide, and silicon dioxide, comm only referred to as a soda-lime-silica composition (Clean Washington Center 1996 a). Common glass c ontains about 70 percent silicon dioxide. In addition, othe r compounds used in glass manufacturing are present in the final glass product. Soda ash (anhydrous sodium carbonate) acts as a fluxing agent in the melt. It lowers the melting point and the viscosity of the formed glass, releases carbon dioxide, and helps stir the melt. Either limestone or

dolomite are sometimes used in lieu of s oda ash. Alumina, lead, and cadmium are used to increase the strength of the gl ass and increase resistance to chemical attack. Various iron compounds, chromi um compounds, carbon, and sulfur are used as coloring agents (Turner Fa irbank Highway Research Center).

• Most glass bottle and window glass is made from soda-lime glass, which accounts for approximately 90 percent of the glass produced in the United States. Leadalkali-silicate glasses are used in the ma nufacture of light bulbs, neon signs, and crystal and optical glassware. Borosili cate glasses, which have extraordinary chemical resistance and high-temperatur e softening points, are used in the manufacture of cooking a nd laboratory ware. Exhibi t 2 presents the typical chemical composition of these glasses.

• The principle element of c ontainer glass, silica (SiO 2 ), is a naturally occurring mineral. The majority of silica occurs as quartz, a crystalline form of SiO 2

. Exhibit 2 presents the typical chemical composition of container glass (Clean Washington Center , 1996a, 1996b).

• The major contaminants present in glass-manufacturing material from the fiberoptics industry include: carbonaceous materi al, tiny noble metal particles, as well as trace amounts of Zr, Sr, Cr, Cu, Mg, Zn, Fe, Ba, V, and Mn (Argonne National Laboratory).Secondary Glass Material

5 • According to an industry source, contaminan t levels in glass produced with cullet are equal to or lower than in glass made without cullet (Glass Packaging Institute 2010).

Exhibit 2. Chemical Compositio n of Different Types of Glass

Constituent Soda-Lime

Glass 1 Lead-AlkaliSilicate Glass 1 Borosilicate

Glasses 1 Container Glass (Grade C&D Recycled Glass) 2

Silicon Dioxide (SiO 2 ) 70-73 60-70 60-80 66-88

Aluminum Oxide (Al 2 O 3 ) 1.7-2.0 a 1.0-4.0 a 0-7

Iron Oxide (Fe 2 O 3 ) 0.06-0.24 <0.5

Chromium Oxide (Cr 2 O 3 ) 0.1 b <0.1
Calcium Oxide (CaO) 9.1-9.8 1 0-15
Magnesium Oxide (MgO) 1.1-1.7 0-5
Barium Oxide (BaO) 0.14-0.18

Sodium Oxide (Na 2 O) 13.8-14.4 7.0-10.0 45 8.0-18

Potassium Oxide (K 2 O) 0.55-0.68 7 0-4
Lead Oxide (PbO) 15-25 8.0-25

Boron Oxide (B 2 O 3 )

Sulfur Trioxide (SO 3 ) <0.2

All Other Oxides <0.1
Carbon (C) <0.1

Notes: Blank cells indicate no data available a Higher levels for amber-colored glass b Only present in green glass

Sources: 1 TFHRC (2010) 2 Clean Washington Center (1996a, 1996b)

(2) Impacts of secondary glass material use:

• Using cullet saves money and helps the environment. Cullet costs less than raw materials, prolongs furnace life since it me lts at a lower temperature than sand, and demands less energy. Avoided energy use results in reduced emissions of nitrogen oxide and carbon dioxide. Use of cullet also can reduce the unit consumption of virgin glass materials (primarily sand).

• The specific lifecycle impacts of culle t use as a raw material in glass manufacturing are not evaluated here b ecause of uncertainties in lifecycle scenario development. For example, it is difficult to determine the replacement

ratio between cullet and ot her raw materials in glass production. Thus, the correct quantity of material to be modeled is unclear.

• The ability to use recycled glass fibers in fiber optic applica tions lowers energy costs by an average of $3-$8 per ton of glass fibers, when compared to using virgin raw materials. If these glass ma terial streams are recycled, the glassSecondary Glass Material

6 industry will annually save over $2 million in energy costs and over $5 million in disposal costs. Associated with th e energy savings is also a 70,000 ton/year

reduction in CO 2 emissions and a significant reduction in NO

x emissions (Argonne National Laboratory).Secondary Glass Material

7 References

Argonne National Laboratory, Energy Systems Division, Recovery and Recycling of Glass Manufacturing Waste and Fiberglass Scrap , accessed at: http://www.es.anl.gov/Energy_systems/Proce ss_Engineering/Technologies/Documents/8- Glass%20Recycling-2003.pdf

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Cattaneo, Joselph, public comment in response to EPA’s Proposed Rulemaking for Identification of Non-Hazardous Materials That Are Solid Waste, EPA docket/ document number EPA-HQ-RCRA-2008-0329-1606, submitted on behalf of the Glass Packaging Institute, August 3, 2010.

Clean Washington Center. Chemical Composition of Container Glass: Material: Recycled Glass. November 1996,

accessed at: http://www.cwc.org/gl_bp/gbp3-0101.htm (“1996a”)

Clean Washington Center. Methods for Sampling and Te sting Recycled Glass. December 1996, accessed at: http://www.cwc.org/glass/gl979rpt.pdf (“1996b”

Turner Fairbank Highway Research Center and the Federal Highway Administration, User Guidelines for Waste and Byproduct Materials in Pavement Construction , accessed at: http://www.tfhrc.gov/hnr20/recycle/waste/begin.htm

.

United States Environmental Protectio n Agency (EPA). 2008, “Municipal Solid Waste: Glass,” accessed at: http://www.epa.gov/osw/cons erve/materials/glass.htm

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United States Environmental Protection Agency (EPA). 2007, “Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2007.” Available at: http://www.epa.gov/epawaste/nonhaz/municipal/msw99.htm