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Title 40

Displaying title 40, up to date as of 7/08/2026. Title 40 was last amended 7/08/2026.
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  1. Title 40 —Protection of Environment
  2. Chapter I —Environmental Protection Agency
  3. Subchapter C —Air Programs
  4. Part 63 —National Emission Standards for Hazardous Air Pollutants for Source Categories
  5. Subpart G   View Full Text
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Title 40Protection of EnvironmentPart / Section
Chapter IEnvironmental Protection Agency1 – 1099
Subchapter CAir Programs50 – 99
Part 63National Emission Standards for Hazardous Air Pollutants for Source Categories63.1 – 63.12099
Subpart GNational Emission Standards for Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater63.110 – 63.153
§ 63.110Applicability.
§ 63.111Definitions.
§ 63.112Emission standard.
§ 63.113Process vent provisions—reference control technology.
§ 63.114Process vent provisions—monitoring requirements.
§ 63.115Process vent provisions—methods and procedures for process vent group determination.
§ 63.116Process vent provisions—performance test methods and procedures to determine compliance.
§ 63.117Process vent provisions—reporting and recordkeeping requirements for group and TRE determinations and performance tests.
§ 63.118Process vent provisions—periodic reporting and recordkeeping requirements.
§ 63.119Storage vessel provisions—reference control technology.
§ 63.120Storage vessel provisions—procedures to determine compliance.
§ 63.121Storage vessel provisions—alternative means of emission limitation.
§ 63.122Storage vessel provisions—reporting.
§ 63.123Storage vessel provisions—recordkeeping.
§ 63.124Process vents and storage vessels that are in ethylene oxide service—procedures to determine compliance.
§ 63.125 [Reserved]
§ 63.126Transfer operations provisions—reference control technology.
§ 63.127Transfer operations provisions—monitoring requirements.
§ 63.128Transfer operations provisions—test methods and procedures.
§ 63.129Transfer operations provisions—reporting and recordkeeping for performance tests and notification of compliance status.
§ 63.130Transfer operations provisions—periodic recordkeeping and reporting.
§ 63.131 [Reserved]
§ 63.132Process wastewater provisions—general.
§ 63.133Process wastewater provisions—wastewater tanks.
§ 63.134Process wastewater provisions—surface impoundments.
§ 63.135Process wastewater provisions—containers.
§ 63.136Process wastewater provisions—individual drain systems.
§ 63.137Process wastewater provisions—oil-water separators.
§ 63.138Process wastewater provisions—performance standards for treatment processes managing Group 1 wastewater streams and/or residuals removed from Group 1 wastewater streams.
§ 63.139Process wastewater provisions—control devices.
§ 63.140Process wastewater provisions—delay of repair.
§§ 63.141-63.142 [Reserved]
§ 63.143Process wastewater provisions—inspections and monitoring of operations.
§ 63.144Process wastewater provisions—test methods and procedures for determining applicability and Group 1/Group 2 determinations (determining which wastewater streams require control).
§ 63.145Process wastewater provisions—test methods and procedures to determine compliance.
§ 63.146Process wastewater provisions—reporting.
§ 63.147Process wastewater provisions—recordkeeping.
§ 63.148Leak inspection provisions.
§ 63.149Control requirements for certain liquid streams in open systems within a chemical manufacturing process unit.
§ 63.150Emissions averaging provisions.
§ 63.151Initial notification.
§ 63.152General reporting and continuous records.
§ 63.153Implementation and enforcement.
Table 1 to Subpart G of Part 63
Process Vents—Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams
Table 1A to Subpart G of Part 63
Applicable 40 CFR Part 63 General Provisions
Table 2 to Subpart G of Part 63
Process Vents—Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and Halogenated Vent Streams
Table 3 to Subpart G of Part 63
Process Vents—Process Vents—Monitoring, Recordkeeping, and Reporting Requirements for Control Devices and Recapture Devices
Table 4 to Subpart G of Part 63
Process Vents—Monitoring, Recordkeeping, and Reporting Requirements for Maintaining a TRE Index Value >1.0 and. ≤4.0 [No Longer Applicable in Accordance With § 63.113(a)(4)]
Table 5 to Subpart G of Part 63
Group 1 Storage Vessels at Existing Sources
Table 6 to Subpart G of Part 63
Group 1 Storage Vessels at New Sources
Table 7 to Subpart G of Part 63
Transfer Operations—Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98 Weight-Percent Reduction of Total Organic Hazardous Air Pollutants Emissions or a Limit of 20 Parts per Million by Volume
Table 8 to Subpart G of Part 63
Organic HAP's Subject to the Wastewater Provisions for Process Units at New Sources
Table 9 to Subpart G of Part 63
Organic HAP's Subject to the Wastewater Provisions for Process Units at New and Existing Sources and Corresponding Fraction Removed (Fr) Values
Table 10 to Subpart G of Part 63
Wastewater—Compliance Options for Wastewater Tanks
Table 11 to Subpart G of Part 63
Wastewater—Inspection and Monitoring Requirements for Waste Management Units
Table 12 to Subpart G of Part 63
Monitoring Requirements for Treatment Processes
Table 13 to Subpart G of Part 63
Wastewater—Monitoring Requirements for Control Devices
Tables 14-14b to Subpart G of Part 63 [Reserved]
Table 15 to Subpart G of Part 63
Wastewater—Information on Table 8 and/or Table 9 Compounds To Be Submitted With Notification of Compliance Status for Process Units at New and/or Existing Sources a b
Table 16 to Subpart G of Part 63 [Reserved]
Table 17 to Subpart G of Part 63
Information for Treatment Processes To Be Submitted With Notification of Compliance Status a b
Table 18 to Subpart G of Part 63
Information for Waste Management Units To Be Submitted With Notification of Compliance Status a b
Table 19 to Subpart G of Part 63
Wastewater—Information on Residuals To Be Submitted With Notification of Compliance Status a b
Table 20 to Subpart G of Part 63
Wastewater—Periodic Reporting Requirements for Control Devices Subject to § 63.139 Used To Comply With §§ 63.13 Through 63.139
Table 21 to Subpart G of Part 63
Average Storage Temperature (Ts) as a Function of Tank Paint Color
Table 22 to Subpart G of Part 63
Paint Factors for Fixed Roof Tanks
Table 23 to Subpart G of Part 63
Average Clingage Factors (c) a
Table 24 to Subpart G of Part 63
Typical Number of Columns as a Function of Tank Diameter for Internal Floating Roof Tanks With Column Supported Fixed Roofs a
Table 25 to Subpart G of Part 63
Effective Column Diameter (Fc)
Table 26 to Subpart G of Part 63
Seal Related Factors for Internal Floating Roof Vessels
Table 27 to Subpart G of Part 63
Summary of Internal Floating Deck Fitting Loss Factors (KF) and Typical Number of Fittings (NF)
Table 28 to Subpart G of Part 63
Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks
Table 29 to Subpart G of Part 63
Seal Related Factors for External Floating Roof Vessels
Table 30 to Subpart G of Part 63
Roof Fitting Loss Factors, KFa, KFb, and m, a and Typical Number of Fittings, NT
Table 31 to Subpart G of Part 63
Typical Number of Vacuum Breakers, NF6 and Roof Drains, a NF7
Table 32 to Subpart G of Part 63
Typical Number of Roof Legs, a NF8
Table 33 to Subpart G of Part 63
Saturation Factors
Table 34 to Subpart G of Part 63
Fraction Measured (Fm) and Fraction Emitted (Fe) For HAP Compounds in Wastewater Streams
Table 35 to Subpart G of Part 63
Control Requirements for Items of Equipment That Meet the Criteria of § 63.149 of Subpart G
Table 36 to Subpart G of Part 63
Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes (See § 63.145(h))
Table 37 to Subpart G of Part 63
Default Biorates for List 1 Compounds
Table 38 to Subpart G of Part 63
Toxic Equivalency Factors
Figure 1 to Subpart G of Part 63
Definitions of Terms Used in Wastewater Equations
eCFR Content