Mandatory Greenhouse Gas 

Reporting Rule: EPA's 

Response to Public Comments 

Subpart I - Electronics 

Manufacturing 
Subpart I – Electronics 

Manufacturing 

U.S. Environmental Protection Agency 

Office of Atmospheric Programs 

Climate Change Division 

Washington, D.C. 
November 2010 2

FOREWORD 

This document provides responses to public comments on the U.S. Environmental 

Protection Agency’s (EPA’s) Proposed Mandatory Greenhouse Gas Reporting Rule: 

Additional Sources of Fluorinated GHGs: Subpart I, Electronics Manufacturing. EPA 

published a Notice of Proposed Rulemaking in the Federal Register (FR) on April 12, 

2010 (75 FR 18652). EPA received comments on this proposed rule via mail, e-mail, 

and at a public hearing held in Washington D.C. on April 20, 2010. Copies of all 

comments submitted are available at the EPA Docket Center Public Reading Room. 

Comments letters and transcripts of the public hearings are also available electronically 

through http://www.regulations.gov by searching Docket ID EPA-HQ-OAR-2009-0927. 

EPA prepared this document in multiple sections, with each section focusing on a 

different broad category of comments on the rule. In light of the large number of 

comments received and the significant overlap between many comments, this 

document does not respond to each comment individually. Rather, EPA summarized 

and provided a single response to each significant argument, assertion, and question 

contained within the totality of comments. Within each comment summary, EPA 

provides in parentheses one or more lists of Docket ID numbers for commenters who 

raised particular issues; however, these lists are not meant to be exhaustive, and EPA 

does not individually identify each and every commenter who made a certain point in all 

instances, particularly in cases where multiple commenters expressed essentially 

identical arguments. 

EPA’s responses to comments are generally provided immediately following each 

comment summary. In some cases, EPA provided responses to specific comments or 

groups of similar comments in the preamble to the final rulemaking. Rather than 

repeating those responses in this document, EPA has referenced the preamble. 

Comments were assigned to specific section of this document based on an assessment 

of the principal subject of the comment; however, some comments inevitably overlap 

multiple subject areas. For this reason, EPA encourages the public to read the other 

sections of this document relevant to their interests. 
November 2010 3

Table of Contents 

1. Definition of the Source Category .............................................................................................. 7

2. Reporting Threshold ...................................................................................................................... 9

2.1 Threshold Applicability Equations ........................................................................ 9

2.2 Alternative Methods for Determining Threshold Applicability ................... 11

2.3 De Minimis Threshold and Other Exemptions............................................... 12

3. GHGs to Report............................................................................................................................ 16

4. Emissions Calculation Methods .............................................................................................. 17

4.1 Gas Consumption .................................................................................................. 17

4.1.1 Facility-Wide Gas Specific Heel Factors .................................................... 18

4.1.1.1 Accuracy and Precision of Measuring Instruments ................... 21

4.1.1.2 Exceptional Circumstance ......................................................... 24

4.1.1.3 Recalculation of Facility-Wide Gas-Specific Heel Factors ......... 26

4.1.2 Apportioning Gas Consumption to Process Categories with a 

Facility-Specific Engineering Model Based on an Activity Indicator................ 28

4.2 Emission Estimation Methods for Semiconductor Facilities ..................... 33

4.2.1 Refined Method .................................................................................................. 34

4.2.1.1 Other Methods of Categorizing Processes ................................ 36

4.2.1.2 Draft Default Emissions Factors for Refined Process 

Categories.................................................................................36

4.2.1.2.1Frequency and Process of Updates ............................................... 39

4.2.2 IPCC Tier 3 Method .......................................................................................... 40

4.2.2.1 300 mm and Smaller Wafer Technologies ................................ 40

4.2.2.2 Greater than 300 mm Wafer Technologies ............................... 44

4.2.3 Alternative Methods for Calculating Emissions from 

Semiconductor Facilities............................................................................................... 46

4.3 CEMS (Continuous Emissions Monitoring System(s)) ............................... 49

4.4 N2O ............................................................................................................................. 50

4.4.1 Default N2O Utilization Factors ...................................................................... 51

4.5 Heat Transfer Fluids .............................................................................................. 53

5. Monitoring and QA/QC Requirements .................................................................................. 57

5.1 Use of the 2006 ISMI Guidelines ...................................................................... 57

5.2 Controlled Emissions from Abatement Systems .......................................... 58

5.2.1 Proper Installation, Operation, and Maintenance .................................... 59

5.2.2 Accounting for Abatement System Uptime ................................................ 60

5.2.2.1 Semi E-10 Standard .................................................................. 62

5.2.3 EPA Default DRE Value .................................................................................. 63

5.2.3.1 System Certification .................................................................. 67

5.2.4 Proper Measurement of Abatement DRE .................................................. 68

5.2.4.1 EPA’s DRE Protocol .................................................................. 69

5.2.4.2 Random Sampling Abatement System Testing Program .......... 70

5.3 Other QA/QC Procedures.................................................................................... 74

6. Data Reporting Requirements ................................................................................................. 77

6.1 DRE Reporting ........................................................................................................ 80

7. Records that Must be Retained ............................................................................................... 82

8. Cost Data/Burden ........................................................................................................................ 84
November 2010 4

9. Confidential Business Information (CBI)............................................................................... 91

10. Uncertainty Analysis ................................................................................................................... 95

11. Other Subpart I Comments ....................................................................................................... 99

12. Relevant Comments from the April 2009 Proposed Rule on Electronics 

Manufacturing ...................................................................................................................................... 105

12.1 Calculating GHG Emissions: Emission Estimation Methods for 

Semiconductor Facilities ................................................................................................. 105

12.2 Monitoring and QA/QC Requirements: Use of the 2006 ISMI 

Guidelines............................................................................................................................ 112

13. Other Changes ........................................................................................................................... 115

Appendix A: List of Commenters Sorted by Submission Number ....................................... 118

Appendix B: Additional Comments on the EPA DRE Protocol (Submitted by SIA – 

EPA-HQ-OAR-2009-0927-0131) ................................................................................................... 119
November 2010 5

List of Acronyms 

BAU Business As Usual 

CAA Clean Air Act 

CBI Confidential Business Information 

CEMS Continuous Emissions Monitoring System 

CFR Code of Federal Regulations 

CVD Chemical Vapor Deposition 

DRE Destruction or Removal Efficiency 

Electronics Manufacturing TSD Technical Support Document for Process Emissions 

from Electronics Manufacture (e.g., Micro-ElectroMechanical Systems, Liquid Crystal Displays, 

Photovoltaics, and Semiconductors): Proposed Rule 

for Mandatory Reporting of Greenhouse Gases1

EPA U.S. Environmental Protection Agency 

EPA DRE Protocol EPA’s Protocol for Measuring Destruction or Removal 

Efficiency of Fluorinated Greenhouse Gas Abatement 

Equipment in Electronics Manufacturing (EPA 430-R10-003) 

Final MRR Final Rule, Mandatory Reporting of Greenhouse 

Gases, October 30, 2009 (74 FR 56260) 

Fluorinated GHG Fluorinated Greenhouse Gas 

F-HTF Fluorinated Heat Transfer Fluid 

FTIR Fourier Transform Infrared Spectroscopy 

GAO U.S. Government Accountability Office 

GHG Greenhouse Gas 

GWP Global Warming Potential 

HAP Hazardous Air Pollutants 

HTF Heat Transfer Fluid 

IPCC Intergovernmental Panel on Climate Change 

ISMI International SEMATECH Manufacturing Initiative 

ITRI Industrial Technology Research Institute 

ITRS International Technology Roadmap for 

Semiconductors 

 

1

 This is the REVISED November 2010 version unless otherwise noted as the March 22, 2010 version. 
November 2010 6

JETIA Japan Electronics and Information Technology 

Industries Association 

LED Light-Emitting Diode 

MES Manufacturing Execution Software 

MFC Mass Flow Controller 

MOU Memorandum of Understanding 

MtCOe Metric tons of Carbon Dioxide Equivalents 

NDIR Nondispersive Infrared 

NIST National Institute of Standards and Technology 

NODA EPA’s Notice of Data Availability; Default Emission 

Factors for Semiconductor Manufacturing Refined 

Process Categories, May 2010 (75 FR 26904) 

Pa Pascal (unit of pressure) 

PFC Perfluorocompound 

POU Point of Use 

PV Photovoltaic 

RFID Radio Frequency Identification 

RSASTP Random Sampling Abatement System Testing 

Program 

R&D Research and Development 

SIA Semiconductor Industry Association 

SIP State Implementation Plan 

TFT-FPD Thin-Film-Transistor Flat Panel Display 

Tier 1 2006 IPCC Tier 1 Method (Volume 3, Chapter 6) 

Tier 2b 2006 IPCC Tier 2b Method (Volume 3, Chapter 6) 

Tier 3 2006 IPCC Tier 3 Method (Volume 3, Chapter 6) 

VOCs Volatile Organic Compounds 
November 2010 7

1. Definition of the Source Category 

Comment Summary 1-a: One commenter (0110) proposed that if light-emitting diode 

(LED) production is to be included in the final rule, the emissions should be calculated 

using the Modified Tier 2b Method2 since the number and amount of fluorinated 

greenhouse gases (fluorinated GHGs) used is much lower in LED production than in 

semiconductor manufacturing. 

Response 1-a: In the final rule (§98.90), EPA clarified that under the electronics 

manufacturing source category, semiconductors include, among others, light-emitting 

diodes (LEDs). EPA made this clarification because LEDs are semiconductor light 

sources—when a LED is switched on, electrons are able to recombine with holes 

within the device, releasing energy in the form of light whose color is governed by the 

nature of the semiconductor. Many LEDs are manufactured on a wafer (usually 

different than silicon) using methods that are similar to the manufacture of integrated 

circuits.3

 Therefore, facilities that manufacture LEDs must use either the Tier 2c 

method4

 or the Tier 2d method,5 as appropriate, consistent with all other facilities that 

manufacture semiconductor devices. 

EPA’s information on LED manufacturing facilities is limited and the commenter did not 

provide any quantitative information to support the claim that the number and amount of 

fluorinated GHG used in LED production is much lower than in semiconductor 

manufacturing. EPA has concluded that it has no information to support subdividing 

semiconductor manufacturers into different distinct semiconductor device types, each 

required to use a different emission estimation method. 

Comment Summary 1-b: One commenter (0095) stated that the proposed rule as 

written did not distinguish between electronics manufacturing facilities and facilities that 

manufacture the equipment used to manufacture electronics (tool research and 

development [R&D] facilities). The commenter asserted that such facilities may engage 

in plasma etching, chamber cleaning, and CVD processes as part of their R&D 

activities, but are not engaged in “production processes” as the wafers are not 

completely manufactured but go through limited semiconductor processes. The 

 

2

 EPA proposed in the Modified Tier 2b method in the April 2010 proposal for other Electronics 

Manufacturing facilities including those that manufacture LCDs, MEMS, and PV. 

3

 For reference that many LEDs are produced on single wafer see: 

http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/perkins_fairfax09.pdf. 4

 Under the final rule, semiconductor manufacturing facilities that manufacture devices on wafers 

measuring 300 mm or less in diameter and that have an annual manufacturing capacity equal to or less 

than 10,500 m2

 of substrate are required to estimate and report their emissions using the Tier 2c method. 

See preamble section D, Electronics Manufacturing, (Subpart I), section 1 (“Summary of the Final Rule”) 

for a detailed discussion on the Tier 2c method. 

5

 Under the final rule, semiconductor manufacturing facilities that manufacture devices on wafers 

measuring 300 or less mm in diameter and that have an annual manufacturing capacity greater than 

10,500 m2

 of substrate are required to estimate and report their emissions using the Tier 2d method. 

See preamble section D, Electronics Manufacturing, (Subpart I), section 1 (“Summary of the Final Rule”) 

for a detailed discussion on the Tier 2d method. 
November 2010 8

commenter asserted that it would be challenging to calculate greenhouse gas (GHG) 

emissions based on manufacturing capacity or wafer starts because these metrics are 

not relevant for R&D facilities. The commenter also noted that semiconductor R&D 

facilities contribute minimally to the overall GHG emissions from electronics 

manufacturing sources. To this end, the commenter argued that R&D facilities should 

be exempt from the proposed rule to help facilitate the development of new 

technologies. 

Response 1-b: Under the final rule, per §98.90(a), facilities that engage in the following 

production processes are covered under the electronics manufacturing source 

category: 

(1) Electronics manufacturing production process in which the etching process 

uses plasma-generated fluorine atoms and other reactive fluorine-containing fragments, 

which chemically react with exposed thin-films (e.g., dielectric, metals) or substrate 

(e.g., silicon) to selectively remove portions of material; 

(2) Electronics manufacturing production process in which chambers used for 

depositing thin films are cleaned periodically using plasma-generated fluorine atoms 

and other reactive fluorine-containing fragments from fluorinated and other gases; 

(3) Electronics manufacturing production process in which wafers are cleaned 

using plasma-generated fluorine atoms or other reactive fluorine-containing fragments 

to remove residual material from wafer surfaces, including the wafer edge; 

(4) Electronics manufacturing production process in which the chemical vapor 

deposition (CVD) process or other manufacturing processes use N2O; and 

(5) Electronics manufacturing production process in which fluorinated GHGs are 

used as heat transfer fluids (HTFs) to cool process equipment, to control temperature 

during device testing, to clean substrate surfaces and other parts, and for soldering 

(e.g., vapor phase reflow). 

 If a facility engages in the covered processes listed above and they meet the 

threshold per §98.91(a), it is required to estimate and report their emissions under 

subpart I (Electronics Manufacturing), with the exception of emissions from R&D 

activities. 

 Under the Final Mandatory Reporting Rule (Final MRR), R&D activities (as 

defined in 40 CFR 98.6) are not considered to be part of any source category subject to 

the rule. If a facility engages in R&D activities, the facility is not required to report the 

emissions from that R&D activity. See the preamble to the Final Mandatory Reporting 

Rule (Final MRR) for a more detailed discussion on the exemption for R&D activities 

(74 FR 56285, October 2009). Pursuant to 40 CFR 98.6, “Research and development 

means those activities conducted in process units or at laboratory bench-scale settings 

whose purpose is to conduct research and development for new processes, 

technologies, or products and whose purpose is not for the manufacture of products for 

commercial sale, except in a de minimis manner.” 
November 2010 9

2. Reporting Threshold 

Comment Summary 2-a: One commenter (0128) supported the reporting threshold of 

25,000 MtCO2e (metric tons of carbon dioxide equivalents) per year, which would 

embrace roughly 96 percent of emissions from semiconductor facilities. 

Response 2-a: EPA thanks the commenter for their input. EPA is maintaining the 

25,000 MtCO2e per year reporting threshold for electronics manufacturing facilities in 

the final rule (see §98.91). See preamble section D, Electronics Manufacturing 

(subpart I), section 1, for a summary of the reporting threshold for electronics 

manufacture and the preamble to the Final MRR (74 FR 56272) for additional 

responses to comments on EPA’s selection of a 25,000 MtCO2e per year reporting 

threshold. 

2.1 Threshold Applicability Equations 

Comment Summary 2.1-a: One commenter (TRANS-DC-02) asserted that proposed 

Equation I-1 appears flawed, as it lacks a step to convert process emissions to CO2

equivalents based on global warming potential (GWP). 

Response 2.1-a: EPA thanks the commenter for their input. In the final rule, EPA has 

corrected the threshold applicability equation, Equation I-1, as well as Equations I-2 and 

I-3, to include a GWP term (a gas-appropriate GWP as provided in Table A-1 to subpart 

A of part 98) used to convert process emissions to CO2 equivalents.

Comment Summary 2.1-b: One commenter (TRANS-DC-02) asserted that the 

proposed threshold applicability determination equation for semiconductor facilities 

(Equation I-1) was a potential to emit calculation based on 100 percent of the 

manufacturing capacity of a facility, as opposed to an actual emission calculation that 

should serve as a reporting trigger. 

Response 2.1-b: EPA agrees with the commenter that the threshold applicability 

equation for semiconductor facilities is based on a facility’s potential to emit. EPA is 

finalizing this requirement for the following reasons: 1) Calculating a facility’s potential 

emissions is relatively simple and less burdensome than calculating actual emissions; 

and 2) Studies indicate facilities using fluorinated GHG abatement systems may 

underestimate their actual emissions due to widespread overestimation of these 

systems’ fluorinated GHG destruction or removal efficiencies (DRE) (see the preamble 

to the proposed rule (75 FR 18652, April 2010) for a more detailed discussion on EPA’s 

rationale for not permitting a facility to account for destruction by abatement systems in 

the threshold applicability calculation). 

Although the threshold applicability equations for subpart I are based on potential to 

emit, the cease-reporting provisions in the Final MRR allow facilities, regardless of their 

applicability threshold, to cease reporting based on the facility’s actual emissions as 

submitted in their annual report. See the preamble to the October 2009 final rule for a 
November 2010 10

more detailed discussion and responses to comments related to the provisions to cease 

reporting (74 FR 56276, October 2009). 

Comment Summary 2.1-c: One commenter (0110) asserted that “full planned design 

capacity” (used in the threshold applicability equations) is ambiguous, because actual 

capacity fluctuates due to process changes made in a fab and varying manufacturing 

levels spurred by the dynamic nature of the industry.

Another commenter (0095) asserted that the 2006 IPCC Tier 1 (“Tier 1”) method does 

not specify whether the manufacturing capacity is based on the volume of wafers 

manufactured or the number of wafer passes. The commenter also stated that it was 

unclear whether wafers that are processed without the use of GHGs were to be 

included in manufacturing capacity. Lastly, the commenter noted that a semiconductor 

facility may also use wafers for processes that do not use GHGs. 

Response 2.1-c: In the final rule, in §98.91,EPA has modified the term “full designed 

capacity” from the April 2010 proposed rule to be “100 percent of annual manufacturing 

capacity.” For further clarity, EPA also provided a new equation, Equation I-5 in the 

final rule in §98.91, for facilities to use when determining this capacity value in threshold 

applicability calculations. Equation I-5 will be used to determine 100 percent of annual 

manufacturing capacity of a facility by summing the area of maximum designed 

substrate starts of a facility per month over the reporting period. 

In addition, also for further clarification in §98.98, EPA defined the term “maximum 

designed substrate starts” as the maximum quantity of substrates, expressed as 

surface area that could be started each month during a reporting year, if the facility 

were fully equipped as defined in the facility design specifications and if the equipment 

were fully utilized. 

In response to the commenter who asserted that it was unclear whether manufacturing 

capacity would include wafers used for processes that do not use fluorinated GHGs, 

EPA is requiring all substrate starts, regardless of their manufacturing fate, be included 

as part of the maximum designed substrate starts. This requirement is being adopted 

to simplify and minimize the burden associated with the threshold applicability 

determination and to make the results of the determination more conservative. 

Comment Summary 2.1-d: One commenter (0128) supported the exclusion of 

emission reductions from abatement technologies in calculations to determine whether 

a facility meets the reporting threshold. The commenter asserted that given EPA’s 

statement that manufacturers’ estimates of abatement system efficacy is often 

inaccurate, leading to overstated system efficiencies resulting from improper 

installation, maintenance, or operation, EPA is correct to exclude the use of abatement 

systems in determining threshold applicability. 
November 2010 11

Response 2.1-d: EPA thanks the commenter for their input. EPA is finalizing a method 

for the threshold applicability determination that excludes emission reductions from 

abatement technologies. See the Electronics Manufacturing TSD available in the 

docket (EPA-HQ-OAR-2009-0927) for a discussion supporting this exclusion. 

2.2 Alternative Methods for Determining Threshold Applicability 

Comment Summary 2.2-a: As an alternative to EPA’s proposed threshold applicability 

calculation, a commenter (0110) proposed applying Tier 1 emission factors to annual 

fluorinated GHG consumption for threshold determination in a manner similar to that of 

photovoltaic (PV) manufacturing. 

Response 2.2-a: EPA disagrees with the commenter that proposed to allow facilities to 

determine their threshold applicability by applying Tier 1 emission factors to annual 

fluorinated GHG consumption. The method suggested by the commenter is not a valid 

or plausible method. Tier 1 emission factors are based on the known capacity of a 

facility; these emission factors have units of the mass of gas emitted per area (m2

) of 

substrate produced. To apply an emission factor with these units to a gas consumption 

number, also in the units of mass of gas, would result in an emission estimate that does 

not physically or mathematically make sense. EPA would like to clarify that the 

threshold determination method for PV facilities is based upon gas consumption and 

gas appropriate GWPs, not gas consumption and Tier 1 emission factors. 

Comment Summary 2.2-b: One commenter (0095) asserted that semiconductor 

facilities should be permitted to use the 2006 IPCC Tier 2b Method (“Tier 2b”) for 

threshold determination instead of the Tier 1 Method, provided that the facility uses 

abatement systems. As an alternative, the commenter suggested that facilities be 

allowed to use an alternative destruction removal efficiency (DRE) value that exceeds 

the default IPCC DRE value based on section 98.94 of the proposed rule. The 

commenter asserted that the Tier 1 methodology does not distinguish between the 

volume of wafers manufactured or the number of wafer passes. 

The commenter asserted that the use of the Tier 2b method should be allowed since 

the Tier 2b method is more accurate for evaluating actual emissions. The commenter 

argued that the use of the Tier 2b methodology for threshold determination would be 

consistent with the requirements of AB32 Greenhouse Gas Emission Reduction, 

California Air Resources Board (reference: California Code of Regulations, Title 17, 

Subchapter 10, Article 4, Subarticle 2). 

Response 2.2-b: EPA does not agree with the commenter that the threshold 

applicability requirements in the final rule should be modified. EPA is not modifying the 

applicability threshold requirements because, as compared to the Tier 2b method, the 

Tier 1 method is relatively simple and less burdensome to determine whether or not a 

facility is required to report. Further, EPA is not permitting the use of DREs in the 

threshold applicability determination for reasons previously stated in the preamble to 

the April 2010 proposed rule (75 FR 18659). Please see the preamble to the April 2010 
November 2010 12

proposed rule (75 FR 18659, April 2010) for a more detailed discussion on EPA’s 

rationale for not permitting a facility to account for destruction by abatement systems in 

the threshold applicability calculation. Please also see response to comment 2.1-c for 

information on the how EPA has clarified the threshold applicability determination using 

the Tier 1 method in the final rule. 

 

2.3 De Minimis Threshold and Other Exemptions 

Comment Summary 2.3-a: Five commenters (0089, 0099, 0110, 0123, and 0131) 

noted facilities routinely employ small quantities of chemicals used as HTFs and for 

other uses. The commenters expressed concern EPA has not established a de minimis 

standard for reporting. Two commenters (0123 and 0110) recommended a de minimis 

level be established for calculation and reporting emissions from the use of HTFs. 

Another commenter (0099) asserted that establishing a de minimis threshold for HTFs 

would be “consistent with the refrigerant management requirements found in 40 Code 

of Federal Regulations (CFR) part 82 which apply to the most detailed tracking 

requirements only to refrigerant units containing more than 50 pounds of refrigerant.” 

Other commenters (0089, 0131) expressed similar sentiments. 

One commenter (0089) asserted that the definition of “fluorinated greenhouse gas” 

found in 40 CFR 98.6 is broad and using this definition without a de minimis value 

below which reporting is not required may cause problems. Two commenters (0089 

and 0099) noted that companies often experiment with a variety of chemicals before 

high volume manufacturing, and requiring that emissions factors be developed, and 

emissions reported will present a significant burden for a small amount of emissions. 

These commenters (0089 and 0099) stated that it is also likely that there are many 

gases for which a GWP value has not been established. One commenter (0089) 

asserted that the requirements be revised to require reporting for only those fluorinated 

GHGs which are used in excess of 100 pounds and that have an established GWP. 

The commenter also suggested that the same criteria be applied to the gas 

consumption reporting required in §98.96(f). 

One commenter (0099) proposed that EPA include provisions to allow facilities to 

exclude from emissions calculations any fluorinated GHG that does not have an 

established GWP or comprises less than 5 percent of total usage of fluorinated GHGs 

where: 1) The de minimis amount of the fluorinated GHG used in etch comprise less 

than 5 percent of the total usage of all fluorinated GHG compounds in etch, 2) the de 

minimis amount of the fluorinated GHG used in CVD chamber cleaning comprises less 

than 5 percent of the total usage of all fluorinated GHG compounds in CVD chamber 

cleaning, 3) the de minimis amount of the fluorinated HTF comprises less than 5 

percent the total usage of all fluorinated HTFs compounds. 

Similarly, another commenter (0131) proposed that EPA include provisions to allow 

facilities to exclude from emissions calculations any fluorinated GHGs that comprises 

less than 5 percent of the total usage of fluorinated GHGs where: 1) The de minimis 

amount of the fluorinated GHG used in etch comprises less than 5 percent of the total 

usage of all fluorinated GHG compounds in etch, 2) the de minimis amount of the 
November 2010 13

fluorinated GHG used in CVD chamber cleaning comprises less than 5 percent of the 

total usage of all fluorinated GHG compounds in CVD chamber cleaning, 3) the de 

minimis amount of the fluorinated GHG used in wafer cleaning comprises less than 5 

percent of the total usage of all fluorinated GHG compounds in wafer cleaning, 4) the 

de minimis amount of the fluorinated HTF comprises less than 5 percent the total usage 

of all fluorinated HTFs compounds. 

Response 2.3-a: EPA does not agree with the comments that a de minimis threshold 

should be established for either HTF emissions or process fluorinated GHG emissions. 

When EPA published the Final MRR, EPA determined de minimis provisions were not 

necessary because a de minimis provision would compromise the quality and 

usefulness of the data collected (74 FR 56260, October 2009). For additional 

background on EPA’s decisions to exclude de minimis provisions, please see response 

to comments in the preamble to the Final MRR (74 FR 56278-56279, October 2009) 

and also ‘‘Reporting Methods for Small Emission Points (De Minimis Reporting)’’ (EPA–

HQ–OAR– 2008–0508–0048). 

With respect to the comments that reporting emissions from chemicals that facilities use 

in small quantities to experiment is burdensome, EPA recognizes that it may be 

burdensome for facilities to develop facility-wide gas-specific heel factors and emission 

factors for fluorinated GHGs and N2O that are used in small quantities. In response, 

consistent with the Final MRR, in §98.93, EPA has made changes to the calculation 

requirements that further reduce any need for de minimis reporting provisions by 

allowing simpler methods for fluorinated GHGs and N2O that are used in small 

quantities. For any fluorinated GHG used in production processes or N2O for which a 

facility consumes 50 kg or less during a reporting year, the facility has the option to 

assume that the amount of that gas emitted is equal to the amount of that gas 

consumed. To determine the amount of gas consumed, EPA is allowing facilities to 

assume that the gas-specific heel factor is equal to zero. EPA has provided this option 

only for fluorinated GHG process gases and N2O. EPA has not made any modifications 

to the reporting requirements for HTFs because EPA concludes that the mass balance 

method is simple and will effectively capture all emissions of HTFs. 

With respect to commenter’s assertion that EPA should adopt a de minimis threshold 

for HTFs because it is “consistent with the refrigerant management requirements found 

in 40 Code of Federal Regulations (CFR) part 82 which apply the most detailed tracking 

requirements only to refrigerant units containing more than 50 pounds of refrigerant,” 

EPA does not agree that it should adopt a threshold designed for a specific existing 

program. While EPA is not opining on the commenter’s characterization of 40 CFR part 

82, EPA does not agree with the commenter’s suggestion because the purpose of this 

rule is to collect data for use in developing future GHG policies and programs. 

Collecting accurate data of GHG emissions is important to the future value of the data 

for informing policy decisions and designing new GHG policies and programs. 

Receiving data on emissions from HTFs will provide EPA with comprehensive 

information on all emissions, including quantities and sources, from electronics 

manufacturing facilities. 
November 2010 14

In response to the commenters’ suggestion that only chemicals with established GWPs 

should be reported, EPA does not agree. EPA acknowledges there may be cases 

where a facility is required to report fluorinated GHG emissions for which GWPs have 

not yet been assigned in either IPCC or World Meteorological Organization (WMO) 

Scientific Assessments (i.e., fluorinated GHGs for which Table A–1 of 40 CFR part 98, 

subpart A does not provide GWPs). As acknowledged by commenters, Table A-1 of 40 

CFR part 98, subpart A is not a complete listing of current or potential fluorinated 

GHGs; the IPCC and WMO lists on which it is based reflect only the facts that the listed 

materials have been synthesized, their atmospheric properties investigated, the results 

published, and the publications found by the IPCC and WMO Assessment authors. 

Table A–1 omits some fluorinated GHGs, and it unavoidably omits future fluorinated 

GHGs that have not yet been synthesized. Given the radiative chemical properties of 

the carbon-fluorine bond, any fluorocarbon emitted into the atmosphere may have a 

significant GWP. However, the lack of GWPs for some fluorinated GHGs will not 

impede reporting because EPA is requiring that emissions be reported on a mass basis 

rather than a CO2e basis. 

Reporting of fluorinated GHGs that do not appear in Table A–1 of 40 CFR part 98, 

subpart A will provide valuable information on types of fluorinated GHGs being used in 

electronics manufacturing. Further, this information can be used to assess the volume 

of emissions for which GWPs have not been evaluated and to help prioritize the 

evaluation of GWPs. For more responses to comment on the definition of “fluorinated 

GHG” and the reasons why EPA is requiring facilities to report fluorinated GHGs that do 

not appear in Table A-1, please see the preamble to the Final MRR (74 FR 56348, 

October 2009). 

EPA anticipates that as GWPs are evaluated or reevaluated by the scientific 

community, the Agency will update Table A–1 of 40 CFR part 98, subpart A through 

notice and comment rulemaking. EPA may also, through rulemaking, establish a more 

proactive process for ensuring that GWPs are appropriately evaluated or reevaluated. 

Please also see the Response to Comment Document for OO available at 

http://www.epa.gov/climatechange/emissions/downloads09/documents/SubpartOOSuppliersofIndustrialGHGs.pdf. 

Comment Summary 2.3-b: One commenter (0131) stated that “small electronics 

manufacturing processes with wafer production capacities of less than 1,080 m2

 emit 

less than 5% of the 25,000 metric ton CO2e reporting threshold for this rule. However, 

some of these small processes are located at large integrated manufacturing facilities 

that have on-site power generating utilities (e.g. Boilers for generating heat and 

electricity). GHG emissions from combustion operations at these facilities typically 

exceed the 25,000 tons CO2e threshold and, therefore, bring the entire facility into the 

reporting rule, including the small electronics manufacturing process.” The commenter 

proposed revisions to the regulatory text of subpart I, section 98.91, to exclude 

electronics manufacturing processes with a production capacity of 1,080 m2 or less. 
November 2010 15

Response 2.3-b: EPA does not agree with the commenter’s proposed regulatory text 

revisions that exclude reporting emissions from processes with production capacities of 

1,080 m2 or less. Any facility that engages in the production processes defined in the 

electronics manufacture source category and exceeds the 25,000 MtCO2e threshold, 

with both process and combustion emissions, must report fluorinated GHG and N2O 

emissions and consumption for all of the process covered by the electronics 

manufacture source category. 6 EPA does not agree that particular processes at a 

facility should be excluded from facility reporting because this would provide EPA with 

an incomplete picture of actual facility emissions. EPA has also concluded that it is 

necessary to include combustion emissions in the threshold determination because 

many electronics manufacturing facilities emit GHGs from both manufacturing 

processes and combustion sources. It is important to EPA that both process and 

combustion emissions are considered in threshold determinations so EPA can gain a 

more complete picture of total U.S. emissions to inform future policy and regulatory 

decisions. 

In the final rule electronics manufacturing facilities that meet or exceed the 25,000 

metric tons of CO2e threshold must report, which is consistent with most other subparts 

of the rule. Please see the preamble to the Final MRR for more details on the 

appropriateness of this threshold for the MRR, and how this threshold was selected (74 

FR 56271, October 2009).

In response to the commenter’s concern that small electronics manufacturing 

processes may be brought into the GHG Reporting Program, and this will impose some 

level of regulatory burden, EPA points to the fact that efforts have been made to help 

simplify reporting requirements for relatively smaller emissions sources. First, the rule 

excludes small facilities through the application of the 25,000 metric tons of CO2e 

threshold. This threshold balances the number and size of reporter with the coverage of 

emissions. Second, reporters must report only the emissions from sources for which 

calculation methods are provided in the rule. Calculation methods are generally not 

included for smaller sources of emissions (e.g., coal piles on industrial sites). In some 

cases, where a source category includes relatively small emission sources, the rule 

provides simplified emissions calculation methods for those sources. Given that EPA 

has taken steps to simplify emissions monitoring methods in this rule, EPA has 

concluded that reporting cutoffs, such as the production capacity cutoff proposed by the 

commenter, are not necessary. 

 

6

 As defined in §98.6, a facility means any physical property, plant, building, structure, source, or 

stationary equipment located on one or more contiguous or adjacent properties in actual physical contact 

or separated solely by a public roadway or other public right-of-way and under common ownership or 

common control, that emits or may emit any greenhouse gas. Operators of military installations may 

classify such installations as more than a single facility based on distinct and independent functional 

groupings within contiguous military properties. 
November 2010 16

3. GHGs to Report 

Comment Summary 3-a: One commenter (0099) asserted that the definition of GHGs 

is much broader than the Kyoto basket of gases. The commenter further stated that the 

definition of fluorinated GHGs is very broad and potentially includes many materials that 

have not been quantified. The commenter further noted that it is unclear whether 

accurate measurement methods (or GWP values) even exist for these compounds. 

The commenter suggested that initially the rule should focus on the Kyoto Protocol 

basket of gases and NF3. 

Another commenter (0108) suggested that EPA’s online GHG emissions reporting tool 

must easily accommodate mass emissions reporting in an uncomplicated manner for 

HTFs and fluorinated GHGs like C5F8 for which calculation of CO2e is not possible 

because GWPs were not published in subpart A, Table A-1. 

Response 3-a: The definition of fluorinated GHG was promulgated in the Final MRR, 

and EPA did not revisit it in this rulemaking. For response to comments regarding the 

definition of “fluorinated GHG” please see the preamble to the Final MRR (74 FR 

56348, October 2009). Please also see the Response to Comment Document for OO 

available at 

http://www.epa.gov/climatechange/emissions/downloads09/documents/SubpartOOSuppliersofIndustrialGHGs.pdf. 

In regards to the commenters’ concerns about GWPs that may not exist or be 

published, please see response to comment 2.3-a. 

EPA acknowledges the commenter’s concern about the reporting tool. While EPA is 

currently developing the reporting tool, at this time, EPA does not anticipate that 

reporting emissions from gases that do not have GWPs will be a problem because 

semiconductor manufacturing facilities are required to report emissions on a mass 

basis as opposed to a CO2e basis. Please see the preamble to the Final MRR for more 

information on the electronic reporting tool (74 FR 56282, October 2009). 
November 2010 17

4. Emissions Calculation Methods 

4.1 Gas Consumption 

Comment Summary 4.1-a: Five commenters (0099, 0110, 0112, 0123, and 0131) did 

not support the proposed gas inventory requirements as part of determining overall gas 

consumption. Three commenters (0099, 0112, and 0131) expected that, year-to-year, 

the total inventory of each gas would not vary widely. Commenters (0099, 0110, 0112, 

0123, and 0131) also suggested that if gas usage for a previous reporting year is 

“under-reported” or “over-reported,” the usage for the following reporting year would 

account for the deficit or excess amount. 

One commenter (0110) stated that site purchase and inventory records are typically 

used to track gas usage. The commenter asserted that this standard practice is widely 

accepted for criteria pollutants under the Clean Air Act (CAA) and for emissions 

accounting under state implementation plans (SIPs) approved by EPA. The commenter 

noted that these methods are also used for compliance and enforcement of emission 

limitations under the CAA, and that they believe that a similar approach can be used for 

estimating and reporting GHG emissions. In line with these sentiments, another 

commenter (0131) suggested that only purchase records showing acquisitions and 

disbursements, combined with heel factors, be utilized to determine consumption; the 

commenter asserted that cylinders changed out prematurely do not need to be 

accounted for separately from purchase records. 

Response 4.1-a: EPA does not agree with the commenters that asserted purchase 

records would be sufficient for tracking gas consumption, or that only purchase records 

showing acquisitions and disbursements combined with heel factors should be utilized 

to determine consumption; as opposed to purchase records, gas inventories, and 

facility-wide gas-specific heel factors. In the final rule, EPA is maintaining the 

requirement for facilities to determine the amount of gas consumed based on a mass 

balance method, which utilizes an inventory of gas at a facility. The use of this method, 

which involves an inventory of gas stored in containers in the beginning and end of the 

reporting year, ensures that any fugitive emissions that may arise from gas handling are 

accounted for, and that fluctuations in gas consumption from year-to-year at facilities 

are accounted for. While commenters note that year-to-year the total inventory of each 

gas would not vary widely, information was not provided to EPA to verify this statement. 

With respect to the commenter that asserted chemical use should be tracked using site 

purchase and inventory records, similar to how emissions are calculated for other CAA 

requirements and under SIPs approved by EPA, it is important to clarify that the 

purpose of this rule differs from those regulatory programs. In contrast to other 

regulatory programs which generally focus on whether a facility's emissions are below a 

specified limit, this rule focuses on establishing each facility’s annual GHG emissions in 

metric tons per year with the goal of gathering accurate facility-level data. EPA plans to 

use such data to inform future policy and regulatory decisions. EPA has concluded that 

the gas consumption requirements in subpart I help ensure that this goal is achieved. 
November 2010 18

Comment Summary 4.1-b: In response to EPA’s request for comment on how to 

account for the amount of gas in containers in service in an annual inventory, 

commenters did not support determining the quantity of gas in partially used in-service 

cylinders at the end of the reporting year, citing a significant amount of burden and 

difficulty in complying with this proposed requirement with little improvement in 

calculation certainty. One commenter (0131) cited burden as an issue in particular 

because a facility may have hundreds of gas cylinders in service. 

Response 4.1-b: EPA agrees with commenters that the additional amount of labor and 

difficulty required to inventory the quantity of gas in partially used in-service cylinders at 

the end of a reporting year is not justified by any gains in accuracy. To reduce burden, 

EPA has modified the rule to allow facilities to account for the total quantity of gas in 

containers in service at the end of a reporting year as if the in-service containers were 

full. Facilities must also then account for this same quantity in the inventory of gas 

stored in containers at the beginning of the subsequent reporting year. EPA 

understands that any “under-reporting” or “over-reporting” that is a consequence from 

this modification will be balanced out in subsequent reporting years. EPA believes this 

modification will have a minimal effect on the accuracy of emission estimates. 

4.1.1 Facility-Wide Gas Specific Heel Factors 

Comment Summary 4.1.1-a: Two commenters (0099 and 0131) proposed that in lieu 

of using heel factors, EPA should permit facilities to determine gas consumption by 

tracking individual containers. The commenters stated that tracking individual gas 

containers will provide consumption estimates that are as accurate as EPA’s proposed 

method of using heel factors. 

Response 4.1.1-a: EPA is not clear as to what the commenters are suggesting. If the 

commenters are suggesting that gas containers can be tracked but that the heels of 

gas containers should not be accounted for, EPA does not agree. By tracking 

individual cylinders and not accounting for cylinder heels, as opposed to using facilitywide gas-specific heel factors to estimate gas consumption, the estimates will not be 

accurate. As one commenter (0112) explained, “The heels that are returned to the 

manufacturer represent 4.3 percent of the total gas used.” Therefore, in not accounting 

for heels in gas consumption estimates, a facility would be knowingly over-estimating 

gas consumption. This conflicts with EPA’s intention to gather accurate facility-level 

information. In addition, EPA understands that many electronics manufacturing 

facilities already estimate gas consumption based on purchase records and a default 

factor. According to one commenter (0131), 81 percent of semiconductor facilities that 

participated in the 2009 ISMI survey used purchase records and a default heel factor to 

estimate gas consumption. EPA also understands that in business as usual (BAU) 

facility operations, mass-based or pressure-based trigger points for change out are 

used to determine when gas containers are to be changed. EPA is therefore requiring 

these trigger points for change out be used to calculate facility-wide gas-specific heel 

factors for each gas container type, based on trigger points established as part of 

facility operations, rather than permitting facilities to track individual containers. 
November 2010 19

Comment Summary 4.1.1-b: One commenter (0095) requested clarification on the 

average facility-wide gas-specific heel factor and whether it is a monthly or yearly 

average. 

Response 4.1.1-b: EPA is requiring gas consumption to be determined based on 

knowledge of the actual amount of each gas consumed during the reporting period by 

determining a gas and facility-specific heel factor for each container type used during a 

reporting year. This approach does not require the facility to develop a monthly or 

annual average heel factor; rather, EPA is requiring the facility to develop a facilitywide, gas-specific heel factor that is based on the concept of a "constant" facility-wide 

gas-specific “trigger point for change out.” This trigger point for change out denotes a 

specific amount of gas in a cylinder--an amount that requires the cylinder to be 

exchanged, typically for a full cylinder, at or just before the trigger amount is reached. 

That triggering amount, along with the initial full mass of a gas container, may be used 

to calculate heel factors throughout a reporting period provided the trigger point does 

not change by more than 5 percent. If the trigger point should change by more than 5 

percent, then the new trigger point is to be used to calculate gas consumption for the 

remainder of that reporting period. The amount of gas consumed for a reporting year 

would be the sum of a gas consumed for each period in a reporting year during which 

the trigger point for change out did not vary by more than 5 percent. EPA believes this 

method is appropriate and reliable because for a "constant" trigger amount, the 

corresponding heel will also be constant provided cylinders of the size for that trigger 

are filled to the same amount. EPA understands that it is the practice of gas suppliers 

to fill cylinders of the same size and the same gas with identical amounts. 

Comment Summary 4.1.1-c: Four commenters (0099, 0100, 0112, and 0131) 

supported the use of site-specific gas heel factors in conjunction with purchase records. 

One commenter (0112) asserted that the use of facility-wide gas-specific heel factors at 

their facilities increased the accuracy of the estimated gas consumed by 5.9 percent, 

and increased the accuracy of the emission calculations. Two commenters (0099 and 

0131) asserted that the use of site-specific gas heel factors would greatly improve the 

accuracy of gas usage determinations over the IPCC default heel factor of 10 percent. 

One commenter (0131) asserted that using site-specific heel factors eliminates the 

costly installation of gas distribution and measurement infrastructure. 

Response 4.1.1-c: EPA thanks the commenters for their input. EPA is finalizing the 

requirement to use facility-wide gas-specific heel factors. 

Comment Summary 4.1.1-d: One commenter (0108) suggested that EPA “...not 

mandate the development and use of site-specific and gas-specific cylinder heel factors 

for ‘relatively smaller’ semiconductor facilities. Rather, allow the optional use of 0.00 (0 

percent) as the heel factor [i.e., all of a cylinder’s gas is used, none returned to the 

supplier], and for ‘relatively smaller semiconductor facilities’ who may ultimately choose 

to install large numbers of cylinder scales to develop accurate cylinder heel factors, 

allow the use of the IPCC and industry-standard cylinder heel factor of 0.10 (10 

percent) through reporting year 2013 to spread the cost over three years.” The 
November 2010 20

commenter noted that in order to comply with the proposed requirements of the rule, it 

will have to purchase additional scales. These purchases would have to occur over a 

short timeframe, and the company has not budgeted for them. The commenter was 

therefore open to either option stated above, recognizing the first would overstate GHG 

emissions. 

Response 4.1.1-d: EPA does not agree with either of the commenter’s suggestions. 

Heels vary among gases and container sizes and shapes and so using either 0 or the 

IPCC default heel factor will result in less accurate estimates of gas consumption and 

emissions. In addition, the use of heel factors that are specific to a facility will account 

for the differences in gas usage practices between facilities. Use of the commenter’s 

suggestions would conflict with EPA’s intention to gather accurate facility-level 

information 

EPA understands that in normal facility operations, mass-based or pressure-based 

trigger points for change out are used to determine when gas cylinder/containers are to 

be changed. EPA anticipates that facilities should be able to implement practices in 

accordance with EPA’s heel factor requirement for the first year of data collection and 

reporting. 

A facility may use Best Available Monitoring Methods (BAMM) for the first six months of 

the first data collection year without submitting a request to the Administrator. Under 

the BAMM provisions in the final rule for subpart I in §98.94(a), facilities must use the 

calculation methods prescribed by the rule, but BAMM is permitted for any parameter 

for which it is not reasonably feasible to acquire, install, or operate a required piece of 

monitoring equipment in a facility or to procure necessary monitoring services from 

providers. For more information on the use of BAMM, please see the preamble section 

D, Electronics Manufacturing (subpart I), section 1 (“Summary of the Final Rule”). 

 

Comment Summary 4.1.1-e: One commenter (0131) stated that according to a 2009 

International SEMA TECH Manufacturing Initiative (ISMI) survey, 80 percent of 

respondents currently estimate gas consumption based on purchase records and an 

assumed heel factor. Therefore, the rule would require facilities to change their current 

practices to determine facility-wide gas-specific heel factors. 

Response 4.1.1-e: EPA thanks the commenter for its input. EPA understands that the 

requirement for facility-wide gas-specific heel factors may require new practices to be 

instituted at electronics manufacturing facilities. However, EPA is finalizing the 

requirement for facilities to develop and use facility-wide gas-specific heel factors. EPA 

is not allowing facilities to use an assumed or default heel factor because heels may 

vary among gases and container sizes and shapes. Therefore, applying a broad 

default or assumed value to every gas container will lead to estimations that may not 

accurately represent the facility’s actual gas consumption, and hence the facility’s 

emissions. (See the Electronics Manufacture TSD available in the docket (EPA-HQOAR-2009-0927) for more details). See response to comment 4.1.1-d for more 
November 2010 21

discussion regarding why for facility-wide gas-specific heel factors are required in the 

final rule. 

Comment Summary 4.1.1-f: One commenter (0131) provided the following response 

to EPA’s request for comment in a meeting on May 19, 2010 on requiring the gas 

supplier to measure and track cylinders: “While this may be practical at some facilities 

at additional cost, Semiconductors Industry Association (SIA) believes this would not be 

practical in most cases. Specific ‘used’ cylinders may not be uniquely identified once 

they are removed from service such that their correlation of their incoming weight to 

their outgoing weight may not be possible. Furthermore, suppliers often pick up used 

cylinders from customers in multi-facility trips, also known as ‘milk runs’. This would 

convolute the requirement to weigh specific cylinders for specific customers when they 

return to the supplier location. In any case, this would require the establishment of an 

‘on and off’ facility tracking system for which facilities and supplier protocols are not 

currently equipped or staffed. Most certainly all costs for this tracking would be incurred 

ultimately by the facility, thus avoiding no part of the cost and burden associated with 

gas usage tracking as proposed.” 

Response 4.1.1-f: EPA thanks the commenter for this information. EPA has not 

modified the rule to require gas suppliers to measure and track cylinders. Please see 

the preamble section D, Electronics Manufacturing (subpart I), section 1 (“Summary of 

the Final Rule”), for a summary of the gas consumption requirements in the final rule. 

Comment Summary 4.1.1-g: One commenter (0131) suggested that unless it is 

infeasible, facilities should develop a “heel factor specific to each type of cylinder and 

for each gas type based on the point established as the trigger for changing out the 

cylinder.” 

Response 4.1.1-g: EPA agrees that facilities should develop a heel factor specific to 

each type of cylinder and for each gas type based on the point established as the 

trigger for changing out the cylinder. EPA does not anticipate there would be any 

circumstance in which this would be infeasible for a facility. Therefore, EPA is 

maintaining the requirement that facilities must estimate gas consumption based on 

facility-wide gas-specific heel factors. See response to comment 4.1.1-a and 4.1.1-d 

for more discussion on the required gas consumption methods using facility-wide gasspecific heel factors. 

4.1.1.1 Accuracy and Precision of Measuring Instruments 

Comment Summary 4.1.1.1-a: One commenter (0107) presented a technology that it 

believes can provide a cost-effective and efficient measurement of a gas container’s 

heel with 1 percent accuracy or better. The integrated pressure sensing technology 

monitors the container’s contents with pressure transducing and active Radio 

Frequency Identification (RFID) technologies. The commenter requested confirmation 
November 2010 22

by EPA that the proposed technology satisfies the requirements of the proposed rule 

and can be used for compliance with the final rule. 

Response 4.1.1.1-a: EPA thanks the commenter for supplying this information about 

its technology. Provided that measurement instrumentation used by a facility to 

measure the residual weight or pressure of a cylinder, which in turn is used to 

determine facility-wide gas specific heel factors, meets the one percent of full scale 

accuracy and precision requirement, the use of that instrumentation is permitted under 

the rule. 

Comment Summary 4.1.1.1-b: One commenter (0107) stated that according to its 

understanding, many electronics manufacturing facilities do not have the ability to meet 

the required precision requirements to measure gas containers heels. The commenter 

stated that it will be costly for many companies to install flowmeters in the timeframe 

required to prepare to comply with the rule. 

Three other commenters (0099, 0112, and 0131) opposed the requirement that all 

instrumentation must have accuracy and precision of 1 percent full scale or better, 

citing in some cases the infeasibility to comply and the burden to obtain instrumentation 

to meet EPA’s requirement. One commenter (0112) asserted that a significant portion 

of its equipment has accuracies of 2 percent to 5 percent, while others can reach 1 

percent accuracy. One commenter (0131) provided the following information: “The 

majority of new fabricators and new equipment will be able to meet the 1 percent 

requirement ... According to the 2010 Supplemental ISMI Survey, 74 percent of the 

respondents have measurement devices that meet the 1 percent accuracy/precision 

requirement while 26 percent may not. Of this 26 percent, the measurement devices 

used likely have an accuracy/precision in the 2-4 percent range. This 26 percent of 

facilities can be expected to incur additional capital costs to meet this instrumentation 

requirement.” The commenter (0131) also stated that no respondents utilize flow 

meters with an accuracy of 1 percent for tracking gas consumption. In order to meet the 

requirement, commenters asserted that they will have to incur costs of purchasing and 

installing new equipment. The commenters proposed the use of a 5 percent accuracy 

requirement as provided in the general provisions of the Final MRR. In addition to the 

proposed 5 percent requirements; a commenter (0099) suggested that the performance 

of the instrumentation would be verified using methods consistent with an industry 

accepted practice at least annually. 

Another commenter (0110) expressed appreciation that the April 2010 proposed rule no 

longer included the requirement for flowmeters and scales to be calibrated using 

National Institute of Standards and Technology (NIST)-traceable standards; however, 

the commenter is concerned that the 1 percent of full scale accuracy and precision 

requirement for instrumentation is still included in the rule. The commenter asserted 

that a significant burden exists with little environmental benefit in requiring 

measurement devices with accuracies to 1 percent or less. 
November 2010 23

Response 4.1.1.1-b: EPA is not requiring the use of flowmeters to comply with gas 

consumption requirements of the final rule. The commenter (0107) may have 

misunderstood the proposed gas consumption requirements, and this 

misunderstanding may have led it to make incorrect assumptions about the costs and 

technical challenges associated with the rule. 

Further, it is possible that some commenters may have misunderstood the proposed 

precision and accuracy requirement. EPA proposed to require an accuracy and 

precision to be achieved on an instrument’s full scale basis, as opposed to the more 

stringent true value basis. In other words, for a scale capable of measuring 300 

pounds, regardless of the amount of gas being weighed on the scale, the final rule 

requires that the measured weight of gas must be accurate within +/- 3 pounds. Where 

as an accuracy based on the true weight of the gas in the cylinder would vary 

depending on the amount of gas in the cylinder. 

EPA has concluded that it is feasible for facilities to comply with the accuracy and 

precision requirement to achieve +/-1 percent of full scale or better for measurement 

instrumentation as part of determining gas containers heels, and is therefore not 

modifying it as commenters suggested. As some of the commenters asserted (0112 

and 0131), many facilities already will be able to meet the +/-1 percent of full scale or 

better accuracy and precision requirement. “According to the 2010 supplemental ISMI 

survey, 74 percent of respondents have measurement devices that meet the 1 percent 

accuracy/precision requirement while 26 percent may not.”7

 If a facility needs to 

procure new instrumentation that achieves 1 percent of full scale or better accuracy and 

precision, EPA believes there is sufficient time to obtain the appropriate 

instrumentation. Further, EPA evaluated various types of scales that were available, 

and their ranges of achievable accuracy and precision. Through this evaluation EPA 

concluded that instrumentation was available that meets the accuracy and precision 

requirements. 

EPA acknowledges that the general provisions of the Final MRR allows for different 

accuracy for measurement instrumentation. However, this requirement is not 

comparable to what is being required in subpart I. The subpart I accuracy and 

precision requirement to achieve one percent of full scale or better is consistent with 

some other subparts covering fluorinated GHGs being finalized at this time. For 

example, subpart SS, which covers the manufacture of electric transmission and 

distribution equipment, requires facilities to achieve the same 1 percent of full scale 

accuracy and precision. EPA has concluded given the very high GWPs and often long 

atmospheric lifetimes of many fluorinated GHGs, it is important to gather gas 

consumption and hence emission information to a high degree of accuracy. 

Comment Summary 4.1.1.1-c: One commenter (0089) stated, “While we understand 

the need to quantify this material accurately, we don’t believe the 1 percent requirement 

is achievable or necessary. Some of the cylinders containing covered materials may 

hold as little as ten pounds of material when full. The amount of material remaining 

 

7

 See EPA-HQ-OAR-2009-0927-0131. 
November 2010 24

when the cylinder is changed may be as little as one pound or less. Therefore, this 

would require ensuring that the residual mass may vary by no more than 0.01 lbs each 

time the cylinder is changed. Not only is such a small quantity insignificant in terms of 

total emissions, but it is doubtful equipment can be found that can consistently measure 

to this level. Many existing gas cabinet scales are maintained to an accuracy of 1 

percent or even better at full scale. However, this same accuracy as a percent of mass 

will not be achieved when the cylinder is consumed all the way down to the residual 

heel and only a fraction of the initial mass remains. Some very large containers are 

actually weighed with truck scales, which usually have increments of 10 or 20 lbs. The 

same point is true when cylinders are monitored by pressure instead of mass. 

Commonly used pressure transducers are accurate to 1 percent of full scale, or 

sometimes better. Again, this percent accuracy will not be achieved when only a 

fraction of the full scale mass remains and it will not be possible to manage residual 

heels within 1 percent consistently. Intel suggests that a more reasonable requirement 

is that cylinder changes be maintained within a limit of +/- 10 percent, or +/- 5 lbs. 

mass, whichever is higher.” 

Response 4.1.1.1-c: It is possible that the commenter may have misunderstood the 

proposed precision and accuracy requirement. The April 2010 proposed preamble 

states: “We are proposing that all flowmeters, weigh scales, pressure gauges, and 

thermometers used to measure quantities that are monitored or used in calculations in 

this proposal have an accuracy and precision of 1 percent of full scale or better.” (75 FR 

18661, April 2010). In the final rule, EPA is requiring an accuracy and precision to be 

achieved on a full scale basis, as opposed to the more stringent true value basis, as the 

commenter described. Please see response to comments 4.1.1.1-b for information on 

the required accuracy and precision for measurement instruments, and responses in 

section 4.1.1.3 on heel factor recalculation requirements. 

4.1.1.2 Exceptional Circumstance 

Comment Summary 4.1.1.2-a: Five commenters (0099, 0110, 0112, 0123, and 0131) 

opposed the requirement to measure residual weight and pressure of a gas container in 

an exceptional circumstance. One commenter (0112), who stated that an exceptional 

circumstance is unlikely, proposed making measurement optional. In this instance, the 

facility would decide whether the extra burden of tracking and measurement is worth 

the cost relative to any inaccuracy gained from over-estimating gas usage, and hence 

emissions. Two commenters (0110 and 0123) stated that a difference of 20 percent 

from a trigger point may be in some cases such a small difference that it may be 

beyond the capacity of measurement equipment. These two commenters also stated 

that exceptional circumstances will happen so infrequently that not accounting for them 

would have a minimal effect on overall reporting accuracy and would not justify the 

increased tracking effort. Therefore, the two commenters suggested that the 

exceptional circumstance requirement be eliminated. One commenter (0131) reported 

that only 6 percent of 1,000 cylinder changes in a typical year would be considered to 

be under an exceptional circumstance. Two commenters (0099 and 0131) asserted 
November 2010 25

that the burden of additional manual tracking of exceptional circumstance gas 

containers would be unwarranted given the unlikely event of underreported gas usage. 

One commenter (0131) presented the following information: “The 2010 Supplemental 

ISMI Survey asked about exceptional circumstances for cylinder changes differing from 

the trigger point. Of the respondents, only one facility reported that because they 

currently track all cylinders, they could track these exceptional cylinder changes. 

According to this company, however, exceptional cylinder changes occur very 

infrequently (facility reported 6 percent or less). The typical reasons for changing out a 

cylinder at a different point are customer request and engineering development 

activities. Given the sensitive nature of semiconductor processes, cylinders would 

rarely – if ever – be changed 20 percent past the trigger point by any facility; they would 

only be changed prematurely – or before the trigger point had been reached. A facility 

can change out 1,000 or more cylinders of fluorinated GHG and N2O per year. Each 

cylinder changed out 20 percent prematurely would have to be specifically removed 

from the purchase record accounting and the calculation of Equation I-10, measured, 

and tracked manually. The burden of this independent tracking is not warranted given 

that under-reporting of gas usage is highly unlikely.” 

Response 4.1.1.2-a: EPA does not agree with the commenters’ assertions and 

suggestions. EPA appreciates the information provided by the commenter (0131) on 

one company’s actual experience with tracking exceptional circumstances, but EPA can 

not make broad conclusions about the industry based on one company’s experience. 

EPA is finalizing the requirement that where a container is changed in a exceptional 

circumstance (a point that differs by more than 20 percent from the trigger point for 

change out used to calculate the facility-wide gas-specific heel factor for that gas 

container type), rather than using a heel factor, a facility must weigh that container or 

measure the pressure of that container with a pressure gauge. 

Given that facilities will have to track cylinders to some degree to adhere to other gas 

consumption requirements of the rule and that the occurrence of exceptional 

circumstances, as stated by commenters, is infrequent, quantifying the exceptional 

circumstance cylinders should not impose a high level of burden on facilities. 

Additionally, EPA does not agree that it should be optional to track exceptional 

circumstances because this may result in undesirable inconsistencies among methods 

facilities are using to estimate gas consumption. It would be most beneficial to EPA to 

analyze emissions and trends using data and information that has been consistently 

developed (where feasible). The commenters who asserted that a difference of 20 

percent from a trigger point may be in some cases such a small difference that it may 

be beyond the capacity of measurement equipment provided no supporting evidence of 

this. For all of the aforementioned reasons, EPA is maintaining the exceptional 

circumstance requirement in the rule. It is a means to gather accurate facility-level 

information and should impose minimal burden on facilities because exceptional 

circumstances are infrequent. 

In regards to the commenter who stated that the under-reporting of gas usage is highly 

unlikely, EPA would like to clarify that the requirement to weigh or measure the 
November 2010 26

pressure of a cylinder that is changed in an exceptional circumstance applies not only 

to instances where a cylinder is changed 20 percent past a trigger point. The 

requirement applies to instances where a cylinder is changed at any point that differs 

(over or under) by more than 20 percent from a trigger point for change out. A primary 

goal of this rule is to gather accurate (i.e., neither under or over-reported) facility-level 

emissions. EPA has determined that this requirement contributes to meeting that goal. 

4.1.1.3 Recalculation of Facility-Wide Gas-Specific Heel Factors 

Comment Summary 4.1.1.3-a: Five commenters (0089, 0099, 0112, 0123, and 0131) 

opposed the 1 percentage point threshold for recalculating heel factors. As an 

alternative, four commenters (0099, 0112, 0123, and 0131) recommended that heel 

factors should be recalculated if a trigger point for change out used to establish a heel 

factor differs by 5 percent or more of full weight or pressure or from the current trigger 

value. Another commenter (0089) suggested that cylinders be maintained at within a 

limit of +/- 10 percent or +/- 5 lbs. mass, whichever is higher. One commenter (0112) 

noted that changes in the production process and experimentation often produce trigger 

changes of a few percent, but that a recalculation would be burdensome. The 

commenter explained, “The heels that are returned to the manufacturer represent 4.3 

percent of the total gas used. A 1 percent increase in the trigger point will only 

represent an increase in usage (assuming the trigger point was reduced by 1 percent) 

of .4 percent, an extremely small number. Setting an adjustment factor of 5 percent 

change in the trigger point arguably will only increase use by 0.2 percent across the 

facility assuming that all changes increased the gas utilized from the cylinder. In fact, 

the majority of the trigger changes result in a decrease in the gas used from the 

cylinder because of quality concerns generated by maximizing the use of gas in the 

cylinders.” Two commenters (0099 and 0131) explained, “In the course of minor 

operational modifications, a facility may adjust a certain trigger point for a single 

cylinder or a small quantity of cylinders by a small amount to determine the effect on 

the process. This may be a temporary or permanent adjustment – and may only be for 

a small number of cylinders of that gas type. In some of these instances, the 

percentage change from the original trigger point may exceed the 1 percent 

requirement to recalculate, but may not result in any significant change in the amount of 

residual gas in the cylinder due to the amount of gas contained in the cylinder. A 

facility-wide gas-specific heel factor recalculation requirement of 5 percent of trigger 

point may be more reasonable and practical and would likely be representative of any 

significant change. It would also reduce the burden of tracking multiple facility-wide gasspecific changes (and the intervals during which the change applied) that may only be 

temporary.” 

Response 4.1.1.3-a: EPA has taken into consideration all the commenters’ concerns. 

In particular, EPA understands commenters’ concerns about the burden associated 

with tracking minor modifications to facility processes. EPA appreciates commenters’ 

various suggestions about how to modify the heel factor recalculation requirement, and 

has decided to accept the suggestion to modify the requirement to be based on a 5 

percent change in trigger point as opposed to the previously proposed 1 percent. 
November 2010 27

Specifically, in the final rule, EPA has finalized a provision which requires facilities to recalculate a facility-wide gas-specific heel factor if a trigger point for change out for a gas 

and container type differs by more than 5 percent from the previously used trigger point 

for change out for the gas and container type. EPA has determined that this 

modification will help to balance the burden imposed on facilities with EPA’s goal of 

obtaining accurate, facility-level data. Requiring heel factor recalculation at a 5 percent 

change helps reduce burden by excluding recalculations for minor operational 

modifications that may be made to investigate process performance while it also 

captures any substantial changes in gas consumption practices. 

Comment Summary 4.1.1.3-b: Two commenters (0110 and 0123) requested more 

specificity in the heel factor recalculation requirement in order to better understand the 

meaning and benefit of it. 

Response 4.1.1.3-b: In the final rule, EPA has clarified the language around the 

recalculation requirement to better articulate the requirement by making some editorial 

changes to the regulatory text. EPA is finalizing § 98.94 (b)(5) as follows: 

You must re-calculate a facility-wide gas-specific heel factor if you use a trigger 

point for change out for a gas and container type that differs by more than 5 

percent from the previously used trigger point for change out for that gas and 

container type. 

EPA is finalizing the requirement for facilities to recalculate facility-wide gas specific 

heel factors as a means for EPA to ensure that facilities are accurately estimating gas 

consumption even as facilities’ operations change over time. Please see response 

4.1.1.3-a for a more detailed discussion regarding the final requirements for heel factor 

recalculation. 

Comment Summary 4.1.1.3-c: One commenter (0095) requested guidance on how far 

back in time to go in order to recalculate a heel factor, if the heel factor differs by more 

than 1 percent from the previous heel factor. 

Response 4.1.1.3-c: Because EPA is requiring facilities to rely on facility-specific 

trigger point for change out for developing heel factors and because a change-out 

factor may be used provided it has not changed by more than 5 percent, there is no 

need to go back in time to recalculate a heel factor. Please see response to comment 

4.1.1-b on the requirements for calculating heels factors. 
November 2010 28

4.1.2 Apportioning Gas Consumption to Process Categories with a 

Facility-Specific Engineering Model Based on an Activity 

Indicator 

Comment Summary 4.1.2-a: One commenter (0131) asserted the following: “The 

results of the supplemental 2010 ISMI survey clearly indicate that using wafer pass as 

the required metric to apportion gas usage is not appropriate for a variety of reasons.” 

The commenter stated that fab tracking systems and tool recipe data based on wafer 

pass tracking are not readily available, and recipe mixes are very complex and 

dynamic, with different types and ranges of recipes varying literally on a daily basis due 

to changes in production mix. The commenter asserted that “wafer pass, therefore, 

may not be viable as a required quantifiable indicator for all facilities. The ISMI 

assessment of semiconductor facilities in the United States has indicated that each 

facility is unique in terms of its wafer size, process technologies and product mix, gas 

distribution systems, and production management systems. As such, there is no ‘one 

size fits all’ approach to apportion gas use and estimate perfluorocarbon (PFC) process 

emissions.” Two commenters (0099 and 0112) also asserted that wafer passes was not 

feasible as a quantifiable indicator due to the complexity and variability of process 

recipes. 

In a similar sentiment, another commenter (0110) asserted, “In the case of etch 

processes in particular, it is common to have an etch process start on one film type and 

finish on a different film in the same wafer pass; i.e., oxide, nitride, polysilicon in a 

single wafer move. Etch recipes in particular vary from part to part and film type/stack, 

and are modified quite frequently, so re-establishing gas consumption for each new 

etch recipe would be burdensome. Over the period of development and production of a 

single part type, hundreds of unique recipe changes are expected to occur.” 

One commenter (0131) further proposed the following: “Apportionment must occur 

based on at least one quantifiable indicator and engineering judgment. A facility may 

determine the most appropriate indicator based on its configuration and 

processes...Flexibility to choose indicators facility-by-facility by process category will 

provide more accurate estimates now and the option to implement improved methods 

later when new technologies develop.” The commenter provided several example 

methodologies for apportioning gas consumption. In summary the commenter stated, 

“In all cases, the facility develops a location-specific fluorinated GHG gas use 

monitoring and calculation plan detailing the specific data collection processes, 

apportionment methodologies, and calculation and modeling processes used to 

determine actual facility gas use and emissions. The specific quantifiable indicators 

used should not be prescribed by this Rule.” Another commenter (0099) also expressed 

similar sentiments. 

One commenter (0112) supported the “Refined Process” concept, but recommended a 

modified approach to apportioning gas consumption. The commenter argued that 

basing the method on wafer passes is not feasible and would cause a facility to have to 

make substantial investments in upfront and operating costs. The commenter stated, 

“The proposal for apportioning fluorinated GHG (PFC) use across process types and 
November 2010 29

the number of proposed process categories does not take into account the limited 

capabilities of the majority of the U.S. semiconductor manufacturing facilities to monitor, 

report, and segregate PFC gas use based on process data and wafer passes.” The 

commenter recognized that there is no one-size-fits-all approach to apportion gas 

usage but provides a detailed process by which it may occur at their facility. The 

commenter (0112) provided details on alternative apportioning methodologies for EPA 

to consider, but maintains that the best approach for apportioning gas consumptions is 

for a facility to develop site-specific methods. 

Four commenters (0099, 0100, 0110, and 0131) presented similar sentiments that a 

facility should be permitted to use a Facility-Wide Apportioning Protocol based on 

appropriately selected quantifiable indicators for a facility’s process tool capabilities and 

configurations and engineering judgment. Two commenters (0099 and 0131) asserted 

that most facilities will need to employ more than one quantifiable indicator in facilityspecific engineering models to accurately apportion gas consumption. The 

commenters also asserted that some facilities may already have facility management 

software which obtains process and tool information that may be used in models to 

apportion gas consumption. 

Response 4.1.2-a: EPA understands commenters’ concerns with the proposed method 

to apportion gas consumption based on wafer pass and is sensitive to the burden and 

the potential limitations on operational flexibility this may have on facilities. EPA has 

therefore modified the gas apportioning requirements for the final rule (see §98.94(c)). 

EPA will permit the use of facility-specific engineering models based on a quantifiable 

metric selected by the facility (such as wafer passes or wafer starts) to apportion gas 

consumption. In the final rule, facilities are required to develop an engineering model 

that utilizes measurable process information to develop apportioning factors. EPA does 

not specify the quantifiable metric that must be used in these models; rather, EPA is 

allowing reporters the flexibility to select the most appropriate quantifiable metric on 

which to base the facility-specific engineering model, provided model documentation 

and verification requirements are met. EPA has concluded that the gas apportioning 

methods provided in the final rule should accommodate approaches suggested by the 

commenter. See the preamble section D, Electronics Manufacturing (subpart I), section 

3 (“Summary of Comments and Responses”), for a more detailed response to 

comments on apportioning gas consumption. 

Comment Summary 4.1.2-b: One commenter (0122) stated that they employ the IPCC 

Tier 2b methods in their emissions reporting for their operations in Europe. In this 

regard, the commenter noted that they routinely track PFC use for CVD chamber 

cleaning (using in-situ NF3 cleaning, coupled with POU abatement) and etch processes 

(also coupled with POU abatement) based on configurations of equipment at the 

facility. However, the commenter stated that there is no mechanism to apportion PFC 

use and emissions to specific etch subcategories because it would be very difficult to 

collect such data and match it to specific calculation of PFC gas consumption. 
November 2010 30

Response 4.1.2-b: EPA does not agree with the commenter that it is too difficult to 

calculate emissions from more than one broad etch category. EPA has concluded that 

it is feasible for facilities to apportion gas consumption to more than just two broad etch 

and clean categories using the methods EPA has prescribed in the final rule. EPA 

understands that while some semiconductor facilities may not already have the 

necessary mechanisms in place to track and record the necessary information to 

apportion gas consumption, in the final rule, EPA is permitting a method that allows 

facilities to select and use the quantifiable metric that works best for a particular facility. 

Wafer pass counts in modern fabs, for example, may be available through the 

manufacturing execution software (MES) that comes with process equipment. MES is 

capable of tracking the activities associated with each piece of manufacturing 

equipment. In older fabs that may not employ MES, wafer pass counts are available 

through process flow information for each product manufactured. While wafer pass 

count information is available, EPA understands that it may not be routinely gathered 

for gas apportioning purposes. Instead, it may be gathered at the request of facility and 

product line managers for purposes of managing work in process load, reducing fab 

cycle time, reducing product cycle time, identifying and removing process bottlenecks, 

etc. For estimating gas usage, it appears wafer pass counts would be collected either 

electronically or physically and used to develop the apportioning model. For an 

expanded explanation of this example, please see the Electronics Manufacturing TSD 

available in the docket (EPA-HQ-OAR-2009-0927). 

EPA understands that facilities may incur a cost to implement the mechanism 

necessary to track and record already existing quantifiable metrics, such as wafer pass 

or wafer starts, to apportion gas consumption; however, EPA has made efforts in the 

final rule to balance the burden imposed on facilities with EPA’s goal of obtaining 

accurate, facility-level data. EPA has accounted for such costs in the Economic Impact 

Analysis (see sections 4 & 5 of the Economic Impact Analysis available in the docket, 

EPA-OAR-2009-0927). 

Please see the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Responses to Comments and Responses”), for the response to 

comments on apportioning gas consumption. Please also see response to comment 

4.1.2-a for apportioning gas consumption using facility-specific engineering models 

based on quantifiable metrics 

Comment Summary 4.1.2-c: One commenter (0110) questioned EPA’s statement in 

the proposal that engineering judgment was not acceptable in estimating apportioned 

gas usage. The commenter stated that at its facilities, engineering judgment and other 

factors are used for air toxics and priority pollutants to fulfill other regulatory 

requirements (e.g., reporting of annual emissions of criteria pollutants and hazardous 

air pollutants), and the commenter questioned why engineering judgment is not also 

acceptable for apportioning in the GHG MRR. 
November 2010 31

Response 4.1.2-c: While EPA is not opining on the requirements of other regulatory 

programs, in contrast to those requirements that generally focus on whether a facility’s 

emissions are below a specified limit, this rule focuses on establishing each facility’s 

annual GHG emissions in tons per year. For this reason, EPA is finalizing certain 

requirements in this rule to ensure that EPA receives accurate facility-level emissions 

data. 

EPA is not allowing the use of “engineering judgment” to develop apportioning factors 

because, unlike quantifiable metrics, engineering judgment is subjective and could 

cause apportioning factors to vary. This presents an issue for multiple reasons. First, 

without the use of a quantifiable metric on which to base gas apportioning factors, it is 

not possible for EPA to verify the method by which gas consumption is apportioned to 

process recipes, sub-types, or types. EPA must be able to verify the data being used to 

calculate emissions. Second, engineering judgment is not always accurate, precise, or 

repeatable. Third, changes in staff responsible for developing apportioning factors 

(e.g., staff turnover, staff reassignments, changes in priorities, or some combination 

thereof within a facility) may lead to unintended variations in gas consumption 

calculations, and hence emission estimates. 

As a result, the use of engineering judgment to apportion gas consumption to process 

recipes, sub-types, or types, as opposed to the use of an engineering model based on 

a quantifiable metric, would lead to increased uncertainty in reported emissions. EPA is 

permitting the use of considerable engineering knowledge in the design of a facility’s 

apportionment model because the quality of that knowledge will be tested based on 

empirical data via the required performance verification of the model. An engineering 

model that apportions gas consumption based on tool-specific activity records or logs is 

preferred to engineering judgment based on general technical knowledge of processes 

utilized at a facility because tool-specific activity is quantifiable. Please see response to 

comment 4.1.2-a for additional details on the methodology in the final rule for 

apportioning gas consumption using facility-specific engineering models based on 

quantifiable metrics. 

Comment Summary 4.1.2-d: One commenter (0089) expressed its support of the use 

of facility-specific engineering models to apportion gas consumption, and asserted that 

the way the rule was proposed prohibits the use of some valid approaches. The 

commenter noted that a 2006 IPCC Tier 3 Method (Tier 3) is used at its facility in which 

gas usage is measured at a broader facility level and then apportioned down 

appropriately based on knowledge of process recipes. Specifically, the commenter 

stated, “The actual apportionment quantifying the portion of material used in a given 

group of process steps is estimated based on knowledge of the process recipe. Intel’s 

factories typically manufacture one or two different product lines, each of which has a 

tightly defined set of process steps required, and a recipe for each of these steps that 

specifies the amount of chemical used. The factories also track the number of wafer 

starts of each different process the facility is running. The recipe information detailing 

the use breakdown is combined with the number of wafer starts for each process run to 

develop an overall estimate of material used on different process steps. While the 
November 2010 32

number of wafer passes is a factor in determining the amount of chemical an operation 

uses, it is not an indicator that is ultimately tracked. This method definitely relies on 

some quantifiable indicators such as total fab gas usage and total wafers 

manufactured. However, the apportioning of gas among process steps also involves 

some engineering judgment. The gas use in those individual steps is not actually 

measured, but is assumed to be proportional to the amounts specified in the process 

recipes.” The commenter suggested that the use of knowledge of process operations 

gas consumption should be allowed, even where that use is not specifically measured 

at the tool level. 

 

Response 4.1.2-d: In the proposed rule, EPA would have required facilities to use 

wafer pass as the quantifiable indicator with which to apportion the facility’s gas 

consumption. At the time the rule was proposed, the information available to EPA 

about methods to apportion gas consumption was limited. To this end, in that proposal, 

EPA also stated that it recognized that facilities may use other types of quantifiable 

indicators of gas-usage activity to develop facility-specific engineering models to 

estimate gas consumption, and requested information about other quantifiable 

indicators. 

It is unclear how the commenters specific suggestions to allow for the use of both 

knowledge of process operations and engineering judgment as a means for 

apportioning gas usage would actually be implemented in that is unclear what 

quantitative information would be tracked or measured and used. Therefore it is not 

feasible for EPA to finalize the suggested method in the rule. However, based on this 

comment, other information received in the public comment period, and additional 

analyses, EPA has modified the gas apportioning requirements in the final rule to 

provide more flexibility. In the final rule, a facility has the option to choose the 

quantifiable metric from which to base their facility-specific gas apportioning model 

provided the facility documents and verifies the model. The method for gas 

apportioning in the final rule will ensure that facility-specific models result in 

apportioning factors that are precise and accurate. Please see the preamble section D, 

Electronics Manufacturing (subpart I), section 3 (“Summary of Comments and 

Responses”), for the response to comments on apportioning gas consumption. Please 

also see response to comment 4.1.2-a for additional details on the methodology in the 

final rule for apportioning gas consumption using facility-specific engineering models 

based on quantifiable metrics. 

Comment Summary 4.1.2-e: One commenter (0095) asserted that for a 

semiconductor R&D facility, it will be difficult to apportion gas consumption for the 

Refined Method because one bulk cylinder may support multiple chambers of process 

tools on which multiple refined process categories may be run. The commenter stated 

that determining the amount of gas fed into each process category is therefore difficult 

because gas utilization varies between chambers depending on business needs, 

customer demands, and concept and feasibility studies for new processes. 
November 2010 33

Response 4.1.2-e: EPA is clarifying in the final rule that if a facility engages in R&D 

activities, they are not required to report the emissions from that activity. Please see 

response to comment 1-b for a more detailed discussion on the exemption for R&D 

activities. Please also see the preamble section D, Electronics Manufacturing (subpart 

I), section 3 (“Summary of Comments and Responses”), for the response to comments 

on apportioning gas consumption. 

 

Comment Summary 4.1.2-f: One commenter (0110) stated that while it meters gas 

that is going to processes using mass flow controllers (MFCs), their current operations 

do not log and record flow data. The commenter asserted that to log and record this 

data would be burdensome. 

Response 4.1.2-f: Although facilities may utilize flow meters to apportion gas 

consumption, EPA is not requiring gas consumption to be apportioned based on 

information gathered from flow meters. In the final rule, EPA has provided a flexible 

method for facilities to develop apportioning factors. These flexible requirements are 

intended to reduce the burden associated with apportioning gas consumption that more 

stringent requirements, such requiring the measurement of mass flow of gases using 

mass flow meters, may impose. 

Please see response to comment 4.1.2-a for additional details on the methodology for 

apportioning gas consumption finalized in the rule. Please also see also the preamble 

section D, Electronics Manufacturing (subpart I), section 3 (“Summary of Comments 

and Responses”), for additional response to comments on apportioning gas 

consumption. 

 

4.2 Emission Estimation Methods for Semiconductor Facilities 

Comment Summary 4.2-a: One commenter (0122) stated that semiconductor 

manufacturing processes change frequently, with ongoing improvements to current 

methodologies requiring installation of new or modified equipment on a regular basis. 

The commenter further stated that larger-scale migrations to the next “technology 

node”- representing the ever-smaller features created on the silicon wafer—typically 

happen as often as every two years. The commenter asserted that when EPA 

postponed finalizing the electronics portion of the GHG Reporting Rule, the Agency 

recognized the difficulties and complexities inherent in estimating emissions in the 

semiconductor manufacturing sector. The commenter further stated, “There are 

currently no agreed-upon methods for quantifying and reporting PFC emissions from 

semiconductor and other electronics facilities, other than those developed under the 

IPCC.” 

Response 4.2-a: EPA’s goal for this rule differs from the goal of the IPCC 2006 

Guidelines. EPA's goal for this rule is to require facilities to report as accurate as 

practical, facility-level emissions, while the IPCC methods are intended for voluntary 

reporting of country-level emissions inventories. In addition, since the IPCC methods 

were developed (based on information collected prior to 2006), the industry has moved 
November 2010 34

from manufacturing 200 mm to 300 mm substrates (with higher gas flows), has reduced 

feature size 3-fold with a corresponding 20 percent increase in number of levels 

manufactured (resulting in more etching and chamber cleaning), and adopted new 

etching and chamber cleaning methods to achieve the required technical and economic 

performance (requiring the use of updated emission factors). 

 

The emissions estimation methods for electronics manufacturing facilities required in 

the final rule may be viewed generally as an extension from and building upon the 

IPCC’s methods; however EPA’s required methods are more distinct in terms of 

applicability and level of detail. EPA has improved upon the IPCC methods in several 

ways. First, the number of emitting categories (process types/sub-types) has been 

expanded from the IPCC methods. Second, the emission factors in the final rule have 

been updated, to the extent possible based on information available to EPA, from the 

IPCC Tier 2b factors. Third, EPA has also finalized methods for estimating gas 

consumption in this rule that are improvements over the IPCC gas consumption 

estimation methods (e.g., the use of facility-wide, gas specific heel factors, as opposed 

to a default factor – see section 4.1.1). And lastly, EPA has also made improvements 

over the IPCC methods in regards to accounting for controlled emissions; the IPCC 

methods utilized a default DRE that was based on anecdotal information rather than the 

direct in-fab measurements EPA used to develop its default value for DRE (see section 

5.2). These updates and improvements in emission estimation methods, moving 

forward from the IPCC methods, are crucial for gathering accurate facility-specific 

emissions data in an industry that is constantly evolving, and will enable EPA to collect 

data for use in developing future GHG policies and programs. 

Please see response to comments 4.2.3-a and b for more discussion on why EPA is 

not finalizing the Tier 2b for semiconductor manufacturing facilities. Please also see 

the preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses”), for a more detailed response to comments on emission 

estimation methods for semiconductor facilities and apportioning gas consumption. 

4.2.1 Refined Method 

Comment Summary 4.2.1-a: One commenter (0122) stated that it is highly uncertain 

whether the Refined Method would actually reduce uncertainty in emissions 

calculations. The commenter also argued that because a mature foundry fab requires 

the use of a variety of process flows and varying recipes to be run at any one time, the 

complexity and cost associated with the Refined Method is not warranted. One 

commenter (0110) suggested that the goal of the proposed Refined Method is good, 

but that it does not accomplish its goal and imposes a significantly greater burden on 

industry. The commenter also asserted that any increase in accuracy from using the 

Refined Method in comparison to the Tier 2b method is minimal. Two commenters 

(0099 and 0131) stated that the Refined Method stems from a deeply flawed 

uncertainty analysis and misunderstandings or incorrect assumptions of current 

industry processes. The commenters asserted that the Refined Method would result in 

significant capital and ongoing compliance costs. One commenter (0099) also stated 

that “It [the Refined Method] would not achieve EPA’s stated objective to obtain 
November 2010 35

‘information...relevant to implementing the existing CAA’ that ‘produces a more 

representative and accurate emissions estimate’ (75 FR 18655 and 18663, April 2010).” 

The commenter argued that further data collection under the Refined Method should 

not be pursued. 

Another commenter (0108) stated that it does not have the necessary data available to 

comply with the Refined Method, and that compliance would be unnecessarily 

burdensome. The commenter also expressed concern that the Refined Method would 

not lead to accurate results. The commenter stated that, “In the very early 1990’s when 

crafting Microchip’s emissions profiles for its first (Tempe Fab 2) air permit we 

attempted to use a process gas flow recipe-based methodology to estimate gas usage 

tool by tool and per wafer. The result significantly underestimated overall gas usage 

compared to the quantity issued from raw material stockrooms because gases flowed 

for a variety of calibration and maintenance procedures where wafers were not 

processed; gas flow rate and duration for these procedures were not consistent over 

time. The recipe did not adequately characterize total gas usage. Only a per-gas 

inventory-based approach was accurate.” 

Response 4.2.1-a: It is unclear how the commenter (0108) implemented a method to 

use a process gas flow recipe-based methodology to estimate gas usage tool by tool 

and per wafer because the commenter did not provide any supporting or detailed 

information. It is also not clear how the commenter quantified “significantly 

underestimated gas usage,” or how the commenter arrived at this conclusion. Based 

on the limited information the commenter provided pertaining to their experience in 

using a process gas flow recipe-based methodology to estimate gas usage, at this time 

EPA can not compare the method the commenter attempted to use, and the methods 

EPA is requiring to apportion gas consumption in the final rule. As such, EPA can also 

not draw inferences about the robustness or accuracy of the method described. Please 

see section 4.1.2 and the preamble section 3 (“Summary of Comments and 

Responses”), for a more detailed response to comments on apportioning gas 

consumption. 

Please see the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Comments and Responses”), for a more detailed response to comments 

on emission estimation methods for semiconductor facilities and apportioning gas 

consumption. Please also see sections 8 and 10 for more information on the costs 

associated with the rule and the uncertainty associated with the Refined Method, 

respectively. 

Comment Summary 4.2.1-b: One commenter (TRANS-DC-03) noted their shared 

interest with EPA in accurate, reliable data, and system-wide accuracy. The 

commenter encouraged EPA to ensure that the Refined Method does indeed provide 

accurate data. 

 

Response 4.2.1-b: EPA has determined that the methods provided in the final rule 

effectively balance EPA’s objectives of obtaining accurate, facility-level data against 
November 2010 36

burden to industry. Please see response to comment 4.2.1-a on the Refined Method 

and the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Comments and Responses”), for a more detailed response to comments 

on emission estimation methods for semiconductor facilities. 

4.2.1.1 Other Methods of Categorizing Processes 

Comment Summary 4.2.1.1-a: One commenter (0112) responded to EPA’s request for 

comment on the use of feature-based or filmed-based apportioning instead of processtype categories and asserted that categorization by etch type is the most effective 

approach as multiple categories for etch processes are developed. 

Response 4.2.1.1-a: EPA appreciates the commenter’s input. However, in the final 

rule, EPA is not requiring a method to estimate emissions for semiconductor 

manufacturers that is based on plasma etching sub-types (please see response to 

comment 4.2.1-a). 

It is unclear what the commenter’s preference for “etch type” is referring to, that is, it is 

unclear if the commenter is associating etch-type with either film-based or featurebased etching sub-types. Nonetheless the methods EPA has included in the final rule 

are not based on etching sub-types in this rule. However, EPA maintains that 

estimating emissions based on process sub-types for etch with robust default emission 

factors would result in more accurate facility-level emission estimates as compared to 

estimating emissions using a single broad etch process type. This is because the 

variability in processes would be captured with more granular etch process sub-types. 

In future years EPA may evaluate the recipe-specific emission factors received through 

the final rule to determine whether a sufficiently robust data set exists to establish 

default emission factors for process sub-types for plasma etching. In the future, EPA 

may consider requiring the semiconductor facilities that will be using a default emission 

factor for the etch process type under the final rule to estimate and report emissions 

using an approach based on multiple etch and chamber clean process sub-types 

similar to the Refined Method EPA proposed in April 2010. 

At this time, EPA does not have enough data and information to determine if etch subtypes established in the future would be feature-based or film-based. For this reason, 

in the final rule, EPA is requiring facilities that develop recipe-specific emission factors 

for etch recipes to identify these factors by both the film and substrate that was etched 

and the feature type that was produced. EPA plans to consider such information 

received as a result of this final rule in potential future actions. 

4.2.1.2 Draft Default Emissions Factors for Refined Process Categories 

Comment Summary 4.2.1.2-a: Two commenters (0099 and 0131) noted that 

“emission factor coverage on the multiple etch categories is inadequate and data 

quality is not sufficient to support the differentiation of etch processes into multiple 
November 2010 37

categories...The overarching issue is that both the number and accuracy of the 

available etch emissions factors is not adequate to support refinement of the etch 

category for this rule.” 

Response 4.2.1.2-a: EPA agrees with commenters that the available data at the time 

of the proposal was insufficient to support establishing default emission factors for etch 

process sub-types. EPA did not receive enough additional data during the comment 

period to address this insufficiency.8

 Accordingly, EPA is finalizing provisions in the 

rule that do not establish default emissions factors for etch sub-types. EPA can not 

make any assertions about the quality of the data at this time given limited information, 

and the commenter who noted that the data quality was not sufficient did not provide 

information supporting their claim. Please see the preamble section D, Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for the 

response to comments on emission estimation methods for semiconductor facilities. 

Comment Summary 4.2.1.2-b: One commenter (0131) requested to be provided with 

the background data used to generate the Refined Method emission factors. 

Response 4.2.1.2-b: EPA made available to the public all of the underlying data used 

to generate the Refined Method emission factors in Table 5 of the report Draft Emission 

Factors for Refined Semiconductor Manufacturing Process Categories (EPA-HQ-OAR2009-0927-0073). In the aforementioned report, EPA was also transparent about the 

details on the methods and assumptions that were used when developing the proposed 

Refined Method emission factors. 

Comment Summary 4.2.1.2-c: One commenter (0110) noted a lack of understanding 

between EPA and industry regarding the availability of emission factor data to support 

the Refined Method. Two other commenters (0099 and 0131) asserted that for the 

majority of GHG usage (72 percent), the emission factors are unchanged compared to 

the Tier 2b emission factors. The commenters asserted that this highlights the 

appropriateness of using the Tier 2b factors at this point in time. One of the 

commenters (0131) also supported the use of the Tier 2b emission factors by stating, 

“The 2006 IPCC Tier 2b methodology is a globally accepted method for estimating 

GHG emissions for a semiconductor manufacturing facility. The Tier 2b factors were 

developed using 190 distinct measured emission factors for CVD chamber cleaning and 

etch processes and are accurate for developing an inventory of GHG emissions.”9,10 

 

8

 In its proposed rule (75 FR 18652, April 2010), EPA published a range of values for each emission 

factor for the nine proposed process categories. EPA proposed a range of values because it had not 

received sufficient data to select a specific value within each range. Based on additional information 

received after publication of the proposed rule, EPA published a Notice of Data Availability where it made 

available to the public draft default emission factors for semiconductor manufacturing refined process 

categories (75 FR 26904, May 2010). As of publication of the final rule, EPA has not received additional 

data (i.e., utilization and by-product formation rates). 9

 This commenter supported the use of a mix of the IPCC Tier 2b factors and EPA NODA factors for the 

“Alternative Refined Method.” 
November 2010 38

Response 4.2.1.2-c: Based on industry public statements, EPA understood that 

equipment manufacturers were measuring emissions and emission factors by virtue of 

device manufacturer equipment purchase requirements, augmented by ISMI Guidelines 

for Emissions Characterization. EPA learned, however, through the development of its 

Notice of Data Availability; Default Emission Factors for Semiconductor Manufacturing 

Refined Process Categories, May 2010 (NODA) that this was not the case, and that few 

additional emission factor measurements had been made (since the start of the 2006 

IPCC process in 2004) by either equipment manufacturers or device manufacturers. 

In light of the lack of available data for some categories, EPA has not established 

emission factors for all of the proposed Refined Method process categories. Although 

EPA agrees that many of the emission factors proposed for the Refined Method in the 

May 2010 NODA have not substantially changed from the IPCC Tier 2b factors, EPA 

has published default emission factors that improve upon the IPCC Tier 2b factors 

because they reflect a more recent and robust set of data. Please see response to 

comment 4.2.3-a and b on why EPA is not finalizing the Tier 2b method for 

semiconductor manufacturing facilities. 

EPA used industry data provided in cooperation with Semiconductor Equipment and 

Materials International to develop the published factors in the May 2010 NODA.11 The 

data EPA received were data that had been previously used to establish the 2006 IPCC 

emission factors, as well as additional and more recent emission factor data that were 

not available during the 2006 IPCC factor development. Because the data set EPA 

used to develop the emission factors presented in the May 2010 NODA is more robust, 

EPA elected to publish updated default factors using the data presented in the May 

2010 NODA as opposed to allowing the use of the IPCC Tier 2b factors. 

Comment Summary 4.2.1.2-d: Two commenters (0099, 0131) noted that an emission 

factor development process similar to the AP-42 process could be utilized in the future 

if EPA wants to establish revised emission factors and improve the accuracy of the 

data. As an alternative, the commenters also suggested that EPA and industry engage 

in a memorandum of understanding (MOU) “to develop and execute a voluntary, 

cooperative plan...to develop emissions factors, with defined uncertainties, to model 

and determine the degree of refinement that can be achieved in the uncertainty of the 

emissions calculations.” One commenter (0131) also stated, “...it is not appropriate to 

include such emission factors in the text of the Re-Proposed Rule itself, since modifying 

or adding new emission factors as new tools and processes are adopted, or as 

emissions factors for existing tools are refined, would be hampered by the formal 

rulemaking that would be required to modify the text of the Rule. Moreover, the short 

period of time between the Rule proposal and finalization simply does not provide 

sufficient opportunity to develop appropriate emission factors.” 

 10 This commenter supported the use of a mix of the IPCC Tier 2b factors and EPA NODA factors for the 

“Alternative Refined Method.” 

11 See Appendix C of the Electronics Manufacture TSD (Mar. 22, 2010) and the May 2010 NODA and 

accompanying report for more details.
November 2010 39

Response 4.2.1.2-d: EPA appreciates the industry’s offer to work with EPA to develop 

emission factors; however, in general, EPA disagrees with commenters’ suggestions. 

While EPA is not ruling out the possibility of using the AP-42 process as a means to 

update emission factors for electronics manufacturing in the future, EPA is not finalizing 

such a process at this time. EPA has determined that at this time it is most appropriate 

to develop and update emission factors for electronics manufacturing through the 

Mandatory Reporting Rule regulatory framework. The objective of the Mandatory GHG 

Reporting Program is to obtain facility-specific data to use in developing future GHG 

policies and programs. To serve its intended purpose, EPA believes that the data must 

be collected according to consistent methodologies that are prescribed in the rule. 

Similarly, EPA is not ruling out the possibility of engaging with the industry to develop 

emission factors for electronics manufacturing through an MOU. However, for 

purposes of meeting EPA’s goals for this rule, EPA has determined that it is most 

appropriate to develop and update emission factors for electronics manufacturing 

through a regulatory framework where facilities are required to use consistent 

methodologies. 

Please also see the preamble to the Final Rule for additional discussion on how the 

GHG Reporting Program relates to EPA and U.S. government climate change efforts 

and to other State and Regional Programs (74 FR 56265-56266, October 2009). In 

addition, please refer to the preamble to the proposed rule on Mandatory Reporting of 

Greenhouse Gases: Additional Sources of Fluorinated GHGs (75 FR 18655, April 

2010). 

4.2.1.2.1 Frequency and Process of Updates 

Comment Summary 4.2.1.2.1-a: One commenter (0128), who supported the adoption 

of the Tier 3 method, insists that EPA commit to frequently reviewing and updating 

default factors if EPA continues to rely on less accurate default emission factors. The 

commenter acknowledged the release of the draft emission factors published in EPA’s 

NODA. The commenter encouraged EPA to make all of the data underlying the 

emission factors available to the public for independent verification and review of the 

data and emission factors. 

Response 4.2.1.2.1-a: EPA believes that, where feasible, it is important to provide the 

public with an opportunity to review the underlying data that EPA uses to develop 

emission factors. All of the underlying data that was used to establish the default 

emission factors published in the final rule for semiconductor manufacturing were made 

available to the public in Table 5 of the report to the May 2010 NODA (Draft Emission 

Factors for Refined Semiconductor Manufacturing Process Categories, EPA-HQ-OAR2009-0927-0073). Please see the Electronics Manufacture TSD (Mar. 22, 2010) for 

more details on how the data was obtained. 
November 2010 40

In addition, in future years, EPA may evaluate the recipe-specific emission factors 

received through this final rule to determine whether a sufficiently robust data set exists 

to establish default emission factors for plasma etching process sub-types. In the 

future, EPA may consider requiring the semiconductor facilities that will be using a 

default emission factor for the etch process type under this final rule to estimate and 

report emissions using an approach based on multiple etch and chamber clean process 

sub-types similar to the Refined Method EPA proposed in April 2010. 

4.2.2 IPCC Tier 3 Method 

Comment Summary 4.2.2-a: One commenter (0089) asserted that the final rule should 

make clear that facilities that use Tier 3 methods are not required to report emissions 

under the process categories as proposed, but that instead they will be able to use the 

process steps defined at that facility. 

Response 4.2.2-a: In the final rule, EPA is not requiring that emissions estimated using 

the Tier 3 method be reported under specific process sub-types. 

It is unclear how the commenter is defining a process step, however in the final rule, the 

Tier 3 method consists of calculating and reporting emissions using recipe-specific 

emission factors for all production processes that use fluorinated GHGs. As required in 

the final rule, emission factors must be developed for each individual recipe or set of 

similar recipes used at a facility and emissions must be calculated and reported for 

each recipe (including those in a set of similar recipes) using the recipe-specific factors. 

Facilities must then aggregate emissions calculated for each individual recipe or set of 

similar recipes for each of three process types defined by the rule– plasma etching, 

chamber cleaning, and wafer cleaning. 

4.2.2.1 300 mm and Smaller Wafer Technologies 

Comment Summary 4.2.2.1-a: One commenter (0131) did not support requiring the 

use of IPCC Tier 3 methodology. The commenter, who supported the use of the Tier 

2b emission factors (see comment summary 4.2.1.2-c), asserted that most facilities do 

not use a Tier 3 method, and therefore there is a limited data set that is representative 

of manufacturing conditions on which to base the assertion that the Tier 3 method 

results in improved accuracy of emission estimates. 

Response 4.2.2.1-a: While EPA is not requiring semiconductor manufacturing facilities 

manufacturing wafers 300 mm or smaller to estimate emissions from all production 

processes that use fluorinated GHGs using recipe-specific emission factors because it 

is mindful of the burden this may impose, EPA continues to maintain that the Tier 3 

method will result in the most accurate facility-specific emission estimates. For 

example, the IPCC 2006 Guidelines state “When using Tier 3 method for 

semiconductor and TFT-FPD manufacturing, the resulting estimates of emissions will 

be more accurate than the Tier 2a, 2b or Tier 1 methods, on the order of ± 30 percent 

(95 percent confidence interval).” The IPCC 2006 Guidelines are a consensus 
November 2010 41

document, and were prepared with substantial input from and agreement among 

industry experts. To balance burden and the need for accurate facility level data in the 

final rule, EPA is requiring only semiconductor manufacturing facilities that manufacture 

wafers that are 300 mm or smaller, to calculate and report their etch process emissions 

using directly measured recipe-specific emission factors. 

Because EPA does not want to prohibit facilities from gathering more accurate data, the 

final rule allows any semiconductor manufacturing facility that manufacturers wafers 

that are 300 mm or smaller to use the Tier 3 method to estimate and report emissions 

for all processes that use fluorinated GHGs if they elect to do so (see §98.93(a)(3)). 

Please see the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Comments and Responses”), for the response to comments on emission 

estimation methods for semiconductor facilities. 

Comment Summary 4.2.2.1-b: One commenter (0110) stated that it had not 

determined any emission factors through testing, and that based on their review of the 

record and the SIA/ISMI Facility results presented to EPA, only one company in the US 

estimates emissions using a Tier 3 methodology. The commenter further stated that it 

received limited information from their equipment supplier in regards to developing 

emission factors. The commenter noted that one major U.S. equipment supplier had 

provided the company with over ten emission characterization reports based on one 

recipe. The commenter stated, “In light of the uncertainties of EPA’s proposal and the 

enormous complexity of our facilities, however, it isn’t clear how this information would 

be utilized to develop factors if we were required to do so for hundreds of recipes in 

multiple facilities across an entire company.” The commenter argued that given the 

challenges involved in obtaining site-specific data for such complex facilities and that 

the Tier 2b average emission factors established by the IPCC are conservative, the Tier 

2b factors should be allowed for large facilities. 

Response 4.2.2.1-b: EPA does not agree with the commenter that semiconductor 

manufacturing facilities should be allowed to estimate and report emissions using the 

2006 IPCC Tier 2b method. While the 2006 IPCC Guidelines are a consensus 

document, and were prepared with substantial input from and agreement among 

industry experts, the Guidelines were prepared with the intention of serving national 

GHG emissions inventorying purposes. The Tier 3 method requires facility-specific 

emission information; however other methods such as the Tier 2b method do not. The 

Guidelines specifically state that the IPCC Tier 2b factors presented were “developed 

specifically for this guidance.” In using the IPCC Tier 2b factors in a facility-level 

emission estimation method uncertainty assessment, EPA found that the IPCC Tier 2b 

factors are likely to understate facility emissions, not result in conservative emission 

estimates (see the Electronics Manufacture TSD, Appendix C for more details) as the 

commenter asserted. Further, because the IPCC Tier 2b factors are simple averages, 

EPA has no basis on which to infer that the IPCC Tier 2b factors would overstate 

emissions. 
November 2010 42

EPA acknowledges that at this time, semiconductor facilities may not have 

characterized emissions from all production processes that use fluorinated GHGs. To 

this end, EPA has structured the final rule to minimize the burden imposed on facilities 

in conducting direct measurements. For example, EPA is requiring only direct 

measurement for the etching process type. In addition, EPA is requiring only the 

largest facilities to estimate and report their etch emissions using recipe-specific 

emission factors. Lastly, EPA is allowing any factors that were developed for one 

individual recipe to be applied to similar recipes (as defined in the final rule). 

In the final rule, EPA has specified that when reporting recipe-specific emission factors, 

reporters must identify the film or substrate that was etched/cleaned and the feature 

type that was etched. Reporting emission factors in this manner will give EPA the 

opportunity to evaluate various options for developing default emission factors for future 

use. 

It is important to note that in the final rule facilities are allowed to use BAMM for the first 

six months of data collection for any parameter, such as recipe-specific emission 

factors, for which it is not reasonably feasible to acquire, install, or operate a required 

piece of monitoring equipment or to procure necessary measurement services. 

Facilities are also given the opportunity to apply for extensions for the use of BAMM 

through the full first year of data collection. Please see the preamble section D, 

Electronics Manufacturing (subpart I), section 1 (“Summary of the Final Rule”) for more 

information on the BAMM provisions for electronics manufacturing facilities. Please 

also see the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Comments and Responses”), for a more detailed response to comments 

on emission estimation methods. 

Comment Summary 4.2.2.1-c: One commenter (0128) was concerned that switching 

from the Tier 3 method to the Refined Method will result in less accurate emissions data 

for cleaning and etching in semiconductor facilities. The commenter stated, “We 

encourage EPA to require Tier 3 reporting for these processes given the need for 

accurate data and the significant emissions from this sector. The Tier 3 approach relies 

on facility-specific emissions data on gas consumption, gas utilization, by-product 

formation, and DRE rather than default emission factors.12 EPA concluded that use of 

the Tier 3 method would result in the most accurate estimates amongst the methods 

presented by the IPCC.13 By contrast, the Tier 2b is inherently less accurate because it 

relies on default values for gas consumption, gas utilization, by-product formation, and 

DREs, and only distinguishes between two broad process types – etching and cleaning 

– rather than the roughly 450 process categories examined under Tier 3. The Refined 

Method represents a middle ground of sorts, achieving improved accuracy vis-à-vis the 

Tier 2b method by expanding on the two process types to include emissions factors 

 

12 See 2006 IPCC Guidelines for National Greenhouse Gas Inventories at 6.11; see also EPA, Technical 

Support Document (Updated) for Process Emissions from Electronics Manufacture (Mar. 22, 2010) 

(“Electronics Manufacture TSD”) at page 11. 

13 Electronics Manufacture TSD (Mar. 22, 2010) at page 12.
November 2010 43

specific to nine different refined process categories.14 While the Refined Method yields 

emissions estimations that are approximately twice as accurate as the Tier 2b 

approach, the Method nonetheless produces estimates that suffer from a high degree 

of uncertainty.15 EPA assigned an absolute uncertainty of + 27,000 MtCo2e to the 

typical semiconductor facility with emissions of around 113,000 MtCO2e, meaning that 

a facility’s reported emissions could differ from actual emissions by as much as 24 

percent.16 Such a degree of uncertainty is unacceptably high given the availability of a 

more accurate reporting method. 

While we believe EPA should require Tier 3 reporting for all semiconductor facilities, at 

minimum, EPA should rely on Tier 3 estimation for ‘large facilities,’ as it did in its initial 

proposal. As EPA initially concluded, large facilities have the capability to easily collect 

this data, and as subsequent comments confirmed, at least one facility already does.17

Further proof of the feasibility of Tier 3 estimation is this proposal’s requirement that 

facilities producing large wafers – greater than 300mm in diameter – employ Tier 3 

reporting. We strongly support this requirement and encourage EPA to ensure 

consistent facility-level data by at least applying the Tier 3 requirement to large facilities 

producing other sizes of wafer as well. At an absolute minimum, any facility that is 

currently using Tier 3 reporting should be required to report that data to EPA.” 

Response 4.2.2.1-c: EPA agrees that the use of the Tier 3 method will result in the 

most accurate facility-specific emission estimates. However, EPA is mindful of the 

burden associated with requiring the Tier 3 method to estimate and report emissions 

from all production processes that use fluorinated GHGs. In the final rule, there are the 

two methods for estimating emissions for facilities that manufacture semiconductors, 

depending on the annual manufacturing capacity of the facility. One method, the Tier 

2d method, which is required for the largest semiconductor facilities, requires recipespecific emission factors to be used to estimate emissions for only the etching process 

type; other emissions would be estimated using EPA-provided default factors (a partial 

Tier 3 approach). The other method, the Tier 2c method, relies only on EPA-provided 

default emission factors. In these methods, both of which move beyond the Tier 2b 

method, EPA is balancing the burden placed on industry in implementing a full Tier 3 

method against the goal of collecting accurate facility-level information. In addition, 

EPA has also provided facilities with the option to use the Tier 3 method to estimate 

emissions from all production process that use fluorinated GHGs in lieu of any other 

method required by the rule. Please see response to comment 4.2.1-a and the 

preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses”), for the response to comments on emission estimation 

methods for semiconductor facilities. 

EPA is also finalizing the requirement for semiconductor manufacturing facilities that 

fabricate devices on wafers measuring greater than 300 mm in diameter, regardless of 

their manufacturing capacity, to calculate and report all of the emissions from 

 

14 75 FR 18656. 

15 See footnote 14. 

16 See footnote 14. 

17 See footnote 14.
November 2010 44

processes that use fluorinated GHGs using directly-measured recipe-specific emission 

factors (i.e., the Tier 3 method). As EPA stated in the preamble to the April 2010 

proposed rule, by including this requirement only for the wafers larger than 300 mm, 

“we anticipate a reduction in burden because emission factors (i.e., gas utilization and 

by-product formation rates) can be developed over a number of years as 

semiconductor manufacturers begin to transition to 450 mm tools and develop the 

estimating and reporting infrastructure. The commissioning process for new tools is an 

ideal opportunity for emission factor development and/or verification.” 

 

4.2.2.2 Greater than 300 mm Wafer Technologies 

Comment Summary 4.2.2.2-a: One commenter (0131) asserted that industry 

transitions to new wafer sizes are the best opportunity to introduce new equipment 

requirements. The commenter asserted that the most appropriate introduction point for 

consistent application of Tier 3 factors is with the introduction of production-ready 450 

mm tools. 

Response 4.2.2.2-a: EPA agrees with the commenter that semiconductor 

manufacturing facilities that manufacture wafers greater than 300 mm in size should be 

required to calculate and report emissions using the Tier 3 method, and in §98.93(a)(4) 

EPA is finalizing this requirement in the final rule. Please see response to comment 

4.2.2.1-c and response to comments in section 4.2.2.2 for a more detailed discussion 

on EPA’s rationale for requiring semiconductor manufacturing facilities that fabricate 

devices on wafers measuring greater than 300 mm in diameter (e.g., 450 mm) to 

calculate and report emissions based on the 2006 IPCC Tier 3 method. 

Comment Summary 4.2.2.2-b: One commenter (0110) noted that the adoption of the 

Tier 3 methodology is a large addition to the overwhelming costs associated with an 

upgrade to a 450 mm facility. The commenter noted that, depending on the scope of 

testing, costs could be six or seven figures per facility and add weeks or months to 

complete. The commenter cited a tool manufacturer that would be willing to perform 

emission factor testing as a customer service provided the customer was willing to pay 

extra. The commenter stressed that, in the current economic downturn that has 

affected the semiconductor industry, testing would consume financial resources needed 

for a facility to operate. The commenter noted that the U.S. Government Accountability 

Office (GAO) has cited with approval the measuring, monitoring, and reporting 

standards of the EPA Climate Leaders, Chicago Climate Exchange, and the Climate 

Registry, none of which require Tier 3 estimation methods. 18

Response 4.2.2.2-b: EPA does not agree with the commenter that requiring 

semiconductor manufacturing facilities that manufacture wafers greater than 300 mm to 

calculate and report emissions using the Tier 3 method is overly burdensome and 

costly. For example, one commenter (0122) stated that the total capital budget for a 

 

18 U.S. Government Accountability Office (GAO). High Quality Greenhouse Gas Emissions Data are a 

Cornerstone of Programs to Address Climate Change. February 24, 2009. 

http://www.gao.gov/new.items/d09423t.pdf. 
November 2010 45

new facility designed to fabricate 300 mm wafers using 28 nanometer technologies is 

$4.5 billion. Recognizing that this commenter is providing information that includes new 

construction costs, the information can still be used for general comparison purposes 

(note, EPA expects that the capital costs of a 450 mm plant to be much more than a 

300 mm plant). EPA expects that the costs of Tier 3 measurements relative to the 

capital costs of a 450 mm fab are small (see sections 4 & 5 of the Economic Impact 

Analysis (EIA), available in the docket, EPA-HQ-OAR-2009-0927).19

The industry transition to 450 mm wafers presents an opportunity, consistent with 

historical industry practices, reflected in International Technology Roadmap for 

Semiconductors (ITRS)20 to move the industry forward in terms of emission estimation 

practices. As operations are being upgraded and constructed, consistent, robust, and 

accurate practices can be established. Other commenters have supported this idea as 

well. 

EPA acknowledges the GAO has identified examples of reporting standards that do not 

require the use of the Tier 3 method; however, the goals of this final rule are different 

from that of the GAO document. The purpose of the final rule is to collect facilityspecific emissions data for use in developing future GHG policies and programs. 

Collecting accurate data of GHG emissions is important to the future value of the data 

for informing policy decisions and designing new GHG policies and programs. EPA has 

concluded that the requirements finalized in this rule accomplish that goal while at the 

same time balance burden to the industry. Please also see the preamble to the Final 

Rule (74 FR 56265, October 2009) for additional discussion on how the GHG Reporting 

Program relates to EPA and U.S. government climate change efforts and other State 

and Regional Programs. 

Comment Summary 4.2.2.2-c: One commenter (0095) proposed that R&D facilities 

should be allowed to utilize the IPCC Tier 2b methodology instead of the IPCC Tier 3 

methodology for estimating emissions from fabricating devices on wafers that are 

greater than 300 mm. The commenter suggested this because it would not be 

financially viable for an R&D facility to do emissions testing for a process that is in the 

concept and feasibility phase. 

Response 4.2.2.2-c: EPA is clarifying that if a facility engages in R&D activities, they 

are not required to report the emissions from that activity. Please see response to 

comment 1-b for a more detailed discussion on the R&D activity exemption. 

 

19 For comparison EPA estimated that the Tier 2d method, which requires direct recipe-specific 

measurements for all etch process at a large semiconductor facility will cost $23,407. 20 ITRS (2010) International Technology Roadmap for Semiconductors 2009. This and earlier editions 

and updates are available at http://www.itrs.net/Links/2009ITRS/Home2009.htm.
November 2010 46

4.2.3 Alternative Methods for Calculating Emissions from 

Semiconductor Facilities 

Comment Summary 4.2.3-a: One commenter (0095) stated that electronics 

manufacturing facilities should be allowed to utilize the IPCC Tier 2b methodology 

provided that “...affected tools have point-of-use abatement units for perfluorinated 

compounds and DRE published by the abatement unit vendors for PFCs be equal to or 

above those of the IPCC Guidelines.” Other commenters (0108 and 0110) noted that 

the Tier 2b methodology provides adequate granularity/accuracy with an appropriate 

level of investment for “relatively smaller” and large semiconductor facilities. One of 

these commenters (0110) specifically stated that the Tier 2b should be allowed “given 

the challenges involved in obtaining site-specific data for such complex facilities.” 

 

Response 4.2.3-a: EPA does not agree with the commenters that the IPCC Tier 2b 

method should be allowed for semiconductor manufacturing facilities (with or without 

requiring that each tool has a POU unit attached). Although the Tier 2b method may be 

less costly to implement, EPA does not agree that the Tier 2b method (based on two 

broad process types) provides adequate granularity/accuracy for any semiconductor 

manufacturing facility because it does not capture variability in processes, nor does it 

account for emissions from wafer cleaning. 

Please see the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Comments and Responses”), for the response to comments on emission 

estimation methods for semiconductor facilities. 

For more information on EPA’s rationale for not allowing the use of DREs published by 

abatement unit vendors or the IPCC defaults, please see response to comments in 

section 5.2., and also see the preamble section D, Electronics Manufacturing (subpart 

I), section 3 (“Summary of Comments and Responses”). 

Comment Summary 4.2.3-b: One commenter (0122) supported retaining a single etch 

category at this time for which a Tier 2b emission factor would be used for estimating 

and reporting emissions. In a similar regard, three commenters (0099, 0100, and 0131) 

stated that electronics manufacturing facilities should be allowed to utilize an 

“Alternative Refined Method” based on 5 process categories – etch, in-situ plasma CVD 

chamber clean, remote plasma CVD chamber clean, in-situ thermal CVD chamber 

clean, and wafer cleans. The commenters stated that this methodology would improve 

the accuracy of emissions estimates and also make gas apportioning less burdensome. 

The commenters (0099 and 0100) suggested that reporters should use the IPCC Tier 

2b and/or EPA NODA emission factors for these five process categories. 

Response 4.2.3-b: EPA has decided, in part, to accept commenters’ suggestions to 

retain a single etch process type, with no relating process sub-types. EPA determined 

that the available emission factor data is sufficient to establish default emissions factors 

for multiple chamber clean process sub-types, but insufficient to support establishing 

default emission factors for multiple etch process sub-types. Therefore facilities that 
November 2010 47

manufacture semiconductors are required to use either default emission factors (the 

Tier 2c method) or recipe-specific emission factors (the Tier 2d method) for the etch 

process type. In the final rule, for the Tier 2c method, EPA is requiring facilities to use 

EPA developed default emission factors for the etch process type, as opposed to using 

the IPCC Tier 2b factors as suggested by commenters. The EPA published default 

emission factors were developed with a more robust set of data than that used to 

develop the IPCC Tier 2b emission factors. See response to comment 4.2.1-a and the 

preamble section D, Electronics Manufacturing (subpart I), section 3, for the response 

to comments on emission estimation methods for semiconductor facilities. 

Comment Summary 4.2.3-c: Two commenters (0099 and 0131) supported the use of 

Tier 3 emission factors for the Alternative Refined Method if a facility has the Tier 3 

factors and if the Tier 3 factors meet the following 2 specifications: (1) Factors are 

“either from tool suppliers and already in their physical possession or through a facility’s 

own measurement methodologies consistent with the ISMI Guidelines”; and (2) 

Facilities “conclude that – based on their professional judgment - factors are 

representative of their particular process.” 

Response 4.2.3-c: EPA agrees with the commenters who suggest that Tier 3 emission 

factors should be allowed if a facility has them, but only if the facility has Tier 3 factors 

that represent all production processes that use fluorinated GHGs. EPA is not allowing 

the use of a hybrid method, or a method using facility-developed default emission 

factors for process types or sub-types. This means that a single facility must choose 

between using only default emission factors and using recipe-specific emission factors 

for all process types; hybrid methods using both default emission factors and recipespecific factors within the same reporting year are not permitted. This restriction will 

enable EPA to analyze emissions and trends using a consistent set of data. The only 

exception is where a facility is required to use a method using default emission factors 

but no defaults are provided in Tables I-3, I-4, I-5, I-6, or I-7 for a particular fluorinated 

GHG and process type or sub-type combination. Where defaults are not provided, a 

facility must either use utilization and by-product formation rates of 0 or, in that 

particular instance, use directly measured recipe-specific emission factors measured 

using the 2006 ISMI Guidelines, International SEMATECH #06124825A-ENG, with 

limited exceptions. 21 

 EPA does not agree with commenters that EPA should allow facilities to estimate 

emissions using emission factors that were measured with a facility’s methods that 

could be consistent with the ISMI Guidelines. Rather, in the final rule EPA is requiring 

that facilities measure their recipe-specific emission factors using the methods specified 

in the 2006 ISMI Guidelines or the 2001 ISMI Guidelines provided that measurements 

were made prior to January 1, 2007. By requiring the use of the Guidelines, as 

opposed to allowing facility to use their own methods independently judged as 

consistent with the Guidelines, EPA can ensure that the methods for developing 

 

21 EPA is permitting facilities to use emission factors measured using the 2001 ISMI Guidelines, 

International SEMATECH #01104197A-XFR, provided the emissions factors were measured prior to 

January 1, 2007. Documentation for the measurements is required. 
November 2010 48

emission factors are being used throughout industry are consistent. This will provide 

EPA with emissions information that can be analyzed and compared across the 

industry. See response to comment 5.1-a for more details on why EPA is requiring 

measurements to be made using the ISMI Guidelines. 

EPA does not agree facilities should be allowed to conclude based on professional 

judgment that emission factors used are representative of their own processes, as this 

method does not provide EPA with any means to verify emissions data being reported. 

Professional judgment is subjective and depends on the values of the person making 

the judgment. This may create inconsistencies between facilities when applying the 

Tier 3 method for fluorinated GHG emissions, particularly given the high variability in 

the quantities and types of fluorinated GHGs in the vast number of recipes used 

throughout the industry. Instead, EPA is requiring facilities who obtain Tier 3 emission 

factors from third parties to ensure, and to provide supporting documentation, that the 

emission factors provided are for recipes that are similar to those used at the facility.22 

Please see the Electronics Manufacture TSD, Appendix D for more details supporting 

the definition of “similar recipe.” 

Comment Summary 4.2.3-d: Two commenters (0099 and 0131) suggested two 

alternative measurement approaches for fluorinated GHGs and N2O; these included the 

development of an accurate facility-wide emission factor using statistical parameters 

and the use of “factory modeling” for new facilities based on representative process 

steps and gas consumption. Specifically, the commenters suggested that a facilitywide emission factor could be established by: 

“a) Characterization of the facilities final exhaust using an approved protocol (e.g. 2006 

ISMI, 2010 EPA protocol) 

i) Sampling would include sufficient final exhaust data to understand the 

variability and develop an average factor and uncertainty range 

ii) The method could contain a requirement to retest and establish new 

emission factors if gas usage increased by 20 percent 

b) Develop an average emission factor with uncertainties comparable to other 

acceptable methods utilizing the final exhaust data 

 i) Use mass balance to quantify constituents below methods detection limits 

c) Calculate emissions over time by applying this average emission factor to actual gas 

consumptions (i.e. emissions = gas consumption * EF)” 

The commenters described “factory modeling” as the following: “Factory modeling may 

be possible for new factories if the appropriate software is integrated into new systems. 

With the appropriate capability built into new tools, it may become possible to track tool 

level gas consumption and develop emission factors for a representative sample of 

 

22 In the final rule, a similar recipe is defined as those recipes that have identical chemical compositions 

and where differences, considered separately, in reactor pressure, individual gas flows, applied RF 

power, and flow stabilization time, relative to equipment manufacturers’ best known method or a facility’s 

process of record, are less than or equal to plus or minus 10 percent. 
November 2010 49

process steps. Total emissions could then be expressed as a function of chemical use 

multiplied by the average emission factors. 

As measurement technologies are likely to improve over time, we believe it is important 

that the final rule contain flexibility that would allow for the use of alternative methods 

without future rule change.” 

The commenters stated that it provided these alternatives because they believe in the 

importance of flexibility in the final rule to allow alternative methods without future 

modifications to the rule. 

Response 4.2.3-d: EPA agrees that the final rule should provide flexible approaches, 

but only where the methods provide accurate facility-specific emissions data. If an 

alternative method is developed that is not included in the final rule and EPA 

determines that it meets the goals of the GHG Reporting Program then in the future, 

EPA may consider updating the Electronics Manufacturing subpart to allow the use of 

such an alternative methodology. 

EPA is not finalizing the methods the commenters provided as options because the 

commenters did not provide sufficient details for EPA to effectively evaluate the 

accuracy or feasibility of the methods. 

4.3 CEMS (Continuous Emissions Monitoring System(s)) 

Comment Summary 4.3-a: One commenter (0074) states that the use of Fourier 

transform infrared (FTIR) spectroscopy, as used in continuous emissions monitoring 

systems(CEMS), is a technology that is well established and mature. The commenter 

noted that technology is currently being used in both the electronics industry and the 

fluorinated GHG manufacturing industry. About using FTIR for CEMS, the commenter 

asserted that “the hardware and software are readily configurable to a range of 

applications, and the sampling equipment is sufficiently resistant to the corrosive 

components expected in these process gas streams (e.g., HF, F2) that they operate for 

months at a time with little or no evidence of damage.” The commenter goes on to 

present multiple applications and various locations in a facility where FTIR CEMS can 

be used to “cost-effectively monitor GHG gases as required.” 

Response 4.3-a: EPA appreciates the information on FTIR CEMS provided by the 

commenter. In the final rule, EPA is not providing for the use of CEMS for measuring 

process emissions from electronics manufacturing facilities. Although the use of CEMS 

is well established for measuring emissions from single steady flow stacks, such as 

stack emissions from stationary combustion, information available at this time about the 

technical feasibility, accuracy and costs of estimating emissions from electronics 

manufacturing using CEMS is limited. CEMS-like emissions monitoring technologies, 

such as FTIR are being evaluated for this sector, but they are still in the developmental 

stages. For these reasons EPA is not including a CEMS method in the rule for 

electronics manufacturing at this time. 
November 2010 50

EPA welcomes information on using CEMS to measure GHG emissions from the 

electronics manufacturing industry. In future years, given more information about the 

feasibility, implementation methods, and costs of CEMS, and the accuracy of estimating 

emissions from CEMS, EPA may consider updating the rule to allow for the use of this 

technology for electronics manufacturing. 

Comment Summary 4.3-b: Four commenters (0089, 0110, 0112, and 0131) asserted 

that CEMS are not appropriate for quantifying fluorinated GHG emissions from 

semiconductor manufacturing. According to the commenters, requiring the use of 

CEMS is unnecessary, potentially not feasible, and not economically justified. The 

commenters provided EPA with their insight about using CEMS in the electronics 

manufacturing sector. These commenters stated that CEMS have historically been 

used to measure single pollutants in steady-state processes in stack exhaust streams. 

This presents an issue for semiconductor manufacturing because these facilities 

typically use 8-10 different fluorinated GHGs which then flow into an exhaust stream 

and have 20-30 stacks (for a large facility). While FTIR has been used for short-term 

discrete measurements of the mix of fluorinated GHGs used at a semiconductor 

manufacturing facility, FTIR has not been used widely for CEMS, and it presents many 

inherent difficulties in terms of technology and cost. One commenter (0089) stated that 

“Requiring the use of CEMS would require the semiconductor manufacturing industry to 

invest significant resources to develop and demonstrate some type of continuous 

monitoring technology that would ultimately still yield inaccurate results in place of the 

currently established conservative approaches.” Another commenter (0131) also 

supported the previous statement by stating, “even if FTIR could be adapted for CEMS, 

the results would be extremely inaccurate.” Another commenter (0110) supported the 

continued use of emissions factors and a material balance over CEMS. 

Response 4.3-b: It is unclear to EPA how the commenter (0131) arrived at the 

conclusion that the results of using FTIR CEMS would be inaccurate, given that CEMS 

is not widely used throughout industry and EPA is unaware of robust studies comparing 

the use of CEMS to other emission estimation methods. EPA would welcome any 

further information on which the commenter based the aforementioned assertion, and is 

interested in further study on the use of CEMS, based on FTIR or other techniques. 

At this time EPA agrees that it is not appropriate to require CEMS to estimate 

fluorinated GHG emissions in the electronics manufacturing industry. Please see 

response to comment 4.3-a on the use of CEMS. However EPA is not ruling out the 

possibility of the use of CEMS in for estimating emissions in the electronics 

manufacturing source category in the future. Despite the limited information available 

about the use of CEMS for electronics manufacturing (as discussed in comment 

response 4.3-a) work to establish the use of CEMS for electronics manufacturing is 

ongoing, as detailed in one commenter’s (0074) submission. 

4.4 N2O 
November 2010 51

Comment Summary 4.4-a: One commenter (0131) supported the inclusion of nitrous 

oxide (N2O) in inventory requirements and views it as an improvement in accuracy of 

emission reporting when using the IPCC Tier 2b method. 

Response 4.4-a: EPA agrees with the commenter that the inclusion of N2O in the 

facility emissions estimate is an improvement over using the IPCC Tier 2b method to 

estimate facility emissions, as the IPCC does not provide default N2O emission factors, 

and hence the IPCC Tier 2b method does not include estimating emissions from the 

use of N2O. 

Comment Summary 4.4-b: One commenter (0112) asserted that EPA should allow 

facilities to develop a facility-specific factor for N2O utilization through facility testing and 

measurement in CVD and other processes where N2O is used. 

Response 4.4-b: EPA agrees with the commenter that facility-specific N2O factors 

should be allowed. In the final rule, in §98.93(b), EPA is allowing facilities to develop 

facility-specific N2O utilization factors for CVD and for other N2O-using production 

processes. If a facility elects to use facility-specific N2O utilization factors, one must be 

developed for each CVD and for other N2O-using processes. Further, the 

measurements must be made using the 2006 ISMI Guidelines, with limited 

exceptions.23 

4.4.1 Default N2O Utilization Factors 

Comment Summary 4.4.1-a: One commenter (0112) accepted EPA’s proposal for a 

utilization factor of 0.2 for N2O CVD processes, given a lack of detailed data available 

to justify a higher utilization factor for CVD and other processes. The commenter stated 

that N2O is highly reactive and is likely to quickly degrade in the processes. The 

commenter further stated that it expects utilization rates to be higher than 20 percent, 

but that there is a lack of data to justify a higher utilization factor for CVD or other N2O 

using processes. 

Response 4.4.1-a: EPA thanks the commenter for their support. EPA agrees that at 

this time there is a lack of data to justify a default N2O factor for CVD higher than 0.2. 

To this end, in §98.93(b), EPA is finalizing the proposed default utilization factor of 20 

percent for N2O for CVD. EPA is maintaining the proposed default factor of 0 for other 

N2O-using manufacturing processes. For more information regarding the N2O default 

factors included in the final rule, please see response to comment 4.4.1-b. 

Comment Summary 4.4.1-b: One commenter (0131) noted that it provided data in 

their comments to the initial proposed rule to support a 40 percent default factor for 

CVD processes. The commenter supported the use of 40 percent for CVD as it is a 

conservative default factor. Two commenters (0110 and 0131) also proposed the same 

40 percent default factor to be applied for other N2O-using processes. 

 

23 See footnote 21. 
November 2010 52

Response 4.4.1-b: EPA does not agree with the commenters that a 40 percent default 

factor should be applied for CVD processes or for other N2O-using processes. EPA 

appreciates the information that one commenter submitted previously on N2O utilization 

rates; however, EPA is maintaining the proposed utilization factors of 20 percent for 

CVD and 0 percent for all other N2O-using processes as discussed in the following 

paragraph. 24 

While the information the commenter supplied to EPA about N2O utilization was 

considered in determining the default utilization factors that were proposed and now 

being finalized, EPA did not accept the commenter’s suggested 40 percent for several 

reasons (which were also noted in the preamble to the proposed rule). First, the 

industry survey on which the 40 percent was based was comprised for the most part of 

measured utilization factors that were largely from newer 300 mm manufacturing 

equipment. EPA did not consider the 40 percent as representative because N2O 

utilization of older manufacturing equipment, such as 150 mm and 250 mm tools, was 

not fully represented. In addition, the information provided did not fully identify the 

specific processes from which the average N2O utilization factor was calculated. Since 

the majority of N2O is used in CVD processes and given the lack of information 

available about the actual utilization of N2O in other manufacturing processes, EPA only 

considered the 40 percent value provided by the commenter in finalizing the CVD N2O 

utilization factor. 

Commenters did not provide any additional quantitative information on N2O utilization 

factors to support their claims. To this end, EPA was not able to evaluate additional 

emission factors to develop alternative default emission factors for N2O. In the future, 

based on additional information on N2O utilization rates, EPA may consider updating 

the N2O default emission factors. 

Comment Summary 4.4.1-c: One commenter (0095) proposed that EPA should 

publish a default utilization factor of at least 50 percent for a CVD process because N2O 

utilization efficiency is relatively high since SiH4 and N2O are relatively reactive with 

each other. 

Response 4.4.1-c: EPA does not agree with the commenter. While N2O and SiH4 are 

relatively reactive, if N2O is used in any amount that exceeds the stochiometric amount 

of N2O that will react with SiH4, that excess amount of N2O will be unused and emitted. 

Information is not currently available to EPA that would support utilization factor higher 

than 20 percent at this time. Further, EPA did not receive additional data from the 

 

24 EPA proposed a range of 0 percent to 40 percent for the default utilization factor for N2O for CVD. EPA 

determined the upper bound of this range through information collected in an industry survey presented 

in a comment received in response to the initial rule proposal. This industry survey concluded that on 

average the utilization of N2O for all processes at a fab is ~40 percent. EPA selected the lower bound to 

be conservative. EPA is finalizing the midpoint of this range, 20 percent, as the default CVD N2O 

utilization factor. EPA proposed a default utilization factor of 0 for other N2O-using processes due to a 

lack of information regarding other processes for which N2O is used and N2O utilization data in those 

processes. 
November 2010 53

commenter to support the higher value. Please see response to comment 4.4.1-b for 

more discussion on the default N2O factors. 

Comment Summary 4.4.1-d: One commenter (0100) proposed that EPA should 

provide default emissions factors for all processes using N2O. 

Response 4.4.1-d: In the final rule EPA is including two default emission factors for 

N2O- using processes: 20 percent for N2O CVD processes and 0 percent for other N2Ousing processes. See response to comment 4.4.1-b for additional details on the N2O 

utilization default emission factors. 

4.5 Heat Transfer Fluids 

Comment Summary 4.5-a: One commenter (0108) suggested that EPA should not 

require the use of the detailed mass balance for HTFs (proposed Equation I-12) for the 

“relatively smaller semiconductor facilities.” The commenter alternatively proposed the 

optional use of an emission factor of 1.0 for simplicity (“i.e., all heat transfer fluid 

replacement from raw materials stockrooms and heat transfer fluid sent offsite in 

equipment but not returned would be considered emitted”). The commenter suggested 

that these losses are too low to significantly contribute to a facility’s CO2e calculations, 

especially given that the particular fluids used do not have a published GWP in subpart 

A. The commenter argued further that to calculate these emissions would be 

disproportionally resource intensive compared to any benefit in accuracy. Another 

commenter (0089) expressed that many of the heat transfer uses occur in closed loop 

systems that do not require periodic addition of refrigerant or other onsite service. The 

commenter asserted that requiring that an inventory be kept identifying when such units 

arrive and leave the site is an unnecessary burden that provides no real information 

about emissions. The commenter argued that the fluorinated heat transfer tracking 

requirements should focus on consumptive uses of fluorinated liquids such as thermal 

testing that actually generate emissions. 

Response 4.5-a: EPA does not agree with the commenters. HTFs are widely used in 

semiconductor manufacturing, regardless of facility size.25 Further, EPA does not 

agree that these emissions from the use of HTFs are too low to significantly contribute 

to total facility emissions in CO2e as there is not enough quantitative evidence available 

to support this conclusion, and the commenter didn’t provide any quantitative detail to 

support their claim. As stated in 3M’s July 2009 Solid State Technology article 

Reduction of PFC emissions from heat transfer fluids,

26 “A fab’s PFC heat transfer 

liquid emissions are a significant and growing portion of its total PFC emissions.” In a 

3M presentation at the 2010 IHTESH conference the following is also stated, “It is 

estimated that a fab’s PFC/PFPE liquid emissions can be 15-50 percent of its gaseous 

 

25 Please see “Uses and Emissions of Liquid PFC Heat Transfer Fluids from the Electronics Sector (EPA 

430-R-06-901), available at http://www.epa.gov/semiconductorpfc/documents/pfc_heat_tranfer_fluid_emission.pdf. 26 Please see http://www.electroiq.com/index/display/article-display/365819/articles/solid-statetechnology/semiconductors/materials/2009/07/reduction-of-pfc-emissions-from-heat-transfer-fluids.html.
November 2010 54

PFC emissions.”27 Given EPA’s goals for this rule, EPA believes that it is important to 

accurately capture the emissions from HTFs as part of overall facility emission 

estimates. Applying a factor of 1.0 for simplicity as the commenter suggested does not 

achieve those goals. 

Although in the final rule facilities must report emissions of HTFs in absolute mass, not 

in CO2e, EPA may convert the absolute reported HTF emissions to CO2e for 

comparison purposes across the industry and national GHG emissions. In an EPA 

report (EPA 430-R-06-901)28, EPA estimates that HTFs have GWPs that range from 

>6,000-9,000 and some are long-lived pollutants, persisting in the atmosphere as long 

as 3200 years.29 In addition, a commenter (0131) provided input that HTF GWPs range 

from 55-9,400. EPA does not consider these GWPs insignificant. 

If in the commenter’s assertion that HTFs are used in closed loop systems, the 

commenter is also asserting that there are no emissions associated with the use of 

HTFs, EPA does not agree. There is very limited information available about the actual 

emissions of HTFs. Facilities often top off HTFs used in “closed loop systems” (e.g., 

chillers or heat exchangers) without tracking the exact amount that is lost (see EPA 

430-R-06-901).30 Some facilities may collect some portion of the lost material and then 

ship it off site, although this quantity is typically not tracked. Additionally, with the use 

of HTFs, there are often losses that occur due to evaporation or leaks, which are also 

not tracked by facilities. As stated in the 2006 IPCC Guidelines, “3M, a manufacturer of 

a popular HTF estimates that a vintage 2000 manufacturing plant may lose 1,900 

litres/year via evaporation. Manufacturers of testing equipment that use heat transfer 

fluids report loss rates of approximately 30 litres/year/system for newer designs that 

reduce evaporative losses and 50 litres/year/system for older designs.” 

While a facility may actually emit a small amount of HTFs in one reporting year, such as 

30 liters/year, given that facilities for the most part do not actually track HTF losses, the 

actual amount of HTFs that facility emits may vary in the next year due to any changes 

in evaporation or if any leaks occur. For these reasons, EPA is maintaining its 

requirement for facilities to use a simple mass balance method, which utilizes inventory 

quantities, to estimate HTF emissions. The use of this method ensures that emissions 

due to losses, evaporation, and leaks are accounted for in a manner that is less 

burdensome than direct measurement and equipment testing. The mass balance 

method, unlike the methods the commenters suggested, will provide accurate 

information about the actual quantity of HTFs that are being emitted. This method also 

 

27 Liaw, William, Weli Lin and Phillip Tuma. Low GWP Alternatives to PFC/PFPE Heat Transfer Fluids 

As a Means to Decrease Facility Greenhouse Gas Emissions. 3M Electronics Markets Material Division. 

Presented at the 2010 IHTESH conference. HsinChu, Taiwan, 2010. Available in the docket EPA-HQOAR-2009-0927.

28 See footnote 25. 

29 Tuma, Phillip and Lew Tousignant. Reducing Emissions of PFC Heat Transfer Fluids. 3M. Presented in 

the EHS Challenges and Analytical Methodologies session at the SEMI Technical Symposium: 

Innovations in Semiconductor Manufacturing during SEMICON®West, July 16, 2001. Available at: 

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtlXfVM8TtEVuQEcuZgVs6EVs6E666

666--. 

30 See footnote 25. 
November 2010 55

allows EPA to compare varying emissions of HTFs consistently across facilities. In the 

final rule, any facilities reporting under the Mandatory Greenhouse Gas Reporting Rule 

and engaging in production processes which use fluorinated GHGs as heat transfer 

fluids to cool process equipment, to control temperature during device testing, to clean 

substrate surfaces and other parts, and for soldering (e.g., vapor phase reflow) are 

required to use the mass balance method specified in subpart I ((see §98.93(h)) for 

estimating and reporting HTF emissions. 

Comment Summary 4.5-b: One commenter (0089) stated that the definition of 

fluorinated HTFs should be more explicit to clarify reporting requirements and to focus 

on materials and uses most likely to generate emissions. The commenter noted that it 

is unclear whether the reporting of emissions would be required for fluorinated liquids 

used in applications other than heat transfer. The commenter stated that tracking 

requirements should focus on consumptive uses of fluorinated liquids such as thermal 

testing that do generate emissions. Another commenter (0131) also asserted that 

HTFs are not only used to transfer heat. These other uses of HTFs are not expected to 

result in a significant amount of emissions, and using the mass balance method may 

not be warranted. The commenter suggested that facilities should not be required to 

report emissions from the use of HTFs used for purposes other than transferring heat 

unless the usage exceeds a de minimis value of 20 kg. The commenter also suggested 

facilities only be required to report HTFs with vapor pressures that exceed 400 Pa and 

have an assigned IPCC AR4 GWP value. (See also the de minimis reporting threshold 

section 2.3) 

Response 4.5-b: In regards to the commenter who suggested that EPA should focus 

on the uses of HTFs most likely to generate emissions, EPA does not agree with this 

suggestion. All uses of HTFs may generate emissions. To single out certain uses of 

HTFs to be reported will give EPA an incomplete picture of actual HTF emissions. EPA 

also disagrees that is unclear whether HTFs used in all applications must be reported. 

As stated in the rule for subpart I, HTFs are defined as fluorinated GHGs used for 

temperature control, device testing, and soldering in certain types of electronic 

manufacturing production processes. HTFs used in the electronics sector include 

perfluoropolyethers, perfluoroalkanes, perfluoroethers, tertiary perfluoroamines, and 

perfluorocyclic ethers. HTFs commonly used in electronics manufacturing include 

those sold under the trade names "Galden® " and "FluorinertTM." Electronics 

manufacturers may also use these same fluorinated chemicals to clean substrate 

surfaces and other parts. By defining HTFs in this manner, EPA intends to capture 

HTFs that are used for transferring heat and for other uses such as cleaning substrates. 

EPA appreciates the input from the commenter who suggested a de minimis value of 

20 kg for HTFs with vapor pressures that exceed 400 Pa and have an assigned IPCC 

AR4 GWP value. However, EPA does not agree with the suggestion as discussed in 

responses to comments in Section 2.2. 

Comment Summary 4.5-c: One commenter (0131) suggested a mass balance method 

that is keyed to purchase and offsite shipment for HTFs. 
November 2010 56

Response 4.5-c: EPA appreciates the commenter’s suggestion, however EPA did not 

modify the mass balance that facilities are required to use to determine HTF emissions 

in the final rule. EPA does not believe that the method the commenter suggested will 

accurately capture HTF emissions because it is not a complete mass balance method 

as required in the final rule. The commenter’s suggested method does not take into 

account the complete picture of the use of HTFs in a facility, as it appears the 

commenter is neglecting to account for the inventory of HTFs stored onsite at the 

beginning and end of the reporting year. All purchases of HTFs may not be used in a 

reporting year, and in this instance a mass balance method that accounts only for 

purchases and offsite shipments, as opposed to accounting for the inventory of HTFs 

stored on-site as well, may result in an overestimation of HTF emissions. 

Requiring beginning and end of year inventories is also a QA/QC measure for EPA and 

a facility. If end of year inventories do not equal beginning of the subsequent year 

inventories it is a signal that inventorying or emission estimations methods may not 

have been carried out properly. 

Please see response to comment 4.5-a for additional information on EPA’s rationale for 

finalizing methods for estimating emissions from HTFs. 

Comment Summary 4.5-d: One commenter (0131) suggested alternative variable 

definitions for the HTF mass balance equation, as it found some of the definitions to be 

confusing. The commenter also identified an error in the units assigned to variables in 

the equation. 

Response 4.5-d: EPA appreciates the commenter’s suggestions. EPA has accepted 

two of the commenter’s proposed definitions of variables, for the variable Iio and for Iit. 

These variable definitions have been revised as follows: 

Iio = Inventory of fluorinated heat transfer fluid i (in containers, not equipment) in 

containers other than equipment at the beginning of the reporting year (in stock or 

storage). 

Iit = Inventory of fluorinated heat transfer fluid i (in containers, not equipment) in 

containers other than equipment at the end of current reporting year (in stock or 

storage). 

EPA has not revised other variable definitions in the HTF mass balance equation 

because EPA does not agree that the commenter’s suggestions improve the clarity of 

the definitions. In the final rule, EPA corrected the unit assignment error for the input of 

the mass balance equation. 
November 2010 57

5. Monitoring and QA/QC Requirements 

5.1 Use of the 2006 ISMI Guidelines 

Comment Summary 5.1-a: One commenter (0089) proposed that the requirement to 

use the 2006 ISMI guidelines for developing site-specific emission factors apply only 

from the effective date of the final rule onward. The commenter proposed that emission 

factors and DRE values developed prior to the final rule’s effective date be 

“grandfathered” in by not requiring adherence to the 2006 ISMI Guidelines. The 

commenter noted that many site-specific emission factors were developed from testing 

prior to 2006 and thus would not qualify. The commenter asserted that this would 

discourage the use of the Tier 3 method under this regulation. Furthermore, the 

commenter asserted that tests performed more recently may not meet the requirement 

since prior documentation may be lacking to verify the use of the 2006 ISMI Guidelines, 

as there was no regulatory requirement in place previously that would have required 

facilities to maintain this documentation. The commenter asserted that retesting 

process tools in accordance with 2006 ISMI Guidelines would likely take years. 

Response 5.1-a: This rule’s reporting requirements are prospective only. For facilities 

to use historical emissions measurements, EPA needs to verify that appropriate QA/QC 

procedures were followed for any measurements made and factored into emission 

estimation methods, regardless of when the measurements occurred, to ensure the 

quality of the data being used to estimate emissions. In general, EPA designed these 

requirements with the expectation that the measurements would be made in future. 

However, to provide more flexibility for facilities that have already made Tier 3 

measurements prior to the publication of the rule, EPA is allowing facilities to use 

measurements made in the past if sufficient supporting documentation is available. 

EPA is understanding of the burden that requiring only the use of the 2006 ISMI 

Guidelines may impose on facilities that have already developed Tier 3 emission factors 

prior to the publication of the final rule. Therefore, for measurements made to develop 

recipe-specific factors prior to January 1, 2007, EPA is permitting facilities to use 

factors developed in accordance with the 2001 ISMI Guidelines in the final rule. This 

flexibility will allow facilities to use measurements made prior to the publication of the 

2006 ISMI Guidelines. 

EPA is not, however, allowing facilities to report measurements that were not made 

using either the 2006 or 2001 ISMI Guidelines. Requiring the use of the 2006 or 2001 

ISMI Guidelines, which were developed by and within the industry, is the means for 

EPA to ensure that measured emission factors are robust, consistent, repeatable, and 

precise. By requiring that emission factors be measured using the 2001 or 2006 ISMI 

Guidelines, EPA is relying on the only established industry practices for quantitatively 

characterizing emissions under conditions of actual wafer processing.31 DRE values 

developed prior to publication of the EPA’s DRE Protocol can be utilized as long as 

 

31 According to the authors listed to the antecedent guidelines, the Guidelines were not only developed 

among industry experts. ISMI sought and secured the expertise of NIST, a federal technology agency, in 

developing its guidelines for characterizing emissions. 
November 2010 58

documentation demonstrates compliance with the principles and requirements of the 

Protocol. 

For additional responses to comment on the required use of EPA’s DRE Protocol see 

section 5.2.4.1. For more information on the required documentation for historical 

emission measurements made using the 2001 or 2006 ISMI Guidelines please see 

response to comment 7-b. 

5.2 Controlled Emissions from Abatement Systems 

Comment Summary 5.2-a: One commenter (0112) asserted that facilities should be 

able to receive credit for the performance of the PFC gas destruction systems in which 

they have invested. 

Response 5.2-a: EPA’s final rule does not prohibit a facility from accounting for a 

fluorinated GHG and N2O abatement systems’ properly measured performance. EPA is 

requiring facilities to adhere to methods that will help ensure controlled emissions are 

accurately reflected in facilities’ total emission estimates. Based on the information 

available to EPA at this time, EPA is providing facilities with two options, with various 

levels of associated burden, to account for the use of abatement systems. In using 

either method to account for the use of abatement systems (i.e., either EPA’s default 

DRE or properly measured DREs), facilities must ensure that abatement systems are 

properly installed, operated, and maintained, and that facilities account for abatement 

system uptime. For more details on the importance of these components and 

discussion on why they are required to receive credit for the use of abatement systems, 

see the preamble to the April 2010 proposed rule (75 FR 18667, April 2010). Please 

also see sections 5.2.1 and 5.2.2 for information on proper installation, operation, and 

maintenance of abatement systems and accounting for abatement system uptime, 

respectively. 

One of the methods provided in the rule to account for the use of fluorinated GHG and 

N2O abatement systems, the use of EPA’s default DRE, strikes an appropriate balance 

between being conservative and being representative where equipment is properly 

operated and maintained. The second method, using properly measured DREs, 

requires gradual testing of all abatement systems, and retesting individual abatement 

systems over time. While this may be more burdensome than using a default DRE, it 

offers facilities an option to more accurately reflect the use of fluorinated GHG and N2O 

abatement systems. For more discussion on the use of properly measured DREs, 

please see the preamble to the April 2010 proposed rule (75 FR 18668, April 2010), as 

well as section 5.2.4. 

Comment Summary 5.2-b: One commenter (0112) proposed that facilities be allowed 

to calculate fluorinated GHG emissions based upon gas used multiplied by 1 minus the 

DRE for destruction systems without having to adjust for utilization if the facility so 

chooses. The commenter asserted that this will result in conservative reporting of 
November 2010 59

emissions, would simplify the emissions calculations, and would avoid unnecessary 

process analysis work. 

Response 5.2-b: EPA does not agree with the commenter’s suggestion that emissions 

can be estimated using only the amount of fluorinated GHGs consumed and a DRE, 

without taking into account gas utilization in the process tool. Although EPA agrees 

that the method proposed by the commenter will result in an overestimation of 

emissions, it would be inconsistent with a goal of this rule in having facilities report 

accurate emissions. In some cases, the amount of gas utilized in a process may be as 

much as 90 percent or higher’32 not accounting for this in estimating emissions will lead 

to known and preventable inaccuracies in data reported to EPA. EPA intends to use 

the accurate facility specific information gathered by this program to inform future policy 

design and regulatory decisions. EPA has concluded that the method suggested by the 

commenter is not sufficient for this purpose. 

5.2.1 Proper Installation, Operation, and Maintenance 

Comment Summary 5.2.1-a: One commenter (0128) strongly supported EPA’s 

emphasis on ensuring proper installation, operation, and maintenance of abatement 

systems. The commenter noted that the variability in DREs is partially attributable to 

installation and maintenance practices. The commenter asserted that independent 

inspection and maintenance is essential to ensure that default DREs bear some 

relationship to real emissions. 

Response 5.2.1-a: EPA appreciates the commenter’s support for the required 

certification of properly installed, operated, and maintained abatement systems. 

However, EPA does not agree with the commenter’s assertion that independent 

inspection and maintenance is essential for ensuring that default DREs reflect actual 

emissions. While independent inspections may be effective, requiring independent 

inspection and maintenance would be burdensome for facilities. Therefore, to reduce 

burden, EPA is permitting facilities to self-certify proper installation, operation, and 

maintenance by documenting that the abatement systems are installed, operated, and 

maintained in accordance with abatement system manufacturers’ specifications. 

Comment Summary 5.2.1-b: Two commenters (0110 and 0123) asserted that on-site, 

independent inspection of abatement system installation, operation, and maintenance is 

unnecessary and burdensome, particularly on an annual basis. The commenters 

suggested that facilities be allowed to self-certify proper installation, operation, and 

maintenance of abatement systems as self-certification is allowed for compliance and 

enforcement for similar permit conditions under the CAA. 

Two other commenters (0099 and 0131) stated that third-party quality assurance and 

inspection of abatement systems is unnecessary. The commenters asserted that 

certification by a responsible company official is consistent with other programs and 

 

32 As demonstrated in Table 5 of the report Draft Emission Factors for Refined Semiconductor 

Manufacturing Process Categories (EPA-HQ-OAR-2009-0927-0073). 
November 2010 60

appropriate for fluorinated GHG reporting. The commenters expressed concern that 

restricting the facility to only the abatement equipment manufacturers’ maintenance 

specifications would not allow for future improvement in operational and maintenance 

procedures, and that the requirement, which restricts facilities to staying within 

abatement systems manufacturer installation, operation and maintenance 

specifications, may not allow competition for maintenance contracts. 

Response 5.2.1-b: While independent inspections may be effective, EPA has 

determined that requiring independent inspection and maintenance would be more 

burdensome for facilities. EPA is therefore permitting facilities to self-certify proper 

installation, operation, and maintenance by providing documentation that abatement 

systems are installed, operated, and maintained in accordance with abatement system 

manufacturers’ specifications. EPA does not find it plausible that requiring facilities to 

follow manufacturers’ specifications would preclude further improvements in O&M 

procedures or practices. Facilities may adopt additional measures as long as they do 

not conflict with the rule requirements. Additionally, no part of the requirement 

specifically limits to whom a facility may award maintenance contracts. Please see 

response to comment 5.2.1-a. 

5.2.2 Accounting for Abatement System Uptime 

Comment Summary 5.2.2-a: One commenter (0131) confirmed that facilities may be 

able to monitor abatement system operations, but the commenter also cited ISMI 

survey findings that additional labor and cost will be required to install and maintain 

monitoring systems to track uptime. The commenter proposed: “That EPA allow for a 

facility specific monitoring systems and to calculate uptime as the percent of the total 

abatement operation and included in the fraction of input gas in Eqs. I-7 and I-8 and 

multiplied by the DRE in the equation.” 

Response 5.2.2-a: EPA maintains that applying a DRE value that is not discounted 

for abatement system uptime would result in an underestimation of total facility 

emissions as abatement systems are not fully operational for 100 percent of the 

reporting year. For example, the time during which a system is by-passed, undergoing 

maintenance, or not operating with O2-flow (in the case of a CF4 combustion system) 

should not be taken into account33 when estimating and reporting controlled emissions 

as this would result in a mis-estimation of controlled emissions. EPA is providing two 

new equations in the final rule (Equations I-14 and I-15) to which facilities must adhere 

when calculating uptime of an abatement system, and when accounting for uptime in 

the DRE values applied to estimate emissions. EPA is not specifying the methods that 

a facility must use to monitor the parameters required to calculate uptime of abatement 

systems (the total time each abatement system is in operational mode and fluorinated 

 

33 An exception to this is time during which exhaust flows are passed through a redundant abatement 

system that is in the same abatement system class (discussed below) as the primary abatement system. 

Such time may be included in the uptime of the primary system. A redundant abatement system is 

defined as a system that is specifically designed, installed and operated for the purpose of destroying 

fluorinated GHGs and N2O gases. A redundant abatement system is used as a backup to the main 

fluorinated GHGs and N2O abatement system during those times when the main system is not 

functioning or operating in accordance with design and operating specifications. 
November 2010 61

GHGs or N2O are flowing through the connected process tools and the total time 

fluorinated GHGs or N2O are flowing through process tools connected to each 

abatement system). See response to comments in section 5.2.2 and the preamble 

section D, Electronics Manufacturing (subpart I), section 3, for the response to 

comments on uptime. 

Comment Summary 5.2.2-b: Two commenters (0089 and 0112) indicated that it is 

reasonable for EPA to require consideration of abatement unit uptime, but that the 

specific procedures outlined in the rule may not reflect actual practices of facilities. The 

commenters stated that their POU abatement devices are interlocked with fab tools, so 

that the tools will shut down at abatement device failure or at the end of the wafer run. 

In either case, the commenters asserted that the tool cannot be further operated until 

the abatement device is operational. One commenter (0112) proposed, “An option for 

tracking abatement device uptime for systems with a tool interlock by reporting the 

number of times an abatement unit failure occurred. Where the tool shuts down when 

the abatement device fails, no adjustment to the emissions calculations would be 

needed. For those situations where the tool continues to run, a process could be 

worked out estimate the additional gas emissions per chamber process for tool type 

and the calculated emissions increased by that quantity of additional emissions times 

the number of times the tool failed. If possible, the rule should allow companies to do a 

significance test and establish a minimal number of failures below which the additional 

emissions are not significant (say a half a percent of the total emissions for a specific 

gas).” One commenter (0089) asserted that a viable method for determining uptime for 

interlocked abatement tools should involve documenting that tools are in fact 

interlocked and documenting instances where failure occurred during processing.

Two other commenters (0110 and 0123) stated that their POU abatement systems are 

typically configured that if the abatement system is down or operating abnormally, the 

system will either shut down gas to the process tool or divert flow to a redundant 

abatement system. The commenters asserted that allowance of this method ensures 

proper abatement and accurate emissions estimates without additional costs 

associated with tracking and recording abatement system uptime parameters. The 

commenters suggested that significant additional costs would be incurred to otherwise 

modify or upgrade operational controls and data acquisition systems.

Response 5.2.2-b: EPA is not modifying uptime requirements as suggested because 

EPA expects that facilities with interlocked abatement systems should be able to easily 

monitor and account for uptime of abatement systems using the methods provided in 

this rule. EPA is also not modifying the uptime requirements to accommodate one 

commenter’s suggestion of developing and establishing a significant test for 

determining the number of systems failures for which emissions would be insignificant. 

Such a test may be practical, however EPA does not have and the commenter did not 

offer any data regarding the nature or support for such a test. 

EPA is not permitting facilities to use the methods suggested by the commenters as this 

would allow the use of multiple methods to monitor and account for uptime. Where 
November 2010 62

feasible, EPA would like to ensure that facilities are using consistent methods in 

estimating emissions because this will create a consistent basis on which to compare 

industry emissions and will also reduce EPA’s administrative burden. EPA is requiring 

detailed monitoring and reporting of uptime because this information will allow EPA to 

carry out emissions verification to ensure the consistency and accuracy of data 

collected under this rule. See response to comment 5.2.2-a on requiring facilities to 

account for uptime and the preamble section D, Electronics Manufacturing (subpart I), 

section 3 (“Summary of Comments and Responses”), for the response to comments on 

uptime and interlocked abatement systems. 

5.2.2.1 Semi E-10 Standard 

Comment Summary 5.2.2.1-a: One commenter (0093) argued that: “the abatement 

system uptime calculation described in the proposed rule does not comply with SEMI 

E10-0304E

, which does not include the concept of co-dependent uptimes of different 

equipment (e.g., abatement systems and associated manufacturing tool(s)) in any of its 

metrics. Based on the classification of time periods (e.g., productive time) listed and 

assuming that these time periods have the same definitions as in SEMI E10-0304E, the 

commenter asserted that the calculation is very similar to, but is not the same as, the 

operational uptime formula defined in SEMI E10-0304E paragraph 6.3.3.” The 

commenter asked that references to SEMI E10-0304E in the rule should be removed 

and that the appropriate calculation and its individual terms be completely defined 

within the EPA document unless the EPA determines that one of the SEMI E10-0304E 

formulas may be used. The commenter proposed that EPA edit the original language 

of Proposed subpart I, Section 98.94(f)(2) to read as follows: 

“(2) You shall take into account and report the uptime of abatement systems when 

using destruction or removal efficiencies to reflect emission reductions. Abatement 

system uptime is expressed the total time the abatement system is operating when 

greenhouse gas(es) is flowing in process tool divided by the total time during which the 

process tool is flowing greenhouse gas(es). This calculation must be done for each 

greenhouse gas and combination of process tool(s) and abatement system(s), and can 

be summed into one value for each greenhouse gas for each facility. 

The uptime calculation must be performed for each greenhouse gas, and it shall be 

ensured that abatement devices are operating in a mode appropriate to abate that 

specific greenhouse gas. For example, the abatement device may be capable of 

destroying SF6 to 90 percent, but only 60 percent for CF4. If the abatement device has 

been put into bypass during maintenance, this does not count as uptime, regardless of 

any activity on the process tool.” 

Response 5.2.2.1-a: EPA modified the procedures for calculating and accounting for 

uptime by removing reference to SEMI E-10-0304E

 because EPA agrees with the 

commenter that SEMI E-10-0304E does not fit appropriately in the rule. EPA has taken 

the concept presented by the commenter in the suggested regulatory text and has 

modified it accordingly to fit within the regulatory text of the final rule. In the final rule, 

EPA is requiring facilities to calculate an abatement system’s uptime by taking the ratio 
November 2010 63

of (1) The total time during which the abatement system is in an operational mode when 

fluorinated GHGs or N2O are flowing through production process tool(s) connected to 

that abatement system, to (2) the total time during which fluorinated GHG or N2O in 

which fluorinated GHGs or N2O are flowing through production process tool(s) 

connected to that abatement system (see §98.98). Further, EPA has defined 

operational mode as the time in which an abatement system is being operated within 

the range of parameters as specified in the operations manual provided by the system 

manufacturer (see §98.98). Please also see the preamble section D, Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for 

response to comments on uptime. 

5.2.3 EPA Default DRE Value 

Comment Summary 5.2.3-a: One commenter (0128) stated that it recognizes that 

abatement systems often have a high DRE and are an important factor in accurate 

accounting of overall emissions. However, the commenter raised concerns with EPA’s 

proposal and stated that the abatement estimation flexibilities in the proposal do not 

accurately capture abatement systems’ DREs. The commenter was also concerned 

that EPA’s default DRE is based upon a small sample size of diverse abatement 

technologies, and that existing IPCC and industry DRE factors also are inadequate. 

Therefore, the commenter encouraged EPA to permit reporters to rely only on properly 

measured DREs to better account for variability in installation, operation, and 

maintenance practices. 

Response 5.2.3-a: EPA maintains that the use of properly measured DREs will result 

in more accurate emission estimates; however, EPA finalized provisions to permit 

facilities to use a default DRE as a means to reduce burden on facilities that are 

properly equipped and would like to account for controlled emissions due to the use of 

abatement systems. EPA developed the default DRE with the best and only 

information available to the Agency at this time.34 The data available to EPA are limited 

today and additional data were not made available by way of the public review and 

comment process. EPA agrees with the commenter that IPCC and industry default 

DRE factors are inadequate for purposes of this rule (see response to comment 5.2.3-c 

and the Electronics Manufacture TSD for a discussion on why EPA is not permitting the 

use of IPCC and manufacturer provided default DREs). 

Comment Summary 5.2.3-b: Six commenters (0099, 0110, 0112, 0122, 0123, and 

0131) asserted that the proposed default factor of 60 percent for the DRE of all 

abatement systems is overly conservative (low) and would over-state emissions from 

facilities with abatement systems. Two commenters (0099 and 0131) appreciated 

EPA’s approach to establish and provide default DRE values for abatement systems. 

However, one commenter (0131) noted that the proposed 60 percent default factor is 

based on the destruction of CF4, and should not apply to other fluorinated GHGs where 

 

34 The 60 percent default DRE value was calculated using data from measurements assured to properly 

account for the effects of dilution. In addition, the tested systems were properly installed, operated, and 

maintained. 
November 2010 64

emissions would be significantly overstated. One commenter (0122) specifically argued 

that because of the low value of the default DRE, the practical value of investments in 

abatement technology will be reduced, and it may be a disincentive for voluntary 

adoption of abatement technologies. Other commenters (0099 and 0131) stated that 

the 60 percent default value penalizes semiconductor manufacturers who have 

voluntarily employed POU devices under the EPA and industry voluntary MOU and 

other GHG-reduction programs. 

Response 5.2.3-b: EPA’s default DRE was developed based on the only publicly data 

which properly accounted for the effects of dilution available to EPA at this time. While 

commenters asserted that EPA’s default DRE value is too low, EPA did not receive any 

further information or data in the public comments that would lead EPA to revise this 

value. In regards to the commenters that stated the 60 percent default value penalizes 

semiconductor manufacturers who have voluntarily employed POU devices under the 

EPA and industry voluntary MOU and other GHG-reduction programs, EPA does not 

agree. Although EPA is unsure exactly to which “other GHG-reduction programs” the 

commenter is referring, in contrast to other regulatory programs that generally focus on 

whether a facility's emissions are below a specified limit, this rule focuses on 

establishing each facility’s annual GHG emissions in tons per year. For this reason, 

EPA is finalizing certain requirements in this rule to ensure that EPA receives accurate 

facility-level emissions data. Please also see the preamble section D, Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for 

response to comments on the default DRE value. 

In light of the widely reported variability in fluorinated GHG abatement system 

performance,35 and in order to provide a default DRE option in the final rule, EPA had to 

rely on data obtained through the EPA DRE measurement program (mainly CF4 DREs). 

Please see the Electronics Manufacture TSD for more information on the data used for 

and the development of the EPA default DRE. Please also see response to comment 

5.2.3-c on why EPA is not relying on manufacturer or the IPCC default DRE. 

Because some facilities have already adopted abatement technologies as a means to 

reduce fluorinated GHG emissions, EPA does not agree that the default DRE will 

reduce the practical value of investments in abatement technologies, be a disincentive 

for the use of abatement technologies, or penalize those who have voluntarily adopted 

abatement technologies at their facilities. The default DRE is provided in this rule to 

offer facilities an option, alternative to properly measuring abatement system DREs 

which is also provided in the final rule, to account for the performance of installed 

abatement systems. 

Comment Summary 5.2.3-c: Two commenters (0099 and 0112) proposed that a 

facility be allowed to use a manufacturer’s certified destruction factor discounted by 10 

 

35 Beu, L. (2005). “Reduction of Perfluorocarbon (PFC) Emissions: 2005 State-of-the-Technology 

Report”, TT#0510469A-ENG, International SEMATECH Manufacturing Initiative (ISMI), December 2005. 

Available at: http://www.epa.gov/highgwp/semiconductor-pfc/documents/final_tt_report.pdf 
November 2010 65

percent to account for potential field conditions and result in the application of DREs 

that are more accurate. One commenter (0112) stated that this would be consistent 

with EPA’s proposal in 2009 where EPA allowed the use of manufacturer’s DRE data 

generated using the EPA abatement systems testing protocol. 

Another commenter (0131) proposed the following in relation to the use of default 

DREs: “Provide additional default factors for C2F6 and the other fluorinated GHGs that 

are easier to abate. Allow the use of manufacturer’s certified DREs discounted by 10 

percent to account for differences between field and lab certification conditions. 

Discounted manufacturer’s DREs would account for both the installed equipment’s 

capability and the slight reductions in DREs resulting from use under field conditions. 

Note, EPA’s 2009 proposal allowed the use of manufacturer’s DRE data generated 

using the EPA abatement systems testing protocol. Systems processing CF4 emissions 

would continue to use the EPA 60 percent default DRE. Allow facilities to calculate 

emissions using the average DRE for a gas or gas type determined by testing a 

representative sample of abatement units. These methods will result in the application 

of more accurate DREs.” Another commenter (0099) expressed the same sentiments 

regarding the use of other default DREs for fluorinated GHGs that are easier to abate 

and to the use of manufacturer DREs. 

Two commenters (0110 and 0123) suggested it is contradictory that EPA is not 

permitting the use of IPCC default factors or supplier provided DRE values and EPA is 

also requiring abatement systems to be installed, operated, and maintained in 

accordance with manufacturers’ recommendations. Facilities should be permitted to 

use IPCC and manufacturer DRE values (which commenter 0110 asserted are based 

on measurement data). Another commenter (0122) added that there is substantial 

experience in the industry that point of use (POU) abatement devices achieve DREs 

from 95-99 percent, notwithstanding some examples of poorly installed or operated 

equipment. The commenter stated that it is therefore reasonable to rely on the 

guarantees of abatement system manufacturers regarding the performance of their 

equipment, along with the appropriate diligence to ensure proper installation and 

monitoring of field operations. 

Response 5.2.3-c: In the original April 2009 proposal, EPA did propose to permit a 

third party (e.g., Underwriters Labs) to test abatement equipment on behalf of the 

manufacturer of the abatement equipment; testing would be done on representative 

samples of the abatement equipment in order to verify the DRE of abatement 

equipment. Under this approach, electronics manufacturing facilities would have been 

required to buy equipment that had been certified under this third-party testing. EPA 

does not agree that the commenter’s suggested method to use manufacturer 

guaranteed DREs discounted by 10 percent is consistent with the approach proposed 

in the April 2009 rule for two reasons. First, EPA’s proposal did not mention 

discounting manufacturer supplied DREs, and the commenter did not provide EPA with 

any independently determined data supporting the selection of the discount value of 10 

percent. The 10 percent discount appears arbitrary and was not accompanied by any 

empirical data. Second, the commenter did not specify if manufacturer supplied DRE 

must be developed consistently and properly to account for the effects of dilution (e.g., 
November 2010 66

using EPA’s DRE Protocol). A t the time of the original proposed rule (April 2009) EPA’s 

DRE Protocol had not yet been completed, but EPA proposed that all abatement 

system testing be performed with an industry standard or protocol, or using a consistent 

approach, such as the in-development EPA DRE Protocol, to ensure dilution would be 

properly accounted for. However, EPA is not aware of any abatement system 

manufacturers who have used the EPA DRE Protocol to develop manufacturer claimed 

DREs. 

EPA does not support the use of manufacturer supplied DREs even with proper 

installation and monitoring of abatement systems. Manufacturer supplied DREs may 

result in emissions estimates that are not representative of actual facility operations 

because the DRE itself may have been incorrectly measured due to a failure to account 

for the effects of dilution (e.g., CF4 can be off by as much as a factor of 20 to 50 and 

C2F6 can be off by a factor of up to 10 [Burton, 2007].) This understanding is supported 

by industry assessments as presented in Beu, 2005. Please see the April 2010 

preamble (75 FR 18668, April 2010) and the Electronics Manufacture TSD for the 

reasons why abatement system manufacturer supplied DREs are not permitted in the 

final rule. 

EPA also does not support the use of the IPCC default DRE in this rule because the 

IPCC default DRE was chosen by consensus prior to EPA developing its DRE testing 

program. The IPCC default DRE was based on anecdotal information rather than the 

direct in-fab measurements EPA used to develop its default value for DRE. The 

uncertainties associated with the IPCC default DRE helped spur EPA to embark on its 

DRE measurement program with its industry Partners. 

EPA acknowledges that the 2009 proposal would have allowed for abatement system 

manufacturers to develop DREs using the EPA DRE Protocol. However, EPA has 

reassessed this requirement and is not allowing the use of any abatement equipment 

manufacturer supplied DREs because EPA has concluded that DREs developed in outof-fab settings may not be representative of DREs achieved during full production, infab conditions. Abatement device manufacturer-specified installation, operation, and 

maintenance practices are based upon the testing and development of abatement 

systems in controlled settings that are not experimentally established as representative 

of actual fab environments. When using these systems in actual fab settings, ensuring 

the proper installation, operation, and maintenance of abatement systems may not 

guarantee that the abatement system will perform as abatement manufacturers 

intended, or that the manufacturer supplied DRE will be achieved. EPA’s in-fab DRE 

testing revealed that abatement system performance was well below promises provided 

by abatement systems manufacturers. Additionally, EPA has no information that 

supports claims that continual maintenance in accordance with abatement system 

manufacturer supplied schedules will ensure that abatement systems will meet their 

designed expectations indefinitely. Therefore, EPA is not permitting the use of 

manufacturer supplied DREs in any instance, including instances where facilities 

adhere to manufacturer specifications and instances where the manufacturer 

developed their guaranteed DREs using the EPA DRE Protocol. Please see response 

to comments 5.2.3-b and c for more details on EPA’s default DRE. Please also see the 
November 2010 67

preamble section D, Electronics Manufacturing (subpart I), section 3, for the response 

to comments on the default DRE and properly measured DREs. 

5.2.3.1 System Certification 

Comment Summary 5.2.3.1-a: Two commenters (0089 and 0108) requested further 

explanation of the proposed certification of abatement systems. One commenter 

(0108) requested clarification on who certifies the two apparent certification types 

(proper installation, operation, and maintenance, and abatement system design), how 

often the certification must occur, in what form and containing what specific information, 

and whether EPA envisions third-party certification. The commenter was concerned 

that a foreign manufacturer of abatement systems may be reluctant to participate in a 

design certification scheme by a foreign regulatory agency. One commenter (0089) 

was uncertain whether existing abatement equipment would require certification. The 

commenter suggested that certain technologies (e.g., thermal destruction) that have 

been widely used for PFCs could be considered “certified” if they meet certain key 

operating parameters (e.g., combustion temperature). 

Response 5.2.3.1-a: In the final rule, EPA is requiring any facility that wants to account 

for the use of abatement systems to certify and document that their abatement systems 

(either those previously installed or newly installed) are or have been properly installed, 

operated, and maintained. A facility must show this by self-certifying the proper 

installation, operation, and maintenance, and providing EPA with documentation that 

proves that abatement systems are/were installed, operated, and maintained in 

accordance with the manufacturers' specifications. Alternately, if a facility elects to use 

the EPA default DRE value, a facility must certify that the abatement system, either 

existing or new, for which the default DRE is being applied, is designed specifically to 

abate fluorinated GHG and N2O. EPA clarified in the final rule that a facility must 

support its certification that the abatement system is designed specifically for 

fluorinated GHG and N2O abatement by documenting and reporting the abatement 

system supplier’s specifications for the system (see §98.96(q)). A facility may provide 

this certification without the involvement of third parties. Therefore, because adhering to 

this certification only requires a facility to obtain the design specifications of abatement 

systems, which should be part of BAU documentation that is provided when a facility 

purchases a system, EPA does not foresee the need to involve foreign manufacturers 

in facility self-certification. EPA does not agree with one commenter’s suggestion that 

certain technologies (e.g., thermal destruction) that have been widely used for PFCs 

could be considered “certified” if they meet certain key operating parameters, as the 

method suggested by the commenter would complicate the verification of the proper 

installation, maintenance, or design of systems. Further, while manufacturers of 

thermal destruction systems cite the importance of temperature in determining DRE 

performance, peer review comments on the EPA DRE Protocol (see response to 

comments on the DRE Protocol, available in docket EPA-HQ-OAR-2009-0927) noted 

the difficulties in knowing and measuring what this temperature is for installed systems. 

Because of these concerns, EPA removed temperature as a parameter to decide 

whether a system was capable of abating CF4, for example. See the section 5.2.1 and 
November 2010 68

the Electronics Manufacture TSD for more discussion on proper installation, operation, 

and maintenance. 

5.2.4 Proper Measurement of Abatement DRE 

Comment Summary 5.2.4-a: One commenter (0128) encouraged EPA to finalize a 

rule that relies exclusively on direct measurement for DRE factors. The commenter 

asserted that direct measurement of abatement efficiency maximizes accuracy and can 

better account for variability across facilities in installation, maintenance, and operation. 

Response 5.2.4-a: Although direct, proper measurement of DREs will more accurately 

reflect the use of abatement systems, as well as account for variability among 

abatement systems, EPA is mindful of the burden direct measurement may impose on 

a facility. To reduce burden, EPA is maintaining the option in the final rule for facilities 

to report controlled emissions from the use of fluorinated GHG and N2O abatement 

systems, using a default DRE provided that the systems are certified as being designed 

to abate fluorinated GHGs and N2O. See section 5.2.3 for more details on the default 

DRE provided in the rule. Additionally, as a way for EPA to ensure that variability due 

to installation, operation, and maintenance practices is reduced, facilities that use 

EPA’s default DRE are also required to verify the proper installation, operation and 

maintenance of the abatement systems for which the default DRE is being applied. 

The same verification is also required when using properly measured DREs. 

Comment Summary 5.2.4-b: One commenter (0089) expressed concern that DREs 

obtained from abatement system testing performed prior to the publication of the EPA 

DRE Protocol are not permitted to be used. The commenter asserted that a default 

DRE would have to be used until a facility could complete new tests. The commenter 

suggested that DREs obtained from prior testing should be permitted, provided that a 

facility can show that the testing methods used were substantially similar to the method 

in the EPA DRE Protocol. The commenter also suggested that semiconductor 

processes that have been previously validated and tested by the abatement 

manufacturer should be exempt from additional emission testing for DRE re-validation, 

provided that the units are operated, maintained, and serviced according to the 

manufacturer’s specifications. 

Response 5.2.4-b: Facilities are allowed to use previously measured DREs. A facility 

may use previously measured DREs provided the facility can demonstrate that the 

measurements were made in accordance with the EPA’s DRE Protocol. Facilities may 

demonstrate this by providing documentation of compliance with the principles and 

requirements of the Protocol. 

See response to comments in section 5.2.4.2 for a discussion of the required use of the 

RSASTP. See the response to comment 5.2.3-c about using abatement system 

manufacturer supplied DREs for abatement systems that are properly installed, 

operated, and maintained in accordance with manufacturers’ specifications. 
November 2010 69

5.2.4.1 EPA’s DRE Protocol 

Comment Summary 5.2.4.1-a: One commenter (0131) restated its comments, and 

made some new comments on the EPA DRE Protocol made in a prior public peer 

review process and again urged EPA to accept them. The commenter also asserted 

that FTIR is already an acceptable approved EPA method (e.g., EPA Method 320, or 

EPA Method 301 validation) to characterize other air emissions without the need for 

additional analytic equipment (e.g., Quadrapole Mass Spectroscopy). Another 

commenter (0099) supported these comments as well. 

Response 5.2.4.1-a: Most of the comments from commenter 0131 on the EPA DRE 

Protocol were previously submitted to EPA as part of the two public peer review 

processes EPA undertook for the DRE Protocol. EPA responded to these comments 

during that process. The comments and responses are available in the docket EPAHQ-OAR-2009-0927. The new comments commenter 0131 submitted on the DRE 

Protocol are addressed in Appendix B of this document. 

The use of an FTIR without the use of additional analytical equipment, such as a QMS, 

is an acceptable means to measure DREs only in certain instances. EPA is allowing 

the use of an FTIR without the use of a QMS in certain cases. In the DRE Protocol, 

EPA permits the use of an FTIR in place of a QMS when tracer gases, such as CF4 and 

SF6, are used in place of an inert gas to measure dilution (provided the abatement 

system which is being tested does not abate the tracer gas (CF4 or SF6)). The DRE 

Protocol does not permit, however, the use of an FTIR in place of a QMS for measuring 

dilution with tracers that are inert because, although a method that uses FTIRmeasurable gases may become available, no robust in-fab measurements exist today 

that demonstrate the veracity of such a method. 

Comment Summary 5.2.4.1-b: One commenter (0112) recommended that EPA allow 

facilities to use CF4 as a tracer gas to determine dilution in abatement testing. The 

commenter asserted that the use of CF4 will offer flexibility to the facility performing the 

testing, since CF4 destruction during low-fire temperatures will be minimal, resulting in a 

conservative assessment of destruction efficiency. 

Response 5.2.4.1-b: EPA does not wholly prohibit the use of CF4 as a tracer in the 

DRE Protocol, and hence in the rule. Specifically, with respect to measuring systems 

that do not abate CF4 and/or SF6, EPA’s DRE Protocol states, “In such systems, CF4 or 

SF6 can be used in place of an inert gas since their DREs are zero percent. Table 2 

provides a list of acceptable gases for measuring total abatement system flows, along 

with their use conditions.” As discussed in this excerpt, EPA’s DRE Protocol does not 

permit the use of either CF4 or SF6 as tracer gases in abatement systems that are 

designed to abate these gases. EPA does prohibit the use of CF4 as a tracer in 

fluorinated GHG abatement systems operating in “low fire” because reviewers of early 

drafts of EPA’s DRE Protocol made repeated claims that one could not be certain that 

some abatement of CF4 was not occurring, which would bias dilution and hence DRE 

measurements. For more discussion on the use of CF4 as a tracer gas please see the 
November 2010 70

responses to comments on the DRE Protocol, available in docket EPA-HQ-OAR-2009-

0927. 

Comment Summary 5.2.4.1-c: One commenter (0112) proposed the use of a 

performance based standard, rather than a technology based standard, for testing of 

destruction unit efficiency. A performance based standard would be better able to 

accommodate evolving technology, such as nondispersive infrared sensor (NDIR), 

which may include those that are more cost effective and capable. The commenter 

asserted that proscribing an FTIR methodology for DRE testing limits the use of current 

and future improvements in monitoring technologies and will limit cost-effectively 

meeting EPA’s monitoring requirements. 

Response 5.2.4.1-c: The final rule requires the use of the EPA DRE Protocol, which is 

based on the use of some technologies such as QMS or FTIR used to measure DREs, 

as opposed to other technologies such as NDIR which may be used to monitor the 

performance of abatement systems. The final rule does not specifically prohibit or 

require facilities to use technologies such as NDIR to monitor the performance of 

abatement systems. Please see the responses to comments on the DRE Protocol, 

available in docket EPA-HQ-OAR-2009-0927 for EPA’s previous response to 

comments on the use of NDIR from the Protocol’s public peer review process. 

5.2.4.2 Random Sampling Abatement System Testing Program 

Comment Summary 5.2.4.2-a: One commenter (0112) supported allowing facilities 

that have undertaken Random Sampling Abatement System Testing Program 

(RSASTP) for abatement devices to use actual tested values on the tested units and 

the average destruction value for all other units. The commenter asserted that this 

enables accurate representation of PFC gas emissions. 

However, the commenter proposes the following approach to testing and certifying the 

performance of abatement equipment as an alternative that is less burdensome: 

“Facilities should be required to test 20 percent of the abatement fleet at a facility for 

the first two years of the reporting requirements. If the two years of testing verifies that 

the abatement systems are performing within 10 percent of the manufacturer’s 

specification, the facility should be allowed to certify that its abatement devices are 

being maintained in accordance with a documented maintenance plan based on, but 

not necessarily in complete conformance with, the manufacturer’s recommended 

maintenance procedures, and reduce the testing frequency as described below. In the 

third year and beyond, the facility shall perform a single test of a randomly selected 

abatement unit for each abatement system class to verify continued performance. This 

will provide the base data to demonstrate the current performance of abatement 

systems while enabling facilities to perform less frequent testing to demonstrate system 

performance in recognition that the properly maintained units are expected to perform 

to their specifications.” 
November 2010 71

Two other commenters (0099 and 0131) proposed a similar, but less detailed, 

alternative approach to the RSASTP: a facility should instead be able to use the 

average DRE based on performance testing data. The commenters also propose: “A 

facility can provide test data for an abatement system class to certify annual emissions. 

Upon completion of two (2) years of random testing of at least two (2) abatement 

systems by class at a facility, the DRE by class should be able to be certified in 

subsequent years.” A commenter (0131) went on to state, “In addition, the facility would 

be expected to perform the required system maintenance.” 

One of the commenters (0131) further asserted that periodic testing is not necessary 

when the facility operates abatement equipment properly. The commenter stated that 

where a device has been designed for GHG reduction, default factors reflect test data 

with sufficient accuracy, and thus testing should be required only for new models, not 

variants of existing systems. 

Response 5.2.4.2-a: EPA appreciates one commenter’s support of the RSASTP. EPA 

considered the commenters’ suggested alternatives to the RSASTP; however, in the 

final rule EPA is maintaining that facilities using properly measured DREs must adhere 

to the RSASTP (see §98.94(f)(4). EPA developed the RSASTP, in the absence of data 

about abatement system time to failure or DRE performance drift, to provide an efficient 

and relatively reliable device measurement scheme when compared to requiring a 

facility to test annually all abatement systems used. The RSASTP still allows EPA to 

ensure a facility has measured DREs accurately and at least once every five years. 

This is an essential part of the RSASTP because abatement system performance 

varies greatly depending on a variety of abatement device and process parameters 

such as temperature, flow, and exhaust composition. Facilities develop and ultimately 

use new processes potentially every year, and the parameters of these processes vary. 

Given this, by requiring the gradual testing and retesting of abatement systems over 

time through the RSASTP, EPA can ensure properly measured DREs, and DRE class 

averages used at a facility will accurately reflect controlled emissions. Please see the 

preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses”), for the response to comments on the RSASTP and 

section 5.2.3 for details on the use of default DREs. 

Comment Summary 5.2.4.2-b: One commenter (0122) noted that, for a facility under 

construction, the commenter plans to utilize approximately 200 POU abatement devices 

(some that do not solely abate PFCs). The commenter expected that for this facility, 

approximately three models of device will be represented, depending on how the rule 

defines a “model,” because models often encompass multiple configurations. The 

commenter estimated testing costs for 20 percent of these devices, in accordance with 

the RSASTP, to be in excess of $500,000 annually. The commenter asserted this 

testing requirement is expensive and redundant because (1) testing would serve to 

validate equipment with which industry has substantial field experience, and (2) given 

the small number of abatement equipment models expected to be deployed at a facility, 

multiple tests would be required to be done on the same abatement systems under the 
November 2010 72

RSASTP. The commenter indicated that, given these costs, a broader application of the 

default DRE factor may be expected, resulting in emission over-estimates. 

Response 5.2.4.2-b: EPA does not agree that the RSASTP is expensive and 

redundant. EPA has concluded that more in-fab direct measurement of DREs, beyond 

what has already been done, is necessary, because, as shown in EPA’s DRE testing 

program, in some cases installed abatement system DREs for popular and difficult to 

abate gases like CF4 and C2F6 do not achieve guaranteed DRE provided by abatement 

manufacturers. The RSASTP provides a much less burdensome device measurement 

scheme than requiring a facility to test all abatement systems used annually, but still 

allows EPA to ensure a facility has measured DREs accurately and at least once every 

five years. EPA has determined that this testing frequency is necessary for all 

abatement systems used, regardless of the model, because the RSASTP anticipates 

reliable maintenance periods and useful lifetimes of abatement systems. Also, it is 

necessary to test every system used at a facility, regardless of the model of system, 

because it is well known across the industry that abatement system performance varies 

greatly depending on the type of abatement device and process parameters such as 

temperature, flow, and exhaust composition.36 As stated by many commenters, facilities 

develop and ultimately use new processes potentially every year, and the parameters 

of these processes vary. Therefore, gradual testing over a five year period is not 

redundant as DREs between the same abatement system models may vary between 

years depending on the process exhaust fed into the abatement systems, which may 

also cause RSASTP class average DREs to vary between years. See the preamble 

section D, Electronics Manufacturing (subpart I), section 3, for the response to 

comments on the RSASTP. See response to comments in section 5.2.3 on the 

application of default DREs. 

Comment Summary 5.2.4.2-c: Two commenters (0123 and 0110) asserted that the 

frequency of required testing using the RSASTP is burdensome and unnecessary. 

Further, the commenters asserted that new abatement systems that are installed, 

operated, and maintained according to the manufacturer’s recommendations should not 

require annual testing. 

The commenters believed the use of manufacturer specified DRE values and less 

frequent testing was sufficient, because facilities may have a small number of 

abatement systems (e.g., facilities that have three abatement systems) and for new 

processes that become part of production, new abatement systems associated with 

these new classes could require annual testing. For these types of facilities 

commenters believed that instead of testing 20 percent or 3 abatement systems in each 

year as in the proposed RSASTP, that abatement systems be tested on a set schedule. 

One commenter (0123) proposed once every three years, and the other commenter 

(0110) proposed testing a maximum of once every five years. 

 

36 Beu, L. (2005). “Reduction of Perfluorocarbon (PFC) Emissions: 2005 State-of-the-Technology 

Report”, TT#0510469AENG, International SEMATECH Manufacturing Initiative (ISMI), December 2005. 

Available at: http://www.epa.gov/highgwp/semiconductor-pfc/documents/final_tt_report.pdf. 
November 2010 73

Response 5.2.4.2-c: EPA does not agree with commenters who asserted the RSASTP 

is burdensome and unnecessary, provided abatement systems are designed and 

operated to abate fluorinated GHGs. EPA’s DRE provisions address the dearth of 

published data on abatement system DRE performance for systems designed to abate 

fluorinated GHGs and the variability in those DRE values over time, under in-fab 

conditions. Commenters did not provide EPA sufficient information or data to mitigate 

concerns regarding the varying performance of abatement systems over time. See 

response to comment 5.2.4.2-b and see the preamble section D, Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for the 

response to comments on the RSASTP and discussion on why EPA is requiring the 

RSASTP. See also responses to comments in section 5.2.3 on why EPA is not 

allowing the use of manufacturer specified DREs. 

Comment Summary 5.2.4.2-d: One commenter (0089) asserted that testing of 20 

percent of units each year is burdensome at large fabrication sites that may have more 

than 100 individual devices in operation. Testing can negatively affect manufacturing as 

most tools would need to be taken offline during the testing period. As an alternative, 

the commenter proposed: “Destruction removal efficiency testing should only be 

required on a representative portion of identical POU devices. This initial testing can be 

used to characterize the key operating parameters (e.g., operating temperature, 

residence time, etc.) the device must meet in order to achieve the efficiency measured 

during the test. The unit, and similar units, can then be assumed to be achieving this 

efficiency as long as it can be documented that they are operating within the key 

parameters, without a need for ongoing testing. This approach is consistent with the 

methods that state and local air pollution control agencies have used for years to 

establish DRE for control devices on other pollutants. Intel has many control devices in 

place at its fabs to treat volatile organic compounds (VOCs) or hazardous air pollutants 

(HAPs). The DRE for those devices is typically established in a manner similar to that 

described above, without the need for ongoing testing, or even for testing each 

individual unit.” The commenter asserted that EPA at least implicitly endorses this 

approach because the permits under which these sites operate are considered 

“federally enforceable” for purposes of maintaining emissions below major source 

thresholds. Another commenter (0131) also asserted that the testing frequency 

requirements are excessive and a cost burden given that EPA has not provided data to 

support annual testing beyond what is required for other EPA regulations. 

Response 5.2.4.2-d: EPA does not agree with the commenter that testing 20 percent 

of units a year is an excessive burden for large facilities. EPA acknowledges that tools 

do need to be offline for a portion of the time required for DRE testing, but it is not 

plausible that a facility will be running tools 100 percent of the available time. During 

downtime periods, abatement systems attached to such tools may be tested. Given that 

the RSASTP requires testing of an abatement system essentially once every five years, 

there should be points within that period where tools are offline that DRE testing can be 

done. Through EPA’s experience in the DRE measurement program, EPA has found 

that testing can be done within the constraints of manufacturing environments and that 
November 2010 74

manufacturing schedules can accommodate a period for testing without adverse 

effects. 

EPA considered the commenters’ suggested alternatives to the RSASTP; however, in 

the final rule EPA is maintaining that facilities using properly measured DREs must 

adhere to the RSASTP. See the preamble section D, Electronics Manufacturing 

(subpart I), section 3 (“Summary of Comments and Responses”), for the response to 

comments on the RSASTP. Please also see response to comment 5.2.4.2-a and 

5.2.4.2-b for more discussion on the required use of the RSASTP. 

The testing frequency required through the RSASTP is aligned with the purpose and 

goal of the GHG Reporting Program which, in contrast to other regulatory programs 

with different goals, is to collect accurate facility-level GHG emission information to 

inform future policy and regulatory decisions. Please see response to comment 4.1.2-c 

for more discussion on the relationship between this rule and air quality regulations. 

Comment Summary 5.2.4.2-e: One commenter (0095) noted that it is not clear 

whether the RSASTP is intended to include only processes that have not yet gone 

through emission testing, or if it also includes processes that have already been tested. 

The commenter suggested that semiconductor processes that have been validated and 

tested by the abatement manufacturer should be exempt from additional emission 

testing for DRE re-validation, provided that the abatement units are operated, 

maintained, and serviced according to the manufacturer’s specification. 

Response 5.2.4.2-e: EPA is not permitting the use of measurements made previously 

by an abatement system manufacturer, as discussed in response to comment 5.2.4.2-

b. EPA is permitting only measurements made at a facility using the EPA DRE Protocol 

to be used to account for the use of abatement systems. EPA is allowing the use of 

these measurements if a facility has conducted DRE measurements using the EPA 

DRE Protocol published in March of 2010. Please see the preamble section D, 

Electronics Manufacturing (subpart I), section 3 (“Summary of Comments and 

Responses”), for the response to comments on the RSASTP. 

5.3 Other QA/QC Procedures 

Comment Summary 5.3-a: One commenter (0112) asserted that EPA needs to 

provide more flexibility for facilities to develop inline calibration procedures for PFC gas 

flow measuring devices. The commenter stated that most of the mass flow controllers 

purchased have guaranteed performance accuracy within 1 percent. The commenter 

asserted it would be better if flow calibration was run less frequently and while the 

meters were installed on the tool; removing each mass flow controller for bench 

calibration introduces significant costs, downtime, and contamination exposure. 

Response 5.3-a: In the final rule, EPA has removed the calibration requirement 

proposed in §98.94(i) (75 FR 18702, April 2010) because the calibration aspects of the 

2006 ISMI Guidelines and the EPA DRE Protocol are sufficient for purposes of the rule. 
November 2010 75

Comment Summary 5.3-b: One commenter (0131) asserted that scales and pressure 

monitoring devices are not currently calibrated per ISO 9000 Quality Standards, NIST 

traceable standards, or other methods that would be considered “true calibration.” In 

many cases, calibration of a measurement device would require removing it from 

service and possibly disconnecting it from the tool. The commenter asserted that this is 

unacceptable because facilities operate continuously and are subject to rigorous 

contamination control for replaced or removed equipment. Currently, performance 

verification is conducted on measurement devices as needed since the trigger point for 

change-out is a highly critical measurement to ensure that the integrity of gas delivery is 

not compromised. 

Response 5.3-b: Please see response to comment 5.3-a for information on how EPA 

addressed calibration requirements in the final rule. 

Comment Summary 5.3-c: One commenter (0089) suggested that the requirement for 

facilities to follow QA/QC procedures in the 2006 ISMI Guidelines and in EPA’s DRE 

Protocol should be applicable only from the effective date of the rule forward. Facilities 

should not be required to retroactively show compliance with these procedures for 

measurements or testing done prior to the publication of the rule. 

Response 5.3-c: This rule is not retroactive. This rule does not impose any new 

liability or obligation on the basis of past conduct and its emission reporting 

requirements are prospective only. For facilities to use historical emissions 

measurements, they must show compliance with QA/QC procedures for the appropriate 

ISMI Guidelines. EPA needs to verify that appropriate QA/QC procedures were 

followed for any measurements made and factored into emission estimation methods, 

regardless of when the measurements occurred, to ensure the quality of the data being 

used to estimate emissions. In general, EPA designed these requirements with the 

expectation that the measurements would be made in future, because according to an 

industry survey the majority of semiconductor manufacturers have not performed Tier 3 

measurement testing.37 However, to provide more flexibility for facilities that have 

already made Tier 3 measurements prior to the publication of the rule, EPA is allowing 

facilities to use measurements made in the past if sufficient supporting documentation 

is available. In the final rule EPA is permitting facilities to use measurements made in 

accordance with not only the 2006 ISMI Guidelines, but the 2001 ISMI Guidelines as 

well. For facilities to use historical measurements made with the 2001 ISMI Guidelines, 

EPA is requiring facilities to document that the QA/QC procedures from the 2001 ISMI 

Guidelines were followed. Please see response to comment 5.1-a for details on the 

required use of the 2001 or 2006 ISMI Guidelines. 

Because the DRE Protocol was published recently (2010), in general EPA assumes 

that the first year of data collection for this rule would correspond to the first year of the 

 

37 EPA is also unaware of any other type of electronics manufacturer (MEMS, LCD, PV) that have 

performed Tier 3 measurements. 
November 2010 76

RSASTP for many facilities. However if there are instances where a facility has DRE 

measurements made prior to the effective date of a rule, but within the time span of the 

required RSASTP (5 years) the facility would be permitted to use those measurements 

provided sufficient documentation is available to show that the QA/QC procedures in 

the DRE Protocol were followed, and the measurements were made using EPA’s DRE 

Protocol. 
November 2010 77

6. Data Reporting Requirements 

Many comments on data reporting and confidential business information (CBI) were 

interrelated. Responses to comments may appear in this section 6 (Data Reporting 

Requirements) or in section 9 (Confidential Business Information). 

Comment Summary 6-a: With respect to EPA’s proposed requirement in §98.95(g) 

(that a facility calculates and reports the facility-wide consumption of gas based on the 

modeling calculations performed using engineering and process data), one commenter 

(0112) proposed that the required reported data be moved to recordkeeping. The 

commenter asserted that the calculations have a degree of uncertainty due to process 

and measurement variation, and thus the calculations will not directly match actual 

usage. The commenter stated that there is no reason to report this data and that the 

facility should maintain the data and have it available for inspection and discussion. 

The commenter also stated that the model will need to use statistical methods to 

reconcile use calculations based on process and fab data to actual gas use as 

determined by cylinder disbursements. 

Response 6-a: With respect to the commenter’s request that a facility should maintain 

data on the modeling calculation performed using engineering and process data as a 

recordkeeping requirement and not be required to report such data, this requirement as 

proposed is not being finalized in this rule. EPA has modified the procedures by which 

facilities are required to develop gas consumption apportioning factors, and is requiring 

that facilities submit to EPA specific information on the model (see §98.94(c)). The 

information that EPA is requiring facilities to submit about facility-specific engineering 

models to apportion gas consumption will provide EPA with data to verify the models. 

Thus, it is important that this information be reported to the Agency. For additional 

comment responses on the facility-specific engineering model, please see also the 

preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses.”) 

Comment Summary 6-b: One commenter (0089) asserted that submitting results of all 

test data for the Tier 3 approach is an unnecessary burden, and would likely provide 

EPA with more data than it can review. The commenter noted that a single fab may 

have 100 or more individual tool tests covering all processes steps and all covered 

fluorinated gases. In addition, the commenter asserted that this type of information is 

confidential business information (CBI). The commenter proposed that facilities that 

use the Tier 3 approach submit data on chemical use, emissions factors used, and a 

detailed summary explaining methods for apportioning chemical use amongst process 

steps with supporting documentation. The commenter proposed that actual copies of 

emission tests be maintained on site and available for inspection. These methods 

would be consistent with requirements for verifying emissions of regulated pollutants 

with state and local agencies. 
November 2010 78

Response 6-b: Although EPA is unsure exactly to which state and local agency 

requirements the commenter is referring, in contrast to other regulatory programs, this 

rule focuses on establishing each facility’s annual GHG emissions in tons per year, 

not on whether a facility's emissions are below a specified limit. EPA considered 

reporting and recordkeeping requirements (see §98.96 and §98.97) and strived for a 

balance between information that is critical for analyzing and verifying reported 

emissions and minimizing reporting burden. 

EPA concurs with the commenter’s suggestion that the detailed Tier 3 emission 

measurement documentation should be retained onsite for inspection. EPA is requiring 

facilities to report data on gas usage, emission factors (utilization and byproduct 

formation rates), the type of film and feature that was etched, the source of the 

emission factor information for that recipe, and certification that the measurements 

were made using the 2006 ISMI Guidelines, or the 2001 ISMI Guidelines if 

measurements were made prior to January 1, 2007. Other information including 

documentation that measurements were made using the ISMI Guidelines must be 

retained as records. EPA is requiring reporting, rather than simply retention, of certain 

data in order to permit EPA to conduct an annual verification of the emissions quantities 

reported by each facility. Due to EPA resource constraints, it is unlikely that EPA would 

be able to make site visits annually to verify reports based on facility records. Without 

reporting of verification data, therefore, the frequency of verification would be lower, 

while the costs of such verification would be much higher. Nonetheless, EPA is aware 

of the commenters’ concerns and may consider moving certain requirements from the 

reporting section to the recordkeeping section of the rule following further analysis. 

With respect to the commenter’s concern that Tier 3 test data is CBI, today’s action 

does not address whether data reported under subpart I will be treated as CBI. EPA is 

addressing CBI issues in a separate rulemaking. EPA published a proposed 

confidentiality determination on July 7, 2010 (75 FR 39094) which addressed the CBI 

status of certain data elements. In that action, EPA proposed which specific data 

elements would be treated as CBI and which data elements must be available to the 

public under section 114 of the CAA. EPA has received comments on the proposal and 

is in the process of considering these comments. A final determination will be issued 

before any data is released, and the final determination will include all of the data 

elements under these subparts. (For more information on the CBI rulemaking, please 

see, http://www.epa.gov/climatechange/emissions/CBI.html#proposal ). 

Comment Summary 6-c: One commenter (0099) proposed that EPA only require 

facilities to submit annual emissions and the method of emissions calculations. 

Facilities would keep all other data elements on site and available for inspection. The 

commenter asserted, “this is consistent with management of the underlying emissions 

calculations data in other air quality and permitting programs.” 

Response 6-c: EPA does not agree with the commenter that it should only require 

facilities to submit annual emissions and the method of emissions calculation. Although 

EPA is unsure exactly to which other air quality and permitting programs the 
November 2010 79

commenter is referring, in contrast to other regulatory programs, this rule focuses on 

establishing each facility’s annual GHG emissions in tons per year, not on whether a 

facility's emissions are below a specified limit. EPA is requiring reporting, rather than 

simply retention, of certain information relating to the emissions calculation to permit 

EPA to verify the data reported by each facility. Since emission factors can vary 

significantly between processes, and hence facilities, it is important for EPA to have a 

high degree of granularity in reported emissions information to facilitate verification and 

evaluation of individual components of a reported emission estimate. Due to EPA 

resource constraints, it is unlikely that EPA would be able to make site visits annually to 

verify reports based on facility records. Without reporting of verification data, therefore, 

the frequency of verification would be lower, while the costs of such verification would 

be much higher. Nonetheless, EPA is aware of the commenters’ concerns and may 

consider moving certain requirements from the reporting section to the recordkeeping 

section of the rule following further analysis. Please see Response 6-b for additional 

response to comments on data reporting requirements. 

Comment Summary 6-d: One commenter (0095) requested clarification on whether 

production based on substrate area is based on the total number of fully processed 

wafers or on the number of wafer starts. The commenter requested this clarification 

because it asserted that certain semiconductor companies that appear to be covered by 

subpart I do not manufacture wafers and process wafers, but only partially process 

wafers for research and development (R&D) purposes. 

Response 6-d: EPA is requiring semiconductor manufacturing facilities to use their full 

facility design capacity, in terms of substrate surface area (e.g., silicon), in the threshold 

determination calculation which is based on the 2006 IPCC Tier 1 method.38 Under this 

approach, a facility’s potential to emit determines whether the facility meets or exceeds 

the reporting threshold. As a result of using a facility's full annual design capacity in 

terms of substrate surface area, the distinction between processed wafers and partiallyprocessed R&D wafers is not relevant to the threshold analysis. For data reporting, 

EPA is requiring facilities to provide the total substrate surface area processed. 

However, if the partial wafer processing was associated with R&D activities (as defined 

in 40 CFR 98.6), that substrate area should not be reported to EPA. Please see 

comment response 1-b for responses to comment on R&D activities. 

Comment Summary 6-e: Two commenters (0089 and 0112) requested that annual 

surface area production be removed from reporting requirements because it is CBI and 

it does not actually affect emission results. 

Response 6-e: EPA acknowledges the commenter’s suggestion to shift annual 

substrate area processed per year from the reporting to the recordkeeping provisions. 

EPA carefully considered reporting and recordkeeping requirements and strived to 

balance its need for information that is critical for analyzing and verifying reported 

 

38 See the preamble to the final rule for more information about the reporting threshold determination 

calculations. 
November 2010 80

emissions and the goal of minimizing reporting burden. EPA determined that a facility's 

annual substrate processed is an important manufacturing activity datum and that it 

should be retained as a data reporting requirement. Receiving this data will enable the 

Agency to track facility level emission intensity trends, identify reporting anomalies, and 

develop future GHG policies and programs. EPA is requiring reporting, rather than just 

retention, of certain data to allow EPA to annually verify the emission quantities 

reported by each facility. Due to EPA resource constraints, it is unlikely that EPA would 

be able to make site visits annually to verify reports based on facility records. Without 

reporting of verification data, therefore, the frequency of verification would be lower, 

while the costs of such verification would be much higher. Nonetheless, EPA is aware 

of the commenters’ concerns and may consider moving certain requirements from the 

reporting section to the recordkeeping section of the rule following further analysis. 

In regards to the commenter’s assertion that substrate surface area processed is 

considered CBI, today’s action does not address whether data reported under subpart I 

will be treated as CBI. Please also see comment responses in 6-b. Please also see 

comment responses in section 9 on CBI. 

 

6.1 DRE Reporting 

Comment Summary 6.1-a: Two commenters (0099 and 0131) were concerned that 

the proposed rule would require semiconductor manufacturers to generate a large 

amount of information pertaining to the abatement systems used at a facility for 

fluorinated GHG control. The commenters asserted that this requirement would prove 

quite costly and burdensome. 

Response 6.1-a: To comply with the final rule requirements for reporting controlled 

emissions, facilities may have to generate new information pertaining to the use of 

abatement systems each year, and EPA recognizes that there is some associated 

burden. However, EPA has determined that such information is essential to verify 

reported controlled emissions. 

For example, abatement system installation, maintenance, and testing are critical 

components of DRE performance. Therefore, it is important from a reporting 

perspective to ensure that proper documentation is developed and retained that would 

support the reported emissions of a given facility. In addition, information about 

abatement devices used at an electronics manufacturing facility will enable EPA to 

track emission trends from the industry to develop future GHG policies and programs. 

Much of the documentation for using either the EPA default DRE or properly measured 

DREs can be efficiently developed and stored by reporting entities. For example, the 

DRE Protocol contains a simple and repeatable example template for certifying the 

measurement results. In addition, the bulk of the information required for abatement 

system certification and monitoring is a recordkeeping requirement that can efficiently 

be accomplished through electronic file (e.g., Microsoft Word or Excel and Adobe PDF) 

management and storage. 
November 2010 81

In addition, it is important to note that as a means to balance burden EPA has provided 

facilities with the option of reporting detailed information on measured DREs or using 

EPA’s default DRE, the latter of which will require less information to be reported to 

EPA. 
November 2010 82

7. Records that Must be Retained 

Comment Summary 7-a: One commenter (0112) asserted that invoices for gas 

purchases should only be required to be retained for 3 years. Longer retention times 

are unreasonable and likely to conflict with company internal recordkeeping 

requirements. 

Response 7-a: EPA appreciates the commenter’s concern regarding the length of 

record retention. Consistent with the Final MRR, under this rule facilities are required to 

retain records for three years. As EPA stated in the preamble to the Final MRR, “a 

three- year time period is sufficient to allow for EPA to audit and review of records 

needed to verify the emission data submitted in annual reports” (74 FR 56281, October 

2009). It is important to note, in that final rule, EPA reduced the record retention 

requirements from five (as proposed) to three years. Please see the preamble to the 

Final MRR for responses to comments on record retention (74 FR 56281, October 

2009). 

Comment Summary 7-b: With respect to EPA’s requirement for facilities to maintain 

records for testing done at a facility, including documentation to demonstrate that 

emissions measurements were made using the 2006 ISMI Guidelines and 

documentation that DREs were measured in accordance with EPA’s DRE Protocol, one 

commenter (0089) suggested that these record keeping requirements should not apply 

retroactively. The commenter asserted that facilities that have conducted emissions 

measurement tests prior to the publication of the rule would be unable to comply. The 

commenter argued that this requirement would disallow the use of any measurements 

made before the effective date of the rule. The commenter expressed a similar concern 

regarding obtaining certification about the design purpose for abatement systems, citing 

that facilities would have to assume a DRE of zero if retroactive certification were 

required. (Note, in a similar regard, the commenter also asserted that the testing 

requirements for emissions characterization and DRE testing should only be applied to 

measurements going forward. Please see comment responses 5.1-a and 5.2.4-b for 

responses to comments on the required use of the EPA DRE Protocol and the ISMI 

Guidelines). 

Response 7-b: This rule is not retroactive. It does not impose any new liability or 

obligation on the basis of past conduct and its emission reporting and recordkeeping 

requirements are prospective only. This rule does not require any facility to take into 

account reductions achieved by its abatement system in reporting its GHG emissions. 

To the extent a facility chooses this option, the facility may choose to use the default 

DRE or a properly measured DRE (i.e., DREs measured in accordance with EPA’s 

DRE Protocol). Only in the latter instance must the facility maintain as a record a 

certification that the DRE was calculated according to methods in EPA’s DRE Protocol. 

The other requirement referred to by the commenter applies only to facilities using 

facility-specific, recipe-specific utilization and by-product formation rates. In general, 

EPA designed these requirements with the expectation that the measurements would 
November 2010 83

be made in the future. However, to provide more flexibility, EPA is allowing facilities to 

use measurements made in the past if sufficient supporting documentation is available. 

EPA is not permitting emission factor and DRE measurements that have not been 

made in accordance with the requirements finalized in the rule to be “grandfathered” in 

as the commenter suggested. EPA’s final rule allows a facility to document and use 

historical emission measurement results provided the measurements were made using 

the 2006 ISMI Guidelines (or the 2001 ISMI Guidelines for measurements made prior to 

January 1, 2007) and abatement system DRE measurements, if made in accordance 

with the EPA DRE Protocol. If misplaced, the facility may have to locate historical test 

plans, log books, and other information pertaining to the measurement studies. With 

regard to the certification of design purpose for abatement systems where the default 

DRE will be used, this is a critical component of the DRE validation process. EPA 

understands that coordination with the abatement system vendor to obtain necessary 

documentation may be required. If the facility cannot obtain documentation that 

demonstrates that an abatement system is designed to destroy fluorinated GHGs 

and/or N2O, then the facility cannot claim a reduction in emissions. If an abatement 

system vendor is claiming a DRE for a given system, then the vendor should be able to 

produce a system design certification. There is nothing retroactive about this 

requirement. EPA is not stating that the vendor must have prepared such a certification 

at the time of sale; the facility may request that the vendor prepare such a certification 

so that the facility may take advantage of the default DRE option under this rule. 

Please also see response to comments 5.1-a and 5.2.4-b on why EPA is requiring 

measurements to be made using the ISMI Guidelines and EPA’s DRE Protocol. 
November 2010 84

8. Cost Data/Burden 

Comment Summary 8-a: One commenter (0124) asserted that the reporting burden 

for the electronics industry is still a concern. Reporting costs for the first year for the 

electronics manufacturing industry, $0.51 per MtCO2e, are higher than EPA’s estimated 

average cost for all sources, $0.04 per MtCO2e. The commenter also asserted that due 

to the high GWP of many gases used in the electronics manufacturing sector and other 

fluorinated GHG-using sectors, facilities with small amounts of actual emissions may 

become subject to reporting under the MRR. 

Response 8-a: EPA acknowledges certain sectors face different reporting costs per 

ton. EPA estimates the average reporting cost for the electronics manufacturing 

industry to be $0.51 per ton. The wide variety of potent and often long-lived GHGs 

used by this sector naturally adds complexity to the monitoring and reporting methods. 

The cost per ton provides a comparison to other subpart in the mandatory reporting 

rule. While in some cases the per ton reporting costs are higher than other subparts, 

the overall goal of the GHG reporting is to provide a comprehensive and accurate 

reporting system. The cost effectiveness metric of cost per ton reported may not be the 

most appropriate means to evaluate the economic impact of the rule and is just one 

means of doing so. Another metric presented in the EIA is cost-to-sales ratios, which 

evaluates the compliance cost against average receipts for like facilities. EPA found the 

cost-to-sales ratio for this industry to generally be below 1 percent. More detail on this 

analysis is available in the Economic Impact Analysis in Section 5.3.1. 

Comment Summary 8-b: One commenter (0112) asserted that the proposed rule 

would cost the company $3-5 million in capital investments if major changes had to be 

made to estimate and apportion gas consumption. The commenter stated “that it will 

require $3-5 million in capital investment if major changes have to be to distribution 

and/or metering systems to segregate distribution systems by process type and to meet 

the 1% accuracy requirement for measurement systems. Annual operating costs could 

approach $1 million per year when including the cost of testing 20 percent of the 

emissions abatement devices, as our EFK facility will have over 200 abatement units 

installed.” The commenter also asserted that “in aggregate, the rule drives capital 

investments of $1.5 million to $5 million and between $500,000 and $2,000 for ongoing 

operation and maintenance cost to comply with the requirements in the re-proposal of 

the GHG reporting rule for ‘Additional Sources of Fluorinated Gases’.”

Response 8-b: In the final rule, EPA has made efforts to balance burden to the 

industry while maintaining requirements that EPA has determined are necessary to 

obtain facility-specific emission estimates. Please see the preamble section D, 

Electronics Manufacturing (subpart I), section 3 (“Summary of Comments and 

Responses”), for the responses to comments which discuss burden-reducing efforts. 

Although the commenter asserted that the proposed rule would result in significant 

costs, the commenter did not provide details on how their costs were estimated. EPA 

has updated the Economic Impact Analysis (EIA) to reflect the requirements finalized in 
November 2010 85

the rule. For example, EPA has now included capital costs associated with 

apportioning gas consumption. For details on how EPA developed its final costs for this 

rule, see sections 4 & 5 of the EIA (available in the docket, EPA-HQ-OAR-2009-0927). 

Please see response to comments in section 4.1.1.1 for a discussion on the accuracy 

and precision requirements in the final rule. 

EPA is mindful of the costs associated with reporting controlled emissions by properly 

measuring the DRE of the abatement systems in accordance with EPA’s DRE Protocol 

(the approach for which the commenter is basing their cost estimates). As a burdenreducing measure EPA has provided the RSASTP, which requires a facility to test 20 

percent of its abatement systems in each reporting year, as opposed to requiring a 

facility to test every abatement system in each reporting year for properly measuring 

abatement system DREs. EPA estimates that the costs associated with properly 

measuring abatement system DREs would be $70,000 per year for a facility. This 

estimate assumes that a facility has 50 abatement systems total, and hence is testing 

10 systems a year to comply with the RSASTP, where 5 systems can be tested in a 

week and one week of testing costs $35,000. This cost estimate is based on EPA 

experiences actually measuring the DREs of operational abatement systems. The cost 

EPA estimated for optional proper DRE measurement will vary, however, depending on 

the number of abatement systems a facility has. As another means to reduce burden 

associated with reporting controlled emissions, EPA has provided a default DRE factor 

that facilities may opt to use instead of properly measured DREs.39 EPA has estimated 

that using the EPA default value is less costly than properly measuring the DRE of 

abatement equipment in accordance with EPA’s DRE Protocol. 

Comment Summary 8-c: One commenter (0122) estimated that testing 20 percent of 

abatement devices expected to be used at a facility currently under construction, to 

comply with the requirements of the RSASTP, would cost in excess of $500,000 per 

year. The commenter asserted that this testing would be unnecessarily expensive, 

highly redundant, and carry a significant cost and burden without corresponding 

benefits of improved data accuracy or reduced emissions. The commenter expected 

that given these costs, a broader use of default DRE factors would be seen, resulting in 

an over-estimation of emissions. The commenter asserted that the proposed rule as 

written presents challenges for a company that is currently making significant 

investments in emission reductions on a voluntary basis. The commenter indicated that 

the recordkeeping burden is excessive given the complexity of semiconductor 

manufacturing, the relatively low GHG emissions compared to the whole economy, and 

the industry’s long history of proactive GHG emission reductions. 

 

39 To report controlled emissions using the EPA default DRE value of 60 percent, a facility must certify 

that the abatement system for which they are reporting controlled emissions is installed, operated, and 

maintained in accordance with the manufacturers’ specifications. In addition, the facility must also obtain 

documentation from the abatement system supplier certifying that the abatement system is specifically 

designed to abate fluorinated GHG and N2O. 
November 2010 86

Response 8-c: EPA disagrees with the commenter’s statement that the RSASTP 

would be highly redundant and would provide limited improvement in data accuracy or 

reduced emissions. EPA has concluded that there is a need for gradually testing all of 

the abatement systems within a single class of abatement systems and for retesting 

individual abatement systems over time. As EPA stated in the preamble to the April 

2010 proposed rule (75 FR 18652, April 2010), some fluorinated GHGs, such as CF4, 

are harder to destroy than others; thus, the performance of abatement systems with 

one fluorinated GHG cannot be assumed to apply to other fluorinated GHGs. It is well 

known across the industry that abatement system performance varies greatly 

depending on the abatement device and process parameters such as temperature, 

flow, and exhaust composition. Abatement system performance is also highly 

dependent on effective maintenance. By requiring the gradual testing and retesting of 

abatement systems over time through the RSASTP, EPA can ensure properly 

measured DREs, and DRE class averages used at a facility will accurately reflect 

controlled emissions. 

Also, through the use of the RSASTP, EPA is reducing burden, for instance, for 

facilities that continually modify their processes. EPA is basing the RSASTP around 

classes, defined as abatement systems grouped by manufacturer model number(s) and 

by the gas which the system is used to abate; varying process parameters, such as 

flows, temperature, and exhaust composition, do not factor into the requirements of the 

RSASTP. EPA has provided facilities with the flexibility to use a default DRE value of 

60 percent as a less burdensome option for reporting controlled emissions. (see section 

5.2.3 for more discussion on the EPA default DRE.) EPA has included the cost 

associated with DRE measurement testing in the EIA. For details on how EPA 

developed its final costs for this rule, see sections 4 & 5 of the EIA (available in the 

docket, EPA-HQ-OAR-2009-0927). 

EPA appreciates its industry Partners’ efforts to reduce emissions under the PFC 

Reduction/Climate Partnership for the Semiconductor Industry, and EPA disagrees that 

this rule presents challenges for a company that is currently making significant 

investments in emission reductions on a voluntary basis. The rule is aimed at gathering 

accurate facility-level information, and gathering this information does not inhibit a 

company from reducing emissions or accounting for those controlled emissions in GHG 

reporting. 

EPA acknowledges the commenter’s concerns about the burden of data reporting and 

recordkeeping under the rule. EPA carefully considered reporting and recordkeeping 

requirements and strived for a balance between reporting burden and the need for 

information that is critical for analyzing and verifying reported emissions (see §98.96 

and §98.97). Because emission factors can vary significantly between processes, EPA 

is requiring a high degree of granularity in reported emissions information to facilitate 

verification and evaluation of individual components of an emissions estimate. EPA has 

determined that each piece of information required to be reported or retained as a 

record is directly relevant to the development of reported emissions. 
November 2010 87

Comment Summary 8-d: One commenter (TRANS-DC-02-4) expressed appreciation 

that the proposed rule allows for an emission factor approach and is responsive to 

suggestions to allow gas usage heel factors based on cylinder-change triggers. 

However, the commenter indicated the proposed rule may impose an equal or greater 

burden compared to the original due to gas accounting in the nine process categories 

and N2O. Additionally, the commenter noted that the reporting scheme may impose 

significant compliance burdens and costs due to necessary quantifiable indicators and 

the disqualification of engineering judgment. 

Two other commenters (0123 and 0110) asserted that the EIA of the proposed rule 

shows a misunderstanding of current industry practices and data collection capabilities, 

severely underestimating the fiscal impacts. Specifically, the commenters raised 

concern with EPA’s assumptions that information required by the Refined Method (i.e., 

gas consumption data and indicators of activity used to apportion gas consumption) is 

collected as part of BAU operations and that no capital costs are associated with rule 

compliance. 

Response 8-d: EPA thanks the commenter for noting appreciation of the efforts EPA 

had made to balance burden for estimating gas consumption for the industry. 

Although the EPA has not at this time finalized the Refined Method, which is based on 

nine process sub-types for estimating fluorinated GHG emissions,40 the methods in the 

final rule (the Tier 2c and the Tier 2d) are similar to the Refined Method in that gas 

consumption must be estimated and apportioned to process types, sub-types, or 

recipes. EPA therefore considered the commenters’ concerns that gas consumption 

and apportioning compliance costs for the Refined Method were underestimated in the 

proposed EIA. EPA revised the cost estimates for apportioning gas consumption for 

the final EIA to account for capital costs associated with tracking information to 

apportion gas consumption. EPA has concluded that its final cost estimates 

appropriately account for the compliance burden under this rule. Please see sections 4 

& 5 of the EIA (available in the docket, EPA-HQ-OAR-2009-0927) for more details on 

the cost estimates and analysis. 

The revised cost estimates represent the costs of the methods that facilities must use to 

apportion gas consumption in the final rule. The finalized methods are flexible, allowing 

facilities to develop apportioning factors based on a quantifiable metric of the facility’s 

choosing, provided the method is described in writing, is repeatable, and is verified 

through comparison with actual gas consumption. This approach provides facilities 

flexibility in the choice of apportioning methods, thereby allowing facilities to develop 

what will be their most cost-effective approach, and assuring the high degree of data 

quality that EPA needs. Please see response to comment 4.1.2-a for more details on 

the revised gas apportioning methods and the preamble section D. Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for 

 

40 Please see response to comments in section 4.1.1 on the Refined Method and the preamble section D, 

Electronics Manufacturing (Subpart I), section 3 (“Summary of Comments and Responses”), for a more 

detailed response to comments on emission estimation methods for semiconductor facilities and 

apportioning gas consumption. 
November 2010 88

additional discussion on EPA’s responses to comments regarding burden for 

apportioning methods. 

Comment Summary 8-e: Five commenters (0099, 0110, 0122, 0123, and 0131) 

asserted that the rule puts U.S. companies at a disadvantage globally because of the 

high associated costs. One commenter (0123) asserted that relative to this competitive 

disadvantage, there is little environmental benefit. Another of the commenters (0099) 

states that the burden imposed by the rule may put pressure on U.S. companies to 

move overseas. 

Response 8-e: While EPA appreciates the global competition inherent in the 

electronics industry, the Agency is establishing a reporting program with sufficient rigor 

as to allow for accurate quantification of U.S. GHG emissions to inform policy and 

regulatory decisions. From a global perspective, GHG emission inventory development 

and mitigation are priorities, and have been for many years in countries such as Japan 

and the European Union. Other key electronics manufacturing nations such as Taiwan 

and China actively view GHG emission inventory development and mitigation as 

important policy initiatives. Please see the preamble section D, Electronics 

Manufacturing (subpart I), section 3 (“Summary of Comments and Responses”), for the 

responses to comments which discuss burden-reducing efforts. 

Comment Summary 8-f: One commenter (0089) supported accurate reporting of GHG 

emissions, but stressed that it is imperative to accomplish the reporting in a manner 

that does not result in unnecessary burden, especially when more streamlined 

approaches can produce comparable accuracy. 

Response 8-f: EPA considered all comments associated with burden, and evaluated 

alternative methods for calculating controlled and uncontrolled GHG emissions for 

electronics manufacturing. EPA carefully explored alternative methods that would 

result in reduced burden on industry while ensuring the quality and breadth of reported 

data. In this final rule, EPA has made every effort to reduce burden to the industry 

while maintaining requirements necessary to obtain facility-specific emission estimates. 

For example, based on comments received, EPA revised the gas apportioning method 

to allow for the usage of quantifiable indicators other than wafer passes. As another 

means to reduce burden to the industry, EPA is requiring only the “largest” 

semiconductor manufacturing facilities to calculate and report emissions using directly 

measured recipe-specific emission factors, ensuring that burden is commensurate with 

potential to emit. In addition, the largest semiconductor manufacturing facilities are only 

required to directly measure etching process emissions. Only facilities that 

manufacture semiconductors using wafers measuring greater than 300 mm are 

required to use recipe-specific emission factors. This requirement takes advantage of 

the opportunity, consistent with historical industry practices, reflected in International 

Technology Roadmap for Semiconductors (ITRS)41, to move the industry forward in 

 

41 ITRS (2010) International Technology Roadmap for Semiconductors 2009. This and earlier editions 

and updates are available at http://www.itrs.net/Links/2009ITRS/Home2009.htm.
November 2010 89

terms of emission estimation practices. As operations are being upgraded and 

constructed, consistent, robust, and accurate emission estimation practices can be 

established, and costs for these practices can be incorporated into BAU operating costs 

for a facility. 

In general, while commenters characterized EPA’s proposed requirements as 

burdensome and costly, the comments lacked sufficient quantitative detail or 

substantiation. However, in response to concerns that EPA did not fully account for 

compliance costs in its economic analysis, EPA did update its costs estimates to reflect 

the costs associated with the requirements finalized in the rule. EPA has concluded 

that its final cost estimates appropriately account for the compliance burden under this 

rule. For details on how EPA developed its final costs for this rule, please see sections 

4 & 5 of the EIA (available in the docket, EPA-HQ-OAR-2009-0927). Please also see 

the preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses”), for additional discussion on EPA’s responses to 

comments regarding burden. 

Comment Summary 8-g: One commenter (0131) cited the 2010 ISMI survey and 

stated that the semiconductor industry would incur an estimated $2.6 million in capital 

expenditures and $22 million in annual labor and operations and maintenance costs for 

apportioning gas usage according to refined process categories. 

Response 8-g: Please see response to comment 8-b and 8-d for a discussion on costs 

associated with the final rule and sections 4 & 5 of the EIA (available in the docket, 

EPA-HQ-OAR-2009-0927). EPA notes that the commenter did not provide sufficient 

information on how the cost and burden estimates were developed. It is unclear to EPA 

how ISMI’s survey respondents developed cost estimates for their facilities. See the 

preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses”), for additional discussion on EPA’s responses to 

comments regarding burden. 

Comment Summary 8-h: One commenter (0131) stated that for the semiconductor 

industry, migrating away from using default heel factors and meeting specific gas 

consumption tracking requirements would cause the industry to incur significant costs 

that are higher than EPA-estimated costs. The associated costs would be in excess of 

$3 million per year in labor and operations and maintenance costs and $3 million in 

capital expenditures in gas usage consumption tracking requirements. Two 

commenters (0110 and 0123) indicated concerns over capital costs associated with 

estimating gas-specific heel factors using equipment with an accuracy and precision of 

1 percent of full scale or better. 

 

Response 8-h: EPA understands that facilities may incur a cost to estimate gas 

consumption using the methods prescribed in the rule; however, EPA has made efforts 

in the final rule to balance the burden imposed on facilities with EPA’s goal of obtaining 

 
November 2010 90

accurate, facility-level data. For more details on burden please see response to 

comment 8-b and 8-d for and sections 4 & 5 of the EIA (available in the docket, EPAHQ-OAR-2009-0927). Please see responses to comments in section 4.1.1 for EPA’s 

responses to comments regarding heel factors. See the preamble section D, 

Electronics Manufacturing (subpart I), section 3 (“Summary of Comments and 

Responses”), for additional discussion on EPA’s responses to comments regarding 

burden. 

Comment Summary 8-i: Two commenters (0099 and 0131) cited the 2010 ISMI 

survey and stated that the semiconductor industry would incur costs of $7 million 

annually for compliance for abatement systems (not including lost production time), 

instead of the $1.61 million estimated by EPA. The commenters stated that this higher 

estimate results from an estimated cost of $242,000 per facility, in comparison to EPA’s 

estimate of $70,000 per facility. The commenters also assumed that 29 facilities employ 

abatement devices and will have to incur these costs, as opposed to the 23 facilities 

which EPA assumed. 

Response 8-i: In the final EIA, EPA revised the assumption about the number of large 

facilities from 23 to 29, per the commenter’s suggestion. Please see response to 

comment 8-b and 8-d and sections 4 & 5 of the EIA (available in the docket, EPA-HQOAR-2009-0927). Please see response to comment 8-b for more discussion about the 

estimated DREs costs associated with the rule.
November 2010 91

9. Confidential Business Information (CBI) 

Comment Summary 9-a: One commenter (0131) asserted that the industry considers 

GHG usage and emissions by process to be highly confidential and sensitive. GHG 

usage and emissions by process can give away confidential information about device 

design and manufacturing processes. Two commenters (0099, 0131) asserted that this 

information, in conjunction with production information for a facility, may cause 

inappropriate characterization of a facility’s manufacturing processes. One of the 

commenters (0131) argued that the information EPA is requiring to be reported under 

subpart I “does not constitute ‘emissions data,’ as it is not necessary for determining 

emissions, given the availability of other, less intrusive means to do so.” The 

commenter went on to argue that there is no definition of “emissions data” under the 

GHG MRR, and “accordingly, the only two federal cases to have squarely addressed 

the meaning of ‘emission data’ under the CAA have held that the term ‘necessary to 

determine’ emissions is to be defined narrowly to include only data actually required to 

determine emissions. Data are not necessary to determine emissions, and therefore 

are not ‘emission data,’ if other methods of determining emissions that do not require 

the disclosure of CBI are available.” Lastly, the commenter argued that the information 

EPA is requiring to be reported under subpart I is within the realm of information to be 

treated as CBI under EPA regulations at 40 CFR part 2, subpart B as it is “1) highlyguarded within the industry, 2) would not qualify as ‘emissions data’ subject to 

disclosure requirements, and 3) would harm the companies’ competitive position if 

disclosed.”

Response 9-a: EPA acknowledges the commenters’ concerns regarding reported 

information that they consider to be CBI. EPA carefully considered reporting and 

recordkeeping requirements and strived for a balance between the need for information 

that is important for analyzing and verifying reported emissions, and industry’s desire to 

protect certain information. At this time, EPA has determined emission factors and gas 

usage and emissions by process type, sub-type, or recipe are important pieces of 

information EPA is requiring to be reported under this rule because the information will 

provide a means for EPA to verify emission estimates. The data elements EPA is 

requiring to be reported in the final rule will permit annual verification of the emissions 

information and data reported by each facility EPA has determined that reporting this 

information is necessary for EPA to determine the emissions and ensure the 

consistency and accuracy of data collected under this rule. Please see response to 

comment 6-b on data reporting requirements. Please also see the preamble to the 

Final MRR for additional information on EPA’s verification approach (74 FR 56282). 

Therefore EPA has not modified the data reporting requirements to exclude emissions 

and gas consumption by process sub-type. 

Although it is not clear from the comment what less intrusive emission determination 

methods the commenter is referencing, EPA assumes the commenter may be 

referencing its suggested alternative methods for estimating emissions based on a 

facility-wide emission factor or factory modeling. However, because these methods 

have never been used in practice to EPA’s knowledge, it is unclear how the 
November 2010 92

implementation of such methods would look and the data that would be used to 

estimate emissions. It also is unclear what data EPA would need to be reported in order 

to verify emission estimates. Therefore, EPA has no basis for conclusions about 

whether the suggested methods would be more or less intrusive than those proposed 

or included in the final rule. EPA considered CEMS as a less intrusive emission 

estimation method in terms of data reporting, however as discussed in section 4.3, 

information available at this time about the technical feasibility, accuracy, and costs of 

estimating emissions from electronics manufacturing using CEMS is limited. 

The final rule does not address whether data reported under subpart I will be treated as 

CBI. EPA is addressing CBI issues in a separate rulemaking. EPA published a 

proposed confidentiality determination on July 7, 2010 (75 FR 39094, July 2010) which 

addressed the CBI status of certain data elements. In that action, EPA proposed which 

specific data elements would be treated as CBI and which data elements must be 

available to the public under section 114 of the CAA. EPA has received several 

comments on the proposal and is in the process of considering these comments. Final 

determinations will be issued before any data is released, and the final determination 

will include all of the data elements under these subparts. For more information on the 

CBI rulemaking, please see, 

http://www.epa.gov/climatechange/emissions/CBI.html#proposal. 

Comment Summary 9-b: While some commenters (0110, 0123, and 0131) 

acknowledged EPA’s need to have the ability to verify emissions reports, many 

commenters raised issues with specific reporting elements of subpart I. Specifically, 

commenters argued that the majority of data required to be reported is not emissions 

data, and they questioned EPA’s need for some data elements. As well, commenters 

argued that providing some of this information to the public would cause substantial 

competitive harm to semiconductor manufacturing companies or cause a facility’s 

manufacturing operations to be inappropriately characterized. These elements, as well 

as who commented on them, are identified below. 

1. substrate area production rates (0089, 0099, 0110, 0123, 0131) (commenters 

also expressed that these values do not affect emissions results); 

2. emission factors and process utilization rates broken out by processes or 

process categories and the source (0089, 0095, 0131); 

3. gas usage and emissions by process, process category, and/or process type 

(0099, 0100, 0110, 0123, 0131); 

4. fraction of gas fed into each process type (0099, 0131); 

5. apportioning factors (0131); 

6. manufacturer and model number of each process tool (0099); 

7. emissions from heat transfer fluid use (0131); 

8. the method of emissions calculation used (0131); 

9. description of individual processes or process categories used to estimate 

emissions (if process categories defined by EPA are not used) (0131); 

10. facility-wide gas-specific heel factors (0131); 

11. fraction of gas fed into each process type with abatement systems (0131); 
November 2010 93

12. description of abatement devices, including the number of devices of each 

manufacturer make and model, manufacturer guaranteed DREs, and record of 

DRE measurements made over its lifetime (0131); 

13. all other information to be reported for abatement systems for which controlled 

emissions are being reported (0131); 

14. inputs to the heat transfer fluid mass balance equation (0131); and 

15. example calculations for fluorinated GHG, N2O, and heat transfer fluid emissions 

(0131). 

Multiple commenters (0089, 0123, 0099, and 0110) suggested that some of this 

information could be kept on site and made available for government inspection; one of 

the commenters (0089) asserts that this is consistent with the management for 

underlying emissions calculation data in other air quality and permitting programs. Two 

other commenters (0110 and 0123) suggested that, “Providing EPA with total emissions 

on a CO2e basis and providing the remaining inputs, such as methods of emissions 

calculations, emission factors used, etc., should provide sufficient data.” One 

commenter (0131) suggested that EPA adopt a proposed alternative approach for 

emissions reporting that would rely on less sensitive information to be reported and that 

if EPA retains certain reporting elements they should explicitly acknowledge in the rule 

what is not considered “emissions data” under EPA regulations and hence will not be 

subject to public disclosure.

Response 9-b: Of the elements identified by commenters as sensitive and listed above 

as items 1-15, all elements other than item 15, “example calculations for fluorinated 

GHG, N2O, and heat transfer fluid emissions” have been retained as reporting 

requirements in the final rule. Item 15 is not included in the final rule because EPA 

determined that this information would be redundant with other information EPA is 

requiring facilities to report for emission calculation verifications. 

Although EPA is unsure exactly to which other air quality and permitting programs 

requirements the commenters are referring, in contrast to other regulatory programs, 

this rule focuses on establishing each facility’s annual GHG emissions in tons per year, 

not on whether a facility's emissions are below a specified limit. For this reason, EPA 

is requiring reporting, rather than simply retention, of certain data in order to permit EPA 

to conduct an annual verification of the emissions quantities reported by each facility. 

Please see response to comment 9-a for details on the current CBI rulemaking and 

EPA’s need for required data reporting elements. No data will be released publicly until 

CBI determinations are made. For more information on the CBI rulemaking, please 

see, http://www.epa.gov/climatechange/emissions/CBI.html#proposal. 

Please see response to comment 2.3-a and 4.5-a for more information about reporting 

of emissions on an absolute mass basis, as opposed to a CO2e basis. 

Comment Summary 9-c: One commenter (0099) supported the current rulemaking 

efforts by EPA to define CBI in the context of the EPA Greenhouse Gas Mandatory 
November 2010 94

Reporting Program. The commenter asserted that neither the 2009 final rule nor the 

April 2010 proposed rule adequately protects CBI against public disclosure because 

emissions data collected under CAA Section 114 is generally not considered CBI. 

Another commenter (0131) strongly urged EPA to move forward with this effort because 

“it is not legally appropriate for EPA to take the position that it can make ‘no promises’ 

at this time and to remain silent. The issue of trade secret protections goes to the heart 

of our business, and without any understanding whatsoever of EPA’s position on this 

issue, SIA does not have an adequate opportunity for comment on this aspect of the 

Re-Proposal.” 

Response 9-c: Please see response to comment 9-a for details on the current CBI 

rulemaking and EPA’s need for required data reporting elements. No data will be 

released publicly until CBI determinations are made. For more information on the CBI 

rulemaking, please see, 

http://www.epa.gov/climatechange/emissions/CBI.html#proposal.
November 2010 95

10. Uncertainty Analysis 

Comment Summary 10-a: One commenter (0112) disagreed with the premise that the 

Refined Method will reduce uncertainty associated with emission estimates by a factor 

of two without imposing undue economic burden on the semiconductor industry. The 

commenter indicated that this premise is not supported by the analysis of the data 

provided by EPA in the re-proposal of the rule and associated documents. The 

commenter constructed a Monte Carlo model and submitted results to EPA, concluding 

that the analysis by EPA contains several flaws. The commenter contended that their 

analysis suggests that the paucity of etch emissions data does not justify or support 

dividing the current Tier 2b etch category into four separate categories. The commenter 

provided detailed descriptions of their model runs and concluded that using four etch 

categories does not reduce uncertainty by half. The commenter asserted that based on 

its analysis, the significant extra cost required to apportion gas use across four etch 

categories is not justified by the minimal improvement in certainty. 

Response 10-a: EPA appreciates the work the commenter did to evaluate the 

uncertainty of the Refined Method. The analysis EPA conducted for the proposed rule 

was based on the information available to EPA at the time. Using new information 

received after the proposed rule (presented in the NODA) and in the public comment 

period, EPA performed another uncertainty analysis evaluating the Refined Method and 

four other emission estimation methods. From this analysis (see the Electronics 

Manufacture TSD, Appendix C) and in working to develop default factors for the 

Refined Method, EPA concluded that the emission factor information available for the 

etching process type is not sufficient at this time to establish four etch sub-types as 

proposed for the Refined Method. Therefore the Refined Method is not a method 

required in the final rule. Additionally, the limited information available does not make it 

possible to draw any meaningful conclusions about the certainty of various EPAdeveloped emission estimation methods and IPCC emissions estimation methods at 

this time. However, information gathered through the final rule will allow EPA to further 

assess alternative emission estimation methods. 

To address the gap for etch data noted above, under the final rule, the “largest” 

semiconductor manufacturing facilities must calculate their etch process emissions 

using recipe-specific emission factors. In future years, EPA may evaluate the recipespecific emission factors received through this final rule to determine whether a 

sufficiently robust data set exists to establish default emission factors for etching 

process sub-types. In the future, EPA may consider requiring the semiconductor 

facilities that will be using a default emission factor for the etch process type under this 

final rule to estimate and report emissions using an approach based on multiple etch 

and chamber clean process sub-types similar to the Refined Method EPA proposed in 

April 2010. At that time, EPA could reassess the certainty of the Refined Method. 

As a means to reduce burden to industry on the whole, all other semiconductor facilities 

(i.e., those not classified as the “largest”) will utilize broad default emission factors for 

the etching process type, which were developed by EPA using the data published in 

Table 5 of the report, “Draft Emission Factors for Refined Semiconductor Manufacturing 
November 2010 96

Process Categories” (EPA-HQ-OAR-2009-0927-0073), to calculate emissions from a 

single etch process category, as opposed to four etch categories. 

For the other process types considered in this rule, EPA developed default factors for 

the three chamber cleaning process sub-types (i.e., in-situ plasma, remote plasma, and 

in-situ thermal) and broad factors for the wafer cleaning process type using data 

presented in the NODA. Please refer the Electronics Manufacture TSD, Appendix B for 

more information on the development of the default factors. Please see section 8 for 

more discussion on the costs associated with the rule. 

Comment Summary 10-b: One commenter (0099) asserted that if the uncertainty 

assigned to emission factors for the Refined Method was reduced in comparison to the 

uncertainty assigned to Tier 2b emission factors in the 2006 IPCC Guidelines, the 

uncertainty for emission factors for the Tier 2b method should be revised (improved) as 

well. This is because Refined Method emission factors are largely unchanged in 

comparison to the IPCC Tier 2b emission factors. 

Response 10-b: Please see response to comment 10-a for information on the data 

available to EPA at the time of the April 2010 proposed rule. The information used to 

estimate emission factor uncertainties, as well as the emission factors themselves used 

for the analysis, was limited (see the March 22, 2010 Electronics Manufacture TSD, 

Appendix B for more details about the analysis). Based on the information, EPA had 

the uncertainty of each emission factor representing a refined process category that 

was calculated based on the standard deviation42 of the emission factors measured for 

that process category in the 2006 IPCC dataset (see section B.2, page 25, of the March 

22, 2010 Electronics Manufacture TSD). The exception was when a standard deviation 

couldn't be calculated because just one datum was available. In that case two runs 

were conducted. For one run, zero percent relative error was assumed around these 

factors and for the other run 10 percent relative error was assumed per the ISMI 

Guidelines. The difference in results between these two runs based on these different 

assumptions was inconsequential (see section B.3, page 28, of the March 22, 2010 

Electronics Manufacture TSD). 

Please see response to comment 10-a for discussion on the emission estimation 

methods for semiconductor facilities included in the final rule and on the updated 

uncertainty analysis. For detailed information on the updated uncertainty analysis 

please see Appendix C of the Electronics Manufacture TSD. 

Comment Summary 10-c: One commenter (0131) presented the ISMI’s supplemental 

survey regarding the Refined Method. The report, as attached by the commenter, 

indicated that the Refined Method would introduce even greater uncertainty than the 

IPCC Tier 2 method. One reason stated is that EPA’s uncertainty analysis fails to 

 

42 In the uncertainty analysis, the 95% confidence intervals presented in the 2006 IPCC Guidelines for 

the Tier 2b emission factors were divided by two so that they would be comparable to the uncertainties 

calculated for the emission factors for the refined process method, which are standard deviations.
November 2010 97

account for the potential magnifying impact on uncertainty that can occur when the 

method establishes more categories for apportionment, due to the large amount of 

process recipes a facility would need to take into account during aggregated 

apportionment across many process tools. 

The ISMI analysis identified the following problems that made the commenter question 

the validity of the analysis: “1. The uncertainties applied to the emissions factors used 

in the uncertainty analysis comparing the 9 category analysis to the Tier 2b categories 

analysis overstated the accuracy of the etch emissions factors. Specifically, the use of 

10 percent uncertainty for emissions factors with only a single data point and no 

specified uncertainty overstates the certainty of the emissions factor value. 2. The 

gamma distribution truncated the distribution for emissions factors less than zero but an 

infinite distribution tail for emissions factors greater than 1 resulted in 2 to 3 percent of 

the runs emitting more gas than was used in the process. This distribution reflects a 

major problem in the analysis. 3. The gamma distribution did not fit well with some of 

the data where the value of Uij was high. A beta distribution provides a better fit to the 

available data and improves the Monte Carlo model output.” The commenter provided 

more information pertaining to the ISMI analysis. 

Response 10-c: Although the Refined Method was not included in the final rule, the 

commenter’s concerns that apportioning gas consumption would introduce greater 

uncertainty to the emission estimates may also apply to other methods that require the 

apportioning of gas consumption beyond the Tier 2b method. However, the commenter 

does not provide quantitative evidence that such additional uncertainty would be 

introduced. In the uncertainty analysis that EPA performed for the April 2010 proposed 

rule, EPA explicitly stated that uncertainties around gas distributions were not 

considered; given the available information (please see response to comment 10-a and 

10-b), it was not feasible for EPA to estimate uncertainties that may be introduced by 

apportioning gas consumption. EPA believes that the methods for apportioning gas 

consumption provided in the rule minimize any uncertainty that may be introduced by 

apportioning gas to multiple process types, sub-types, or recipes, because the 

apportioning factors must be developed based on quantifiable and documented metrics 

and facility-specific gas apportioning models must be verified. 

EPA took into consideration the commenter’s concerns about the uncertainty analysis 

run for the proposed rule. In light of these comments and new information that EPA 

received, EPA performed an updated uncertainty analysis that utilized emission factors 

and uncertainties based on information presented in the report, “Draft Emission Factors 

for Refined Semiconductor Manufacturing Process Categories” (EPA-HQ-OAR-2009-

0927-0073). The beta distribution, which EPA agrees has theoretical appeal because 

all physically impossible emission factors (i.e., those outside of the range of zero to 

one) would not be permitted in a Monte Carlo simulation, was used in the new analysis 

as well. However, two reasons attributed to the paucity of information—1) a small 

number of emission factor estimates for each gas-process type other than the NF3-

remote plasma clean process type, and 2) the unavailability of representative facilitylevel gas usage data. These data gaps precluded EPA from drawing robust 

conclusions about the uncertainty associated with alternative methods for estimating 
November 2010 98

emissions. The small number of measured emission factors for each gas-process type 

precluded assessments of the validity of the theoretically attractive beta distribution. A 

potentially important and unexpected finding was that the IPCC Tier 2b method 

understated emissions compared to a Tier 2b method developed using updated 

emissions factors obtained during EPA’s NODA. While EPA does not consider this 

understatement of emissions established (because it’s based on a single distribution of 

facility-level gas usage), it cannot ignore the finding either (because the reason for this 

bias results from the new emissions factors being larger than the older emissions 

factors on which the IPCC Tier 2b default emission factors were developed). For more 

details on the uncertainty analysis, please see Appendix C of the Electronics 

Manufacture TSD.
November 2010 99

11. Other Subpart I Comments 

Comment Summary 11-a: One commenter (0122) noted that over the last 15 years, 

SIA companies have worked to create a global program for PFC reduction for 

semiconductor manufacturing. Given this effort, the high complexity of semiconductor 

manufacturing, and the fact that the sector has relatively low emissions43 (0.07 percent 

of national U.S. emissions), the proposed rule presented an excessive reporting and 

record keeping burden for facilities. 

Another commenter (0110) noted that GHG emissions from the semiconductor industry 

were 0.55 MMTCE in 2008, comprising 0.07 percent of the total U.S. inventory. The 

commenter asserted that the amount of emissions subject to the rule by the industry is 

small, and that the industry has committed to reducing emissions to 10 percent below 

baseline by 2010. 

Response 11-a: While the emissions from the electronics sector represent a relatively 

small share of total GHG emissions in the U.S. and its industry Partners have reduced 

emissions under the PFC Reduction/Climate Partnership for the Semiconductor 

Industry, EPA concluded it was appropriate to include this sector in the GHG Reporting 

Program. As discussed in section II.D of the Final MRR (74 FR 56270), EPA included 

source categories in the Program that would provide information necessary to evaluate 

facility-specific emissions that exceed the selected emissions threshold across all 

sectors of the economy. Such data will inform the assessment of potential policies and 

programs that could be implemented under the CAA. EPA considered a variety of 

factors in including the electronics manufacturing sector in the Greenhouse Gas 

Reporting Program (GHGRP). First, the gases used in the electronics manufacturing 

industry have extremely high GWPs and are persistent when released to the 

environment. There is a great diversity and significant volume of fluorinated GHGs 

used in electronics manufacturing and the sector’s rapid growth indicates the potential 

for similar significant growth in future emissions. The collection of information through 

this rule will allow EPA to identify and monitor the current and future trends in emissions 

of the potent GHGs used in the electronics manufacturing sector to inform policy and 

regulatory decisions. Please see response to comments in section 8 for information 

about the burden associated with the final rule. Please also see the preamble section 

D, Electronics Manufacturing (subpart I), section 3 (“Summary of Comments and 

Responses”), for the responses to comments which discuss burden-reducing efforts. 

Comment Summary 11-b: One commenter (0099) supported reporting and reducing 

PFC and GHG emissions and has a stated goal of helping to ensure that the final rule is 

based on the best available science without unnecessarily burdening manufacturers. 

Another commenter (0100) stated that a GHG inventory is an important first step toward 

reducing emissions but that emission inventory methodologies should quantify 

 

43 Modern fabs, such as advanced 300 mm fabs, have relatively low emissions because they use both insitu NF3 chamber clean and POU abatement systems.
November 2010 100

emissions reduction without diverting finite resources from reducing actual emissions. 

The commenter asserted that the Proposed Rule does not accomplish this. 

Response 11-b: EPA appreciates the commenter’s stated goal of supporting a final 

rule for the electronics sector that is based on the best available science without 

creating unnecessary burden. As already stated in this response to comment 

document, the EPA has made its best effort to balance the burden imposed on facilities 

with EPA’s goal of obtaining accurate, facility-level data. The methods in the final rule 

ensure that information is reported that helps further EPA’s understanding of the nature 

and magnitude of emissions from the electronics industry and will help inform future 

policy and regulatory actions. Please see response to comment 8-f addressing burden. 

In gathering accurate facility-level uncontrolled and controlled emissions information 

EPA will have an established and accurate baseline on which to use to help inform 

future policy and regulatory decisions, potentially ones about emission reduction 

activities. Without an accurate baseline, the true magnitude and benefit of emission 

reduction activities can not be assessed. 

Comment Summary 11-c: One commenter (0110) supported reporting necessary 

emission data to EPA. Based upon a review of the proposed rule and the results of the 

ISMI survey, the commenter stated that the rule is unnecessarily complex and will result 

in unnecessary burden and costs to the industry. The commenter indicated that there 

are less burdensome monitoring and emission estimation alternatives that can be 

employed to achieve EPA’s goals, based upon the commenter’s experience with the 

EPA PFC Reduction/Climate Partnership for the Semiconductor Industry. 

Response 11-c: There are emission estimation methods available for facilities that 

manufacture semiconductors that may be less burdensome than the methods finalized 

in the rule. However, EPA has concluded that these methods, such as the IPCC Tier 2b 

method, are not sufficient for meeting the goals of this rule (for a discussion on why, 

please see response to comment 4.2-a and response to comments in section 4.2.3). 

EPA is providing two methods in the final rule by which semiconductor facilities are 

required to estimate and report emissions, based on the annual manufacturing capacity 

of a facility. Both of these methods move beyond the Tier 2b method in terms of their 

expected level of accuracy but do not impose as much burden as is associated with a 

full Tier 3 method. The required methods, which are more granular than methods based 

on broad or no process types, help ensure that EPA is gathering accurate facility-wide 

information to inform future policy and regulatory decisions. Please also see response 

to comments 11-a and 11-b, as well as the response to comments on the cost 

associated with the final rule in section 8.

Comment Summary 11-d: One commenter (0112) stated that the MRR must strike a 

balance between investment toward lowering emissions and expenditures on reporting 

related infrastructure. The commenter asserted that the proposed rule goes well 

beyond what is necessary to develop the required emissions inventory at the facility 

level. After the close of the public comment period the commenter provided two 
November 2010 101

proposals for modeling PFC gas use and emissions to promote dialogue between the 

industry and EPA. The commenter encouraged EPA to continue conversations with 

industry after the close of the comment period. 

Response 11-d: EPA appreciates the information on modeling fluorinated GHG gas 

usage the commenter provided. From the examples the commenter provided, EPA 

gained further insight and understanding of plausible methods for apportioning gas 

consumption. In part based on the information provided by the commenter, EPA has 

modified the gas apportioning methods in the final rule. EPA has determined that the 

requirements finalized in the rule are appropriate and effectively balance EPA’s 

objectives while minimizing burden to the industry. As stated throughout this section 

and the comment response document, EPA sought to strike a balance between 

accurate facility-level reporting and burden on industry to comply. EPA did not take into 

account costs associated with emission reduction activities because that is beyond the 

scope of the rule. Please also see response to comments 4.1.2- and 8-d for more 

discussion on gas consumption apportionment modeling methods finalized in the rule. 

EPA thanks the commenter for the information provided to inform this rulemaking effort. 

EPA looks forward to continued collaboration with electronics manufacturers as the 

GHG Reporting Program advances. 

Comment Summary 11-e: One commenter (0122) cited strong support for the 

comments submitted by the SIA on behalf of the U.S. semiconductor industry. 

Response 11-e: Responses to SIA’s comments (commenter 0131) have been provided 

in all sections (1 though 11) of this document. Each of SIA’s comments, as with other 

commenters’ comments, has been segregated by topic area within each section in this 

document. 

 

Comment Summary 11-f: Two commenters (0099 and 0122) appreciated the changes 

in the re-proposed rule, which reduce many aspects of the overall reporting burden 

compared to the original proposal, and EPA’s decision to postpone finalizing 

requirements for the electronics manufacturing sector. One commenter (0122) 

expressed ongoing concern that many aspects of the proposed rule increase burden on 

the industry without corresponding benefits of either improved data accuracy or 

reduced emissions. 

Response 11-f: EPA appreciates the commenters’ support of aspects of the April 2010 

proposed rule that reduce overall reporting burden. In developing the final rule, EPA 

sought to achieve the goals of the rule and minimize burden imposed on industry. 

Details on steps taken to address burden are also provided in the various comment 

responses in the preamble section D, Electronics Manufacturing (subpart I), section 3 

(“Summary of Response to Comments”). 
November 2010 102

EPA does not agree that the rule does not provide the benefits of improved data 

accuracy. The information gathered through this rule will provide EPA with accurate 

facility-level information across many sectors in the U.S.; the rule does not seek to or 

require facilities to reduce emissions. This rule addresses gathering accurate 

emissions, which may or may not eventually lead to potential future emission reduction 

policy decisions. 

Comment Summary 11-g: One commenter (0131) appreciated EPA’s responsiveness 

to their comments on the original proposed rule. In particular, the commenter 

appreciated that the re-proposal would allow manufacturers to calculate emissions 

instead of requiring individual tool measurement or CEMS, neither of which the 

commenter believes is technically or economically feasible. 

Response 11-g: EPA appreciates the commenter’s support for the revised proposal 

but disagrees with the commenter’s conclusion that tool measurements are not 

technically feasible. The emission estimation methods required in the final rule require 

the use of default factors as well as direct measurement of recipe-specific emission 

factors in some cases; direct measurement for recipe-specific factors is feasible. While 

it may be feasible to use CEMS, the information available at this time about the use of 

this technology for the electronics manufacturing sector is limited. Further, information 

about the uncertainty of emission estimates using CEMS also is limited. In future 

years, given more information about the feasibility of CEMS and the accuracy of 

estimating emissions from CEMS, EPA may consider providing provisions to allow for 

the use of CEMS. Please also see response to comment 4.3-a for more discussion of 

CEMS. 

Comment Summary 11-h: One commenter (0131) stated that EPA should allow more 

than the required three months to report prior calendar year data, because three 

months is not sufficient to collect, analyze, prepare, and certify data for submission. The 

commenter noted that other programs allow longer time intervals, such as six months 

for EPA’s Toxic Release Inventory and five months for California’s mandatory GHG 

reporting program. 

Response 11-h: EPA disagrees with the commenter that three months is not a 

sufficient timeframe to prepare data and reports for submission to EPA. In the Final 

MRR, EPA decided that a three month timeframe for compiling, reviewing, certifying, 

and submitting annual GHG reports is sufficient. For additional background on EPA’s 

decision on the March submittal date for annual reports, please see the preamble to the 

October 2009 final rule (74 FR 56278-56279, October 2009). 

Comment Summary 11-i: One commenter (0131) noted that the current proposed rule 

would appear to require gas-by-gas reporting of usage and emissions information by 

process category or sub-category on a mass basis without any CO2e conversion. The 

commenter expressed concern about this approach and saw no indication of whether 
November 2010 103

EPA will make this information publicly available (to the extent not claimed as CBI) or 

will instead undertake to convert the data to CO2e. If EPA intends to undertake the 

conversion, the commenters questioned what methodology and GWP factors will be 

used and how the resulting data will be displayed and explained to the public. The 

commenter proposed that CO2e conversion be performed by the reporting entity using 

the latest IPCC GWPs. 

Response 11-i: EPA is maintaining the requirement of gas-by-gas reporting of usage 

and emissions information on a mass basis. This practice of reporting GHGs on a 

mass basis allows interested readers to easily calculate CO2e using current (or 

historical) GWP values, which have been adjusted over time to reflect improved 

scientific understanding. Reporting emissions by chemical mass eliminates one 

potential opportunity for calculation error and is very important to those investigating the 

concentration of pollutants in the atmosphere and environment. The gas-specific 

reporting and analysis will also help identify chemicals for which GWP values need to 

be determined. Please see response to comment 2.3-a for more details on the GWPs 

used in the MRR. 

As EPA stated in the preamble to the proposed rule to determine the confidentiality 

status of data required to be reported under the MRR (75 FR 39102), “pursuant to CAA 

section 114(c), EPA must make available to the public data submitted under Part 98, 

except for data (other than emission data) that are considered confidential under CAA 

section 114(c). Accordingly, EPA intends to release Part 98 data after their submission 

to EPA in accordance with EPA’s determinations of their confidentiality status in a final 

rule. Specifically, EPA intends to release Part 98 data that are determined in the final 

rule to be emission data or not otherwise entitled to confidential treatment under CAA 

section 114(c) (i.e., ‘‘non-CBI’’). EPA intends to make much of such data available to 

the public through an EPA Web site. Data elements that we determine to be CBI under 

CAA section 114(c) would be published on the Web site only if they can be aggregated 

in a manner that would protect the confidentiality of these data elements (e.g., 

production data determined to be CBI that is aggregated by source category).” 

 

Comment Summary 11-j: One commenter (0131) urged EPA to “recognize the 

significant initial challenges that will be posed by any new GHG reporting regime. Not 

only will companies need to create new compliance systems, but EPA also likely will 

need to supplement any final rule creating, such as a regime with guidance, to address 

technical nuances or to clarify ambiguities. Consistent with EPA’s existing enforcement 

policies and practice, therefore, SIA believes that enforcement should account for these 

initial challenges by using less aggressive mechanisms, such as the warning letter, and 

by encouraging industry to perform auditing and otherwise to take advantage of EPA’s 

Self-Disclosure Policy.” 

Response 11-j: The enforcement provisions of the rule are critical to achieving EPA’s 

objective of collecting accurate GHG emissions data in a timely manner. EPA has 

discretion to pursue a variety of informal and formal actions in order to achieve 

compliance. 
November 2010 104

EPA has implemented a compliance assistance e-mail and telephone hotline for 

answering questions and providing technical assistance. Compliance materials will be 

available for subpart I and are tailored to the needs of the electronics manufacturing 

sector. These materials might include, for example, fact sheets, information sheets, 

plain English guides, frequently asked question and answer documents, applicability 

tools, monitoring and recordkeeping checklists, and training on rule requirements and 

the electronic reporting system. Note that while EPA plans to issue compliance 

assistance materials, reporters should always consult the final rule to resolve any 

ambiguities or questions. For additional discussion of compliance and enforcement, 

including responses on EPA’s approach to enforcement, please see the preamble to 

the Final MRR, section VI. Compliance and Enforcement (74 FR 56359, October 2009). 
November 2010 105

12. Relevant Comments from the April 2009 Proposed Rule on 

Electronics Manufacturing 

12.1 Calculating GHG Emissions: Emission Estimation Methods for 

Semiconductor Facilities 

Comment Summary 12.1-a: One commenter (0498) asserted that while “large 

semiconductor facilities” (those that have an annual manufacturing capacity of greater 

than 10,500 m2

 of substrate) are subject to the most stringent requirements under 

subpart I, they do not have inherently higher emissions of fluorinated GHGs. The 

commenter stated that the second generation of 200 mm fabs and 300 mm fabs have 

significantly lowered their emissions in comparison to older fabs by incorporating 

remote NF3 chamber cleaning and POU abatement systems. The commenter (0498), 

as well as another commenter (0682), stated that “the distinction in the Proposed Rule 

between ‘large’ facilities and other facilities – appears based on the premise that all 

larger facilities will have newer technology – but this premise does not square with the 

current manufacturing realities. Within the semiconductor industry, a large facility may 

rely on older technology. Some facilities may contain multiple fabrication operations, 

with a mix of technology generations.” The two commenters (0498 and 0682) further 

stated that the distinction is contradictory to emission reduction incentives developed 

under the Voluntary EPA Partnership, which does not distinguish facilities by capacities 

in setting emission reduction goals. Therefore these commenters, as well as another 

commenter (1137), asserted that there should be no distinction between large and 

other semiconductor facilities and that the rule should apply to all facilities that emit 

more than 25,000 metric tons of CO2e per year. 

One commenter (0978) asserted that the use of square meters of silicon to establish 

the reporting threshold is inappropriate. The commenter stated that silicon wafer 

throughput is considered CBI and does not provide a meaningful assessment of GHG 

emissions— it is a metric that varies widely depending on the process and the facility. 

The commenter recommended that that the rule should apply to all facilities that emit 

more than 25,000 metric tons of CO2e per year using pre-abatement PFC emissions as 

estimated by IPCC Tier 2 or 3 method. The commenter argued that this would provide 

an effective, easy metric at which to set a reporting threshold. 

Response 12.1-a: In the final rule, for semiconductor facilities that manufacture wafers 

measuring 300 mm and less in diameter, EPA is requiring the use of one of two of the 

following methods for calculating and reporting emissions, depending on the facility’s 

manufacturing capacity: (1) A method for facilities that have an annual manufacturing 

capacity that is less than or equal to 10,500 m2

 of substrate (the Tier 2c method), and 

(2) a method for those that have an annual manufacturing capacity greater than 10,500 

m2 of substrate (the Tier 2d method). 

While EPA acknowledges qualitative reports on second generation 200 mm wafer 

facilities adopting NF3 remote plasma cleans and POU abatement systems as 

presented in comments, EPA is unaware of published studies that quantitatively 
November 2010 106

document the market penetration of either NF3 remote plasma source or point of use 

fluorinated GHG abatement systems in those facilities. EPA could not rely on 

generalizations about how industry practices, such as the use of NF3 RPS and 

abatement systems, affect emissions that are not substantiated by consistent published 

data and supporting information from commenters. Therefore EPA selected a capacitybased emission estimation method distinction of 10,500 m2

 of substrate for the largest 

facilities because facilities above this threshold are expected to account for nearly twothirds of potential emissions, while accounting for less than 20 percent of all facilities 

expected to report under subpart I. This distinction was part of EPA’s initial April 2009 

proposed rule (74 FR 16448, October 2009). By setting this distinction, EPA 

established an easily calculated metric44 which can be used to determine which 

facilities must use the Tier 2c or Tier 2d methods in a consistent manner. EPA has 

concluded that the methods finalized in this rule effectively balance EPA’s objectives 

with an appropriate level of burden to industry. 

EPA does not agree that finalizing a distinction between reporting requirements for the 

larger and relatively smaller semiconductor manufacturing facilities is contradictory to 

emission reduction incentives developed under the EPA’s PFC Reduction / Climate 

Partnership for the Semiconductor Industry because the Partnership and this rule have 

different purposes and goals. The purpose of this rule is to collect data for use in 

developing future GHG policies and programs. In contrast, the Partnership (a nonregulatory program) is designed to support the industry’s voluntary efforts to reduce its 

high GWP GHG emissions. In the final rule, EPA is requiring reporting methods for 

semiconductor manufacturing facilities based on the facility’s manufacturing capacity 

(representative of potential emissions), to effectively balance EPA’s objectives in 

addressing relatively large uncertainties associated with abatement performance with 

an appropriate level of burden to the industry as a whole. 

Please see the preamble section D, Electronics Manufacturing (subpart I), section 3, 

(“Summary of Response to Comments”) for additional response to comments on the 

methodologies for semiconductor manufacturing facilities in the final rule and also on 

steps EPA has taken to reduce burden. 

 

With respect to the commenter that asserted the use of silicon to determine threshold 

applicability is inappropriate, in the final rule, the threshold calculation to determine 

whether a facility is required to report under subpart I is emissions-based (as proposed 

in the April 2010 rule). The emissions-based threshold is different from the capacitybased threshold that was presented in the April 2009 proposed rule. EPA is retaining a 

capacity-based threshold for semiconductor facilities to determine which methodology 

they are required to follow to calculate and report their emissions (please see the first 

paragraph in this response for more information). EPA is not requiring the use of wafer 

throughput in that calculation; rather, the threshold applicability calculation uses the 

facility’s annual manufacturing capacity. 

 

44 In the final rule EPA has clearly specified the equations and information a facility must use to 

determine their annual manufacturing capacity. 
November 2010 107

In the final rule, all electronics manufacturing facilities that emit more than 25,000 

metric tons per year of CO2e are required to report under subpart I. Please see the 

preamble section D, Electronics Manufacturing (subpart I), section 1, for a summary of 

the reporting threshold for electronics manufacture, and the preamble to the Final MRR 

(74 FR 56272, October 2009) for further discussion on EPA’s selection of a 25,000 

MtCO2e per year reporting threshold. Please also see response to comments on CBI in 

section 9. 

Comment Summary 12.1-b: One commenter (0437) asserted that it is unclear, for the 

Tier 3 method, whether every process, every recipe, or every platform would have to be 

tested. The commenter requested clarification regarding how to address similar tools 

and processes used across multiple facilities. The commenter questioned whether 

testing would be required to be company-specific, facility-specific, or tool-specific. The 

commenter also requested clarification on the required testing frequency for the Tier 3 

method and the trigger for testing. In a similar sentiment, another commenter (0498) 

also questioned what would constitute a separate process that would necessitate the 

development of a specific set of Tier 3 emission factors. The commenter asserted that 

it is neither technically appropriate nor workable from a regulatory standpoint to develop 

emission factors for every individual recipe used. Another commenter (0759) 

suggested if the same manufacturing processes were used in multiple company fabs, 

emission factors developed in one fab should be allowed to be applied for the same 

processes run in another fab. The commenter stated that because of the highly precise 

nature of the industry, the same manufacturing processes will be performed identically 

across different facilities; as such, the method suggested would accurately estimate 

emissions. 

Response 12.1-b: In the final rule, EPA is clarifying that for methods which require the 

use of emission factors developed from direct measurements (i.e., both the Tier 2d and 

Tier 3 methods), factors must be developed for each recipe used at the facility. 

However, EPA recognizes that a facility may employ potentially hundreds of individual 

recipes. To this end, as a means to reduce burden for facilities that are required or 

elect to do recipe-specific measurements, EPA is introducing the term “similar,” with 

respect to recipes, to refer to recipes that are composed of the same set of chemicals 

and have the same flow stabilization times and where the documented differences, 

considered separately, in reactor pressure, individual gas flow rates, and applied radio 

frequency (RF) power are less than or equal to plus or minus 10 percent. For purposes 

of comparing and documenting recipes that are similar, facilities may use either the 

best known method provided by an equipment manufacturer or the process of record, 

for which emission factors for either have been measured (see the Electronics 

Manufacturing TSD (EPA-HQ-OAR-2009-0927) for supporting information). Once a 

facility develops a set of recipe-specific emission factors for an individual recipe, it may 

apply those emission factors to “similar recipes.” This provision allows a facility to 

make fewer measurements to develop the emission factors required for Tier 2d and 

Tier 3, thereby reducing burden in comparison to a more stringent approach which 

would require measurements for each and every individual recipe used at a facility. For 

additional information about the Tier 2d and 3 methods, please see the preamble 
November 2010 108

section D, Electronics Manufacturing (subpart I), section 1 (“Summary of the Final 

Rule”). 

As another means to reduce burden, EPA is clarifying that in a given reporting year, a 

facility must develop new recipe-specific emission factors only for recipes which are not 

similar to any recipe used in a previous reporting year. Further, EPA is allowing 

facilities to use recipe-specific utilization and by-product formation rates measured by a 

third party, provided the measured recipes are similar recipes to those used at the 

facility.45 For more information on similar recipes please see the Electronics 

Manufacture TSD. For additional responses to comment on burden, please see the 

preamble section D, Electronics Manufacturing (subpart I), section 3 (“Summary of 

Comments and Responses.”) 

Comment Summary 12.1-c: Three commenters (0437, 0498, and 0978), who 

supported the use of the Tier 2b method, stated that EPA’s understanding of the 

availability of Tier 3 data from tool suppliers, and the current use of the Tier 3 method 

throughout industry, is incorrect. The commenters also asserted that the Tier 3 method 

would be excessively burdensome for facilities to implement. 

One of the commenters (0498) asserted that the cost to implement the Tier 3 method at 

a large fab would range from $0.43 million to $2.7 million, and would require anywhere 

from 12 to 76 weeks of testing, depending on whether every process platform46 or 

whether every individual recipe had to be tested. The cost to the EPA-estimated 29 

“large facilities” was estimated to be $13 million to $77 million total, with an estimated 

360 to 2,200 weeks of testing required. The commenter (0498) also asserted that given 

the limited number of testing service providers, it is unclear how Tier 3 factors could be 

developed for all large semiconductor facilities.47 Another commenter (0978) stated 

that neither of its facilities currently have the capacity to track and record data in 

support of a Tier 3 method. The commenter estimated that $5 million in initial 

investments would be required to implement the Tier 3 method, including modifications 

and upgrade to equipment and software, and $1.5 million per year would be required in 

operating costs. The commenter (0978) was concerned that there would not be 

sufficient time to install required hardware and software systems to implement the Tier 

3 method in order to comply with the rule; the commenter stated that to install the 

required hardware and software may take several years and may introduce risks into 

manufacturing processes. 

 

45 In the final rule, recipe-specific utilization and by-product formation rates are required to be measured 

using the 2006 ISMI Guidelines. EPA is allowing recipe-specific utilization and by-product formation 

rates measured using the 2001 ISMI Guidelines provided they were measured prior to January 1, 2007. 

Documentation for the measurements is required. 

46 The commenter defined a process platform as specific tool models using a specific PFC for either CVD 

chamber clean or etch. 

47 In the April 2009 proposed rule, the largest semiconductor facilities (with annual manufacturing 

capacities of greater than 10,500 m2

) were required to use the Tier 3 method to estimate all etch and 

clean emissions.
November 2010 109

Response 12.1-c: EPA has concluded that an emission estimation approach based on 

the IPCC Tier 3 method would result in the most accurate data. However, EPA is 

mindful of the burden that would be imposed by requiring all covered facilities to apply a 

Tier 3 method for all process emissions. To this end, EPA is not finalizing an approach 

that requires semiconductor manufacturing facilities to calculate and report using a Tier 

3 method for all production processes that use fluorinated GHGs. In the final rule, only 

the largest semiconductor manufacturing facilities are required to calculate and report 

emissions for the plasma etching process type using directly measured emission 

factors (Tier 2d method). 

Note, in the final rule, EPA is finalizing an approach that requires all semiconductor 

manufacturing facilities that fabricate devices on wafers measuring larger than 300 mm 

in diameter to calculate and report all production processes that use fluorinated GHGs 

using a Tier 3 method. As EPA stated in the April 2010 proposed rule, the 

commissioning process for new tools is an ideal opportunity for emission factor 

development and/or verification. Further, EPA stated, by including this requirement 

only for the wafers larger than 300 mm, “we anticipate a reduction in burden because 

emission factors (i.e., gas utilization and by-product formation rates) can be developed 

over a number of years as semiconductor manufacturers begin to transition to 450 mm 

tools and develop the estimating and reporting infrastructure. The commissioning 

process for new tools is an ideal opportunity for emission factor development and/or 

verification.” To this end, EPA does not believe that requiring facilities that fabricate 

devices on wafers measuring larger than 300 mm in diameter to calculate and report 

emissions using a Tier 3 method is overly burdensome. For additional information 

about the methods finalized for semiconductor manufacturing facilities that fabricate 

devices on wafers measuring larger than 300 mm, please see the preamble section D, 

Electronics Manufacturing (subpart I), section 1 (“Summary of the Final Rule”), and 

section 4.2.2.2 more discussion of the required Tier 3 method for facilities fabricating 

devices on wafer measuring greater than 300 mm. 

With respect to the comments on costs, EPA has updated its costs estimates to reflect 

costs associated with the requirements finalized in rule. EPA has concluded that its 

final cost estimates appropriately account for the compliance burden under this rule. 

For details on how EPA developed its final costs for this rule, please see Sections 4 & 5 

of the Economic Impact Analysis (EIA) (available in the docket, EPA-HQ-OAR-2009-

0927). 

For details on steps EPA has taken to reduce the burden, please see the preamble 

section D, Electronics Manufacturing (subpart I), section 3, which contains the response 

to comments on emission estimation methods for facilities that manufacture 

semiconductors and response to comments on burden. 

For those facilities that are required to calculate and report emissions for the plasma 

etching process type using recipe-specific factors, EPA is mindful of the time it may 

take facilities that are required to perform direct emission measurements to comply with 

the rule. To this end, EPA is allowing all facilities to use “best available monitoring 

methods” (BAMM) for the first six months of data collection (through June 30, 2011) for 
November 2010 110

any parameter for which it is not reasonably feasible to acquire, install, or operate a 

required piece of monitoring equipment in a facility or to procure measurement services 

from necessary providers. EPA is also allowing facilities to apply for the extended use 

of BAMM for the remainder of the first year of data collection (through December 31, 

2011). For example, if a facility is unable to procure the necessary measurement 

services by December 31, 2011 to measure all of its plasma etching emissions using 

recipe-specific emission factors, and EPA approves its BAMM request, it may use 

default etch emission factors to calculate and report its 2011 emissions. Under this 

scenario, the facility must then recalculate and report its 2011 emissions with its 2012 

report. Please see the preamble section D, Electronics Manufacturing (subpart I), 

section 1, for more details on the BAMM provisions. Please also see response to 

comment 4.2.1.2-b for responses to comment related to the availability of Tier 3 data. 

Comment Summary 12.1-d: Two commenters (0498 and 0682) asserted that facilities 

that possess Tier 3 measurement data should use the data to estimate emissions, 

provided the data are representative of facility processes and reflective of accepted 

analytical practices, such as the 2006 ISMI Guidelines (although both commenters 

argued that it is not appropriate to mandate the Guidelines). The commenters asserted 

that if a facility does not possess Tier 3 data, the Tier 2b method should be used. 

One commenter (0437) asserted that the published Tier 2 default emission factors are 

objective and the use of Tier 2 factors for all covered facilities would increase regulatory 

certainty and reduce the risk of non-compliance. The commenter further stated that it is 

not clear that the Tier 3 method would necessarily be more accurate than the Tier 2b 

method. Another commenter (0978) also stated that the additional costs of the Tier 3 

method, relative to the Tier 2b method, were not justified because of the limited 

increase in accuracy offered by the Tier 3 method. 

In a similar sentiment, another commenter (0498) stated that the Tier 3 method offers 

only an incremental improvement in accuracy over the IPCC Tier 2 methods. The 

commenter supported this statement by presenting results from an analysis which 

compared emission estimates from multiple fabs resulting from the use of the 2006 

IPCC Tier 2a, Tier 2b, and Tier 3 emissions estimation methods and the related 

uncertainties. The commenter asserted that due to the inherent uncertainties of GWP 

values used in estimating emissions with the IPCC methods, and the incremental 

improvements the Tier 3 method offers may not be justified by the associated costs. 

One commenter (0498) presented the results of an industry survey that showed only 

one company using the Tier 3 method and all other companies who responded to the 

survey using the Tier 2a, 2b, or a combination of those methods. 

One commenter (0759), who relies for the most part on its own developed emission 

factors, compared its own results to the results that would have been obtained if the 

commenter had used the Tier 2b method; the commenter found that on average the 

Tier 2b method overestimated emission by ~10 percent. This commenter asserted that 

if accuracy beyond the Tier 2b method is required, emissions testing should be phased 
November 2010 111

in over time due to the large amount of tests that would be needed in order to comply. 

The commenter asserted that this phase-in approach is consistent with the approach 

used by EPA and state and local agencies for other regulated air pollutants, such as 

VOCs. The commenter argued that in many cases it is considered acceptable to use 

average AP-42 emission factors rather than emission factors measured directly on-site. 

Response 12.1-d: The 2006 IPCC Guidelines state that the Tier 3 method is estimated 

to result in the least uncertain estimates amongst the methods presented by IPCC 

(please see response to comment 4.2.2.1-a for more discussion on the accuracy of the 

Tier 3 method). EPA agrees with the aforementioned statement and continues to 

maintain that the Tier 3 method will result in the most certain emission estimations. For 

this reason EPA does not want to prohibit the use of the Tier 3 method if a facility elects 

to do so; therefore EPA is permitting any facility covered under subpart I to use the Tier 

3 method.48 EPA is also requiring some facilities covered under subpart I 

(semiconductor facilities that manufacture wafers measuring 300 mm and less and that 

have an annual manufacturing capacity of greater than 10,500 m2

, and facilities that 

manufacture wafers measuring greater than 300 mm) to use the use recipe-specific 

emission factors (i.e., a partial or full Tier 3 method, respectively). Please see the 

preamble section D, Electronics Manufacturing (subpart I), section 3, (“Summary of 

Response to Comments”) for additional response to comments on the methodologies 

for semiconductor manufacturing facilities in the final rule and section 4.2.2.2 for 

discussion on the required used of the Tier 3 method for facilities manufacturing wafers 

measuring greater than 300 mm. For more discussion on why EPA did not finalize the 

Tier 2b method as proposed for semiconductor facilities please see response to 

comments 4.2.-a, 4.2.1.2-c and 4.2.3-a. 

For facilities required or that elect to use recipe-specific emission factors (i.e., a full or 

partial the Tier 3 method), EPA has provided means to ease compliance with the rule 

and reduce the burden associated with emissions testing. For example, EPA is 

requiring only direct measurement for the etching process type for some facilities. In 

addition, EPA is requiring only the largest facilities (manufacturing wafers measuring 

300 mm or less) to estimate and report their etch emissions using recipe-specific 

emission factors. Lastly, EPA is allowing any factors that were developed for one 

individual recipe to be applied to similar recipes (as defined in the final rule). EPA is 

also permitting the use of BAMM for any parameter, such as recipe-specific emission 

factors, that can not reasonably be measured within the first six months of data 

collection. Please see response to comment 12.1-c for more information on BAMM. 

 

 

48 To ensure consistent methods of calculating and reporting emissions, EPA is prohibiting a facility from 

creating and using a hybrid method – a facility must use the appropriate methods required in the rule, or 

use recipe-specific emission factors to estimate all production processes that use fluorinated GHGs. This 

restriction will enable EPA to analyze emissions and trends using a consistent set of data. The only 

exception is where a facility is required to use a method using default emission factors but no defaults are 

provided in Tables I-3, I-4, I-5, I-6, or I-7 for a particular fluorinated GHG and process type or sub-type 

combination. Where default emission factors are not provided, a facility must either use utilization and 

by-product formation rates of 0 or, in that particular instance, use directly measured recipe-specific 

emission factors measured using the 2006 ISMI Guidelines with limited exceptions. 
November 2010 112

EPA disagrees with the commenter’s (0498) argument that due to the inherent 

uncertainties of GWP values the incremental improvements the Tier 3 method offers 

may not be justified by the associated costs for two reasons. First, EPA is not requiring 

emissions to be estimated and reported on a CO2e basis; emissions must be reported 

on an absolute mass basis. Second, EPA believes that any uncertainties in GWP 

values would affect any method used to estimate emissions in CO2e, not only the Tier 3 

method. For response to comments about the GWPs used in this rule please see 

response to comment 2.3-a. 

The commenter (0498) did not provide EPA with the underlying data or assumptions 

used to further assess the uncertainty analysis presented in the comment. In regards to 

another commenter’s (0759) analysis, which resulted in the conclusion that on average 

the Tier 2b method overestimated emission by ~10 percent, information and data 

supporting how the commenter arrived at conclusion was also not provided to EPA. 

Based on an uncertainty analysis performed by EPA for this final rule, which compared 

various emission estimation methods for one hypothetical fab, EPA found that the IPCC 

Tier 2b method understates emissions, which is contradictory to what the commenter 

(0759) concluded. The uncertainty analysis run by EPA also led to the conclusion that 

more emissions data, particularly data for the etching process type, is needed to allow 

for robust and meaningful results comparing various methods. Please see the 

Electronics Manufacturing TSD (available in the docket, EPA-HQ-OAR-2009-0927) for 

more information on the uncertainty analysis. The limited information available does not 

make it possible to draw upon any statistically significant results about the certainty of 

various EPA-developed emission estimation methods (e.g., the Refined Method, and 

the Tier 2c and Tier 2d methods) versus IPCC emission estimation methods at this 

time. However, information gathered through the final rule will allow EPA to further 

assess alternative emission estimation methods. 

Also please see response to comment 4.1.2-c for more discussion on the relationship 

between this rule and air quality regulations. 

12.2 Monitoring and QA/QC Requirements: Use of the 2006 ISMI 

Guidelines 

Comment Summary 12.2-a: One commenter (0437) asserted that there may have 

been some misunderstanding in regards to EPA requiring the use of the ISMI 

Guidelines for emissions characterization. The commenter questioned EPA’s 

requirement to use the ISMI Guideline for emissions testing in the rule, because it was 

developed for tool manufacturers as an "aspirational" guide and was "meant to provide 

considerable latitude" in characterizing equipment emissions rather than serve as "a 

complete emission test method...[or]...a complete equipment purchase standard". The 

commenter further argued that the ISMI Guideline is not a SEMI standard49 nor widely 

 

49 Per the commenter: “SEMI is the trade association for the tool manufacturing industry. According to 

SEMI, SEMI standards are voluntary technical agreements between suppliers and customers, aimed at 

improving product quality and reliability at a reasonable price and steady supply. SEMI standards 

purportedly cover every aspect of semiconductor manufacturing: Equipment Automation (Hardware and 

Software), Facilities, Gases, Materials, Microlithography, Packaging, Process Chemicals, and 
November 2010 113

used as such (to the extent of the commenter’s understanding). Two other commenters 

(0498 and 0682), who supported the use of acceptable analytical practices such as the 

2006 ISMI Guidelines in developing Tier 3 emission factors, stated that it is not 

appropriate to mandate the use of the Guidelines. 

Response 12.2-a: EPA has concluded that requiring the use of the Guidelines is 

appropriate and beneficial for purposes of this rule. Therefore in the final rule EPA is 

requiring that recipe-specific emission factors be measured using the 2006 ISMI 

Guidelines, with limited exceptions.50 By requiring that emission factors be measured 

using the 2001 or 2006 ISMI Guidelines, EPA is relying on the only established industry 

practices for quantitatively characterizing emissions under conditions of actual wafer 

processing rather than developing an alternative.51 EPA has not proposed nor does it 

view the ISMI Guideline as an emissions compliance testing method or procurement 

standard, as one commenter asserted. Please also see section 5.1 on the required use 

of the 2006 ISMI Guidelines. 

EPA does not agree that the ISMI Guidelines are “aspirational.” The 2006 version of 

Guidelines explicitly state that: “The semiconductor industry has a responsibility to its 

employees and the community to minimize the environmental impact of its 

manufacturing processes and operations. To fulfill this responsibility, environmental 

performance goals have been set for its processes and operations. It is essential that 

equipment suppliers help the semiconductor industry achieve these goals. 

Consequently, equipment suppliers are expected to design their tools to minimize the 

consumption of chemicals, production of waste emissions, and usage of utilities such 

as energy and water. This document provides guidance to suppliers of process 

equipment and abatement devices on how to characterize the environmental 

performance of their tools and devices. The characterization must include the 

quantification of air emissions, liquid effluents, and solid waste generated by the 

process equipment (tool) or point-of-use (POU) abatement device.” 

The methods provided in the Guidelines specifically require that for all emissions 

measurements, among other things, those making the measurements (1) adhere to the 

use of two protocols that describe FTIR and QMS for the express purpose of measuring 

fluorinated GHG emissions, (2) adopt specific methods of calibration that stipulates a 

minimum number of calibration points, a calibration performance metric (slope of 

calibration curve), and performance standard <=5 percent of that slope, (3) adhere to 

specific methods for calculating utilization efficiency of process gases, (4) achieve a 

fluorine-volume closure standard of >90 percent unless a plausible explanation with 

supporting data is provided, and (5) document results of measurements in a standard 

reporting template. These and other practices provided in the Guidelines will result in 

robust emission factors that are developed in a consistent manner; a feature which 

 Traceability. Guidelines are also developed to cover safety related issues. In addition, standards are 

published for Flat Panel Displays. The publication catalogue provides a listing of the available standards 

and guidelines. www.semLorg/en/Standards/P_000787.”

50 See footnote 21. 

51 According to the authors listed to the antecedent guidelines, the Guidelines were not only developed 

among industry experts. ISMI sought and secured the expertise of NIST, a federal technology agency, in 

developing its guidelines for characterizing emissions. 
November 2010 114

allows EPA to compare emissions across the industry as well as track trends in industry 

practices. 
November 2010 115

13. Other Changes 

General changes: Sections of the proposed regulatory text were reorganized and 

editorial changes were made to improve clarity and readability in the final regulatory 

text. 

General changes: The proposed regulatory text often referred to production, 

production process, process type, and process category. For clarity, in the final 

regulatory text the term “process category” was revised to be “process sub-type.” The 

new suite of terms results in a more understandable and consistent flow of process tiers 

- production processes, process types, and process sub-types. 

To §98.90(a): This paragraph was revised to clarify that it is the manufacturing 

processes (i.e., those defined in §98.90(a)(1) through (5)) that trigger the applicability of 

subpart I rather than a specific product that is manufactured (e.g., semiconductors).

To §98.90(a): The proposed paragraph §98.90 (a)(4), which described the following 

production process, “Each electronics manufacturing production process in which some 

fluorinated compounds can be transformed in the plasma processes into different 

fluorinated compounds, which are then exhausted, unless abated, into the 

atmosphere,” was removed from the regulatory text because it was redundant with 

other production process descriptions and introduced a level of uncertainty regarding 

what is covered under the electronics manufacturing source category. 

To §98.90(a)(5): This paragraph was revised to clarify that production processes for 

heat transfer fluids include cleaning substrate surfaces and other parts. In the April 

2010 proposed rule, proposed in §98.98, the definition of heat transfer fluids included 

cleaning substrate surfaces and other parts. The definition was as follows: 

Heat transfer fluids are fluorinated GHGs used for temperature control, device 

testing, and soldering in certain types of electronic manufacturing. Heat transfer 

fluids used in the electronics sector include perfluoropolyethers, 

perfluoroalkanes, perfluoroethers, tertiary perfluoroamines, and perfluorocyclic 

ethers. Heat transfer fluids commonly used in electronics manufacturing include 

those sold under the trade names ‘‘Galden®’’ and ‘‘FluorinertTM.’’ Electronics 

manufacturers may also use these same fluorinated chemicals to clean 

substrate surfaces and other parts. 

EPA has retained this definition of HTFs in the final rule,52 and has aligned the 

description of process that uses HFTs in the source category with the HTF definition to 

include processes in which HTFs are used to clean substrate surfaces and other parts.

To §98.91: The calculations in this section of subpart I were restructured for clarity in 

calculating emissions for threshold applicability purposes. 

 

52 In the final rule EPA removed reference to the trade names of HTFs in the definition. This edit did not 

change the meaning of and HTF in the final rule. 
November 2010 116

To §98.92(b): This paragraph was added to clarify that consumption of fluorinated 

GHGs and N2O should be reported for all fluorinated GHG and N2O using processes at 

a facility (see proposed §98.96(f), 75 FR 18702, April 2010). EPA is clarifying this point 

to ensure that the Agency will receive comprehensive information on use and emissions 

of GHGs from electronics manufacturing facilities so that EPA may stay fully informed 

of new and emerging uses of these potent GHGs. The trend in electronics 

manufacturing has been to continuously explore and commercialize innovative new 

uses for fluorine-based chemistries and processes. The complete reporting of all 

fluorinated GHG and N2O consumption and uses will advise future policy decisions and 

allow EPA to adjust its emission calculation methods to accurately reflect current 

industry practice. 

To §98.93: This section was restructured for clarity and flow. One example of a change 

made is that process types and process sub-types, previously defined in this section in 

the proposed regulatory text, were moved to §98.98, “Definitions.” 

To §98.93: Paragraph §98.93(a) was expanded and paragraph §98.93(a)(6) was added 

in this section to provide a facility that is using an emission estimation method based on 

default emission factors, methods to estimate emissions in instances where that facility 

uses a fluorinated GHG(s) for a particular process type or sub-type for which default 

emission factors are not available in Tables I-3, I-4, I-5, I-6, or I-7. Where default 

emission factors are not available, a facility has the option to either use utilization and 

by-product formation rates of zero or, in that particular instance, use directly-measured 

recipe-specific emission factors measured using the 2006 ISMI Guidelines, 

International SEMATECH #06124825A-ENG, with limited exceptions.53 EPA 

understands that there are instances where a facility is engaging in a particular 

production process and a default emission factor is not provided in the Tables. For this 

reason, EPA added specific provisions for a facility to follow. 

To §98.93(a)(3): This paragraph was added to allow any electronics manufacturing 

facility reporting under subpart I, regardless of the products it manufactures, to estimate 

and report emissions using recipe-specific emission factors (i.e. a method based on the 

IPCC Tier 3 method.). EPA made this change so that any electronics manufacturing 

facility may report using a methodology that results in the most accurate emission 

estimates. 

To §98.93, Equation I-10: In the proposed rule, EPA required the aggregate amount of 

N2O emitted at a facility to be reported. However, EPA notes that this was not 

consistent with how fluorinated GHG emissions were required to be reported; they were 

required to be reported by process type, not in aggregate amounts. Therefore, for 

consistency the noted equation, to calculate N2O emissions (proposed Eq. I-9), was 

revised to require N2O emissions from each CVD and other N2O-using manufacturing 

process to be calculated and reported separately. This is different from the equation in 

the proposed regulatory text, which required all N2O emissions to be summed and then 

reported as a total quantity. In requiring N2O emissions to be reported for each CVD 

 

53 See footnote 21. 
November 2010 117

and other processes EPA can gain information on N2O consumption practices in the 

industry to help inform future regulatory and policy decisions. 

To §98.93, Equation I-11: The definition of the input variable Di in this equation, to 

calculate gas consumption (proposed Equation I-9), was corrected to account for all 

disbursements of input gases, not just disbursements of input gases in exceptional 

circumstances. 

To §98.93, Equation I-12: This equation, to calculate disbursements of an input gas 

(proposed Equation I-11), was modified to account for an instance where a facility could 

have multiple facility-wide gas-specific heel factors for one input gas. This instance 

would occur where a facility may use multiple container sizes and types of one input 

gas. 

To §98.93, Equation I-13: This equation was added to clarify the method facilities must 

use to calculate the amount of gas apportioned to recipes, process sub-types and 

process types (or CVD and other N2O-using manufacturing processes), using 

apportioning factors developed with facility-specific gas consumption apportioning 

models. 

To §98.94(b)(4): This paragraph was revised to clarify that for mass-based trigger 

points for change out, exceptional circumstances must be determined based on the net 

weight of gas in the container, excluding the tare weight of the container. 

To §98.96 and §98.97: The reporting and recordkeeping requirements were revised in 

some instances to align with new methods provided in subpart I, for reporting clarity, 

and to ensure that EPA would collect necessary information for emissions data 

verification. 

To §98.98: For clarity in complying with the subpart I requirements and to make the 

regulatory language simpler to follow, the following definitions were added to the final 

regulatory text: actual gas consumption, chamber cleaning (including definitions for the 

three chamber cleaning sub-types, in-situ plasma, remote plasma, and in-situ thermal), 

class, dominant gas, modeled gas consumption, plasma etching, process sub-type, 

process type, redundant abatement systems, repeatable, wafer cleaning, and wafer 

starts. In addition, the definition of uptime was modified to account for the changes 

made for calculating uptime in the final regulatory text. 

To Table I-8: This table was created for consistency. Default emission factors for N2O 

that were previously presented in proposed paragraphs §98.93(c)(1)(ii) and (c)(2)(ii) 

were moved out of the regulatory text and are now presented in Table I-8, Default 

Emission Factors for N2O, consistent with the other default emission factors.
November 2010 118

Appendix A: List of Commenters Sorted by Submission Number 

Submission No. Commenter Organization 

EPA-HQ-OAR-2008-0508-0437 Jay Hawkins Micron Technology Inc. 

EPA-HQ-OAR-2008-0508-0498 Thomas Diamond Semiconductor Industry Association 

EPA-HQ-OAR-2008-0508-0682 Laurie A. Lehmberg Texas Instrument Incorporated 

EPA-HQ-OAR-2008-0508-0759 Tim Higgs Intel Corporation 

EPA-HQ-OAR-2008-0508-0978 Jay M. Dietrich IBM 

EPA-HQ-OAR-2008-0508-1137 Robert N, Fielding Freescale Semiconductor 

EPA-HQ-OAR-2009-0927-0074 Joe Van Gompel MIDAC Corp. 

EPA-HQ-OAR-2009-0927-0089 Tim Higgs Intel Corporation 

EPA-HQ-OAR-2009-0927-0093 Sanjay Baliga SEMI 

EPA-HQ-OAR-2009-0927-0095 Nadia Wetzler Applied Materials, Inc. 

EPA-HQ-OAR-2009-0927-0099 Laurie A. Lehmberg Texas Instrument Incorporated 

EPA-HQ-OAR-2009-0927-0100 John D. Holmes Freescale Semiconductor 

EPA-HQ-OAR-2009-0927-0107 Mary K. Smickenbecker Matheson Tri-Gas Inc. 

EPA-HQ-OAR-2009-0927-0108 Alan P. Abbott Microchip Technology 

EPA-HQ-OAR-2009-0927-0110 Dale Eldridge Micron Technology Inc. 

EPA-HQ-OAR-2009-0927-0112 Jay M. Dietrich IBM 

EPA-HQ-OAR-2009-0927-0122 Reed M. Content Global Foundries U.S., Inc. 

EPA-HQ-OAR-2009-0927-0123 Bob Cartensen Transform Manufacturing, LLC 

EPA-HQ-OAR-2009-0927-0124 Mark Vickery Texas Commission on 

Environmental Quality 

EPA-HQ-OAR-2009-0927-0128 Pamela Campos Environmental Defense Fund 

EPA-HQ-OAR-2009-0927-0131 Thomas Diamond Semiconductor Industry Association 

Trans-DC-02 Thomas Diamond Semiconductor Industry Association 

Trans-DC-03 Peter Zalzal Environmental Defense Fund 
November 2010 119

Appendix B: Additional Comments on the EPA DRE Protocol 

(Submitted by SIA – EPA-HQ-OAR-2009-0927-0131) 

The comments included below are only those that have not been previously 

submitted in the DRE Protocol peer review process. Comments received 

previously, and the EPA responses are available in the docket EPA-HQ-OAR2009-0927.

Comment B-1 (General Comment): Why is it acceptable to use a tracer 

approach to determine tool effluent flow but not acceptable for abatement system 

effluent flow? 

Agree with the consideration for a properly mixed sample which the tool pump 

provides at the tool effluent as well as the concern when dealing with non-ideal 

ducts (ones which may not contain laminar flow) as often at the abatement 

system effluents. The missing piece is the demonstration that the injected tracer 

is homogeneously mixed with the abatement system effluent flow. Propose to 

add a stratification test to the protocol in support of the post-abatement flow 

tracer method. This stratification test can be easily performed by stepping the 

FTIR sample probe across the abatement system effluent duct at depths of 25%, 

50% and 75% (or more if desired) while measuring the tracer gas concentrations 

by FTIR. Should the concentrations be consistent at each depth into the 

abatement system effluent duct the tracer/effluent can be considered 

homogenously mixed and the flow determination can continue with the probe 

centered in the duct. Furthermore, the gases incorporated for tracers are also the 

same PFCs commonly monitored at these facilities, albeit absent of the particular 

process for flow determinations. Therefore, if the FTIR data is acceptable for 

concentration measurements used for DRE determinations it should be 

acceptable for flow determination by the process described above. Previous 

results have displayed very repeatable results at various tracer injection rates. 

Two other experiments comparing FTIR and QMS tracer studies for flow 

determination are planned for the next few months. One will be at a laboratory 

using a 4” mixing duct and a second in late June at a semiconductor facility. 

Another issue of concern is the stability of the QMS measurements during these 

tests. Previous testing results demonstrated very tight deviations using FTIR 

concentration results over multiple tracer release flow rates. With the inherent 

drift, ambient pressure inlet and calibration issues associated with the QMS (and 

alluded to in the protocol Section 2.2.4) it is a concern that the QMS will not be 

able to produce data quality equal to the FTIR approach. 

Response B-1: EPA sought comment on the use of the DRE Protocol in the 

proposed rule for Electronics Manufacturing (75 FR 78652, April 2010),,but not 

on the actual content of the Protocol itself. 

EPA began considering the need for a DRE measurement Protocol for the 

semiconductor industry in 2006 as part of the PFC Reduction/Climate 
November 2010 120

Partnership with the Semiconductor Industry. The Protocol development process 

included three DRE measurements studies at three different Partner facilities, 

from May 2007 through December 2008.54 After the first two measurement 

studies and subsequent reports, EPA developed and shared the first draft of the 

DRE Protocol in November 2007 with national and international peer reviewers, 

including the ISMI GHG Working Group, Japan Electronics and Information 

Technology Industries Association (JEITA), Industrial Technology Research 

Institute (ITRI), and other industry consultants. After receiving and responding to 

all comments on the first draft of the Protocol, EPA engaged in a third DRE 

measurement study, which informed preparation of second draft of the Protocol. 

EPA then shared the second draft of the Protocol with peers in June 2009, and 

subsequently responded to all of the comments received on the second draft of 

the DRE Protocol. During these peer review processes, the original 

measurement methods and data treatment methods, together with the testing 

and reporting methodology (which incorporated a performance metric and 

performance standard) were demonstrated to be suitable and practical across 

three US fabs (older and newer). EPA received no peer comments that its 

methodologies were inappropriate or not supported by its data or current industry 

knowledge. The Protocol was then finalized, taking into account all of the 

published, in-fab DRE measurement information, in March 2010. This was just 

prior to the publication of the proposed subpart I (published in April 2010), for 

which development began in response to the FY2008 Consolidated 

Appropriations Act (H.R. 2764; Public Law 110–161). 

EPA sponsored and developed the DRE Protocol in cooperation with its industry 

Partners. The Protocol builds on and augments industry emission 

characterization practices and guidance (e.g., ISMI 2001 and 2006 Guidelines) 

by focusing on proper DRE measurement (e.g., ensuring dilution is properly 

accounted for) whether in voluntary or regulatory circumstances. The publication 

of the DRE Protocol fills a void for technical guidance on proper measurement of 

abatement system DREs. 

EPA viewed the publication of the DRE Protocol just prior to the April 2010 

proposal of subpart I as beneficial for the industry because in seeing the 

measurement guidance that would be incorporated by reference in the final rule, 

EPA believed interested parties—especially non-Partners and the public—could 

comment on the use of the Protocol in the rule. EPA did not receive public 

comments on the rule arguing that requiring the use of the DRE Protocol would 

 

54 For more information about the three studies, please see the following reports: Developing a 

Reliable Fluorinated Greenhouse Gas (F-GHG) Destruction or Removal Efficiency (DRE) 

Measurement Method for Electronics Manufacturing: A Cooperative Evaluation with IBM (EPA 

430-R-10-004); Developing a Reliable Fluorinated Greenhouse Gas (F-GHG) Destruction or 

Removal Efficiency (DRE) Measurement Method for Electronics Manufacturing: A Cooperative 

Evaluation with NEC Electronics, Inc. (EPA 430-R-10-005); and Developing a Reliable 

Fluorinated Greenhouse Gas (F-GHG) Destruction or Removal Efficiency (DRE) Measurement 

Method for Electronics Manufacturing: A Cooperative Evaluation with Qimonda (EPA 430-R-08-

017). 
November 2010 121

lead to DRE measurement practices that would not be robust or results that 

would be inaccurate. 

The method the commenter is proposing, which EPA interprets as the same 

method included in Appendix B of the 2009 ISMI Guidelines and as what has 

been referred to as the JEITA method, had not been subject to an in-fab testing 

environment, nor had it been robustly compared to methods for measuring 

dilution using a QMS at the time the DRE Protocol was published. While there is 

theoretical reason to believe the method may work and should be capable of 

achieving the performance standard set in the Protocol, based on a call with peer 

reviewers of the DRE Protocol on February 25, 2010, it was evident that at the 

time of publication of the DRE Protocol additional research and documented infab testing was needed to demonstrate the validity of the suggested method. For 

these reasons, EPA did not include the “JEITA” method in Version 1 of the DRE 

Protocol. However EPA appreciates that testing of the suggested method is 

currently being planned or performed by industry, and would be open for 

discussion and review of any test results using the method. EPA welcomes more 

information about new qualified measurement methodologies that the Agency 

may consider incorporating into future versions of the Protocol. Please also see 

response to comment 5.2.4.1-a for more information about the use of an FTIR in 

place of a QMS for measuring dilution with tracers that are inert. 

Comment B-2 (Section 1.3. Protocol Scope): Typo in Section 1.3, paragraph 

3, 4th sentence should have the "the" removed between standard and relative. 

Response B-2: EPA thanks the commenter for their input, and will correct the 

typo in future versions of the Protocol. EPA notes that this typo does not change 

the meaning of the sentence. 

Comment B-3 (Section 2.1.1, Description of Experimental System): In Figure 

1 consideration needs to be taken when low purge-flow pumps are employed. If 

the sample exhaust is not returned to the tool effluent downstream of the 

extraction location it will impact the DRE as the inlet mass loading will be lower 

than normal operation. This is only applicable when the extracted flow is not 

negligible compared to the tool effluent flow. 

Response B-3: EPA interprets this comment to apply when measuring DRE 

while simultaneously measuring process gas effluent (PGE) and abatement gas 

effluent and when PGE sampling flow comprises an affecting portion of the total 

PGE flow. Under this condition, the charge into the abatement system is 

understated because in Fig. 1 the PGE sampling flow is returned to the facility’s 

waste stream post abatement (in the abatement system effluent). 
November 2010 122

Experienced metrologists should be aware of such a circumstance in part 

because of their experience. Because PGE concentrations are relatively high 

(1,000 ppm or higher), FTIR sampling cells are of small volume, meaning PGE 

sampling/extraction flows can be low. EPA's experience in the DRE 

measurement program is that PGE sampling/extraction flows are typically <0.5 

LPM. PGE flows, however, are typically 30 - 40 LPM. So, even at 0.5 LPM 

extraction flow, less than 2 percent of the flow is not returned to the abatement 

system, which is inconsequential for DRE measurement. Even for the unusually 

low PGE flow of 10 LPM, the charge to the abatement system would be less than 

5 percent for extraction flows <0.5 LPM. 

Nonetheless, EPA agrees that metrologists should be aware of this rare 

circumstance, which is why the Protocol recommends that only experienced 

metrologists--experienced in FTIR and QMS practices in electronic 

manufacturing facilities-- be permitted to carry out DRE measurements. 

Comment B-4 (Section 2.2.1, Method 1): In section 2.2.1 (DRE determination 

with plasma off) a specified flow of 120% of the process flow is stipulated to 

ensure the abatement system is tested under conditions that may occur during 

processing. The PFC concentrations will be much greater than normal as is (not 

being disassociated by a plasma). 

Response B-4: During the EPA DRE measurement program, EPA used a flow of 

120% of the process flow and found no issues in actual application. The use of 

120% of the process flow for Method 1 is a suggested practice. Given the 

flexibility of the Protocol, a facility could depart from this practice provided there 

is plausible reason, and that this reason is documented. 

Comment B-5 (Section 2.2.2, Method 2): Typo in 2.2.2, 2nd paragraph, 3rd 

sentence “...all operating chambers that are” 

Response B-5: EPA thanks the commenter for their input, and will correct the 

typo in future versions of the Protocol. EPA notes that this typo does not change 

the meaning of the sentence. 

Comment B-6 (Section 2.2.3, Equipment Needed): The suggestion of using a 

PFC that passes through the abatement system with DRE<5% to determine 

abatement system effluent flow forms a circular argument. Per the protocol, one 

must demonstrate that the abatement system DRE for the compound is <5% by 

QMS and tracer studies before using the PFC tracer approach. 

 

Response B-6: The Protocol provides two plausible methods for demonstrating 

a DRE of less than 5% for tracer compounds other than noble gases (e.g., CF4 or 
November 2010 123

SF6): (1) the manufacturer of the POU abatement system provides results, based 

on the methods of this Protocol, that the DRE of the chemical tracer is <5% 

under the operating conditions being tested at the fab using the QMS and the 

noble gas tracer methodology or (2) in-fab tests showing <5% destruction of the 

chemical tracer on a POU abatement system (based on the QMS and noble gas 

tracer methodology of this Protocol for one abatement system in the fab) may be 

used on abatement system in the facility of the same make and model installed 

and operated in the same manner as the abatement system tested. Based on the 

methods suggested, for one abatement system a facility or POU manufacturer 

could use a QMS and the noble gas tracer methodology to demonstrate that for 

that particular abatement system the DRE of the fluorinated GHG tracer gas 

being used (e.g., CF4 or SF6) is less than 5%. This demonstration would then 

hold true for any abatement system in the same class as the tested system, and 

hence an approach using an fluorinated GHG tracer would be permitted for any 

system in that class. Therefore EPA does not agree that a circular argument is 

created as the DRE Protocol does not specify that the demonstration must be 

completed for every individual abatement system for which a facility or POU 

manufacturer wants to use suitable fluorinated GHG tracers. 

Comment B-7 (Section 2.2.4, FTIR and QMS Protocols): Current version 

states scan times should be on the order of 3 seconds. Not all FTIRs have the 

capacity to scan at such a high rate. One of the systems we have collects 1 

scan/1.7 seconds plus you have factor in the processing time. Also short scans 

will increase MDLs at the abatement system effluents. 

Response B-7: The scan times identified in the Protocol are suggested scan 

times based on EPA experience. As such, a facility may use an FTIR that scans 

at a different rate and still adhere to the DRE Protocol provided all data is 

adjusted appropriately. The data treatment methods specified in the DRE 

Protocol correct for various scan rates using a method of weighted variances. 

Comment B-8 (Section 2.2.5, Calibration Curve): Current version states the 

necessity to bracket (within the FTIR reference set for the particular compound) 

the observed concentration ranges and only considers absorption features 

between 0.1 and 1.0 absorbance units (a.u.). Although it is good practice, it is not 

always practical or necessary. Since most PFCs have broad absorption features 

they are linear over large concentration ranges. It is a fair assumption that the 

linear behavior can be extrapolated to concentrations ~50% greater than the 

largest reference should the compound exhibit linear behavior. In the last 

sentence of 2 paragraph of 2.2.5 it alludes to this by stating that all nonlinear 

curves must bracket the observed concentration range. Alternating cells at the 

tool effluent FTIR can eliminate the ability to observe byproducts. It is also 

cumbersome to switch between plasma off/on experiments to ensure that 

concentrations are bracketed or the 0.1-1.0 a.u. range is conserved. 
November 2010 124

Response B-8: The practices regarding the use of FTIRs specified in the DRE 

Protocol are suggested good practices. As such, a facility may deviate from the 

suggested practices if they can not be followed, provided the facility has a valid 

and documented reason for why, and the performance standard set by the DRE 

Protocol is maintained. 

Comment B-9 (Section 2.2.5, Calibration Curve): The suggestion to only 

quantify over FTIR absorbance features between 0.1-1.0 absorbance units (a.u.) 

is rather restricting (Sections 2.2.4, 2.2.5 & 2.2.7). There are often numerous 

usable features outside this 0.1-1.0 range. 

The lower bound of this range would be better represented by a factor offset 

based on the FTIR system noise, say absorbance features at a minimum of 1.5 

times the system noise are acceptable for use. Common system noise levels are 

on the order of 10-3 and most of the time much better. Using 0.1 a.u. as the 

lower bound is requiring that absorbance features be 100 times (or more) your 

system noise to be usable. An illustration of this is depicted below in the FTIR 

reference for SO2 (For illustration see EPA-HQ-OAR-2009-0927-0131). This SO2

feature displayed is the band most often quantified. The peak absorbance is less 

than 0.1 a.u. (0.04 a.u.), but remains well above the system noise. The FTIR cell 

path length of 10.5m is common for semi-conductor sampling, therefore 

normalizing the SO2 concentration to fall within the 0.1-1.0 range yields 

approximately 136 ppm required to quantify SO2 using this absorbance feature. 

Similarly, there is a lot of usable information to be gathered from absorbance 

features greater than 1.0 a.u. I feel a better representation of the upper bound 

would be features that are not opaque (totally absorbing) and quantify at no more 

50% of the concentration of the largest reference in the particular compounds’ 

set. Of course this only applies to linear absorbing compounds which the PFCs 

are. A skilled spectroscopist meteorologist) would know when this is appropriate. 

Furthermore, when determining the tool effluent flow, this is often the case as it is 

necessary to run the process recipe (per the protocol Section 2.2.1) with the tool 

plasma off. This is the case when determining tool utilization as well. 

Granted SO2 is not a GHG but it is a by-product of SF6 processes. The protocol 

also does state that it is acceptable to go outside of this range so long as the 

reference set bracket it which is easy to do on the lower bound by adding a zero 

(or noise spectrum) to your reference set. However, looking forward, if this 

protocol is to be applied for other compounds this restrictive range may provoke 

an issue where good data could be non- acceptable. 

Response B-9: The scope of the DRE Protocol is specifically focused on 

measuring fluorinated GHG abatement. Please see response to comment B-8 

about suggested FTIR practices in the Protocol. 
November 2010 125

Comment B-10 (Section 2.2.6, Flow and Dilution Measurement): Same as 

2.2.3 comment - The suggestion of using a PFC that passes through the 

abatement system with DRE<5% to determine abatement system effluent flow 

forms a circular argument. Per the protocol, one must demonstrate that the 

abatement system DRE for the compound is <5% by QMS and tracer studies 

before using the PFC tracer approach. 

Response B-10: Please see response to comment B-6 about using a fluorinated 

GHG tracer approach.