# NAIMA

NORTH AMERICAN INSULATION MANUFACTURERS ASSOCIATION VIAE-MAIL AND OVERNIGHTMAIL January 28, 2013

Ms. Susan Fairchild SectorPolicies andPrograms Division Metals and Minerals Group (D243-02) Office ofAir QualityPlanning and Standards U.S. Environmental ProtectionAgency 4930 OldPage Road Durham, NC 27703 RE: Follow-Up To Manufacturing FacilityTours DearMs. Fairchild: INTRODUCTION The North American Insulation Manufacturers Association ("NAIMA") and its members appreciate the ongoing dialogue with the Environmental Protection Agency ("EPA") and the opportunity to provide EPA representatives with tours ofvarious manufacturing facilities. The meetings and facility tours helped explain the differences among the various types offurnaces used in the manufacture offiber glass insulation. These distinctions are particularly relevant because the different designs of those furnaces can directly impact the level of hex chrome emissions. As you know, hex chrome emissions are the primary reason NAIMA and its members have had an extended dialogue with EPA in recent months. In fact, EPA has acknowledged that, but for one particular outlier test result from the CertainTeed Kansas City facility, chromium emissions from the fiber glass industrywould notbe a concern for EPA. During the facility tours, EPA representatives were shown operating oxy fuel, air gas, cold top electric, and steel shell furnaces. NAIMA and its members also provided graphic presentations ofthese different furnace types andthe refractorybricks typically used in each. The presentation effectively demonstrated that refractories play a critical role in containing molten glass and protecting facilities and workers. Images of heavily scored and corroded refractory brick dramatically illustrated the necessity of high chrome content bricks. The presentation also demonstrated that chrome emissions do not correlate to the level of chrome content in the refractories. Those graphics are enclosedherewith.

44 CANAL CENTER PLAZA. SUITE 310 • ALEXANDRIA, VA 22314 • TEL 703/684-0084 • FAX 703/684-0427Ms. Susan Fairchild January 28, 2013 Page 2
DIFFERENCES AMONG FURNACE TYPES As the furnace graphics demonstrate, differences in furnace types and design attributes, far more significantly than simply the level ofchrome content in a furnace's refractories, impact chrome emissions. Many facilities' furnaces use high chrome refractories yet have low chromium emissions. Rather, the specific design attributes ofthe individual furnace the chrome content in the above-glass refractory, temperature, water vapor concentration, and other possible factors -arerelevantto the level ofhex chrome emissions. In all gas furnaces

- both oxyfuel and air gas the burners are located above the glass line. But even between oxy fuel and air gas furnaces, there is a significant difference in the peak flame temperatures, and thus the temperature in the furnace above the glass line. This temperature is significantlyhigher in an oxy fuel furnace than in an air gas furnace. Inoxy fuel furnaces, flame temperatures peak above 5,000 degrees Fahrenheit, whereas in air gas furnaces, flame temperatures peak at about 3,560 degrees Fahrenheit. The bulk wall temperature will be lower, drivenbythe heattransferwithinthe furnace. In further contrast, cold top electric melters have no heat source input (absolutely no combustion of natural gas) and virtually no chrome refractory above the glass line. Instead, the glass is heated by electrodes located below the glass line. The temperature above the glass line in these furnaces is driven only by the heat transfer from the molten glass through the batch cover which acts as an insulator, and thus is substantially lower than the above-glass temperature in either type ofgas furnace. Steel shell melters similarly have very low temperatures and no significant chrome refractories above the glass line. Theirheat input is belowthe glass line as well; therefore, heattransfer from the moltenglassthroughthe batchcover drives thetemperature abovethe glass line. The significantly higher temperatures exhibited in the oxy fuel furnaces, along with an oxidizing atmosphere from the use of pure oxygen for combustion, are conditions that increase the potential for chromium emissions from the refractory above the glass line, and, more importantly, to the conversion to hex chrome (Cr206). The higher temperature ofthe oxy fuel burners can volatizethe glass batchcomponents more readilythan inotherfurnaces. These glass volatiles that contain alkaline earth oxides reduce the temperatures that chrome can be vaporized to as lowas 1,832 degrees Fahrenheit. While the chrome must still reachtemperatures ofat least 2,700 degree Fahrenheit to oxidize the Cr203 to Cr206, the potentially increased volatiles can contribute to higher chrome emissions. The 40 percent higher peak flame temperature ofoxy fuel burners compared to air gas furnaces also raise the probability that available chrome will encounterthe conditions thatwill convertitto Cr206. These facts are further verified in the analysis provided by Dr. Denis Brosnan of Clemson University and attached to NAIMA's earlier comments. After thoroughly analyzing the role of temperature in the volatilization ofchromium from pure chromic oxide, Dr. Brosnan found that "[i]n mineral fiberglass furnaces, the local temperature at the surface of chrome alumina

### Ms. Susan Fairchild January 28, 2013 Page 3
refractories [above the glass line] is the single most influential variable influencing hexavalent chromium emissions."l The emissions data submitted to EPA by NAIMA and NAIMA companies corroborate the correlation between differences among furnace types and the respective furnaces' chrome emissions. Therefore, with respect to chrome emissions, oxy fuel furnaces are distinctively unique from other furnaces used in the manufacture of wool fiber glass. They have: 1) a higher flame temperature; 2) more chrome refractories above the glass line; 3) higher water vapor concentration due to the absence of diluting nitrogen; and 4) an oxidizing atmosphere with increased concentration ofoxides. These distinctive characteristics directly affect the amount of hex chrome emissions that can be emitted. Thus, NAIMA asks EPA to address the oxy fuel furnaces differently and separately from the other glass furnaces and to consider that oxy fuel furnaces may be the only furnace type that may need to be identified for potential regulation in developing an area source standard. Specifically, the other glass furnaces air gas, cold top electric, and steel shell

- should not be considered as appropriate candidates for an area source standard. Despite their potential for increased chrome emissions, oxy fuel furnaces will continue to be used for a number ofimportant reasons, including environmental benefits: 1) oxy fuel furnaces reduce NOx and CO emissions because they emit less ofthese pollutants than does combustion with air; 2) oxy fuel firing reduces NOx emissions because it does not introduce nitrogen from combustion air into the furnace; 3) oxy fuel furnaces use less energy than air gas furnaces by obviating the need to heat nitrogen contained in ambient air 

### and thus produce less greenhouse gas emissions; and 4) oxy fuel firing also produces a reduced volume offlue gases which lowers the gas velocity in the furnace combustion zone and lowers the potential to entrain particulate matter. Moreover, oxy and air gas furnaces produce less direct C02 per ton ofglass than the indirect C02 from an electric furnace; this is particularly true in the Midwest and Southeast regions ofthe United States. STARTUP AND SHUTDOWN PROVISIONS NAIMA would support EPA's proposed approachto startup and shutdown as described by Keith Barnett at the December 

## 6, 2012 meeting in Kansas City, Kansas, following the facility tours. This approach recognized that work practices, rather than emission standards, were appropriate during startup and shutdown periods. For gas furnaces, this would mean having the control devices in use while batch was being charged. The Rule would need to make an exception for cold top electric and steel shell furnaces, which need a batch cover established before the temperature is cool enough to allow safe operation ofthe control device. For those furnaces, NAIMA proposes that the Rule require the control device to be started expeditiously after a

I Denis A. Brosnan, Ph.D., PE, "Technology Review, ChromiumEmissions in Wool Fiberglass MeltingFurnaces," December 10,2011,p. 9.Ms. SusanFairchild January 28,2013 Page 4
batch cover is established sufficient to reduce the exhaust temperature to a safe level established bythe recommendations ofthe control device manufacturer. FLAME ATTENUATION EPA's original proposal merged heavy density and pipe produced on flame attenuation lines togetherinto one Standard. NAIMA urges EPAto take no further action on flame attenuation. RISKMODELING NAIMA's request that any area source standard be limited to the consideration ofonly oxy fuel furnaces is also supported bybothEPA and NAIMA companies' risk calculations. Based on EPA's Detailed Risk Modeling Results (Appendix 6), the following facilities are below a cumulative one-in-one-million excess cancerrisk: Knauf

- Lanett, Alabama Johns Manville

- Richmond, Indiana Guardian

- Kingman, Arizona Guardian

- Albion, Michigan Owens Coming

- Eloy, Arizona Johns Manville

- Berlin, NewJersey Johns Manville

- Willows, California Owens Coming

- Mount Vernon, Ohio Knauf

- ShastaLake, California Guardian

- Winnsboro, South Carolina Owens Corning

- Lakeland, Florida Owens Corning

- SaltLake City, Utah Knauf

- Shelbyville, Indiana Guardian

- Inwood, West Virginia Based on additional modeling conducted by Owens Corning and Guardian, pursuant to EPA's methods, the following facilities are below a one-in-one-million excess cancer risk for hex chrome: Guardian

- Mineral Wells, Mississippi Owens Corning

- Santa Clara, California Owens Corning

- Kansas City, Kansas Owens Coming

- Fairburn, Georgia These company-specific modeling results have been or will be provided to EPA. Ifadditional companies conducted individual facility modeling, it would likely show results similar to those from Owens Coming and Guardian given the commonalities of the furnace design characteristics, the manufacturing processes, and the use ofraw materials. The fact that many other facilities were very close to a cumulative one-in-one-million excess cancer risk in EPA's Detailed Risk Modeling Results, they quite likely would be below a one-in-one-million excess cancerrisk for hex chrome.Ms. SusanFairchild January28,2013 Page 5
CONSIDERATION FORANAREA SOURCE STANDARD Based on EPA and company modeling results and different furnace type characteristics that affect each fumace's potential to create hex chrome emissions, NAIMA asks that EPA consider the following for any area source standard EPA determines is needed for the Wool Fiberglass industry. 1. Applicability ofthe Wool Fiberglass AreaSource Standard
• The Area Source Standardapplies onlyto eachoxyfuel furnace that:

- Melts a mixture ofraw materials to produce molten glass that is used to produce wool fiberglass buildinginsulation, and

- Is located at an area source ofhazardous airpollutant ("HAP") emissions, and

- Has a potential to emit hexchrome at a rate equal to orgreaterthan 25 lbs. ofhex chrome peryear. 2. Furnaces ThatAre ExemptFromthe Rule
• Furnaces that are located at an area source that has a cancer maximum risk less than one-in-onemillionbasedonthe geographic centroids ofany censusblock, or • Furnaces thatemithex chrome ata rate less than 25 lbs. ofhexchrome per year. 3. Covered HAPs
• TheArea Source Rule will applyonlyto hex chromeemissions. 4. AreaSource Requirements
• Emissionlimitfor hexchrome: 4.6 x 10-4 lbs/ton 5. Compliance Date
• Existing sourcesmustcomplywithapplicable emissionlimits within a specifiedperiod of time (no less than three years from the effective date of the applicable rule) that recognizes the time needed for manufacturers to implement necessary controls and/or other changes to a glass furnace to avoid applicability ofthe Ru1e or specific language in the Rule that recognizes that ifchanges are made after the effective date ofthe Rule but before the first substantive compliance date that a furnace wou1d be excluded from coverageunder theRu1e; the conceptofonceinalways inwould notapply. Anextension may be requested allowing up to one additional yearto comply with applicable emission limits. • New sources must complywith emissionlimits uponinitial startup ofthe source.Ms. SusanFairchild January 28, 2013 Page 6

• Define affected source to embody the concept that modification to the furnace!source could facilitate non-applicability to the Rule (e.g., change an oxy fuel furnace to a cold top electric). 6. Performance Tests
• Onlyonetestis required for identical furnaces. • EPA andNAIMA would worktogetherto define whatconstitutes identical furnaces. • Emission testing conducted as part ofthe National Emissions Standards For Hazardous Air Pollutants: Wool Fiberglass Manufacturing (Docket: EPA-HQ-OAR-2010-1042) will be allowedto shownon-applicability ofthe Area Source Standard. 7. Testing Method
• Sources should selectthe preferred testingmethod. • The testmethods used for major sources wouldbe appropriate. • The test method used for the NESHAP: Wool Fiberglass Manufacturing (Docket: EPAHQ-OAR-201O-1042) testing is anacceptable testmethod. 8. ComplianceRequirements
• The Area Source Standard should recognize as acceptable any control devices! mechanisms that have been accepted by MACT or Residual Risk Rule as valid control devices for the Area Source Standard. 9. Monitoring and Recordkeeping Requirements
• There should be no additional monitoring requirements above or beyond the MACT Standard. • The area source monitoring, recordkeeping, and reporting requirements should not be as onerous as the MACT Standardrequirements. • Area sources should conduct only stack testing, with no interim monitoring, once every five years or onetime every campaign. Sincerely,

# ~~<&. Angus E. Crane ExecutiveVice President, General Counsel EnclosureMs. SusanFairchild January28,2013 Page7

cc: (WithEnclosure) Mr. Keith W. Barnett Group Leader, Office ofAir Quality andPlanning Standards SectorPolicies andPrograms Division, Mineral andManufacturing Group U.S. EnvironmentalProtectionAgency 4930 OldPageRoad Durham,NC 27703
Mr. Dave Reeves RTIInternational P.O. Box 12194 3040EastCornwallis Road ResearchTriangle Park, NC 27709-2194Air Gas Fumace, 11-30-12
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