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Subpart YY—National Emission Standards for Hazardous Air 

Pollutants for Source Categories: Generic Maximum Achievable 

Control Technology Standards

Table of Contents

§63.1100 Applicability.

§63.1101 Definitions.

§63.1102 Compliance schedule.

§63.1103 Source category-specific applicability, definitions, 

and requirements.

§63.1104 Process vents from continuous unit operations: 

applicability assessment procedures and methods.

§63.1105 Transfer racks.

§63.1106 Wastewater provisions.

§63.1107 Equipment leaks.

§63.1108 Compliance with standards and operation and maintenance 

requirements.

§63.1109 Recordkeeping requirements.

§63.1110 Reporting requirements.

§63.1111 Startup, shutdown, and malfunction.

§63.1112 Extension of compliance, and performance test, 

monitoring, recordkeeping and reporting waivers and 

alternatives.

§63.1113 Procedures for approval of alternative means of 

emission limitation.

§63.1114 Implementation and enforcement.

Tables to Subpart YY of Part 63

Table 1 to §63.1100(a)—Source Category MACT Applicability

Table 1 to §63.1102—Source Category Proposal and Effective Dates

Table 1 to §63.1103(a)—What Are My Requirements If I Own Or 

Operate An Acetal Resins Production Existing Or New Affected 

Source?

Table 2 to §63.1103(b)(3)(i)—What Are My Requirements if I Own 

or Operate an Acrylic and Modacrylic Fiber Production Existing 

or New Affected Source and Am Complying With Paragraph (b)(3)(i) 

of This Section?

Table 3 to §63.1103(b)(3)(ii)—What Are My Requirements If I Own 

Or Operate An Acrylic And Modacrylic Fiber Production Existing 
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Or New Affected Source And Am Complying With Paragraph 

(b)(3)(ii) Of This Section?

Table 4 to §63.1103(c)—What Are My Requirements If I Own or 

Operate a Hydrogen Fluoride Production Existing or New Affected 

Source?

Table 5 to §63.1103(d)—What Are My Requirements If I Own or 

Operate A Polycarbonate Production Existing Affected Source?

Table 6 to §63.1103(d)—What are My Requirements If I Own or 

Operate a Polycarbonate Production New Affected Source?

Table 7 to §63.1103(e)—What Are My Requirements if I Own or 

Operate an Ethylene Production Existing or New Affected Source?

Table 8 to §63.1103(f)—What Are My Requirements if I Own or 

Operate a Carbon Black Production Existing or New Affected 

Source?

Table 9 to §63.1103(g)—What Are My Requirements if I Own or 

Operate a Cyanide Chemicals Manufacturing Existing or New 

Affected Source?

Table 10 to §63.1103(h)—What Are My Requirements if I Own or 

Operate a Spandex Production Process Unit at a New or Existing 

Source?

Table 1 of §63.1104(j)(1)—Coefficients for Total Resource 

Effectiveness

§63.1100 Applicability.

(a) General. This subpart applies to source categories and 

affected sources specified in §63.1103(a) through (h). The 

affected emission points, by source category, are summarized in 

table 1 of this section. This table also delineates the section 

and paragraph of the rule that directs an owner or operator of 

an affected source to source category-specific control, 

monitoring, recordkeeping, and reporting requirements.

Table 1 to §63.1100(a)—Source Category MACTa Applicability
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Source 

category

Storag

e 

vessel

s

Proces

s 

vents

Transfe

r racks

Equipmen

t leaks

Wastewat

er 

streams

Othe

r

Source 

category 

MACT 

requiremen

ts

Acetal 

Resins 

Production

Yes Yes No Yes Yes No §63.1103(a

)

Acrylic and 

Modacrylic

Fibers 

Production

Yes Yes No Yes Yes Yesb §63.1103(b

)

Carbon 

Black 

Production

No Yes No No No No §63.1103(f

).

Cyanide 

Chemicals 

Manufacturi

ng

Yes Yes Yes Yes Yes No §63.1103(g

).

Ethylene 

Production

Yes Yes Yes Yes Yes Yesc §63.1103(e

).

Hydrogen 

Fluoride 

Production

Yes Yes Yes Yes No No §63.1103(c

)

Polycarbona

te 

Production

Yes Yes No Yes Yes No §63.1103(d

)

Spandex 

Production

Yes Yes No No No Yesd §63.1103(h

).

aMaximum achievable control technology.

bFiber spinning lines using spinning solution or suspension 

containing acrylonitrile.

cHeat exchange systems as defined in §63.1103(e)(2).

dFiber spinning lines.
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(b) Subpart A requirements. The following provisions of 

subpart A of this part (General Provisions), §§63.1 through 

63.5, and §§63.12 through 63.15, apply to owners or operators of 

affected sources subject to this subpart.

(c) Research and development facilities. The provisions of 

this subpart do not apply to research and development 

facilities, consistent with section 112(b)(7) of the Act.

(d) Primary product determination and applicability. The 

primary product of a process unit shall be determined according 

to the procedures specified in paragraphs (d)(1) and (2) of this 

section. Paragraphs (d)(3), (4), and (5) of this section discuss 

compliance for those process units operated as flexible 

operation units.

(1) If a process unit only manufactures one product, then 

that product shall represent the primary product of the process 

unit.

(2) If a process unit is designed and operated as a 

flexible operation unit, the primary product shall be determined 

as specified in paragraphs (d)(2)(i) or (ii) of this section 

based on the anticipated operations for the 5 years following 

the promulgation date for existing affected sources and for the 

first 5 years after initial startup for new affected sources.

(i) If the flexible operation unit will manufacture one 

product for the greatest percentage of operating time over the 
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five-year period, then that product shall represent the primary 

product of the flexible operation unit.

(ii) If the flexible operation unit will manufacture 

multiple products equally based on operating time, then the 

product with the greatest production on a mass basis over the 

five-year period shall represent the primary product of the 

flexible operation unit.

(3) Once the primary product of a process unit has been 

determined to be a product produced by a source category subject 

to this subpart, the owner or operator of the affected source 

shall comply with the standards for the primary product 

production process unit.

(4) The determination of the primary product for a process 

unit, including the assessment of applicability of this subpart 

to process units that are designed and operated as flexible 

operation units, shall be reported in the Notification of 

Compliance Status report required by §63.1110(a)(4) when the 

primary product is determined to be a product produced by a 

source category subject to requirements under this subpart. The 

Notification of Compliance Status shall include the information 

specified in either paragraph (d)(4)(i) or (ii) of this section. 

If the primary product is determined to be something other than 

a product produced by a source category subject to requirements 

under this subpart, the owner or operator shall retain 
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information, data, and analyses used to document the basis for 

the determination that the primary product is not produced by a 

source category subject to requirements under this subpart.

(i) If the process unit manufactures only one product 

subject to requirements under this subpart, the identity of that 

product.

(ii) If the process unit is designed and operated as a 

flexible operation unit, the information specified in paragraphs 

(d)(4)(ii)(A) and (B) of this section, as appropriate.

(A) The identity of the primary product.

(B) Information concerning operating time and/or production 

mass for each product that was used to make the determination of 

the primary product under paragraph (d)(2)(i) or (ii) of this 

section.

(5) When a flexible operation unit that is subject to this 

subpart is producing a product other than a product subject to 

this subpart, or is producing a product subject to this subpart 

that is not the primary product, the owner or operator shall 

comply with either paragraph (d)(5) (i) or (ii) of this section 

for each emission point.

(i) The owner or operator shall control emissions during 

the production of all products in accordance with the 

requirements for the production of the primary product. As 

appropriate, the owner or operator shall demonstrate that the 
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parameter monitoring level established for the primary product 

is also appropriate for those periods when products other than 

the primary product are being produced. Documentation of this 

demonstration shall be submitted in the Notification of 

Compliance Status report required by §63.1110(a)(4).

(ii) The owner or operator shall determine, for the 

production of each product, whether control is required in 

accordance with the applicable criteria for the primary product 

in §63.1103. If control is required, the owner or operator shall 

establish separate parameter monitoring levels, as appropriate, 

for the production of each product. The parameter monitoring 

levels developed shall be submitted in the Notification of 

Compliance Status report required by §63.1110(a)(4).

(e) Storage vessel ownership determination. To determine 

the process unit to which a storage vessel shall belong, the 

owner or operator shall sequentially follow the procedures 

specified in paragraphs (e)(1) through (8) of this section, 

stopping as soon as the determination is made.

(1) If a storage vessel is already subject to another 

subpart of this part on the date of promulgation for an affected 

source under the generic MACT, that storage vessel shall belong 

to the process unit subject to the other subpart.

(2) If a storage vessel is dedicated to a single process 

unit, the storage vessel shall belong to that process unit.
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(3) If a storage vessel is shared among process units, then 

the storage vessel shall belong to that process unit located on 

the same plant site as the storage vessel that has the greatest 

input into or output from the storage vessel (i.e., the process 

unit has the predominant use of the storage vessel.)

(4) If predominant use cannot be determined for a storage 

vessel that is shared among process units and if only one of 

those process units is subject to this subpart, the storage 

vessel shall belong to that process unit.

(5) If predominant use cannot be determined for a storage 

vessel that is shared among process units and if more than one 

of the process units are subject to standards under this subpart 

that have different primary products, then the owner or operator 

shall assign the storage vessel to any one of the process units

sharing the storage vessel.

(6) If the predominant use of a storage vessel varies from 

year to year, then predominant use shall be determined based on 

the utilization that occurred during the year preceding the date 

of promulgation of standards for an affected source under this 

subpart or based on the expected utilization for the 5 years 

following the promulgation date of standards for an affected 

source under this subpart for existing affected sources, 

whichever is more representative of the expected operations for 

that storage vessel, and based on the expected utilization for 
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the 5 years after initial startup for new affected sources. The 

determination of predominant use shall be reported in the 

Notification of Compliance Status Report required by 

§63.1110(a)(4). If the predominant use changes, the 

redetermination of predominant use shall be reported in the next 

Periodic Report.

(7) If the storage vessel begins receiving material from 

(or sending material to) another process unit; ceases to receive 

material from (or send material to) a process unit; or if the 

applicability of this subpart to a storage vessel has been 

determined according to the provisions of paragraphs (e)(1) 

through (6) of this section and there is a significant change in 

the use of the storage vessel that could reasonably change the 

predominant use, the owner or operator shall reevaluate the 

applicability of this subpart to the storage vessel.

(8) Where a storage vessel is located at a major source 

that includes one or more process units that place material 

into, or receive materials from, the storage vessel, but the 

storage vessel is located in a tank farm, the applicability of 

this subpart shall be determined according to the provisions in 

paragraphs (e)(8)(i) through (iii) of this section.

(i) The storage vessel may only be assigned to a process 

unit that utilizes the storage vessel and does not have an 

intervening storage vessel for that product (or raw material, as 
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appropriate). With respect to any process unit, an intervening 

storage vessel means a storage vessel connected by hard-piping 

to the process unit and to the storage vessel in the tank farm 

so that product or raw material entering or leaving the process 

unit flows into (or from) the intervening storage vessel and 

does not flow directly into (or from) the storage vessel in the 

tank farm.

(ii) If there is only one process unit at a major source 

that meets the criteria of paragraph (e)(8)(i) of this section 

with respect to a storage vessel, the storage vessel shall be 

assigned to that process unit.

(iii) If there are two or more process units at the major 

source that meet the criteria of paragraph (e)(8)(i) of this 

section with respect to a storage vessel, the storage vessel 

shall be assigned to one of those process units according to the 

provisions of paragraph (e)(6) of this section. The predominant 

use shall be determined among only those process units that meet 

the criteria of paragraph (e)(8)(i) of this section.

(f) Recovery operation equipment ownership determination. 

To determine the process unit to which recovery equipment shall 

belong, the owner or operator shall sequentially follow the 

procedures specified in paragraphs (f)(1) through (7) of this 

section, stopping as soon as the determination is made.
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(1) If recovery operation equipment is already subject to 

another subpart of this part on the date standards are 

promulgated for an affected source, that recovery operation 

equipment shall belong to the process unit subject to the other 

subpart.

(2) If recovery operation equipment is used exclusively by 

a single process unit, the recovery operation shall belong to 

that process unit.

(3) If recovery operation equipment is shared among process 

units, then the recovery operation equipment shall belong to 

that process unit that has the greatest input into or output 

from the recovery operation equipment (i.e., that process unit 

has the predominant use of the recovery operation equipment).

(4) If predominant use cannot be determined for recovery 

operation equipment that is shared among process units and if 

one of those process units is a process unit subject to this 

subpart, the recovery operation equipment shall belong to the 

process unit subject to this subpart.

(5) If predominant use cannot be determined for recovery 

operation equipment that is shared among process units and if 

more than one of the process units are process units that have 

different primary products and that are subject to this subpart, 

then the owner or operator shall assign the recovery operation 

equipment to any one of those process units.
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(6) If the predominant use of recovery operation equipment 

varies from year to year, then the predominant use shall be 

determined based on the utilization that occurred during the 

year preceding the promulgation date of standards for an 

affected source under this subpart or based on the expected 

utilization for the 5 years following the promulgation date for 

standards for an affected source under this subpart for existing 

affected sources, whichever is the more representative of the

expected operations for the recovery operations equipment, and 

based on the expected utilization for the first 5 years after 

initial startup for new affected sources. This determination 

shall be reported in the Notification of Compliance Status 

Report required by §63.1110(a)(4). If the predominant use 

changes, the redetermination of predominant use shall be 

reported in the next Periodic Report.

(7) If there is an unexpected change in the utilization of 

recovery operation equipment that could reasonably change the 

predominant use, the owner or operator shall redetermine to 

which process unit the recovery operation belongs by 

reperforming the procedures specified in paragraphs (f)(2) 

through (6) of this section.

(g) Overlap with other regulations. Paragraphs (g)(1) 

through (6) of this section specify the applicability of this 

subpart YY emission point requirements when other rules may 
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apply. Where subpart YY of this part allows an owner or operator 

an option to comply with one or another regulation to comply 

with subpart YY of this part, an owner or operator must report 

which regulation they choose to comply with in the Notification 

of Compliance Status report required by §63.1110(a)(4).

(1) Overlap of subpart YY with other regulations for 

storage vessels. (i) After the compliance dates specified in 

§63.1102, a storage vessel subject to this subpart YY that is 

also subject to subpart G or CC of this part is required to 

comply only with the provisions of this subpart YY.

(ii) After the compliance dates specified in §63.1102, a 

storage vessel that must be controlled according to the 

requirements of this subpart and subpart Ka or Kb of 40 CFR part 

60 is required to comply only with the storage vessel 

requirements of this subpart.

(2) Overlap of subpart YY with other regulations for 

process vents. (i) After the compliance dates specified in 

§63.1102, a process vent that must be controlled according to 

the requirements of this subpart and subpart G of this part is 

in compliance with this subpart if it complies with either set 

of requirements. The owner or operator must specify the rule 

with which they will comply in the Notification of Compliance 

Status report required by §63.1110(a)(4).
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(ii) After the compliance dates specified in §63.1102, a 

process vent that must be controlled according to the 

requirements of this subpart and subpart III, RRR or NNN of 40 

CFR part 60 is required to comply only with the process vent 

requirements of this subpart.

(3) Overlap of this subpart YY with other regulations for 

transfer racks. After the compliance dates specified in 

§63.1102, a transfer rack that must be controlled according to 

the requirements of this subpart YY and either subpart G of this 

part or subpart BB of 40 CFR part 61 is required to comply only 

with the transfer rack requirements of this subpart YY.

(4) Overlap of subpart YY with other regulations for 

equipment leaks. (i) After the compliance dates specified in 

§63.1102, equipment that must be controlled according to this 

subpart and 40 CFR part 60, subpart VV, or 40 CFR part 61, 

subpart J or subpart V, is required only to comply with the 

equipment leak requirements of this subpart.

(ii) After the compliance dates specified in §63.1102, 

equipment that must be controlled according to this subpart and 

subpart H of this part is in compliance with the equipment leak 

requirements of this subpart if it complies with either set of 

requirements. The owner or operator must specify the rule with 

which they will comply in the Notification of Compliance Status 

report required by §63.1110(a)(4).
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(5) Overlap of subpart YY with other regulations for 

wastewater for source categories other than ethylene production. 

(i) After the compliance dates specified in §63.1102 for an 

affected source subject to this subpart, a wastewater stream 

that is subject to the wastewater requirements of this subpart 

and the wastewater requirements of subparts F, G, and H of this 

part (collectively known as the “HON”) shall be deemed to be in 

compliance with the requirements of this subpart if it complies 

with either set of requirements. In any instance where a source 

subject to this subpart is colocated with a Synthetic Organic 

Chemical Manufacturing Industry (SOCMI) source, and a single 

wastewater treatment facility treats both Group 1 wastewaters 

and wastewater residuals from the source subject to this subpart 

and wastewaters from the SOCMI source, a certification by the 

treatment facility that they will manage and treat the waste in 

conformity with the specific control requirements set forth in 

40 CFR 63.133 through 63.147 will also be deemed sufficient to 

satisfy the certification requirements for wastewater treatment 

under this subpart.

(ii) After the compliance dates specified in §63.1102 for 

an affected source subject to this subpart, a wastewater stream 

that is subject to control requirements in the Benzene Waste 

NESHAP (subpart FF of part 61 of this chapter) and this subpart 

is required to comply with both rules.
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(6) Overlap of subpart YY with other regulations for waste 

for the ethylene production source category. (i) After the 

compliance date specified in §63.1102, a waste stream that is 

conveyed, stored, or treated in a wastewater stream management 

unit, waste management unit, or wastewater treatment system that 

receives streams subject to both the control requirements of 

§63.1103(e)(3) for ethylene production sources and the 

provisions of §§63.133 through 63.147 shall comply as specified 

in paragraphs (g)(6)(i)(A) through (C) of this section. 

Compliance with the provisions of this paragraph (g)(6)(i) shall 

constitute compliance with the requirements of this subpart for 

that waste stream.

(A) Comply with the provisions in §§63.133 through 63.137 

and 63.140 for all equipment used in the storage and conveyance 

of the waste stream.

(B) Comply with the provisions in §§63.1103(e), 63.138, and 

63.139 for the treatment and control of the waste stream.

(C) Comply with the provisions in §§63.143 through 63.148 

for monitoring and inspections of equipment and for 

recordkeeping and reporting requirements. The owner or operator 

is not required to comply with the monitoring, recordkeeping, 

and reporting requirements associated with the treatment and 

control requirements in §§61.355 through 61.357.
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(ii) After the compliance date specified in §63.1102, 

compliance with §63.1103(e) shall constitute compliance with the 

Benzene Waste Operations NESHAP (subpart FF of 40 CFR part 61) 

for waste streams that are subject to both the control 

requirements of §63.1103(e)(3) for ethylene production sources 

and the control requirements of 40 CFR part 61, subpart FF.

(h) Affirmative defense for violation of emission standards 

during malfunction. In response to an action to enforce the 

standards set forth in this subpart, the owner or operator of an 

acrylic and modacrylic fiber production affected source or 

polycarbonate production affected source may assert an 

affirmative defense to a claim for civil penalties for 

violations of such standards that are caused by malfunction, as 

defined at 40 CFR 63.2. Appropriate penalties may be assessed if 

the owner or operator fails to meet their burden of proving all 

of the requirements in the affirmative defense. The affirmative 

defense shall not be available for claims for injunctive relief.

(1) Assertion of affirmative defense. To establish the 

affirmative defense in any action to enforce such a standard, 

the owner or operator must timely meet the reporting 

requirements in paragraph (h)(2) of this section, and must prove 

by a preponderance of evidence that:

(i) The violation: 
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(A) Was caused by a sudden, infrequent, and unavoidable 

failure of air pollution control equipment, process equipment, 

or a process to operate in a normal or usual manner; and 

(B) Could not have been prevented through careful planning, 

proper design or better operation and maintenance practices; and

(C) Did not stem from any activity or event that could have 

been foreseen and avoided, or planned for; and

(D) Was not part of a recurring pattern indicative of 

inadequate design, operation, or maintenance; and

(ii) Repairs were made as expeditiously as possible when a 

violation occurred; and

(iii) The frequency, amount, and duration of the violation 

(including any bypass) were minimized to the maximum extent 

practicable; and

(iv) If the violation resulted from a bypass of control 

equipment or a process, then the bypass was unavoidable to 

prevent loss of life, personal injury, or severe property 

damage; and

(v) All possible steps were taken to minimize the impact of 

the violation on ambient air quality, the environment, and human 

health; and

(vi) All emissions monitoring and control systems were kept 

in operation if at all possible, consistent with safety and good 

air pollution control practices; and
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(vii) All of the actions in response to the violation were 

documented by properly signed, contemporaneous operating logs; 

and

(viii) At all times, the affected source was operated in a 

manner consistent with good practices for minimizing emissions; 

and

(ix) A written root cause analysis has been prepared, the 

purpose of which is to determine, correct, and eliminate the 

primary causes of the malfunction and the violation resulting 

from the malfunction event at issue. The analysis shall also 

specify, using best monitoring methods and engineering judgment, 

the amount of any emissions that were the result of the 

malfunction.

(2) Report. The owner or operator seeking to assert an 

affirmative defense shall submit a written report to the 

Administrator, with all necessary supporting documentation, that 

explains how it has met the requirements set forth in paragraph 

(h)(1) of this section. This affirmative defense report shall be 

included in the first periodic compliance report, deviation 

report, or excess emission report otherwise required after the 

initial occurrence of the violation of the relevant standard 

(which may be the end of any applicable averaging period). If 

such compliance report, deviation report, or excess emission 

report is due less than 45 days after the initial occurrence of 
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the violation, the affirmative defense report may be included in 

the second compliance report, deviation report, or excess 

emission report due after the initial occurrence of the 

violation of the relevant standard.

§63.1101 Definitions.

All terms used in this subpart shall have the meaning given 

them in the Act, in 40 CFR 63.2 (General Provisions), and in 

this section. The definitions in this section do not apply to 

waste requirements for ethylene production sources.

Affirmative defense means, in the context of an enforcement 

proceeding, a response or defense put forward by a defendant, 

regarding which the defendant has the burden of proof, and the 

merits of which are independently and objectively evaluated in a 

judicial or administrative proceeding.

Annual average concentration, as used in the wastewater 

provisions, means the flow-weighted annual average 

concentration, as determined according to the procedures 

specified in §63.144(b).

Annual average flow rate, as used in the wastewater 

provisions, means the annual average flow rate, as determined 

according to the procedures specified in §63.144(c).

Batch cycle refers to manufacturing a product from start to 

finish in a batch unit operation.
Page 21 of 197

Batch emission episode means a discrete venting episode 

that may be associated with a single unit operation. A unit 

operation may have more than one batch emission episode per 

batch cycle. For example, a displacement of vapor resulting from 

the charging of a vessel with organic HAP will result in a 

discrete emission episode. If the vessel is then heated, there 

may also be another discrete emission episode resulting from the 

expulsion of expanded vapor. Both emission episodes may occur 

during the same batch cycle in the same vessel or unit 

operation. There are possibly other emission episodes that may 

occur from the vessel or other process equipment, depending on 

process operations.

Batch unit operation means a unit operation involving 

intermittent or discontinuous feed into equipment and, in 

general, involves the emptying of equipment after the batch 

cycle ceases and prior to beginning a new batch cycle. Mass, 

temperature, concentration and other properties of the process 

may vary with time. Addition of raw material and withdrawal of 

product do not simultaneously occur in a batch unit operation.

Bottoms receiver means a tank that collects distillation 

bottoms before the stream is sent for storage or for further 

downstream processing.

By compound means by individual stream components, not 

carbon equivalents.
Page 22 of 197

Capacity means the volume of liquid that is capable of 

being stored in a storage vessel, determined by multiplying the 

vessel's internal cross-sectional area by the internal height of 

the shell.

Closed vent system means a system that is not open to the 

atmosphere and is composed of piping, ductwork, connections, 

and, if necessary, flow inducing devices that transport gas or 

vapor from an emission point to a control device. A closed vent 

system does not include the vapor collection system that is part 

of any tank truck or railcar or the loading arm or hose that is 

used for vapor return. For transfer racks, the closed vent 

system begins at, and includes, the first block valve on the 

downstream side of the loading arm or hose used to convey 

displaced vapors.

Combined vent stream means a process vent that is comprised 

of at least one gas stream from a batch unit operation 

manifolded with at least one gas stream from a continuous unit 

operation.

Compliance equipment means monitoring equipment used by an 

owner or operator of an affected source under this subpart to 

demonstrate compliance with an operation or emission limit 

standard.

Continuous parameter monitoring system or CPMS means the 

total equipment that may be required to meet the data 
Page 23 of 197

acquisition and availability requirements of this subpart, and 

that is used to sample, condition (if applicable), analyze, and 

provide a record of process or control system parameters.

Continuous unit operation means a unit operation where the 

inputs and outputs flow continuously. Continuous unit operations 

typically approach steady-state conditions. Continuous unit 

operations typically involve the simultaneous addition of raw 

material and withdrawal of the product.

Control device means, with the exceptions noted below, a 

combustion device, recovery device, recapture device, or any 

combination of these devices used to comply with this subpart or 

a referencing subpart. For process vents from continuous unit 

operations at affected sources in source categories where the 

applicability criteria includes a TRE index value, recovery 

devices are not considered to be control devices. Primary 

condensers on steam strippers or fuel gas systems are not 

considered to be control devices.

Day means a calendar day.

Distillate receiver means overhead receivers, overhead 

accumulators, reflux drums, and condenser(s) including ejector 

condenser(s) associated with a distillation unit.

Distillation unit means a device or vessel in which one or 

more feed streams are separated into two or more exit streams,

each exit stream having component concentrations different from 
Page 24 of 197

those in the feed stream(s). The separation is achieved by the 

redistribution of the components between the liquid and the 

vapor phases by vaporization and condensation as they approach 

equilibrium within the distillation unit. Distillation unit 

includes the distillate receiver, reboiler, and any associated 

vacuum pump or steam jet.

Emission point means an individual process vent, storage 

vessel, transfer rack, wastewater stream, kiln, fiber spinning 

line, equipment leak, or other point where a gaseous stream is 

released.

Equipment means each of the following that is subject to 

control under this subpart: pump, compressor, agitator, pressure 

relief device, sampling collection system, open-ended valve or 

line, valve, connector, instrumentation system in organic 

hazardous air pollutant service as defined in §63.1103 for the 

applicable process unit, whose primary product is a product 

produced by a source category subject to this subpart.

Equivalent method means any method of sampling and analysis 

for an air pollutant that has been demonstrated to the 

Administrator's satisfaction to have a consistent and 

quantitatively known relationship to the reference method, under 

specified conditions.

Excess emissions means emissions in excess of those that 

would have occurred if there were no start-up, shutdown, or 
Page 25 of 197

malfunction and the owner or operator complied with the relevant 

provisions of this subpart.

Final recovery device means the last recovery device on a 

process vent stream from a continuous unit operation at an 

affected source in a source category where the applicability 

criteria includes a TRE index value. The final recovery device 

usually discharges to a combustion device, recapture device, or 

directly to the atmosphere.

Flexible operation unit means a process unit that 

manufactures different chemical products periodically by 

alternating raw materials or operating conditions.

Fuel gas means gases that are combusted to derive useful 

work or heat.

Fuel gas system means the offsite and onsite piping and 

flow and pressure control system that gathers gaseous stream(s) 

generated by onsite operations, may blend them with other 

sources of gas, and transports the gaseous stream for use as a 

fuel gas in combustion devices or in-process combustion 

equipment, such as furnaces and gas turbines, either singly or 

in combination.

Group 1 wastewater stream means a process wastewater stream 

at an existing or new source that meets the criteria for Group 1 

status in §63.132(c).
Page 26 of 197

Group 2 wastewater stream means a process wastewater stream 

that does not meet the definition of a Group 1 wastewater 

stream.

Halogens and hydrogen halides means hydrogen chloride 

(HCl), chlorine (Cl2), hydrogen bromide (HBr), bromine (Br2), 

and hydrogen fluoride (HF).

Impurity means a substance that is produced coincidentally 

with the primary product, or is present in a raw material. An 

impurity does not serve a useful purpose in the production or 

use of the primary product and is not isolated.

Initial startup means, for new sources, the first time the 

source begins production. For additions or changes not defined 

as a new source by this subpart, initial startup means the first 

time additional or changed equipment is put into operation. 

Initial startup does not include operation solely for testing 

equipment. Initial startup does not include subsequent startup 

(as defined in this section) of process units following 

malfunctions or process unit shutdowns. Except for equipment 

leaks, initial startup also does not include subsequent startups 

(as defined in this section) of process units following changes 

in product for flexible operation units or following recharging 

of equipment in batch unit operations.
Page 27 of 197

Low throughput transfer rack means a transfer rack that 

transfers less than a total of 11.8 million liters per year of 

liquid containing regulated HAP.

Maintenance wastewater means wastewater generated by the 

draining of process fluid from components in the process unit, 

whose primary product is a product produced by a source category 

subject to this subpart, into an individual drain system prior 

to or during maintenance activities. Maintenance wastewater can 

be generated during planned and unplanned shutdowns and during 

periods not associated with a shutdown. Examples of activities 

that can generate maintenance wastewaters include descaling of 

heat exchanger tubing bundles, cleaning of distillation column 

traps, draining of low legs and high point bleeds, draining of 

pumps into an individual drain system, and draining of portions 

of the process unit, whose primary product is a product produced 

by a source category subject to this subpart, for repair.

Malfunction means any sudden, infrequent, and not 

reasonably preventable failure of air pollution control 

equipment, process equipment, or a process to operate in a 

normal or usual manner which causes, or has the potential to 

cause, the emission limitations in an applicable standard to be 

exceeded. Failures that are caused in part by poor maintenance 

or careless operation are not malfunctions.
Page 28 of 197

Maximum true vapor pressure means the equilibrium partial 

pressure exerted by the total organic HAP in the stored or 

transferred liquid at the temperature equal to the highest 

calendar-month average of the liquid storage or transfer 

temperature for liquids stored or transferred above or below the 

ambient temperature or at the local maximum monthly average 

temperature as reported by the National Weather Service for 

liquids stored or transferred at the ambient temperature, as 

determined:

(1) In accordance with methods described in American 

Petroleum Institute Publication 2517, Evaporation Loss From 

External Floating-Roof Tanks (incorporated by reference as 

specified in §63.14 of subpart A of this part); or

(2) As obtained from standard reference texts; or

(3) As determined by the American Society for Testing and 

Materials Method D2879–83 (incorporated by reference as 

specified in §63.14 of subpart A of this part); or

(4) Any other method approved by the Administrator.

Oil-water separator or organic-water separator means a 

waste management unit, generally a tank used to separate oil or 

organics from water. An oil-water or organic-water separator 

consists of not only the separation unit but also the forebay 

and other separator basins, skimmers, weirs, grit chambers, 

sludge hoppers, and bar screens that are located directly after 
Page 29 of 197

the individual drain system and prior to additional waste 

management units such as an air flotation unit, clarifier, or 

biological treatment unit. Examples of an oil-water or organicwater separator include, but are not limited to, an American 

Petroleum Institute separator, parallel-plate interceptor, and 

corrugated-plate interceptor with the associated ancillary 

equipment.

On-site means, with respect to records required to be 

maintained by this subpart, a location within a plant site that 

encompasses the affected source. On-site includes, but is not 

limited to, the affected source to which the records pertain, or 

central files elsewhere at the plant site.

Organic hazardous air pollutant or organic HAP means any 

organic chemicals that are also HAP.

Permitting authority means one of the following:

(1) The State air pollution control agency, local agency, 

other State agency, or other agency authorized by the 

Administrator to carry out a permit program under part 70 of 

this chapter; or

(2) The Administrator, in the case of EPA-implemented 

permit programs under title V of the Act (42 U.S.C. 7661) and 

part 71 of this chapter.

Plant site means all contiguous or adjoining property that 

is under common control, including properties that are separated 
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only by a road or other public right-of-way. Common control 

includes properties that are owned, leased, or operated by the 

same entity, parent entity, subsidiary, or any combination 

thereof.

Point of determination means each point where process 

wastewater exits the process unit, whose primary product is a 

product produced by a source category subject to this subpart.

Note to definition for point of determination: The 

regulation allows determination of the characteristics of a 

wastewater stream at the point of determination or downstream of 

the point of determination if corrections are made for changes 

in flow rate and annual average concentration of Table 9 

compounds (as defined under this subpart) as determined in 

§63.144. Such changes include losses by air emissions, reduction 

of annual average concentration or changes in flow rate by 

mixing with other water or wastewater streams, and reduction in 

flow rate or annual average concentration by treating or 

otherwise handling the wastewater stream to remove or destroy 

hazardous air pollutants.

Pressure release means the emission of materials resulting 

from the system pressure being greater than the set pressure of 

the pressure relief device. This release can be one release or a 

series of releases over a short time period due to a malfunction 

in the process.
Page 31 of 197

Pressure relief device or valve means a safety device used 

to prevent operating pressures from exceeding the maximum 

allowable working pressure of the process equipment. A common 

pressure relief device is a spring-loaded pressure relief valve. 

Devices that are actuated either by a pressure of less than or 

equal to 2.5 pounds per square inch gauge or by a vacuum are not 

pressure relief devices.

Process condenser means a condenser whose primary purpose 

is to recover material as an integral part of a process. The 

condenser must support a vapor-to-liquid phase change for 

periods of source equipment operation that are above the boiling 

or bubble point of substance(s). Examples of process condensers 

include distillation condensers, reflux condensers, process 

condensers in line prior to the vacuum source, and process 

condensers used in stripping or flashing operations.

Process unit means the equipment assembled and connected by 

pipes or ducts to process raw and/or intermediate materials and 

to manufacture an intended product. A process unit includes more 

than one unit operation.

Process unit shutdown means a work practice or operational

procedure that stops production from a process unit, or part of 

a process unit during which practice or procedure it is 

technically feasible to clear process material from the process 

unit, or part of the process unit, consistent with safety 
Page 32 of 197

constraints and during which repairs can be effected. The 

following are not considered process unit shutdowns:

(1) An unscheduled work practice or operational procedure 

that stops production from a process unit, or part of a process 

unit, for less than 24 hours.

(2) An unscheduled work practice or operational procedure 

that would stop production from a process unit, or part of a 

process unit, for a shorter period of time than would be 

required to clear the process unit, or part of the process unit, 

of materials and start up the unit and result in greater 

emissions than delay of repair of leaking components until the 

next scheduled process unit shutdown.

(3) The use of spare equipment and technically feasible 

bypassing of equipment without stopping production.

Process vent means the point of discharge to the atmosphere 

(or the point of entry into a control device, if any) of a gas 

stream from a unit operation within a source category subject to 

this subpart.

Process vent excludes the following gas stream discharges:

(1) Relief valve discharges;

(2) Leaks from equipment subject to this subpart;

(3) Gas streams exiting a control device complying with 

this subpart;
Page 33 of 197

(4) Gas streams transferred to other processes (on-site or 

off-site) for reaction or other use in another process (i.e., 

for chemical value as a product, isolated intermediate, 

byproduct, or co-product for heat value);

(5) Gas streams transferred for fuel value (i.e., net 

positive heating value), use, reuse, or sale for fuel value, 

use, or reuse;

(6) Gas streams from storage vessels or transfer racks 

subject to this subpart;

(7) Gas streams from waste management units subject to this 

subpart;

(8) Gas streams from wastewater streams subject to this 

subpart;

(9) Gas streams exiting process analyzers; and

(10) Gas stream discharges that contain less than or equal 

to 0.005 weight-percent total organic HAP.

Process wastewater means wastewater which, during 

manufacturing or processing, comes into direct contact with or 

results from the production or use of any raw material, 

intermediate product, finished product, by-product, or waste 

product. Examples are product tank drawdown or feed tank 

drawdown, water formed during a chemical reaction or used as a 

reactant, water used to wash impurities from organic products or 

reactants, equipment washes between batches in a batch process, 
Page 34 of 197

water used to cool or quench organic vapor streams through 

direct contact, and condensed steam from jet ejector systems 

pulling vacuum on vessels containing organics.

Process wastewater stream means a stream that contains 

process wastewater.

Product means a compound or chemical which is manufactured 

as the intended product of the applicable production process 

unit as defined in §63.1103. By-products, isolated 

intermediates, impurities, wastes, and trace contaminants are 

not considered products.

Recapture device means an individual unit of equipment 

capable of and used for the purpose of recovering chemicals, but 

not normally for use, reuse, or sale. For example, a recapture 

device may recover chemicals primarily for disposal. Recapture 

devices include, but are not limited to, absorbers, carbon 

adsorbers, and condensers. For purposes of the monitoring, 

recordkeeping, and reporting requirements of this subpart, 

recapture devices are considered recovery devices.

Recovery device means an individual unit of equipment 

capable of and normally used for the purpose of recovering 

chemicals for fuel value (i.e., net positive heating value), 

use, reuse, or for sale for fuel value. Examples of equipment 

that may be recovery devices include absorbers, carbon 

adsorbers, condensers, oil-water separators or organic-water 
Page 35 of 197

separators, or organic removal devices such as decanters, 

strippers, or thin-film evaporation units. For purposes of the 

monitoring, recordkeeping, and reporting requirements of this 

subpart, recapture devices are considered recovery devices.

Research and development facility means laboratory and 

pilot plant operations whose primary purpose is to conduct 

research and development into new processes and products, where 

the operations are under the close supervision of technically 

trained personnel, and is not engaged in the manufacture of 

products for commercial sale, except in a de minimis manner.

Shutdown means the cessation of operation of an affected 

source or equipment that is used to comply with this subpart, or 

the emptying and degassing of a storage vessel. For the purposes 

of this subpart, shutdown includes, but is not limited to, 

periodic maintenance, replacement of equipment, or repair. 

Shutdown does not include the routine rinsing or washing of 

equipment in batch operation between batches. Shutdown includes 

the decoking of ethylene production unit furnaces.

Startup means the setting into operation of a regulated 

source and/or equipment required or used to comply with this 

subpart. Startup includes initial startup, operation solely for 

testing equipment, the recharging of equipment in batch 

operation, and transitional conditions due to changes in product 

for flexible operation units.
Page 36 of 197

Storage vessel or tank, for the purposes of regulation 

under the storage vessel provisions of this subpart, means a 

stationary unit that is constructed primarily of nonearthen

materials (such as wood, concrete, steel, fiberglass, or 

plastic) that provides structural support and is designed to 

hold an accumulation of liquids or other materials. Storage 

vessel includes surge control vessels and bottoms receiver 

vessels. For the purposes of regulation under the storage vessel 

provisions of this subpart, storage vessel does not include 

vessels permanently attached to motor vehicles such as trucks, 

railcars, barges, or ships; pressure vessels designed to operate 

in excess of 204.9 kilopascals and without emissions to the 

atmosphere; or wastewater storage vessels. Wastewater storage 

vessels are covered under the wastewater provisions of §63.1106.

Subsequent startup means any setting into operation of a 

regulated source and/or equipment required or used to comply 

with this subpart following the initial startup.

Surge control vessel means a feed drum, recycle drum, or 

intermediate vessel. Surge control vessels are used within a 

process unit (as defined in this subpart) when in-process 

storage, mixing, or management of flow rates or volumes is 

needed to assist in production of a product.

Table 9 compounds means compounds listed in Table 9 of 

subpart G of this part.
Page 37 of 197

Total organic compounds or (TOC) means the total gaseous 

organic compounds (minus methane and ethane) in a vent stream, 

with the concentrations expressed on a carbon basis.

Total resource effectiveness index value or TRE index value

means a measure of the supplemental total resource requirement 

per unit reduction of organic HAP associated with a process vent 

stream, based on vent stream flow rate, emission rate of organic 

HAP, net heating value, and corrosion properties (whether or not 

the vent stream contains halogenated compounds), as quantified 

by the equations given under §63.1104(j).

Transfer rack means a single system used to fill bulk cargo 

tanks mounted on or in a truck or railcar. A transfer rack 

includes all loading arms, pumps, meters, shutoff valves, relief 

valves, and other piping and equipment necessary for the 

transfer operation. Transfer equipment and operations that are 

physically separate (i.e., do not share common piping, valves, 

and other equipment) are considered to be separate transfer 

racks.

Unit operation means distinct equipment used in processing, 

among other things, to prepare reactants, facilitate reactions, 

separate and purify products, and recycle materials. Equipment 

used for these purposes includes, but is not limited to, 

reactors, distillation columns, extraction columns, absorbers, 

decanters, dryers, condensers, and filtration equipment.
Page 38 of 197

Vapor balancing system means a piping system that is 

designed to collect organic HAP vapors displaced from tank 

trucks or railcars during loading; and to route the collected 

organic HAP vapors to the storage vessel from which the liquid 

being loaded originated, or to compress collected organic HAP 

vapors and commingle with the raw feed of a production process 

unit.

Wastewater is either a process wastewater or a maintenance 

wastewater and means water that:

(1) Contains either:

(i) An annual average concentration of Table 9 compounds 

(as defined under this subpart) of at least 5 parts per million 

by weight at the point of determination and has an annual 

average flow rate of 0.02 liter per minute or greater, or

(ii) An annual average concentration of Table 9 compounds 

(as defined under this subpart) of at least 10,000 parts per 

million by weight at the point of determination at any flow 

rate, and that

(2) Is discarded from a process unit, whose primary product 

is a product produced by a source category subject to this 

subpart.

Wastewater stream means a stream that contains wastewater.

§63.1102 Compliance schedule.
Page 39 of 197

(a) General requirements. Affected sources, as defined in 

§63.1103(a)(1)(i) for acetyl resins production, 

§63.1103(b)(1)(i) for acrylic and modacrylic fiber production, 

§63.1103(c)(1)(i) for hydrogen fluoride production, 

§63.1103(d)(1)(i) for polycarbonate production, 

§63.1103(e)(1)(i) for ethylene production, §63.1103(f)(1)(i) for 

carbon black production, §63.1103(g)(1)(i) for cyanide chemicals 

manufacturing, or §63.1103(h)(1)(i) for spandex production shall 

comply with the appropriate provisions of this subpart and the 

subparts referenced by this subpart according to the schedule in 

paragraph (a)(1) or (2) of this section, as appropriate, except 

as provided in paragraph (b) of this section. Proposal and 

effective dates are specified in Table 1 to this section.

(1) Compliance dates for new and reconstructed sources. (i) 

The owner or operator of a new or reconstructed affected source 

that commences construction or reconstruction after the proposal 

date, and that has an initial startup before the effective date 

of standards for an affected source, shall comply with this 

subpart no later than the applicable effective date in Table 1 

to §63.1102 of this section.

(ii) The owner or operator of a new or reconstructed 

affected source that has an initial startup after the applicable 

effective date in Table 1 to §63.1102 of this section shall 

comply with this subpart upon startup of the source.
Page 40 of 197

(iii) The owner or operator of an affected source that 

commences construction or reconstruction after the proposal 

date, but before the effective date in Table 1 to this section, 

shall comply with this subpart no later than the date 3 years 

after the effective date if the conditions in paragraphs 

(a)(1)(iii) (A) and (B) of this section are met.

(A) The promulgated standards are more stringent than the 

proposed standards.

(B) The owner or operator complies with this subpart as 

proposed during the 3-year period immediately after the 

effective date of standards for the affected source.

(2) Compliance dates for existing sources. (i) The owner or 

operator of an existing affected source shall comply with the 

requirements of this subpart within 3 years after the effective 

date of standards for the affected source.

(ii) The owner or operator of an area source that increases 

its emissions of (or its potential to emit) HAP such that the 

source becomes a major source shall be subject to the relevant 

standards for existing sources under this subpart. Such sources 

shall comply with the relevant standards within 3 years of 

becoming a major source.

(b) All acrylic and modacrylic fiber production affected 

sources and polycarbonate production affected sources that 

commenced construction or reconstruction on or before [INSERT 
Page 41 of 197

DATE OF PUBLICATION IN THE FEDERAL REGISTER], shall be in 

compliance with the pressure relief device monitoring 

requirements of § 63.1107(e)(3) upon initial startup or 3 years 

after the effective date of the final amendments, whichever is 

later, and the equipment leaks requirements of 40 CFR part 63, 

subpart UU upon initial startup or 1 year after the effective 

date of the final amendments, whichever is later. New acrylic 

and modacrylic fiber production affected sources and 

polycarbonate production affected sources that commence 

construction or reconstruction after [INSERT DATE OF PUBLICATION 

IN THE FEDERAL REGISTER], shall be in compliance with the 

pressure relief device monitoring requirements of §

63.1107(e)(3) upon initial startup or by the effective date of 

the final amendments, whichever is later[Reserved].

Table 1 to §63.1102—Source Category Proposal and Effective Dates

Source category Proposal date

Effective 

date

(a) Acetal Resins Production October 14, 

1998

June 29, 

1999.

(b) Acrylic and Modacrylic Fibers 

Production

October 14, 

1998

June 29, 

1999.

(c) Hydrogen Fluoride Production October 14, 

1998

June 29, 

1999.

(d) Polycarbonate Production October 14, 

1998

June 29, 

1999.

(e) Ethylene Production December 6, 

2000

July 12, 

2002.

(f) Carbon Black Production December 6, July 12, 
Page 42 of 197

2000 2002.

(g) Cyanide Chemicals Manufacturing December 6, 

2000

July 12, 

2002.

(h) Spandex Production December 6, 

2000

July 12, 

2002.

§63.1103 Source category-specific applicability, definitions, 

and requirements.

(a) Acetal resins production applicability, definitions, 

and requirements —(1)Applicability —(i) Affected source. For the 

acetal resins production source category (as defined in 

paragraph (a)(2) of this section), the affected source shall 

comprise all emission points, in combination, listed in 

paragraphs (a)(1)(i)(A) through (D) of this section, that are 

associated with an acetal resins production process unit located 

at a major source, as defined in section 112(a) of the Clean Air 

Act (Act).

(A) All storage vessels that store liquids containing 

organic HAP. For purposes of regulation, surge control vessels 

and bottoms receivers that are located as part of the process 

train prior to the polymer reactor are to be regulated under the 

front-end process vent provisions.

(B) All process vents from continuous unit operations 

(front end process vents and back end process vents).
Page 43 of 197

(C) All wastewater streams associated with the acetal 

resins production process unit as defined in (a)(2) of this 

section.

(D) Equipment (as defined in §63.1101 of this subpart) that 

contains or contacts organic HAP.

(ii) Compliance schedule. The compliance schedule for 

affected sources as defined in paragraph (a)(1)(i) of this 

section is specified in §63.1102(a).

(2) Definitions.

Acetal resins production means the production of 

homopolymers and/or copolymers of alternating oxymethylene 

units. Acetal resins are also known as polyoxymethylenes, 

polyacetals, and aldehyde resins. Acetal resins are generally 

produced by polymerizing formaldehyde (HCHO) with the methylene 

functional group (CH2) and are characterized by repeating 

oxymethylene units (CH2O) in the polymer backbone.

Back end process vent means any process vent from a 

continuous unit operation that is not a front end process vent 

up to the final separation of raw materials and by-products from 

the stabilized polymer.

Front end process vent means any process vent from a 

continuous unit operation involved in the purification of 

formaldehyde feedstock for use in the acetal homopolymer 
Page 44 of 197

process. All front end process vents are restricted to those 

vents that occur prior to the polymer reactor.

(3) Requirements. Table 1 of this section specifies the 

acetal resins production standards applicability for existing 

and new sources. Applicability assessment procedures and methods 

are specified in §§63.1104 through 63.1107. An owner or operator 

of an affected source is not required to perform tests, TRE 

calculations or other applicability assessment procedures if 

they opt to comply with the most stringent requirements for an 

applicable emission point pursuant to this subpart. General 

compliance, recordkeeping, and reporting requirements are 

specified in §§63.1108 through 63.1112. Procedures for approval 

of alternative means of emission limitations are specified in 

§63.1113. The owner or operator must control organic HAP 

emissions from each affected source emission point by meeting 

the applicable requirements specified in table 1 of this 

section.

Table 1 to §63.1103(a)—What Are My Requirements If I Own Or 

Operate An Acetal Resins Production Existing Or New Affected 

Source?

If you own or 

operate. . . And if. . . Then you must. . .

1. A storage 

vessel with: 34 

cubic meters < 

capacity

The maximum true 

vapor pressure of 

organic HAP > 17.1 

kilopascals (for 

existing sources) 

or > 11.7 

a. Reduce emissions of total 

organic HAP by 95 weightpercent by venting emissions 

through a closed vent system 

to any combination of control 

devices meeting the 
Page 45 of 197

kilopascals (for 

new sources)

requirements of subpart SS 

(national emission standards 

for closed vent systems, 

control devices, recovery 

devices, and routing to a 

fuel gas system or a 

process), as specified in 

§63.982(a)(1) (storage vessel 

requirements) of this part; 

or

b. Comply with the 

requirements of subpart WW 

(national emission standards 

for storage vessels (control 

level 2)) of this part.

2. A front end 

process vent 

from continuous 

unit operations

a. Reduce emissions of total 

organic HAP by using a flare 

meeting the requirements of 

subpart SS of this part; or

b. Reduce emissions of total 

organic HAP by 60 weightpercent, or reduce TOC to a 

concentration of 20 parts per 

million by volume, whichever 

is less stringent, by venting 

emissions through a closed 

vent system to any 

combination of control 

devices meeting the 

requirements of subpart SS, 

as specified in §63.982(a)(2) 

(process vent requirements) 

of this part.

3. A back end 

process vent 

from continuous 

unit operations

The vent stream 

has a TREa< 1.0

a. Reduce emissions of total 

organic HAP by using a flare 

meeting the requirements of 

subpart SS of this part; or

b. Reduce emissions of total 

organic HAP by 98 weightpercent, or reduce TOC to a 

concentration of 20 parts per 

million by volume, whichever 

is less stringent, by venting 

emissions through a closed 
Page 46 of 197

vent system to any 

combination of control 

devices meeting the 

requirements of subpart SS, 

as specified in §63.982(a)(2) 

(process vent requirements) 

of this part; or

c. Achieve and maintain a TRE 

index value greater than 1.0.

4. A back end 

process vent 

from continuous 

unit operations

1.0 ≤ TREa≤ 4.0 Monitor and keep records of 

equipment operating 

parameters specified to be 

monitored under subpart SS, 

§§63.990(c)(absorber, 

condenser, and carbon 

adsorber monitoring) or 

63.995(c) (other 

noncombustion systems used as 

a control device monitoring) 

of this part.

5. Equipment as 

defined under 

§63.1101

The equipment 

contains or 

contacts ≥ 10 

weight-percent 

organic HAPb, and 

operates ≤ 300 

hours per year

Comply with the requirements 

of subpart TT (national 

emission standards for 

equipment leaks (control 

level 1)) or subpart UU 

(national emission standards 

for equipment leaks (control 

level 2)) of this part.

6. An acetal 

resins 

production 

process unit 

that generates 

process 

wastewater

The process 

wastewater stream 

is a Group 1 or 

Group 2 wastewater 

stream

Comply with the requirements 

of §63.1106(a).

7. An acetal 

resins 

production 

process unit 

that generates 

maintenance 

wastewater

The maintenance 

wastewater 

contains organic 

HAP

Comply with the requirements 

of §63.1106(b).

8. An item of The item of Comply with the requirements 
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equipment listed 

in 

§63.1106(c)(1)

equipment meets 

the criteria 

specified in 

§63.1106(c)(1) 

through (3) and 

either (c)(4)(i) 

or (ii)

in Table 35 of subpart G of 

this part.

aThe TRE is determined according to the procedures specified in 

§63.1104(j).

bThe weight-percent organic HAP is determined for equipment 

according to procedures specified in §63.1107.

(b) Acrylic and modacrylic fiber production applicability, 

definitions, and requirements —(1) Applicability —(i) Affected 

source. For the acrylic fibers and modacrylic fibers production 

(as defined in paragraph (b)(2) of this section) source 

category, the affected source shall comprise all emission 

points, in combination, listed in paragraphs (b)(1)(i)(A) 

through (E) of this section, that are associated with a 

suspension or solution polymerization process unit that produces 

acrylic and modacrylic fiber located at a major source as 

defined in section 112(a) of the Act.

(A) All storage vessels that store liquid containing 

acrylonitrile or organic HAP.

(B) All process vents from continuous unit operations.

(C) All wastewater streams associated with the acrylic and 

modacrylic fibers production process unit as defined in (b)(2) 

of this section.
Page 48 of 197

(D) Equipment (as defined in §63.1101 of this subpart) that 

contains or contacts acrylonitrile or organic HAP.

(E) All acrylic and modacrylic fiber spinning lines using a 

spinning solution or suspension having organic acrylonitrile or 

organic HAP. For the purposes of implementing this paragraph, a 

spinning line includes the spinning solution filters, spin bath, 

and the equipment used downstream of the spin bath to wash, dry, 

or draw the spun fiber.

(ii) Compliance schedule. The compliance schedule, for 

affected sources as defined in paragraph (b)(1)(i) of this

section, is specified in §63.1102(a.

(2) Definitions.

Acrylic fiber means a manufactured synthetic fiber in which 

the fiber-forming substance is any long-chain synthetic polymer 

composed of at least 85 percent by weight of acrylonitrile 

units.

Acrylic and modacrylic fibers production means the 

production of either of the following synthetic fibers composed 

of acrylonitrile units:

(i) Acrylic fiber.

(ii) Modacrylic fiber.

Acrylonitrile solution polymerization means a process where 

acrylonitrile and comonomers are dissolved in a solvent to form 

a polymer solution (typically polyacrylonitrile). The 
Page 49 of 197

polyacrylonitrile is soluble in the solvent. In contrast to 

suspension polymerization, the resulting reactor polymer 

solution (spin dope) is filtered and pumped directly to the 

fiber spinning process.

Acrylonitrile suspension polymerization means a 

polymerization process where small drops of acrylonitrile and 

comonomers are suspended in water in the presence of a catalyst 

where they polymerize under agitation. Solid beads of polymer 

are formed in this suspension reaction which are subsequently 

filtered, washed, refiltered, and dried. The beads must be 

subsequently redissolved in a solvent to create a spin dope 

prior to introduction to the fiber spinning process.

Fiber spinning line means the group of equipment and 

process vents associated with acrylic or modacrylic fiber 

spinning operations. The fiber spinning line includes (as 

applicable to the type of spinning process used) the blending 

and dissolving tanks, spinning solution filters, wet spinning 

units, spin bath tanks, and the equipment used downstream of the 

spin bath to wash, dry, or draw the spun fiber.

Modacrylic fiber means a manufactured synthetic fiber in 

which the fiber-forming substance is any long-chain synthetic 

polymer composed of at least 35 percent by weight of 

acrylonitrile units but less than 85 percent by weight of 

acrylonitrile units.
Page 50 of 197

Seal means, for the purpose of complying with the 

requirements of § 63.1033(b) of subpart UU of this part, that 

instrument monitoring of the open-ended valve or line conducted 

according to the method specified in § 63.1023(b) and, as 

applicable, § 63.1023(c) of subpart UU of this part, indicates 

no readings of 500 parts per million or greater.

Spin dope means the liquid mixture of polymer and solvent 

that is fed to the spinneret to form the acrylic and modacrylic 

fibers.

(3) Requirements. An owner or operator of an affected 

source must comply with the requirements of paragraph (b)(3)(i) 

or (ii) of this section.

(i) Table 2 of this section specifies the acrylic and 

modacrylic fiber production source category control requirement 

applicability for both existing and new sources. Applicability 

assessment procedures and methods are specified in §§63.1104 

through 63.1107. An owner or operator of an affected source is 

not required to perform tests, or other applicability assessment 

procedures if they opt to comply with the most stringent 

requirements for an applicable emission point pursuant to this 

subpart. General compliance, recordkeeping, and reporting 

requirements are specified in §§63.1108 through 63.1112. 

Procedures for approval of alternative means of emission 

limitations are specified in §63.1113. The owner or operator 
Page 51 of 197

must control organic HAP emissions from each affected source 

emission point by meeting the applicable requirements specified 

in table 2 of this section.

Table 2 to §63.1103(b)(3)(i)—What Are My Requirements if I Own 

or Operate an Acrylic and Modacrylic Fiber Production Existing 

or New Affected Source and Am Complying With Paragraph (b)(3)(i) 

of This Section?

If you own or 

operate... And if... Then you must...

1. A storage 

vessel

The stored 

material is 

acrylonitrile

a. Reduce emissions of 

acrylonitrile by 98 weightpercent by venting emissions 

through a closed vent system 

to any combination of control 

device meeting the 

requirements of subpart SS 

(national emission standards 

for closed vent systems, 

control devices, recovery 

devices, and routing to a fuel 

gas system or a process), as 

specified in §63.982(a)(1) 

(storage vessel requirements) 

of this part, or 95 weightpercent or greater by venting 

through a closed vent system 

to a recovery device meeting 

the requirements of subpart SS 

(national emission standards 

for closed vent systems, 

control devices, recovery 

devices, and routing to a fuel 

gas system or a process), 

§63.993 (recovery device 

requirements) of this part; or

b. Comply with the 

requirements of subpart WW 

(national emission standards 

for storage vessels (control 

level 2)) of this part.

2. A process vent The vent steam a. Reduce emissions of 
Page 52 of 197

from continuous 

unit operations 

(halogenated)

has a mass 

emission rate of 

halogen atoms 

contained in 

organic 

compounds ≥0.45 

kilograms per 

houra and an 

acrylonitrile 

concentration 

≥50 parts per 

million by 

volumeb and an 

average flow 

rate ≥0.005 

cubic meters per 

minute

acrylonitrile or TOC as 

specified for nonhalogenated 

process vents from continuous 

unit operations (other than by 

using a flare) by venting 

emissions through a closed 

vent system to a halogen 

reduction device meeting the 

requirements of subpart SS, 

§63.994 (halogen reduction 

devices requirements) of this 

part that reduces hydrogen 

halides and halogens by 99 

weight-percent or to less than 

0.45 kilograms per year, 

whichever is less stringent; 

or

b. Reduce the process vent 

halogen atom mass emission 

rate to less than 0.45 

kilograms per hour by venting 

emissions through a closed 

vent system to a halogen 

reduction device meeting the 

requirements of subpart SS, 

§63.994 (halogen reduction 

devices requirements) of this 

part and then complying with 

the requirements specified for 

process vents from continuous 

unit operations 

(nonhalogenated).

3. A process vent 

from continuous 

unit operations 

(nonhalogenated)

The vent steam 

has a mass 

emission rate of 

halogen atoms 

contained in 

organic 

compounds <0.45 

kilograms per 

houra, and an 

acrylonitrile 

concentration 

≥50 parts per 

million by 

a. Reduce emissions of 

acrylonitrile by using a flare 

meeting the requirements of 

subpart SS, §63.987 (flare 

requirements) of this part or

b. Reduce emissions of 

acrylonitrile by 98 weightpercent, or reduce TOC to a 

concentration of 20 parts per 

million by volume, whichever 

is less stringent, by venting 

emissions through a closed 

vent system to any combination 
Page 53 of 197

volumeb and an 

average flow 

rate ≥0.005 

cubic meters per 

minute

of control devices meeting the 

requirements of subpart SS 

(national emission standards 

for closed vent systems, 

control devices, recovery 

devices, and routing to a fuel 

gas system or a process), as 

specified in §63.982(a)(2) 

(process vent requirements) of 

this part.

4. A fiber 

spinning line 

that is a new or 

reconstructed 

source

The lines use a 

spin dope 

produced from 

either a 

suspension 

polymerization 

process or 

solution 

polymerization 

process,

a. Reduce acrylonitrile 

emissions by 85 weight-percent 

or more. (For example, by you 

may encloseing the spinning 

and washing areas of the 

spinning line (as specified in 

paragraph (b)(4) of this 

section) and venting through a 

closed vent system and useing

any combination of control 

devices meeting the 

requirements of subpart SS, as 

specified in §63.982(a), of 

this part.); or

b. Reduce acrylonitrile 

emissions from the spinning 

line to less than or equal to 

0.25 kilograms of 

acrylonitrile per megagram 

(0.5 pounds of acrylonitrile 

per ton) of acrylic and 

modacrylic fiber produced; or

c. Reduce the AN acrylonitrile

concentration of the spin dope 

to less than 100 ppmw.

5. A fiber 

spinning line 

that is an 

existing source

The spinning 

line uses a spin 

dope produced 

from a solution 

polymerization 

process

Reduce organic HAP emissions 

from the spinning line to less 

than or equal to 20 kilograms 

of organic HAP per megagram 

(40 pounds of organic HAP per 

ton) of acrylic and modacrylic 

fiber produced.Maintain 

records and report emissions 

as specified in §§63.1109 
Page 54 of 197

through 63.1110. Control of 

spinning line AN emissions is 

not required

6. A fiber 

spinning line 

that is an 

existing source

The spinning 

line uses a spin 

dope produced 

from a 

suspension 

polymerization 

process

a. Reduce the AN acrylonitrile

concentration of the spin dope 

to less than 100 ppmwb, ; or

b. Reduce acrylonitrile 

emissions from the spinning 

line to less than or equal to 

0.025 kilograms of 

acrylonitrile per megagram of 

acrylic and modacrylic fiber 

produced.

7. Equipment as 

defined under 

§63.1101 (with

the differences 

for pressure 

relief devices 

described in item 

11 below)

It contains or 

contacts ≥10 

weight-percent 

acrylonitrilec, 

and operates 

≥300 hours per 

year

For connectors in gas and 

vapor service and in light 

liquid service, comply with 

either § 63.1008 of subpart TT 

(national emission standards 

for equipment leaks (control 

level 1)) of this part, or §

63.1027 of subpart UU 

(national emission standards 

for equipment leaks (control 

level 2)) of this part. For 

all other applicable 

equipment, cComply with the 

requirements of subpart TT 

(national emission standards 

for equipment leaks (control 

level 1)) or subpart UU 

(national emission standards 

for equipment leaks (control 

level 2)) of this part, except 

§ 63.1030.

8. An acrylic and 

modacrylic fiber 

production 

process unit that 

generates process 

wastewater

The process 

wastewater 

stream is a 

Group 1 or Group 

2 wastewater 

stream

Comply with the requirements 

of §63.1106(a).
Page 55 of 197

9. An acrylic and 

modacrylic fiber 

production 

process unit that 

generates 

maintenance 

wastewater

The maintenance 

wastewater 

contains organic 

HAP

Comply with the requirements 

of §63.1106(b).

10. An item of 

equipment listed 

in §63.1106(c)(1)

The item of 

equipment meets 

the criteria 

specified in 

§63.1106(c)(1) 

through (3) and 

either (c)(4)(i) 

or (ii)

Comply with the requirements 

in Table 35 of subpart G of 

this part.

11. Pressure 

relief devices

The pressure 

relief device is 

in organic HAP 

service

Comply with § 63.1107(e).

aThe mass emission rate of halogen atoms contained in organic 

compounds is determined according to the procedures specified in 

§63.1104(i).

bThe percent by weight organic HAP is determined according to the 

procedures specified in §63.1107.

cThe weight-percent organic HAP is determined for equipment 

according to procedures specified in §63.1107.

(ii) The owner or operator must control organic HAP 

emissions from the acrylic and modacrylic fibers production 

facility by meeting the applicable requirements specified in 

table 3 of this section. The owner or operator must determine 

the facility acrylonitrile emission rate using the procedures 

specified in paragraph (b)(5) of this section. Applicability 

assessment procedures and methods are specified in §§63.1104 

through 63.1107. An owner or operator of an affected source does 
Page 56 of 197

not have to perform tests, TRE calculations or other 

applicability assessment procedures if they opt to comply with 

the most stringent requirements for an applicable emission point

pursuant to this subpart. General compliance, recordkeeping, and 

reporting requirements are specified in §§63.1108 through 

63.1112. Procedures for approval of alternative means of 

emission limitations are specified in §63.1113.

Table 3 to §63.1103(b)(3)(ii)—What Are My Requirements If I Own 

Or Operate An Acrylic And Modacrylic Fiber Production Existing 

Or New Affected Source And Am Complying With Paragraph 

(b)(3)(ii) Of This Section?

If you own or operate...

Then you must control total 

organic HAP emissions from the 

affected source by...

1. An acrylic and modacrylic 

fibers production affected 

source and your facility is an 

existing source

Meeting all of following 

requirements:

a. Reduce total acrylonitrile 

emissions from all affected 

storage vessels, process vents, 

wastewater streams associated 

with the acrylic and modacrylic 

fibers production process unit 

as defined in paragraph (b)(2) 

of this section, and fiber 

spinning lines operated in your 

acrylic and modacrylic fibers 

production facility to less 

than or equal to 0.5 kilograms 

(kg) of acrylonitrile per 

megagram (Mg) of fiber 

produced.

b. Determine the facility 

acrylonitrile emission rate in 

accordance with the 

requirements specified in 

paragraph (b)(5) of this 

section.
Page 57 of 197

2. An acrylic and modacrylic 

fibers production affected 

source and your facility is a 

new source

Meeting all of following 

requirements:

a. Reduce total acrylonitrile 

emissions from all affected 

storage vessels, process vents, 

wastewater streams associated 

with the acrylic and modacrylic 

fibers production process unit 

as defined in paragraph (b)(2) 

of this section, and fiber 

spinning lines operated in your 

acrylic and modacrylic fibers 

production facility to less 

than or equal to 0.25 kilograms 

(kg) of acrylonitrile per 

megagram (Mg) of fiber 

produced.

b. Determine the facility 

acrylonitrile emission rate in 

accordance with the 

requirements specified in 

paragraph (b)(5) of this 

section.

3. Equipment as defined under 

§63.1101 and it contains or 

contacts > 10 weight-percent 

acrylonitrile,a and operates > 

300 hours per year (with the 

differences for pressure relief 

devices described in item 4 

below)

For connectors in gas and vapor 

service and in light liquid 

service, comply with either §

63.1008 of subpart TT (national 

emission standards for 

equipment leaks (control level 

1)) of this part, or § 63.1027 

of subpart UU (national 

emission standards for 

equipment leaks (control level 

2)) of this part. For all other 

applicable equipment, cMeeting 

either of the following 

standards for equipment leaks:

a. Comply with subpart TT of 

this part; or

b. Comply with subpart UU of 

this part, except § 63.1030.

4. A pressure relief device in

organic HAP service

Complying with § 63.1107(e).
Page 58 of 197

aThe weight-percent organic HAP is determined for equipment 

according to procedures specified in §63.1107.

(4) Fiber spinning line enclosure requirements. For an 

owner or operator of a new or modified source electing to comply 

with paragraph (b)(3)(i) of this section, the fiber spinning 

line enclosure must be designed and operated to meet the 

requirements specified in paragraphs (b)(4)(i) through (iv) of 

this section.

(i) The enclosure must cover the spinning and washing areas 

of the spinning line.

(ii) The enclosure must be designed and operated in 

accordance with the criteria for a permanent total enclosure as 

specified in “Procedure T—Criteria for and Verification of a 

Permanent or Temporary Total Enclosure” in 40 CFR 52.741, 

appendix B.

(iii) The enclosure may have permanent or temporary 

openings to allow worker access; passage of material into or out 

of the enclosure by conveyor, vehicles, or other mechanical 

means; entry of permanent mechanical or electrical equipment; or 

to direct airflow into the enclosure.

(iv) The owner or operator must perform the verification 

procedure for the enclosure as specified in section 5.0 to 

“Procedure T—Criteria for and Verification of a Permanent or 
Page 59 of 197

Temporary Total Enclosure” initially when the enclosure is first 

installed and, thereafter, annually.

(5) Facility acrylonitrile emission rate determination. For 

an owner or operator electing to comply with paragraph 

(b)(3)(ii) of this section, the facility acrylonitrile emission 

rate must be determined using the requirements specified in 

paragraphs (b)(5)(i) through (iii) of this section.

(i) The owner or operator must prepare an initial 

determination of the facility acrylonitrile emission rate.

(ii) Whenever changes to the acrylic or modacrylic fiber 

production operations at the facility could potentially cause 

the facility acrylonitrile emission rate to exceed the 

applicable limit of kilogram of acrylonitrile per Megagram of 

fiber produced, the owner or operator must prepare a new 

determination of the facility acrylonitrile emission rate.

(iii) For each determination, the owner or operator must 

prepare and maintain at the facility site sufficient process 

data, emissions data, and any other documentation necessary to 

support the facility acrylonitrile emission rate calculation.

(c) Hydrogen fluoride production applicability, 

definitions, and requirements —(1)Applicability —(i) Affected 

source —For the hydrogen fluoride production (as defined in 

paragraph (c)(2) of this section) source category, the affected 

source shall comprise all emission points, in combination, 
Page 60 of 197

listed in paragraphs (c)(1)(i)(A) through (D) of this section, 

that are associated with a hydrogen fluoride production process 

unit located at a major source as defined in section 112(a) of 

the Act.

(A) All storage vessels used to accumulate or store 

hydrogen fluoride.

(B) All process vents from continuous unit operations 

associated with hydrogen fluoride recovery and refining 

operations. These process vents include vents on condensers, 

distillation units, and water scrubbers.

(C) All transfer racks used to load hydrogen fluoride into 

tank trucks or railcars.

(D) Equipment in hydrogen fluoride service (as defined in 

paragraph (c)(2) of this section).

(ii) Compliance schedule. The compliance schedule, for 

affected sources as defined in paragraph (c)(1)(i) of this 

section, is specified in §63.1102(a).

(2) Definitions.

Connector means flanged, screwed, or other joined fittings 

used to connect two pipelines or a pipeline and a piece of 

equipment. A common connector is a flange. Joined fittings 

welded completely around the circumference of the interface are 

not considered connectors for the purposes of this subpart.
Page 61 of 197

Equipment means each pump, compressor, agitator, pressure 

relief device, sampling connection system, open-ended valve or 

line, valve, connector, and instrumentation system in hydrogen 

fluoride service; and any control devices or closed-vent systems 

used to comply with this subpart.

Hydrogen fluoride production means a process engaged in the 

production and recovery of hydrogen fluoride by reacting calcium 

fluoride with sulfuric acid. For the purpose of implementing 

this subpart, hydrogen fluoride production is not a process that 

produces gaseous hydrogen fluoride for direct reaction with 

hydrated aluminum to form aluminum fluoride (i.e., the hydrogen 

fluoride is not recovered as an intermediate or final product 

prior to reacting with the hydrated aluminum).

In hydrogen fluoride service means that a piece of 

equipment either contains or contacts a hydrogen fluoride 

process fluid (liquid or gas).

In vacuum service means that equipment is operating at an 

internal pressure which is at least 5 kilopascals below ambient 

pressure.

Instrumentation system means a group of equipment 

components used to condition and convey a sample of the process 

fluid to analyzers and instruments for the purpose of 

determining process operating conditions (e.g., composition, 

pressure, flow, etc.). Valves and connectors are the predominant 
Page 62 of 197

type of equipment used in instrumentation systems; however, 

other types of equipment may also be included in these systems.

Kiln seal means the mechanical or hydraulic seals at both 

ends of the kiln, designed to prevent the infiltration of 

moisture and air through the interface of the rotating kiln and 

stationary pipes and equipment attached to the kiln during 

normal vacuum operation of the kiln (operation at an internal 

pressure of at least 0.25 kilopascal [one inch of water] below 

ambient pressure).

Leakless pump means a pump whose seals are submerged in 

liquid, a magnetically-driven pump, a pump equipped with a dual 

mechanical seal system that includes a barrier fluid system, a 

canned pump, or other pump that is designed with no externally 

actuated shaft penetrating the pump housing.

Open-ended valve or line means any valve, except relief 

valves, having one side of the valve seat in contact with 

process fluid and one side open to the atmosphere, either 

directly or through open piping.

Pressure release means the emission of materials resulting 

from the system pressure being greater than the set pressure of 

the relief device. This release can be one release or a series 

of releases over a short time period due to a malfunction in the 

process.
Page 63 of 197

Pressure relief device or valve means a safety device used 

to prevent operating pressures from exceeding the maximum 

allowable working pressure of the process equipment. A common 

pressure relief device is a spring-loaded pressure relief valve. 

Devices that are actuated either by a pressure of less than or 

equal to 2.5 pounds per square inch gauge or by a vacuum are not 

pressure relief devices.

Relief device or valve means a valve used only to release 

an unplanned, nonroutine discharge. A relief valve discharge can 

result from an operator error, a malfunction such as a power 

failure or equipment failure, or other unexpected cause that 

requires immediate venting of gas from process equipment in 

order to avoid safety hazards or equipment damage.

Repaired for the purpose of this regulation means equipment 

is adjusted, or otherwise altered, to eliminate a leak 

identified by sensory monitoring.

Sampling connection system means an assembly of equipment 

within a process unit or affected facility used during periods 

of representative operation to take samples of the process 

fluid. Equipment used to take nonroutine grab samples is not 

considered a sampling connection system.

Sensory monitoring means the detection of a potential leak 

to the atmosphere by walk-through visual, audible, or olfactory 
Page 64 of 197

monitoring. Comprehensive component-by-component inspection is 

not required.

Shift means the time a shift operator normally works, 

typically 8 or 12 hours.

(3) Requirements. Table 4 of this section specifies the 

hydrogen fluoride production source category applicability and 

control requirements for both existing and new sources. The 

owner or operator must control hydrogen fluoride emissions from 

each affected source emission point as specified in table 4. 

General compliance, recordkeeping, and reporting requirements 

are specified in §§63.1108 through 63.1112. Specific monitoring, 

recordkeeping, and reporting requirements are specified in table 

4. Minimization of emissions from startups, shutdowns, and 

malfunctions, including those resulting from kiln seals must be 

addressed in the startup, shutdown, and malfunction plan 

required by §63.1111; the plan must also establish reporting and 

recordkeeping of such events. Procedures for approval of 

alternative means of emission limitations are specified in 

§63.1113.

Table 4 to §63.1103(c)—What Are My Requirements If I Own or 

Operate a Hydrogen Fluoride Production Existing or New Affected 

Source?

If you own or 

operate . . . And if . . . Then you must . . .

1. A storage 

vessel

The stored 

material is 

Reduce emissions of hydrogen 

fluoride by venting displacement 
Page 65 of 197

hydrogen fluoride emissions created by normal 

filling or emptying activities 

through a closed-vent system to 

a recovery system or wet 

scrubber that is designed and 

operated to achieve a 99 weightpercent removal efficiency. The 

minimum liquid flow rate to the 

scrubber that achieves a 99 

weight-percent removal 

efficiency shall be established, 

and may be done so by design 

analysis. The liquid flow rate 

to the scrubber shall be 

continuously monitored and 

records maintained according to 

§§63.996 and 63.998(b), (c), and 

(d)(3) of 40 CFR subpart SS of 

this part. The Periodic Report 

specified in §63.1110(a)(5) of 

this subpart shall include the 

information specified in 

§63.999(c) of 40 CFR subpart SS 

of this part, as applicable.

2. A process 

vent from 

continuous 

unit 

operations

The vent stream is 

from hydrogen 

fluoride recovery 

and refining 

vessels

Reduce emissions of hydrogen 

fluoride from the process vent 

by venting emissions through a 

closed-vent system to a wet 

scrubber that is designed and 

operated to achieve a 99 weightpercent removal efficiency. 

Monitoring, recordkeeping, and 

reporting of wet scrubber 

operation shall be in accordance 

with the requirements stated 

above for a wet scrubber 

controlling hydrogen fluoride 

emissions from a storage vessel.

3. A transfer 

rack

The transfer rack 

is associated with 

bulk hydrogen 

fluoride liquid 

loading into tank 

trucks and rail 

cars

Reduce emissions of hydrogen 

fluoride by venting emissions 

through a closed-vent system to 

a recovery system or wet 

scrubber that is designed and 

operated to achieve a 99 weightpercent removal efficiency. 
Page 66 of 197

Monitoring, recordkeeping, and 

reporting of wet scrubber 

operation shall be in accordance 

with the requirements stated 

above for a wet scrubber 

controlling HF emissions from a 

storage vessel. You also must 

load hydrogen fluoride into only 

tank trucks and railcars that 

have a current certification in 

accordance with the U.S. DOT 

pressure test requirements of 49 

CFR part 180 for tank trucks and 

49 CFR 173.31 for railcars; or 

have been demonstrated to be 

vapor-tight (i.e. will sustain a 

pressure change of not more than 

750 Pascals within 5 minutes 

after it is pressurized to a 

minimum or 4,500 Pascals) within 

the preceding 12 months.

4. Equipment It is in hydrogen 

fluoride service 

and operates ≥ 300 

hours per year and 

is not in vacuum 

service

Control hydrogen fluoride 

emissions by using leakless 

pumps and by implementing a 

sensory monitoring leak 

detection program. Equipment 

that is excluded from sensory 

monitoring because it operates 

less than 300 hours per year or 

is in vacuum service shall be 

identified by list, location, or 

other method and the identity 

shall be recorded. An owner or 

operator is required to perform 

sensory monitoring at least once 

every shift, but no later than 

within 15 days. When a leak is 

detected, repair must begin 

within one hour and be completed 

as soon as practical. A record 

shall be kept of each leak 

detected and repaired including: 

equipment identification number, 

date and time the leak was 

detected and that repair was 

initiated, and the date of 
Page 67 of 197

successful repair.

(d) Polycarbonate production applicability, definitions, 

and requirements —(1)Applicability —(i) Affected source. For the 

polycarbonate production (as defined in paragraph (d)(2) of this 

section) source category, the affected source shall comprise all 

emission points, in combination, listed in paragraphs 

(d)(1)(i)(A) through (D) of this section, that are part of a 

polycarbonate production process unit located at a major source 

as defined in section 112(a) of the Act. For the purposes of 

this rule, a polycarbonate production process unit is a unit 

that produces polycarbonate by interfacial polymerization from 

bisphenols and phosgene. Phosgene production units that are 

associated with polycarbonate production process units are 

considered to be part of the polycarbonate production process. A 

phosgene production unit consists of the reactor in which 

phosgene is formed and all equipment (listed in paragraphs 

(d)(1)(i)(A) through (D) of this section) downstream of the 

reactor that provides phosgene for the production of 

polycarbonate. Therefore, for the purposes of this rule, such a 

phosgene production unit is considered to be a polycarbonate 

production process unit.

(A) All storage vessels that store liquids containing 

organic HAP.
Page 68 of 197

(B) All process vents from continuous and batch unit 

operations.

(C) All wastewater streams.

(D) Equipment (as defined in §63.1101 of this subpart) that 

contains or contacts organic HAP.

(ii) Compliance schedule. The compliance schedule, for 

affected sources as defined in paragraph (d)(1)(i) of this 

section, is specified in §63.1102(a).

(2) Definitions.

Polycarbonate production means a process engaged in the 

production of a special class of polyester formed from any 

dihydroxy compound and any carbonate diester or by ester 

exchange. Polycarbonate may be produced by solution or emulsion 

polymerization, although other methods may be used. A typical 

method for the manufacture of polycarbonate includes the 

reaction of bisphenol-A with phosgene in the presence of 

pyridine or other catalyst to form polycarbonate. Methylene 

chloride or other solvents are used in this polymerization 

reaction.

Seal means, for the purpose of complying with the 

requirements of § 63.1033(b) of subpart UU of this part, that 

instrument monitoring of the open-ended valve or line conducted 

according to the method specified in § 63.1023(b) and, as 
Page 69 of 197

applicable, § 63.1023(c) of subpart UU of this part, indicates 

no readings of 500 parts per million or greater.

(3) Requirements. Tables 5 and 6 of this section specify 

the applicability criteria and standards for existing and new 

sources within the polycarbonate production source category. The 

owner or operator must control organic HAP emissions from each 

affected source emission point by meeting the applicable 

requirements specified in tables 5 and 6. Applicability 

assessment procedures and methods are specified in §§63.1104 

through 63.1107. An owner or operator of an affected source is 

not required to perform tests, TRE calculations or other 

applicability assessment procedures if they opt to comply with 

the most stringent requirements for an applicable emission point 

pursuant to this subpart. General compliance, recordkeeping, and 

reporting requirements are specified in §§63.1108 through 

63.1112. Procedures for approval of alternative means of 

emission limitations are specified in §63.1113.

Table 5 to §63.1103(d)—What Are My Requirements If I Own or 

Operate A Polycarbonate Production Existing Affected Source?

If you own or 

operate... And if... Then you must...

1. A storage vessel 

with: 75 cubic 

meters ≤ capacity < 

151 cubic meters

27.6 kilopascals ≤ 

maximum true vapor 

pressure of total 

organic HAP < 76.6 

kilopascals

Reduce emissions of total 

organic HAP by 95 weightpercent by venting 

emissions through a 

closed vent system to any 

combination of control 

devices meeting the 
Page 70 of 197

requirements of subpart 

SS (national emission 

standards for closed vent 

systems, control devices,

recovery devices, and 

routing to a fuel gas 

system or a process), as 

specified in 

§63.982(a)(1) (storage 

vessel requirements) of 

this part; or comply with 

the requirements of 

subpart WW (national 

emission standards for 

storage vessels (control 

level 2)) of this part.

2. A storage vessel 

with: 151 cubic 

meters ≤ capacity

The maximum true 

vapor pressure of 

total organic HAP ≥ 

5.2 kilopascals

Reduce emissions of total 

organic HAP by 98 weightpercent by venting 

emissions through a 

closed vent system to any 

combination of control 

devices meeting the 

requirements of subpart 

SS, as specified in 

§63.982(a)(1) (storage 

vessel requirements) of 

this part

3. A storage vessel 

with: 75 cubic 

meters ≤ capacity < 

151 cubic meters

The maximum true 

vapor pressure of 

total organic HAP ≥ 

76.6 kilopascals

Reduce emissions of total 

organic HAP by 95 weightpercent by venting 

emissions through a 

closed vent system to any 

combination of control 

devices meeting the 

requirements of subpart 

SS, as specified in 

§63.982(a)(1) (storage 

vessel requirements) of 

this part.

4. A process vent 

from continuous 

unit operations or 

a combined vent 

streama

The vent stream has 

a TREb,c≤ 2.7

a. Reduce emissions of 

total organic HAP by 98 

weight-percent; or reduce 

total organic HAP to a 

concentration of 20 parts 
Page 71 of 197

per million by volume; 

whichever is less 

stringent, by venting 

emissions through a 

closed vent system to any 

combination of control 

devices meeting the 

requirements of subpart 

SS, as specified in 

§63.982(a)(2) (process 

vent requirements) of 

this part and vent 

emissions through a 

closed vent system to a 

halogen reduction device 

meeting the requirements 

of subpart SS, §63.994, 

of this part, that 

reduces hydrogen halides 

and halogens by 99 

weight-percent or to less 

than 0.45 kilograms per 

hourd, whichever is less 

stringent; or

b. Reduce the process 

vent halogen atom mass 

emission rate to less 

than 0.45 kilograms per 

hour by venting emissions 

through a closed vent 

system to a halogen 

reduction device meeting 

the requirements of 

subpart SS, §63.994 

(halogen reduction device 

requirements) of this 

part and reduce emissions 

of total organic HAP by 

98 weight-percent; or 

reduce total organic HAP 

or TOC to a concentration 

of 20 parts per million 

by volume; whichever is 

less stringent, by 

venting emissions through 

a closed vent system to 
Page 72 of 197

any combination of 

control devices meeting 

the requirements of 

subpart SS, as specified 

in §63.982(a)(2) (process 

vent requirements) of 

this part; or

c. Achieve and maintain a 

TRE index value greater 

than 2.7.

5. A process vent 

from continuous 

unit operations or 

a combined vent 

streama

2.7 < TREb,c≤ 4.0 Monitor and keep records 

of equipment operating 

parameters specified to 

be monitored under 

subpart SS, §§63.990(c) 

(absorber, condenser, and 

carbon adsorber 

monitoring) or 63.995(c) 

(other noncombustion

systems used as a control 

device monitoring) of 

this part.

6. Equipment as 

defined under 

§63.1101 (with the 

differences for

pressure relief 

devices described 

in item 10 below)

The equipment 

contains or 

contacts ≥ 5 

weight-percent 

total organic HAPe, 

and operates ≥ 300 

hours per year

For connectors in gas and 

vapor service and in 

light liquid service, 

comply with either §

63.1008 of subpart TT 

(national emission 

standards for equipment 

leaks (control level 1)) 

of this part, or §

63.1027 of subpart UU 

(national emission 

standards for equipment 

leaks (control level 2)) 

of this part. For all 

other applicable 

equipment, cComply with 

the requirements of 

subpart TT (national 

emission standards for 

equipment leaks (control 

level 1)) or subpart UU 

(national emission 

standards for equipment 
Page 73 of 197

leaks (control level 2)) 

of this part, except §

63.1030.

7. A polycarbonate 

production process 

unit that generates 

process wastewater

The process 

wastewater stream 

is a Group 1 or a 

Group 2 wastewater 

stream

Comply with the 

requirements of 

§63.1106(a).

8. A polycarbonate 

production process 

unit that generates 

maintenance 

wastewater

The maintenance 

wastewater contains 

organic HAP

Comply with the 

requirements of 

§63.1106(b).

9. An item of 

equipment listed in 

§63.1106(c)(1)

The item of 

equipment meets the 

criteria specified 

in §63.1106(c)(1) 

through (3) and 

either (c)(4)(i) or 

(ii)

Comply with the 

requirements in Table 35 

of subpart G of this 

part.

10. Pressure relief 

devices

The pressure relief 

device is in 

organic HAP service

Comply with § 63.1107(e).

aCombined vent streams shall use the applicability determination 

procedures and methods for process vents from continuous unit 

operations (§63.1104).

bThe TRE equation coefficients for halogenated streams (table 1 

of §63.1104(j)(1)) shall be used to calculate the TRE index 

value.

cThe TRE is determined according to the procedures specified in 

§63.1104(j). If a dryer is manifolded with such vents, and the 

vent is routed to a recovery, recapture, or combustion device, 

then the TRE index value for the vent must be calculated based 

on the properties of the vent stream (including the 

contributions of the dryer). If a dryer is manifolded with other 

vents and not routed to a recovery, recapture, or combustion 

device, then the TRE index value must be calculated excluding 

the contributions of the dryer. The TRE index value for the 

dryer must be calculated separately in this case.
Page 74 of 197

dThe mass emission rate of halogen atoms contained in organic 

compounds is determined according to the procedures specified in 

§63.1104(i).

eThe weight-percent organic HAP is determined for equipment 

according to procedures specified in §63.1107.

Table 6 to §63.1103(d)—What are My Requirements If I Own or 

Operate a Polycarbonate Production New Affected Source?

If you own or 

operate. . . And if. . . Then you must. . .

1. A storage 

vessel with: 38 

cubic meters 

≤capacity <151 

cubic meters

13.1 kilopascals 

≤maximum true 

vapor pressure of 

total organic HAP 

<76.6 kilopascals

a. Reduce emissions of total 

organic HAP by 95 weightpercent by venting emissions 

through a closed vent system 

to any combination of 

control devices meeting the 

requirements of subpart SS 

(national emission standards 

for closed vent systems, 

control devices, recovery 

devices, and routing to a 

fuel gas system or a 

process), as specified in 

§63.982(a)(1) (storage 

vessel requirements) of this 

part; or

b. Comply with the 

requirements of subpart WW 

(national emission standards 

for storage vessels (control 

level 2)) of this part.

2. A storage 

vessel with: 151 

cubic meters 

≤capacity

The maximum true 

vapor pressure of 

total organic HAP 

is ≥5.2 

kilopascals

Reduce emissions of total 

organic HAP by 98 weightpercent by venting emissions 

through a closed vent system 

to any combination of 

control devices meeting the 

requirements of subpart SS, 

as specified in 

§63.982(a)(1) (storage 

vessel requirements) of this 

part.

3. A storage The maximum true Reduce emissions of total 
Page 75 of 197

vessel with: 38 

cubic meters 

≤capacity <151 

cubic meters

vapor pressure of 

total organic HAP 

is ≥76.6 

kilopascals

organic HAP by 95 weightpercent by venting emissions 

through a closed vent system 

to any combination of 

control devices meeting the 

requirements of subpart SS, 

as specified in 

§63.982(a)(1) (storage 

vessel requirements) of this 

part.

4. A process vent 

from continuous 

unit operations or 

a combined vent 

streama

The vent stream 

has a TREb,c≤9.6

a. Reduce emissions of total 

organic HAP by 98 weightpercent; or reduce total 

organic HAP to a 

concentration of 20 parts 

per million by volume; 

whichever is less stringent, 

by venting emissions through 

a closed vent system to any 

combination of control 

devices meeting the 

requirements of subpart SS, 

as specified in 

§63.982(a)(2) (process vent 

requirements) of this part; 

and Vent emissions through a 

closed vent system to a 

halogen reduction device 

meeting the requirements of 

subpart SS, §63.994, of this 

part that reduces hydrogen 

halides and halogens by 99 

weight-percent or to less 

than 0.45 kilograms per 

hourd,d, whichever is less 

stringent; or

b. Reduce the process vent 

halogen atom mass emission 

rate to less than 0.45 

kilograms per hour by 

venting emissions through a 

closed vent system to a 

halogen reduction device 

meeting the requirements of 

subpart SS, §63.994 (halogen 

reduction device 
Page 76 of 197

requirements) of this part; 

and Reduce emissions of 

total organic HAP by 98 

weight-percent; or reduce 

total organic HAP or TOC to 

a concentration of 20 parts 

per million by volume; 

whichever is less stringent, 

by venting emissions through 

a closed vent system to any 

combination of control 

devices meeting the 

requirements of subpart SS, 

as specified in 

§63.982(a)(2) (process vent 

requirements) of this part; 

or

c. Achieve and maintain a 

TRE index value greater than 

9.6.

5. Equipment as 

defined under 

§63.1101 (with the 

differences for 

pressure relief 

devices described 

in item 6 below)

The equipment 

contains or 

contacts ≥ 5 

weight-percent 

total organic 

HPAe, and operates 

≥ 300 hours per 

year

For connectors in gas and 

vapor service and in light 

liquid service, comply with 

either § 63.1008 of subpart 

TT (national emission 

standards for equipment 

leaks (control level 1)) of 

this part, or § 63.1027 of 

subpart UU ((national 

emission standards for

equipment leaks (control 

level 2)) of this part. For 

all other applicable 

equipment, cComply with the 

requirements of subpart TT 

(national emission standards 

for equipment leaks (control 

level 1)) or subpart UU 

(national emission standards 

for equipment leaks (control 

level 2)) of this part, 

except § 63.1030.

6. Pressure relief 

devices

The pressure 

relief device is 

in organic HAP 

Comply with § 63.1107(e).
Page 77 of 197

service

aCombined vent streams shall use the applicability determination 

procedures and methods for process vents from continuous unit 

operations (§63.1104).

bThe TRE equation coefficients for halogenated streams (Table 1 

of §63.1104(j)(1) of this subpart) shall be used to calculate 

the TRE index value.

cThe TRE is determined according to the procedures specified in 

§63.1104(j). If a dryer is manifolded with such vents, and the 

vent is routed to a recovery, recapture, or combustion device, 

then the TRE index value for the vent must be calculated based 

on the properties of the vent stream (including the 

contributions of the dryer). If a dryer is manifolded with other 

vents and not routed to a recovery, recapture, or combustion 

device, then the TRE index value must be calculated excluding 

the contributions of the dryer. The TRE index value for the 

dryer must be calculated separately in this case.

dThe mass emission rate of halogen atoms contained in organic 

compounds is determined according to the procedures specified in 

§63.1104(i).

eThe weight-percent organic HAP is determined for equipment 

according to procedures specified in §63.1107.

(e) Ethylene production applicability, definitions, and 

requirements —(1) Applicability—(i) Affected source. For the 

ethylene production (as defined in paragraph (e)(2) of this 

section) source category, the affected source shall comprise all 

emission points listed in paragraphs (e)(1)(i) (A) through (G) 

of this section that are associated with an ethylene production 

unit that is located at a major source, as defined in section 

112(a) of the Act.

(A) All storage vessels (as defined in §63.1101) that store 

liquids containing organic HAP.
Page 78 of 197

(B) All ethylene process vents (as defined in paragraph 

(e)(2) of this section) from continuous unit operations.

(C) All transfer racks (as defined in paragraph (e)(2) of 

this section) that load HAP-containing material.

(D) Equipment (as defined in §63.1101) that contains or 

contacts organic HAP.

(E) All waste streams (as defined in paragraph (e)(2) of 

this section) associated with an ethylene production unit.

(F) All heat exchange systems (as defined in paragraph 

(e)(2) of this section) associated with an ethylene production 

unit.

(G) All ethylene cracking furnaces and associated decoking 

operations.

(ii) Exceptions. The emission points listed in paragraphs 

(e)(1)(ii) (A) through (L) of this section are in the ethylene 

production source category but are not subject to the 

requirements of paragraph (e)(3) of this section.

(A) Equipment that is located within an ethylene production 

unit that is subject to this subpart but does not contain 

organic HAP.

(B) Stormwater from segregated sewers.

(C) Water from fire-fighting and deluge systems in 

segregated sewers.

(D) Spills.
Page 79 of 197

(E) Water from safety showers.

(F) Water from testing of fire-fighting and deluge systems.

(G) Vessels storing organic liquids that contain organic 

HAP as impurities.

(H) Transfer racks, loading arms, or loading hoses that 

only transfer liquids containing organic HAP as impurities.

(I) Transfer racks, loading arms, or loading hoses that 

vapor balance during all transfer operations.

(J) Air emissions from all ethylene cracking furnaces, 

including emissions during decoking operations.

(K) Pressure vessels designed to operate in excess of 204.9 

kilopascals and without emissions to the atmosphere.

(L) Vessels permanently attached to motor vehicles such as 

trucks, railcars, barges, or ships.

(iii) Exclusions. The provisions of this subpart do not 

apply to process units and emission points subject to subparts 

F, G, H, I and CC of this part.

(iv) Compliance schedule. The compliance schedule for the 

ethylene production source category is specified in §63.1102.

(2) Definitions. Ethylene process vent means a gas stream 

with a flow rate greater than 0.005 standard cubic meters per 

minute containing greater than 20 parts per million by volume 

HAP that is continuously discharged during operation of an 

ethylene production unit, as defined in this section. Ethylene 
Page 80 of 197

process vents are gas streams that are discharged to the 

atmosphere (or the point of entry into a control device, if any) 

either directly or after passing through one or more recovery 

devices. Ethylene process vents do not include relief valve 

discharges; gaseous streams routed to a fuel gas system; leaks 

from equipment regulated under this subpart; episodic or 

nonroutine releases such as those associated with startup, 

shutdown, and malfunction; and in situ sampling systems (online 

analyzers).

Ethylene production or production unit means a chemical 

manufacturing process unit in which ethylene and/or propylene 

are produced by separation from petroleum refining process 

streams or by subjecting hydrocarbons to high temperatures in 

the presence of steam. The ethylene production unit includes the 

separation of ethylene and/or propylene from associated streams 

such as a C4product, pyrolysis gasoline, and pyrolysis fuel oil. 

Ethylene production does not include the manufacture of SOCMI 

chemicals such as the production of butadiene from the C4stream 

and aromatics from pyrolysis gasoline.

Heat exchange system means any cooling tower system or 

once-through cooling water system (e.g., river or pond water). A 

heat exchange system can include an entire recirculating or 

once-through cooling system.
Page 81 of 197

Organic HAP means the compounds listed in Table 1 to 

subpart XX of this part.

Transfer rack means the collection of loading arms and 

loading hoses at a single loading rack that is used to fill tank 

trucks and/or railcars with organic HAP. Transfer rack includes 

the associated pumps, meters, shutoff valves, relief valves, and 

other piping and valves. Transfer rack does not include racks, 

arms, or hoses that contain organic HAP only as impurities; or 

racks, arms, or hoses that vapor balance during all loading 

operations.

Waste means any material resulting from industrial, 

commercial, mining, or agricultural operations, or from 

community activities, that is discarded or is being accumulated, 

stored, or physically, chemically, thermally, or biologically 

treated prior to being discarded, recycled, or discharged.

Waste stream means the waste generated by a particular 

process unit, product tank, or waste management unit. The 

characteristics of the waste stream (e.g., flow rate, HAP 

concentration, water content) are determined at the point of 

waste generation. Examples of a waste stream include process 

wastewater, product tank drawdown, sludge and slop oil removed 

from waste management units, and landfill leachate.

(3) Requirements. The owner or operator must control 

organic HAP emissions from each affected source emission point 
Page 82 of 197

by meeting the applicable requirements specified in Table 7 to 

this section. An owner or operator must perform the 

applicability assessment procedures and methods for process 

vents specified in §63.1104, except for paragraphs (d), (g), 

(h), (i), (j), (l)(1), and (n). An owner or operator must 

perform the applicability assessment procedures and methods for 

equipment leaks specified in §63.1107. General compliance, 

recordkeeping, and reporting requirements are specified in 

§§63.1108 through 63.1112. Minimization of emissions from 

startup, shutdown, and malfunctions must be addressed in the 

startup, shutdown, and malfunction plan required by §63.1111; 

the plan must also establish reporting and recordkeeping of such 

events. Procedures for approval of alternate means of emission 

limitations are specified in §63.1113.

Table 7 to §63.1103(e)—What Are My Requirements if I Own or 

Operate an Ethylene Production Existing or New Affected Source?

If you own or 

operate . . . And if . . . Then you must . . .

(a) A storage 

vessel (as 

defined in 

§63.1101) that 

stores liquid 

containing 

organic HAP

(1) The maximum true 

vapor pressure of total 

organic HAP is ≥3.4 

kilopascals but <76.6 

kilopascals; and the 

capacity of the vessel 

is ≥4 cubic meters but 

≤95 cubic meters

(i) Fill the vessel 

through a submerged pipe; 

or

(ii) Comply with the 

requirements for storage 

vessels with capacities 

≥95 cubic meters.

(b) A storage 

vessel (as 

defined in 

§63.1101) that 

(1) The maximum true 

vapor pressure of total 

organic HAP is ≥3.4 

kilopascals but <76.6 

(i) Comply with the 

requirements of subpart 

WW of this part; or

(ii) Reduce emissions of 
Page 83 of 197

stores liquid 

containing 

organic HAP

kilopascals; and the 

capacity of the vessel 

is ≥95 cubic meters

total organic HAP by 98 

weight-percent by venting 

emissions through a 

closed vent system to any 

combination of control 

devices and meet the 

requirements of 

§63.982(a)(1).

(c) A storage 

vessel (as 

defined in 

§63.1101) that 

stores liquid 

containing 

organic HAP

(1) The maximum true 

vapor pressure of total 

organic HAP is ≥76.6 

kilopascals

(i) Reduce emissions of 

total organic HAP by 98 

weight-percent by venting 

emissions through a 

closed vent system to any 

combination of control 

devices and meet the 

requirements of 

§63.982(a)(1).

(d) An 

ethylene 

process vent 

(as defined in 

paragraph 

(e)(2) of this 

section)

(1) The process vent is 

at an existing source 

and the vent stream has 

a flow rate ≥0.011 scmm 

and a total organic HAP 

concentration ≥50 parts 

per million by volume; 

or the process vent is 

at a new source and the 

vent stream has a flow 

rate ≥0.008 scmm and a 

total organic HAP 

concentration ≥30 parts 

per million by volume

(i) Reduce emissions of 

organic HAP by 98 weightpercent; or reduce 

organic HAP or TOC to a 

concentration of 20 parts 

per million by volume; 

whichever is less 

stringent, by venting 

emissions through a 

closed vent system to any 

combination of control 

devices and meet the 

requirements specified in 

§63.982(b) and (c)(2).

(e) A transfer 

rack (as 

defined in 

paragraph 

(e)(2) of this 

section)

(1) Materials loaded 

have a true vapor 

pressure of total 

organic HAP ≥3.4 

kilopascals and ≥76 

cubic meters per day 

(averaged over any 

consecutive 30-day 

period) of HAPcontaining material is 

loaded

(i) Reduce emissions of 

organic HAP by 98 weightpercent; or reduce 

organic HAP or TOC to a 

concentration of 20 parts 

per million by volume; 

whichever is less 

stringent, by venting 

emissions through a 

closed vent system to any 

combination of control 

devices as specified in 

§63.1105; or
Page 84 of 197

(ii) Install process 

piping designed to 

collect the HAPcontaining vapors 

displaced from tank 

trucks or railcars during 

loading and to route it 

to a process, a fuel gas 

system, or a vapor 

balance system, as 

specified in §63.1105.

(f) Equipment 

(as defined in 

§63.1101) that 

contains or 

contacts 

organic HAP

(1) The equipment 

contains or contacts ≥5 

weight-percent organic 

HAP; and the equipment 

is not in vacuum service

Comply with the 

requirements of subpart 

UU of this part.

(g) Processes 

that generate 

waste (as 

defined in 

paragraph 

(e)(2) of this 

section

(1) The waste stream 

contains any of the 

following HAP: benzene, 

cumene, ethyl benzene, 

hexane, naphthalene, 

styrene, toluene, oxylene, m-xylene, pxylene, or 1,3-butadiene

(i) Comply with the waste 

requirements of subpart 

XX of this part. For 

ethylene manufacturing 

process unit waste stream 

requirements, terms have 

the meanings specified in 

subpart XX.

(h) A heat 

exchange 

system (as 

defined in 

paragraph 

(e)(2) of this 

section)

Comply with the heat 

exchange system 

requirements of subpart 

XX of this part.

(f) Carbon black production applicability, definitions, and 

requirements —(1)Applicability —(i) Affected source. For the 

carbon black production source category (as defined in paragraph 

(f)(2) of this section), the affected source shall comprise each 

carbon black production process unit located at a major source, 

as defined in section 112(a) of the Act. The affected source for 
Page 85 of 197

the carbon black production source category includes all waste 

management units, maintenance wastewater, and equipment 

components that contain or contact HAP that are associated with 

the carbon black production process unit.

(ii) Compliance schedule. The compliance schedule for the 

carbon black production and acetylene decomposition carbon black 

production affected sources, as defined in paragraph (f)(1)(i) 

of this section, is specified in §63.1102.

(2) Definitions. Carbon black production means the 

production of carbon black by either the furnace, thermal, 

acetylene decomposition, or lampblack processes.

Carbon black production unit means the equipment assembled 

and connected by hard-piping or duct work to process raw 

materials to manufacture, store, and transport a carbon black 

product. For the purposes of this subpart, a carbon black 

production process unit includes reactors and associated 

operations; associated recovery devices; and any feed, 

intermediate and product storage vessels, product transfer 

racks, and connected ducts and piping. A carbon black production 

process unit includes pumps, compressors, agitators, pressure 

relief devices, sampling connection systems, open-ended valves 

or lines, valves, connectors, instrumentation systems, and 

control devices or systems.
Page 86 of 197

Dryer means a rotary-kiln dryer that is heated externally 

and is used to dry wet pellets in the wet pelletization process.

Main unit filter means the filter that separates the carbon 

black from the tailgas.

Process filter means the filter that separates the carbon 

black from the conveying air.

Purge filter means the filter that separates the carbon 

black from the dryer exhaust.

(3) Requirements. (i) Table 8 to this section specifies the 

carbon black production standards applicability for existing and 

new sources. Applicability assessment procedures and methods are 

specified in §63.1104. An owner or operator of an affected 

source is not required to perform applicability tests or other 

applicability assessment procedures if they opt to comply with 

the most stringent requirements for an applicable emission point 

pursuant to this subpart. General compliance, recordkeeping, and 

reporting requirements are specified in §§63.1108 through 

63.1112. Procedures for approval of alternative means of 

emission limitations are specified in §63.1113.

(ii) Pressure relief devices used to protect against 

overpressure in the case of catastrophic failure of your process 

filter system are exempt from the closed vent system inspection 

requirements of §63.983(b) and (c). Exempt pressure relief 
Page 87 of 197

devices must be designated and identified in your Notification 

of Compliance Status report.

Table 8 to §63.1103(f)—What Are My Requirements if I Own or 

Operate a Carbon Black Production Existing or New Affected 

Source?

If you own or 

operate . . . And if . . . Then you must . . .

(a) A carbon 

black 

production 

main unit 

filter 

process vent

(1) The HAP 

concentration of the 

emission stream is 

equal to or greater 

than 260 parts per 

million by volumea

(i) Reduce emissions of HAP by 

using a flare meeting the 

requirements of subpart SS of 

this part; or

(ii) Reduce emissions of total 

HAP by 98 weight-percent or to 

a concentration of 20 parts 

per million by volume, 

whichever is less stringent, 

by venting emissions through a 

closed vent system to any 

combination of control devices 

meeting the requirements of 

§63.982(a)(2).

aThe weight-percent organic HAP is determined according to the 

procedures specified in §63.1104(e).

(g) Cyanide chemicals manufacturing applicability, 

definitions, and requirements —(1) Applicability —(i) Affected 

source. For the cyanide chemicals manufacturing source category, 

the affected source shall include each cyanide chemicals 

manufacturing process unit located at a major source, as defined 

in section 112(a) of the Act. The affected source shall also 

include all waste management units, maintenance wastewater, and 

equipment (as defined in §63.1101) that contain or contact 
Page 88 of 197

cyanide chemicals that are associated with the cyanide chemicals 

manufacturing process unit.

(ii) Compliance schedule. The compliance schedule for the 

affected source, as defined in paragraph (f)(1)(i) of this 

section, is specified in §63.1102.

(2) Definitions. Andrussow process unit means a process 

unit that produces hydrogen cyanide by reacting methane and 

ammonia in the presence of oxygen over a platinum/rhodium 

catalyst. An Andrussow process unit begins at the point at which 

the raw materials are stored and ends at the point at which 

refined hydrogen cyanide is reacted as a raw material in a 

downstream process, burned on-site as fuel in a boiler or 

industrial furnace, or is shipped offsite. If raw hydrogen 

cyanide from the reactor is reacted with sodium hydroxide to 

form sodium cyanide prior to the refining process, the unit 

operation where sodium cyanide is formed is considered to be 

part of the Andrussow process unit.

Blausaure Methane Anlage (BMA) process unit means a process 

unit that produces hydrogen cyanide by reacting methane and 

ammonia over a platinum catalyst. A BMA process unit begins at 

the point at which raw materials are stored and ends at the 

point at which refined hydrogen cyanide is reacted as a raw 

material in a downstream process, burned on-site as a fuel in a 

boiler or industrial furnace, or is shipped offsite. If raw 
Page 89 of 197

hydrogen cyanide from the reactor is reacted with sodium 

hydroxide to form sodium cyanide prior to the refining process, 

the unit operation where sodium cyanide is formed is considered 

to be part of the BMA process unit.

Byproduct means a chemical that is produced coincidentally 

during the production of another chemical.

Cyanide chemicals manufacturing process unit or CCMPU means 

the equipment assembled and connected by hard-piping or duct 

work to process raw materials to manufacture, store, and 

transport a cyanide chemicals product. A cyanide chemicals 

manufacturing process unit shall be limited to any one of the 

following: an Andrussow process unit, a BMA process unit, a 

sodium cyanide process unit, or a Sohio hydrogen cyanide process

unit. For the purpose of this subpart, a cyanide chemicals 

manufacturing process unit includes reactors and associated unit 

operations; associated recovery devices; and any feed, 

intermediate and product storage vessels, product transfer 

racks, and connected ducts and piping. A cyanide chemicals 

manufacturing process unit includes pumps, compressors, 

agitators, pressure relief devices, sampling connection systems, 

open-ended valves or lines, valves, connectors, instrumentation 

systems, and control devices or systems.

Cyanide chemicals product means either hydrogen cyanide, 

potassium cyanide, or sodium cyanide which is manufactured as 
Page 90 of 197

the intended product of a CCMPU or a byproduct of the Sohio 

process. Other hydrogen cyanide, potassium cyanide, or sodium 

cyanide byproducts, impurities, wastes, and trace contaminants 

are not considered to be cyanide chemicals products.

Dry-end process vent means a process vent originating from 

the drum filter or any other unit operation in the dry end of a 

sodium cyanide manufacturing process unit. For the purposes of 

this subpart, the dry end of the sodium cyanide process unit 

begins in the unit operation where water is removed from the 

sodium cyanide, usually in the drum filter, and ends when the 

sodium cyanide is used as a raw material in a downstream 

process, or is shipped offsite.

Organic HAP means, for purposes of applicability of the 

requirements of this subpart, all hydrogen cyanide compounds.

Raw hydrogen cyanide means hydrogen cyanide that has not 

been through the refining process. Raw hydrogen cyanide usually 

has a hydrogen cyanide concentration less than 10 percent.

Refined hydrogen cyanide means hydrogen cyanide that has 

been through the refining process. Refined hydrogen cyanide 

usually has a hydrogen cyanide concentration greater than 99 

percent.

Refining process means the collection of equipment in a 

cyanide chemicals manufacturing processing unit used to 

concentrate raw hydrogen cyanide from a concentration around 10 
Page 91 of 197

percent or less to refined hydrogen cyanide at a concentration 

greater than 99 percent.

Sodium cyanide process unit means a process unit that 

produces sodium cyanide by reacting hydrogen cyanide and sodium 

hydroxide via the neutralization, or wet, process. A sodium 

cyanide process unit begins at the unit operation where refined 

hydrogen cyanide is reacted with sodium hydroxide and ends at 

the point the solid sodium cyanide product is shipped offsite or 

used as a raw material in a downstream process. If raw hydrogen 

cyanide is reacted with sodium hydroxide to form sodium cyanide 

prior to the hydrogen cyanide refining process, the unit 

operation where sodium cyanide is formed is not considered to be 

part of the sodium cyanide process unit. For this type of 

process, the sodium cyanide process unit begins at the point 

that the aqueous sodium cyanide stream leaves the unit operation 

where the sodium cyanide is formed. In situations where 

potassium hydroxide is substituted for sodium hydroxide to 

produce potassium cyanide, the process unit is still considered 

a sodium cyanide process unit.

Sohio hydrogen cyanide process unit means a process unit 

that produces hydrogen cyanide as a byproduct of the 

acrylonitrile production process when acrylonitrile is 

manufactured using the Sohio process. A Sohio hydrogen cyanide 

process unit begins at the point the hydrogen cyanide leaves the 
Page 92 of 197

unit operation where the hydrogen cyanide is separated from the 

acrylonitrile (usually referred to as the heads column). The 

Sohio hydrogen cyanide process unit ends at the point refined 

hydrogen cyanide is reacted as a raw material in a downstream 

process, burned on-site as fuel in a boiler or industrial 

furnace, or is shipped offsite. If raw hydrogen cyanide is 

reacted with sodium hydroxide to form sodium cyanide prior to 

the refining process, the unit operation where sodium cyanide is 

formed is considered to be part of the Sohio hydrogen cyanide 

process unit.

Wet-end process vent means a process vent originating from 

the reactor, crystallizer, or any other unit operation in the 

wet end of the sodium cyanide process unit. For the purposes of 

this subpart, the wet end of the sodium cyanide process unit 

begins at the point at which the raw materials are stored and 

ends just prior to the unit operation where water is removed 

from the sodium cyanide, usually in the drum filter. Wastewater 

streams containing discarded wastewater from the sodium cyanide 

production process are not considered to be part of the wet-end 

sodium cyanide process. Discarded wastewater that is no longer 

used in the production process is considered to be process 

and/or maintenance wastewater. Vents from process and 

maintenance wastewater operations are not wet-end process vents.
Page 93 of 197

(3) Requirements. Table 9 to this section specifies the 

cyanide chemicals manufacturing standards applicable to existing 

and new sources. Applicability assessment procedures and methods 

are specified in §63.1104. An owner or operator of an affected 

source is not required to perform applicability tests or other 

applicability assessment procedures if they opt to comply with 

the most stringent requirements for an applicable emission point 

pursuant to this subpart. General compliance, recordkeeping, and 

reporting requirements are specified in §§63.1108 through 

63.1112. Procedures for approval of alternative means of 

emission limitations are specified in §63.1113.

(4) Determination of overall HAP emission reduction for a 

process unit. (i) The owner or operator shall determine the 

overall HAP emission reduction for process vents in a process 

unit using Equation 1 of this section. The overall organic HAP 

emission reduction shall be determined for all process vents in 

the process unit.

Where:

REDCCMPU = Overall HAP emission reduction for the group of 

process vents in the CCMPU, percent.
Page 94 of 197

Eunc,i = Uncontrolled HAP emissions from process vent i that 

is controlled by using a combustion, recovery, or recapture 

device, kg/yr.

n = Number of process vents in the process unit that are 

controlled by using a combustion, recovery, or recapture device.

Ri = Control efficiency of the combustion, recovery, or 

recapture device used to control HAP emissions from vent i, 

determined in accordance with paragraph (g)(4)(ii) of this 

section.

Eunc,j = Uncontrolled HAP emissions from process vent j that 

is not controlled by using a combustion, recovery, or recapture 

device, kg/yr.

m = Number of process vents in the process unit that are 

not controlled by using a combustion, recovery, or recapture 

device.

(ii) The control efficiency shall be assigned as specified 

in paragraph (g)(4)(ii) (A) or (B) of this section.

(A) If the process vent is controlled using a flare in 

accordance with the provisions of §63.987, or a combustion 

device in accordance with the provisions of §63.988(b)(2), for 

which a performance test has not been conducted, the control 

efficiency shall be assumed to be 98 weight-percent. For 

hydrogen-fueled flares, an owner or operator may use a control 

efficiency greater than 98 weight-percent if they can provide 
Page 95 of 197

engineering calculations and supporting information 

demonstrating a greater control efficiency.

(B) If the process vent is controlled using a combustion, 

recovery, or recapture device for which a performance test has 

been conducted in accordance with the provisions of §63.997, the 

control efficiency shall be the efficiency determined by the 

performance test.

(5) Source category specific modifications to testing 

procedures. (i) When identifying equipment subject to any 

equipment leak requirements, an owner or operator is allowed to 

designate specific components of such equipment as never being 

safe to monitor with their Notification of Compliance Status 

report and periodic compliance reports. In order for an owner or 

operator to designate such equipment as never being safe to 

monitor, they must certify that monitoring such equipment at any 

time the CCMPU is operating is never safe (e.g., monitoring this 

equipment would present an unreasonable hazard or preclude 

testing personnel from meeting emergency evacuation 

requirements). If it is demonstrated to the Administrator's 

satisfaction that equipment designated by the owner or operator 

as never safe to monitor is appropriately designated, an owner 

or operator will not be required to monitor such equipment.

(ii) For process vent hydrogen cyanide emissions that are 

vented to a control device other than a flare during startup, 
Page 96 of 197

shutdown, and malfunction, the design evaluation must include 

documentation that the control device being used achieves the 

required control efficiency during the reasonably expected 

maximum flow rate and emission rate during startup, shutdown, 

and malfunction.

(iii) If a facility controls process vent emissions during 

startup, shutdown, and malfunction by using a flare, an owner or 

operator is not required to perform flow rate and heat content 

testing as specified in §63.987(b)(3)(ii) and (iii). In lieu of 

performing flow rate and heat content testing, an owner or 

operator is required to submit engineering calculations that 

substantiate that a flare meets the applicable heat content or 

flow rates, or provide data from a compliance assessment that 

the flare is in compliance under worst case conditions (e.g., 

maximum operating conditions).

(iv) If flare velocity and net heating value testing, as 

specified in §63.11(b)(6)(ii) and (b)(7)(i), would create an 

unreasonable hazard for testing personnel, an owner or operator 

is allowed to submit engineering calculations that substantiate 

vent stream velocity and heat content of a flare in lieu of test 

data. These calculations are required to be submitted with the 

facilities' compliance test notification report for approval by 

the Administrator.
Page 97 of 197

(v) The data from any performance test method used to 

measure HCN concentrations must be validated using EPA Method 

301 (40 CFR part 63, appendix A).

Table 9 to §63.1103(g)—What Are My Requirements if I Own or 

Operate a Cyanide Chemicals Manufacturing Existing or New 

Affected Source?

If you own or operate 

. . . And if . . . Then you must . . .

(a) A storage vessel (1) The storage 

vessel contains 

refined hydrogen 

cyanide

(i) Reduce emissions of 

hydrogen cyanide by 

using a flare meeting 

the requirements of 

§63.982(b); or

(ii) Reduce emissions of 

hydrogen cyanide by 98 

weight-percent, or to a 

concentration of 20 

parts per million by 

volume, by venting 

emissions through a 

closed vent system to 

any combination of 

control devices meeting 

the requirements of 

§63.982(c)(1) or (d).

(b) A process vent 

from a continuous 

unit operations in an 

Andrussow, BMA, or 

Sohio hydrogen 

cyanide process unit

(i) Reduce overall 

annual emissions of 

total HAP from the 

collection of process 

vents from continuous 

unit operations in the 

process by 98 weightpercent in accordance 

with paragraph (g)(4) of 

this section. Any 

control device used to 

reduce emissions from 

one or more process 

vents from continuous 

unit operations in the 

process unit must meet 
Page 98 of 197

the applicable 

requirements specified 

in §63.982(a)(2); or

(ii) Reduce emissions of 

total HAP from each 

process vent from a 

continuous unit 

operation in the process 

unit by using a flare 

meeting the requirements 

specified in §63.982(b); 

or

(iii) Reduce emissions 

of total HAP from each 

process vent from a 

continuous unit 

operation in the process 

unit by 98 weightpercent or to a 

concentration of 20 

parts per million by 

volume, by venting 

emissions through a 

closed vent system to 

any combination of 

control devices meeting 

the requirements of 

§63.982(c)(2) or (d).

(c) One or more wet 

end process vents, as 

defined in paragraph 

(g)(2) of this 

section, in a sodium 

cyanide process unit

(i) Reduce overall 

annual emissions of 

total HAP from the 

collection of process 

vents from continuous 

unit operations in the 

process unit by 98 

weight-percent in 

accordance with 

paragraph (g)(4) of this 

section. Any control 

device used to reduce 

emissions from one or 

more process vents from 

continuous unit 

operations in the 

process unit must meet 
Page 99 of 197

the applicable 

requirements of 

§63.982(a)(2); or

(ii) Reduce emissions of 

total HAP from each wetend process vent in the 

process unit by using a 

flare meeting the 

requirements of 

§63.982(b); or

(iii) Reduce emissions 

of total HAP from each 

wet-end process vent by 

98 weight-percent, or to 

a concentration of 20 

parts per million by 

volume, by venting 

emissions through a 

closed vent system and 

any combination of

control devices meeting 

the requirements of 

§63.982(c)(2) or (d).

(d) One or more dry 

end process vents, as 

defined in paragraph 

(g)(2) of this 

section, in a sodium 

cyanide process unit

(i) Reduce overall 

annual emissions of 

sodium cyanide from the 

collection of process 

vents from continuous 

unit operations in the 

process unit by 98 

weight-percent in 

accordance with 

paragraph (g)(4) of this 

section. Any control 

device used to reduce 

emissions from one or 

more process vents from 

continuous unit 

operations in the 

process unit must meet 

the applicable 

requirements of 

§63.982(a)(2); or

(ii) Reduce emissions of 
Page 100 of 197

sodium cyanide from each 

dry-end process vent in 

the process unit by 98 

weight-percent by 

venting emissions 

through a closed vent 

system to any 

combination of control 

devices meeting the 

requirements of 

§63.982(c)(2) or (d).

(e) A transfer rack (1) The transfer 

rack is used to 

load refined 

hydrogen cyanide 

into tank trucks 

and/or rail cars

(i) Reduce emissions of 

hydrogen cyanide by 

using a flare meeting 

the requirements of 

§63.982(b); or

(ii) Reduce emissions of 

hydrogen cyanide by 98 

weight-percent, or to a 

concentration of 20 

parts per million by 

volume, whichever is 

less stringent, by 

venting emissions 

through a closed vent 

system to any 

combination of control 

devices meeting the 

requirements specified 

in §63.982(c)(1), 

(c)(2), or (d).

(f) A new cyanide 

chemicals 

manufacturing process 

unit that generates 

process wastewater

(1) The process 

wastewater is from 

HCN purification, 

ammonia 

purification, or 

flare blowdown

(i) Achieve a combined 

removal and control of 

HAP from wastewater of 

93 weight-percent.

(g) A cyanide 

chemicals 

manufacturing process 

unit that generates 

maintenance 

wastewater

(1) The maintenance 

wastewater contains 

hydrogen cyanide or 

acetonitrile

(i) Comply with the 

requirements of 

§63.1106(b).

(h) An item of (1) The item of (i) Comply with the 
Page 101 of 197

equipment listed in 

§63.1106(c)(1) that 

transports or 

contains wastewater 

liquid streams from a 

cyanide chemicals 

manufacturing process 

unit

equipment meets the 

criteria specified 

in §63.1106(c)(1) 

through (3) and 

either (c)(4)(i) or 

(ii)

requirements in Table 35 

of subpart G of this 

part.

(i) Equipment, as 

defined under 

§63.1101

(1) The equipment 

contains or 

contacts hydrogen 

cyanide and 

operates equal to 

or greater then 300 

hours per year

(i) Comply with either 

subpart TT or UU of this 

part, and paragraph 

(g)(5) of this section, 

with the exception that 

open-ended lines that 

contain or contact 

hydrogen cyanide are 

exempt from any 

requirements to install 

a cap, plug, blind 

flange, or second valve 

to be capped.

(h) Spandex production applicability, definitions, and 

requirements —(1) Applicability—(i) Affected source. For the 

spandex production (as defined in paragraph (h)(2) of this 

section) source category, the affected source shall comprise all 

emission points listed in paragraphs (h)(1)(i)(A) through (C) of 

this section that are associated with a spandex production 

process unit located at a major source, as defined in section 

112(a) of the Act.

(A) All process vents (as defined in §63.1101).

(B) All storage vessels (as defined in §63.1101) that store 

liquids containing organic HAP.
Page 102 of 197

(C) All spandex fiber spinning lines using a spinning

solution having organic HAP.

(ii) Exceptions. The emission points listed in paragraphs 

(h)(1)(ii)(A) and (B) of this section are in the spandex 

production source category but are not subject to the 

requirements of paragraph (h)(3) of this section.

(A) Equipment that is located within a spandex production 

process unit that is subject to this subpart but does not 

contain organic HAP.

(B) Vessels storing organic liquids that contain organic 

HAP as impurities.

(C) Emission points listed in paragraphs (h)(1)(i)(A) 

through (C) of this section that are associated with a dry 

spinning spandex production process unit.

(iii) Compliance schedule. The compliance schedule for 

affected sources, as defined in paragraph (h)(1)(i) of this 

section, is specified in paragraph (b) of §63.1102.

(2) Definitions. Dry spinning means a fiber-forming process 

where prepolymer is reacted with a chain-extender to generate 

polymer prior to spinning; the polymer is dissolved in a solvent 

and is extruded into a cell of hot gases for fiber formation.

Fiber spinning line means the group of equipment and 

process vents associated with spandex fiber spinning operations. 

The fiber spinning line includes the blending and dissolving 
Page 103 of 197

tanks, spinning solution filters, spinning units, spin bath 

tanks, and the equipment used downstream of the spin bath to 

wash, draw, or dry on the wet belt the spun fiber.

Reaction spinning means a fiber-forming process where 

prepolymer is extruded into a spin bath that contains a chainextender; the chemical reaction to make polymer occurs 

simultaneously with extrusion/fiber formation.

Spandex or spandex fiber means a manufactured synthetic 

fiber in which the fiber-forming substance is a long-chain 

polymer comprised of at least 85 percent by mass of a segmented 

polyurethane.

Spandex production means the production of synthetic 

spandex fibers.

Spandex production process unit means a process unit that 

is specifically used for the production of synthetic spandex 

fibers.

(3) Requirements. Table 10 to this section specifies the

spandex production source category requirements for new and 

existing sources. An owner or operator must perform the 

applicability assessment procedures and methods for process 

vents specified in §63.1104, excluding paragraphs (b)(1), (d), 

(g), (h), (i), (j), (l)(1), and (n). General compliance, 

recordkeeping, and reporting requirements are specified in 

§§63.1108 through 63.1112. Minimization of emissions from 
Page 104 of 197

startup, shutdown, and malfunctions must be addressed in the 

startup, shutdown, and malfunction plan required by §63.1111; 

the plan must also establish reporting and recordkeeping of such 

events. Procedures for approval of alternate means of emission 

limitations are specified in §63.1113.

Table 10 to §63.1103(h)—What Are My Requirements if I Own or 

Operate a Spandex Production Process Unit at a New or Existing 

Source?

If you own or 

operate . . . And if . . . Then you must . . .

(a) A storage 

vessel (as 

defined in 

§63.1101) that 

stores liquid 

containing 

organic HAP

(1) The maximum true 

vapor pressure of 

the organic HAP is ≥ 

3.4 kilopascals; and 

the capacity of the 

vessel is ≥ 47 cubic 

meters

(i) Comply with the 

requirements of subpart WW 

of this part; or

(ii) Reduce emissions of 

organic HAP by 95 weightpercent by venting emissions 

in through a closed vent 

system to any combination of 

control devices meeting the 

requirements of subpart SS 

of this part, as specified 

in §63.982(a)(1).

(b) A process 

vent

Reduce emissions of organic 

HAP by 95 weight-percent, or 

reduce organic HAP or TOC to 

a concentration of 20 parts 

per million by volume, 

whichever is less stringent, 

by venting emissions through 

a closed vent system to any 

combination of control 

devices meeting the 

requirements of 

§63.982(a)(2).

(c) A fiber 

spinning line

Operate the fiber spinning 

line such that emissions are 

captured and vented through 

a line closed vent system to 

a control device that 
Page 105 of 197

complies with the 

requirements of 

§63.982(a)(2). If a control 

device other than a flare is 

used, HAP emissions must be 

reduced by 95 weightpercent, or total organic 

HAP or TOC must be reduced 

to a concentration of 20 

parts per million by volume, 

whichever is less stringent.

§63.1104 Process vents from continuous unit operations: 

applicability assessment procedures and methods.

(a) General. The provisions of this section provide 

calculation and measurement methods for criteria that are 

required by §63.1103 to be used to determine applicability of 

the control requirements for process vents from continuous unit 

operations. The owner or operator of a process vent is not 

required to determine the criteria specified for a process vent 

that is being controlled (including control by flare) in 

accordance with the applicable weight-percent, TOC 

concentration, or organic HAP concentration requirement in 

§63.1103.

(b) Sampling sites. For purposes of determining process 

vent applicability criteria, the sampling site shall be located 

as specified in (b)(1) through (4) of this section, as 

applicable.

(1) Sampling site location if TRE determination is 

required. If the applicability criteria specified in the 
Page 106 of 197

applicable table of §63.1103 includes a TRE index value, the 

sampling site for determining volumetric flow rate, regulated 

organic HAP concentration, total organic HAP or TOC 

concentration, heating value, and TRE index value, shall be 

after the final recovery device (if any recovery devices are 

present) but prior to the inlet of any control device that is 

present, and prior to release to the atmosphere.

(2) Sampling site location if TRE determination is not 

required. If the applicability criteria specified in the 

applicable table of §63.1103 does not include a TRE index value, 

the sampling site for determining volumetric flow rate, 

regulated organic HAP concentration, total organic HAP or TOC 

concentration, and any other specified parameter shall be at the 

exit from the unit operation before any control device.

(3) Sampling site selection method. Method 1 or 1A of 40 

CFR part 60, appendix A, as appropriate, shall be used for 

selection of the sampling site. No traverse site selection 

method is needed for process vents smaller than 0.10 meter (0.33 

foot) in nominal inside diameter.

(4) Sampling site when a halogen reduction device is used 

prior to a combustion device. An owner or operator using a 

scrubber to reduce the process vent halogen atom mass emission 

rate to less than 0.45 kilograms per hour (0.99 pound per hour) 

prior to a combustion control device in compliance with §63.1103 
Page 107 of 197

(as appropriate) shall determine the halogen atom mass emission 

rate prior to the combustion device according to the procedures 

in paragraph (i) of this section.

(c) Applicability assessment requirement. The TOC or 

organic HAP concentrations, process vent volumetric flow rates, 

process vent heating values, process vent TOC or organic HAP 

emission rates, halogenated process vent determinations, process 

vent TRE index values, and engineering assessments for process 

vent control applicability assessment requirements are to be 

determined during maximum representative operating conditions 

for the process, except as provided in paragraph (d) of this 

section, or unless the Administrator specifies or approves 

alternate operating conditions. For acrylic and modacrylic fiber 

production affected sources and polycarbonate production 

affected sources, operations during periods of malfunction shall 

not constitute representative conditions for the purpose of an 

applicability test. For all other affected sources, Ooperations 

during periods of startup, shutdown, and malfunction shall not 

constitute representative conditions for the purpose of an 

applicability test.

(d) Exceptions. For a process vent stream that consists of 

at least one process vent from a batch unit operation manifolded 

with at least one process vent from a continuous unit operation, 

the TRE shall be calculated during periods when one or more 
Page 108 of 197

batch emission episodes are occurring that result in the highest 

organic HAP emission rate (in the combined vent stream that is 

being routed to the recovery device) that is achievable during 

the 6-month period that begins 3 months before and ends 3 months 

after the TRE calculation, without causing any of the situations 

described in paragraphs (d)(1) through (3) to occur.

(1) Causing damage to equipment;

(2) Necessitating that the owner or operator make product 

that does not meet an existing specification for sale to a 

customer; or

(3) Necessitating that the owner or operator make product 

in excess of demand.

(e) TOC or Organic HAP concentration. The TOC or organic 

HAP concentrations shall be determined based on paragraph 

(e)(1), (e)(2), or (k) of this section, or any other method or 

data that have been validated according to the protocol in 

Method 301 of appendix A of 40 CFR part 63. For concentrations 

needed for comparison with the appropriate control applicability 

concentrations specified in §63.1103, TOC or organic HAP 

concentration shall be determined based on paragraph (e)(1), 

(e)(2), or (k) of this section or any other method or data that 

has been validated according to the protocol in method 301 of 

appendix A of this part. The owner or operator shall record the 
Page 109 of 197

TOC or organic HAP concentration as specified in paragraph 

(l)(3) of this section.

(1) Method 18. The procedures specified in paragraph 

(e)(1)(i) and (ii) of this section shall be used to calculate 

parts per million by volume concentration using method 18 of 40 

CFR part 60, appendix A:

(i) The minimum sampling time for each run shall be 1 hour 

in which either an integrated sample or four grab samples shall 

be taken. If grab sampling is used, then the samples shall be 

taken at approximately equal intervals in time, such as 15-

minute intervals during the run.

(ii) The concentration of either TOC (minus methane and 

ethane) or regulated organic HAP emissions shall be calculated 

according to paragraph (e)(1)(ii)(A) or (B) of this section, as 

applicable.

(A) The TOC concentration (CTOC) is the sum of the 

concentrations of the individual components and shall be 

computed for each run using Equation 1:

Where:

CTOC = Concentration of TOC (minus methane and ethane), dry 

basis, parts per million by volume.
Page 110 of 197

Cji = Concentration of sample component j of the sample i, 

dry basis, parts per million by volume.

n = Number of components in the sample.

x = Number of samples in the sample run.

(B) The regulated organic HAP or total organic HAP 

concentration (CHAP) shall be computed according to Equation 1 in 

paragraph (e)(1)(ii)(A) of this section except that only the 

regulated or total organic HAP species shall be summed, as 

appropriate.

(2) Method 25A. The procedures specified in paragraphs 

(e)(2)(i) through (vi) of this section shall be used to 

calculate parts per million by volume concentration using Method 

25A of 40 CFR part 60, appendix A.

(i) Method 25A of 40 CFR part 60, appendix A shall be used 

only if a single organic HAP compound comprises greater than 50 

percent of total organic HAP or TOC, by volume, in the process 

vent.

(ii) The process vent composition may be determined by 

either process knowledge, test data collected using an 

appropriate Environmental Protection Agency method or a method 

or data validated according to the protocol in Method 301 of 

appendix A of part 63. Examples of information that could 

constitute process knowledge include calculations based on 

material balances, process stoichiometry, or previous test 
Page 111 of 197

results provided the results are still relevant to the current 

process vent conditions.

(iii) The organic compound used as the calibration gas for 

Method 25A of 40 CFR part 60, appendix A shall be the single 

organic HAP compound present at greater than 50 percent of the 

total organic HAP or TOC by volume.

(iv) The span value for Method 25A of 40 CFR part 60, 

appendix A shall be equal to the appropriate control 

applicability concentration value specified in the applicable 

table(s) presented in §63.1103 of this subpart.

(v) Use of Method 25A of 40 CFR part 60, appendix A is 

acceptable if the response from the high-level calibration gas 

is at least 20 times the standard deviation of the response from 

the zero calibration gas when the instrument is zeroed on the 

most sensitive scale.

(vi) The owner or operator shall demonstrate that the 

concentration of TOC including methane and ethane measured by 

Method 25A of 40 CFR part 60, appendix A is below one-half the 

appropriate control applicability concentration specified in the 

applicable table for a subject source category in §63.1103 in 

order to qualify for a low organic HAP concentration exclusion.

(f) Volumetric flow rate. The process vent volumetric flow 

rate (QS), in standard cubic meters per minute at 20 °C, shall be 
Page 112 of 197

determined as specified in paragraph (f)(1) or (2) of this 

section and shall be recorded as specified in §63.1109(d).

(1) Use Method 2, 2A, 2C, 2D, 2F, or 2G of 40 CFR part 60, 

appendix A, as appropriate. If the process vent tested passes 

through a final steam jet ejector and is not condensed, the 

stream volumetric flow shall be corrected to 2.3 percent 

moisture; or

(2) The engineering assessment procedures in paragraph (k) 

of this section can be used for determining volumetric flow 

rates.

(g) Heating value. The net heating value shall be 

determined as specified in paragraphs (g)(1) and (2) of this 

section, or by using the engineering assessment procedures in 

paragraph (k) of this section.

(1) The net heating value of the process vent shall be 

calculated using Equation 2:

Where:

HT = Net heating value of the sample, megaJoule per standard 

cubic meter, where the net enthalpy per mole of process vent is 

based on combustion at 25°C and 760 millimeters of mercury, but 

the standard temperature for determining the volume 
Page 113 of 197

corresponding to 1 mole is 20°C, as in the definition of 

Qs(process vent volumetric flow rate).

K1 = Constant, 1.740 × 10−7(parts per million)−1(gram-mole 

per standard cubic meter) (megaJoule per kilocalorie), where 

standard temperature for (gram-mole per standard cubic meter) is 

20°C.

Dj = Concentration on a wet basis of compound j in parts per 

million, as measured by procedures indicated in paragraph (e)(2) 

of this section. For process vents that pass through a final 

steam jet and are not condensed, the moisture is assumed to be 

2.3 percent by volume.

Hj = Net heat of combustion of compound j, kilocalorie per 

gram-mole, based on combustion at 25°C and 760 millimeters 

mercury.

(2) The molar composition of the process vent (Dj) shall be 

determined using the methods specified in paragraphs (g)(2)(i) 

through (iii) of this section:

(i) Method 18 of 40 CFR part 60, appendix A to measure the 

concentration of each organic compound.

(ii) American Society for Testing and Materials D1946–90 to 

measure the concentration of carbon monoxide and hydrogen.

(iii) Method 4 of 40 CFR part 60, appendix A to measure the 

moisture content of the stack gas.
Page 114 of 197

(h) TOC or Organic HAP emission rate. The emission rate of 

TOC (minus methane and ethane) (ETOC) and the emission rate of 

the regulated organic HAP or total organic HAP (EHAP) in the 

process vent, as required by the TRE index value equation 

specified in paragraph (j) of this section, shall be calculated 

using Equation 3:

Where:

E = Emission rate of TOC (minus methane and ethane) (ETOC) 

or emission rate of the regulated organic HAP or total organic 

HAP (EHAP) in the sample, kilograms per hour.

K2 = Constant, 2.494 × 10−6(parts per million)−1(gram-mole 

per standard cubic meter) (kilogram/gram) (minutes/hour), where 

standard temperature for (gram-mole per standard cubic meter) is 

20°C.

n = Number of components in the sample.

Cj = Concentration on a dry basis of organic compound j in 

parts per million as measured by method 18 of 40 CFR part 60, 

appendix A as indicated in paragraph (e) of this section. If the 

TOC emission rate is being calculated, Cj includes all organic 

compounds measured minus methane and ethane; if the total 

organic HAP emission rate is being calculated, only organic HAP 

compounds are included; if the regulated organic HAP emission 
Page 115 of 197

rate is being calculated, only regulated organic HAP compounds 

are included.

Mj = Molecular weight of organic compound j, gram/gram-mole.

Qs = Process vent flow rate, dry standard cubic meter per 

minute, at a temperature of 20°C.

(i) Halogenated process vent determination. In order to 

determine whether a process vent is halogenated, the mass 

emission rate of halogen atoms contained in organic compounds 

shall be calculated according to the procedures specified in 

paragraphs (i)(1) and (2) of this section. A process vent is 

considered halogenated if the mass emission rate of halogen 

atoms contained in the organic compounds is equal to or greater 

than 0.45 kilograms per hour.

(1) The process vent concentration of each organic compound 

containing halogen atoms (parts per million by volume, by 

compound) shall be determined based on one of the procedures 

specified in paragraphs (i)(1)(i) through (iv) of this section:

(i) Process knowledge that no halogen or hydrogen halides 

are present in the process vent, or

(ii) Applicable engineering assessment as discussed in 

paragraph (k) of this section, or

(iii) Concentration of organic compounds containing 

halogens or hydrogen halides as measured by Method 26 or 26A of 

40 CFR part 60, appendix A, or
Page 116 of 197

(iv) Any other method or data that have been validated 

according to the applicable procedures in method 301 of appendix 

A of this part.

(2) Equation 4 shall be used to calculate the mass emission 

rate of halogen atoms:

Where:

E = Mass of halogen atoms, dry basis, kilogram per hour,

K2 = Constant, 2.494 × 10−6(parts per million)−1(kilogrammole per standard cubic meter) (minute per hour), where standard 

temperature is 20°C.

Q = Flow rate of gas stream, dry standard cubic meters per 

minute, determined according to paragraph (f)(1) or (f)(2) of 

this section.

n = Number of halogenated compounds j in the gas stream.

j = Halogenated compound j in the gas stream.

m = Number of different halogens i in each compound j of 

the gas stream.

i = Halogen atom i in compound j of the gas stream.

Cj = Concentration of halogenated compound j in the gas 

stream, dry basis, parts per million by volume.

Lji = Number of atoms of halogen i in compound j of the gas 

stream.
Page 117 of 197

Mji = Molecular weight of halogen atom i in compound j of 

the gas stream, kilogram per kilogram-mole.

(j) TRE index value. The owner or operator shall calculate 

the TRE index value of the process vent using the equations and 

procedures in this paragraph, as applicable, and shall maintain 

records specified in paragraph (l)(1) or (m)(2) of this section, 

as applicable.

(1) TRE index value equation. The equation for calculating 

the TRE index value is Equation 5:

TRE = 1/EHAP*[A+B(QS)+ C(HT)+ D(ETOC)] [Eq. 5]

Where:

TRE = TRE index value.

A, B, C, D = Coefficients presented in table 1 of this 

section.

EHAP = Emission rate of total organic HAP, kilograms per 

hour, as calculated according to paragraph (h) or (k) of this 

section.

QS = process vent flow rate, standard cubic meters per 

minute, at a standard temperature of 20 °C, as calculated 

according to paragraph (f) or (k) of this section.

HT = process vent net heating value, megaJoules per standard 

cubic meter, as calculated according to paragraph (g) or (k) of 

this section.
Page 118 of 197

ETOC = Emission rate of TOC (minus methane and ethane), 

kilograms per hour, as calculated according to paragraph (h) or 

(k) of this section.

Table 1 of §63.1104(j)(1)—Coefficients for Total Resource 

Effectivenessa

Existin

g or 

new?

Halogenate

d vent 

stream?

Control 

device 

basis

Values of coefficients

A B C D

Existin

g

Yes Thermal 

Incinerato

r and 

Scrubber

3.995 5.200×10

−2

−1.769×10

−3

9.700×10−4

No Flare 1.935 3.660×10

−1

−7.687×10

−3

−7.333×10

−4

Thermal 

Incinerato

r 0 

Percent 

Recovery

1.492 6.267×10

−2

3.177×10−2 −1.159×10

−3

Thermal 

Incinerato

r 70 

Percent 

Recovery

2.519 1.183×10

−2

1.300×10−2 4.790×10−2

New Yes Thermal 

Incinerato

r and 

Scrubber

1.0895 1.417×10

−2

−4.822×10

−4

2.645×10−4

No Flare 5.276×10

−1

9.98×10−2 −2.096×10

−3

2.000×10−4

Therman 

Incinerato

r 0 

Percent 

Recovery

4.068×10

−1

1.71×10−2 8.664×10−3 −3.162×10

−4

Thermal 

Incinerato

r 70 

6.868×10

−1

3.209×10

−3

3.546×10−3 1.306×10−2
Page 119 of 197

Percent 

Recovery

aUse according to procedures outlined in this section.

MJ/scm = Mega Joules per standard cubic meter.

scm/min = Standard cubic meters per minute.

(2) Nonhalogenated process vents. The owner or operator of 

a nonhalogenated process vent shall calculate the TRE index 

value by using the equation and appropriate nonhalogenated 

process vent parameters in table 1 of this section for process 

vents at existing and new sources. The lowest TRE index value is 

to be selected.

(3) Halogenated process vents. The owner or operator of a 

halogenated process vent stream, as determined according to 

procedures specified in paragraph (i) or (k) of this section, 

shall calculate the TRE index value using the appropriate 

halogenated process vent parameters in table 1 of this section 

for existing and new sources.

(k) Engineering assessment. For purposes of TRE index value 

determinations, engineering assessments may be used to determine 

process vent flow rate, net heating value, TOC emission rate, 

and total organic HAP emission rate for the representative 

operating condition expected to yield the lowest TRE index 

value. Engineering assessments shall meet the requirements of 

paragraphs (k)(1) through (4) of this section. If a process vent 
Page 120 of 197

flow rate or process vent organic HAP or TOC concentration is 

being determined for comparison with the applicable flow rate or 

concentration value presented in the tables in §63.1103 to 

determine control requirement applicability, engineering 

assessment may be used to determine the flow rate or 

concentration for the representative operating conditions 

expected to yield the highest flow rate or concentration.

(1) If the TRE index value calculated using such 

engineering assessment and the TRE index value equation in 

paragraph (j) of this section is greater than 4.0, then the 

owner or operator is not required to perform the measurements 

specified in paragraphs (e) through (i) of this section.

(2) If the TRE index value calculated using such 

engineering assessment and the TRE index value equation in 

paragraph (j) of this section is less than or equal to 4.0, then 

the owner or operator is required either to perform the 

measurements specified in paragraphs (e) through (i) of this 

section for control applicability assessment or comply with the 

requirements (or standards) specified in the tables presented in 

§63.1103 (as applicable).

(3) Engineering assessment includes, but is not limited to, 

the examples specified in paragraphs (k)(3)(i) through (iv) of 

this section:
Page 121 of 197

(i) Previous test results, provided the tests are 

representative of current operating practices at the process 

unit.

(ii) Bench-scale or pilot-scale test data representative of 

the process under representative operating conditions.

(iii) Maximum flow rate, TOC emission rate, organic HAP 

emission rate, organic HAP or TOC concentration, or net heating 

value limit specified or implied within a permit limit 

applicable to the process vent.

(iv) Design analysis based on accepted chemical engineering 

principles, measurable process parameters, or physical or 

chemical laws or properties. Examples of analytical methods 

include, but are not limited to those specified in paragraphs 

(k)(3)(iv)(A) through (k)(3)(iv)(D) of this section:

(A) Use of material balances based on process stoichiometry 

to estimate maximum TOC or organic HAP concentrations,

(B) Estimation of maximum flow rate based on physical 

equipment design such as pump or blower capacities,

(C) Estimation of TOC or organic HAP concentrations based 

on saturation conditions, and

(D) Estimation of maximum expected net heating value based 

on the stream concentration of each organic compound or, 

alternatively, as if all TOC in the stream were the compound 

with the highest heating value.
Page 122 of 197

(4) All data, assumptions, and procedures used in the 

engineering assessment shall be documented. The owner or 

operator shall maintain the records specified in paragraphs 

(l)(1) through (4) of this section, as applicable.

(l) Applicability assessment recordkeeping requirements —

(1) TRE index value records. The owner or operator shall 

maintain records of measurements, engineering assessments, and 

calculations performed to determine the TRE index value of the 

process vent according to the procedures of paragraph (j) of 

this section, including those records associated with halogen 

vent stream determination. Documentation of engineering 

assessments shall include all data, assumptions, and procedures 

used for the engineering assessments, as specified in paragraph 

(k) of this section. As specified in paragraph (m) of this 

section, the owner or operator shall include this information in 

the Notification of Compliance Status report required by 

§63.1110(a)(4) .

(2) Flow rate records. The owner or operator shall record 

the flow rate as measured using the sampling site and flow rate 

determination procedures (if applicable) specified in paragraphs 

(b) and (f) of this section or determined through engineering 

assessment as specified in paragraph (k) of this section. As 

specified in paragraph (m) of this section, the owner or 
Page 123 of 197

operator shall include this information in the Notification of 

Compliance Status report required by §63.1110(a)(4).

(3) Concentration records. The owner or operator shall 

record the regulated organic HAP or TOC concentration (if 

applicable) as measured using the sampling site and regulated 

organic HAP or TOC concentration determination procedures 

specified in paragraphs (e)(1) and (2) of this section, or 

determined through engineering assessment as specified in 

paragraph (k) of this section. As specified in paragraph (m) of 

this section, the owner or operator shall include this 

information in the Notification of Compliance Status report 

required by §63.1110(a)(4).

(4) Process change records. The owner or operator shall 

keep up-to-date, readily accessible records of any process 

changes that change the control applicability for a process 

vent. Records are to include any recalculation or measurement of 

the flow rate, regulated organic HAP or TOC concentration, and 

TRE index value.

(m) Applicability assessment reporting requirements —

(1) Notification of Compliance Status. The owner or operator 

shall submit, as part of the Notification of Compliance Status 

report required by §63.1110(a)(4), the information recorded in 

paragraph (l)(1) through (3) of this section.
Page 124 of 197

(2) Process change. (i) Whenever a process vent becomes 

subject to control requirements under this subpart as a result 

of a process change, the owner or operator shall submit a report 

within 60 days after the performance test or applicability 

assessment, whichever is sooner. The report may be submitted as 

part of the next Periodic Report required by §63.1110(a)(5). The 

report shall include the information specified in paragraphs 

(m)(2)(i)(A) through (C) of this section.

(A) A description of the process change;

(B) The results of the recalculation of the TOC or organic 

HAP concentration, flow rate, and/or TRE index value required 

under paragraphs (e), (f), and (j), and recorded under paragraph 

(l); and

(C) A statement that the owner or operator will comply with 

the requirements specified in §63.1103 by the schedules 

specified in that section for the affected source.

(ii) If a performance test is required as a result of a 

process change, the owner or operator shall specify that the 

performance test has become necessary due to a process change. 

This specification shall be made in the performance test 

notification to the Administrator, as specified in 

§63.999(a)(1).

(iii) If a process change does not result in additional 

applicable requirements, then the owner or operator shall 
Page 125 of 197

include a statement documenting this in the next Periodic Report 

required by §63.1110(a)(5) after the process change was made.

(n) Parameter monitoring of certain process vents. An owner 

or operator who maintains a TRE index value (if applicable) in 

the applicable TRE index value monitoring range as specified in 

an applicable table presented in §63.1103 of this subpart 

without using a recovery device shall report a description of 

the parameter(s) to be monitored to ensure the process vent is 

operated in conformance with its design or process and achieves 

and maintains the TRE index value above the specified level, and 

an explanation of the criteria used to select parameter(s). An 

owner or operator who maintains a TRE index value (if 

applicable) in the applicable TRE index monitoring range as 

specified in an applicable table presented in §63.1103 of this 

subpart by using a recovery device shall comply with the 

requirements of §63.993(c).

§63.1105 Transfer racks.

(a) Design requirements. The owner or operator shall equip 

each transfer rack with one of the control options listed in 

paragraphs (a)(1) through (4) of this section.

(1) A closed vent system designed to collect HAP-containing 

vapors displaced from tank trucks or railcars during loading and 

to route the collected vapors to a flare. The owner or operator 

must meet the requirements of §63.982(a)(3).
Page 126 of 197

(2) A closed vent system designed to collect HAP-containing 

vapors displaced from tank trucks or railcars during loading and 

to route the collected vapors to a control device other than a 

flare. The owner or operator must meet the requirements of 

§63.982(a)(3).

(3) Process piping designed to collect the HAP vapors 

displaced from tank trucks or railcars during loading and to 

route the collected vapors to a process where the HAP vapors 

shall predominantly meet one of, or a combination of, the ends 

specified in paragraphs (a)(3)(i) through (iv) of this section 

or to a fuel gas system. The owner or operator must meet the 

requirements of §63.982(a)(3).

(i) Recycled and/or consumed in the same manner as a 

material that fulfills the same function in that process;

(ii) Transformed by chemical reaction into materials that 

are not HAP;

(iii) Incorporated into a product; and/or

(iv) Recovered.

(4) Process piping designed to collect the HAP vapors 

displaced from tank trucks or railcars during loading and to 

route the collected vapors to a vapor balance system. The vapor 

balance system must be designed to route the collected HAP 

vapors to the storage vessel from which the liquid being loaded 

originated, or to another storage vessel connected to a common 
Page 127 of 197

header, or to compress and route collected HAP vapors to a 

process.

(b) Operating requirements. An owner or operator of a 

transfer rack shall operate it in such a manner that emissions 

are routed through the equipment specified in paragraph (a) of 

this section.

(c) Control device operation. Whenever HAP emissions are 

vented to a control device used to comply with the provisions of 

this subpart, such control device shall be operating.

(d) Tank trucks and railcars. The owner or operator shall 

load HAP-containing materials only into tank trucks and railcars 

that meet the requirement in paragraph (d)(1) or (2) of this 

section and shall maintain the records specified in paragraph 

(i) of this section.

(1) Have a current certification in accordance with the 

U.S. Department of Transportation (DOT) pressure test 

requirements of 49 CFR part 180 for tank trucks and 49 CFR 

173.31 for railcars; or

(2) Have been demonstrated to be vapor-tight within the 

preceding 12 months as determined by the procedures in paragraph 

(h) of this section. Vapor-tight means that the pressure in a 

truck or railcar tank will not drop more than 750 pascals within 

5 minutes after it is pressurized to a minimum of 4,500 pascals.
Page 128 of 197

(e) Pressure relief device. The owner or operator of a 

transfer rack subject to the provisions of this subpart shall 

ensure that no pressure relief device in the loading equipment 

of each tank truck or railcar shall begin to open to the 

atmosphere during loading. Pressure relief devices needed for 

safety purposes are not subject to the requirements of this 

paragraph.

(f) Compatible system. The owner or operator of a transfer 

rack subject to the provisions of this subpart shall load HAPcontaining materials only to tank trucks or railcars equipped 

with a vapor collection system that is compatible with the 

transfer rack's closed vent system or process piping.

(g) Loading while systems connected. The owner or operator 

of a transfer rack subject to this subpart shall load HAPcontaining material only to tank trucks or railcars whose 

collection systems are connected to the transfer rack's closed 

vent system or process piping.

(h) Vapor tightness procedures. For the purposes of 

demonstrating vapor tightness to determine compliance with 

paragraph (d)(2) of this section, the procedures and equipment 

specified in paragraphs (h)(1) and (2) shall be used.

(1) The pressure test procedures specified in Method 27 of 

appendix A to 40 CFR part 60.
Page 129 of 197

(2) A pressure measurement device that has a precision of 

±2.5 millimeters of mercury or better and that is capable of 

measuring above the pressure at which the tank truck or railcar 

is to be tested for vapor tightness.

(i) Recordkeeping. The owner or operator of a transfer rack 

shall record that the verification of DOT tank certification or 

Method 27 of appendix A to 40 CFR part 60 testing required in 

§63.84(c) has been performed. Various methods for the record of 

verification can be used, such as a check-off on a log sheet, a 

list of DOT serial numbers or Method 27 data, or a position 

description for gate security showing that the security guard 

will not allow any trucks on-site that do not have the 

appropriate documentation.

§63.1106 Wastewater provisions.

(a) Process wastewater. Except as specified in paragraphs 

(a)(1) through (a)(16) and paragraph (d) of this section, the 

owner or operator of each affected source shall comply with the 

HON process wastewater requirements in §§63.132 through 63.148.

(1) When terms used in §§63.132 through 63.148 are defined 

in §63.1101, the definition in §63.1101 shall apply, for the 

purposes of this subpart. For terms used in §§63.132 through 

63.148 that are not defined in §63.1101, the definitions in 

§§63.101 and 63.111 shall apply.
Page 130 of 197

(2) When the term chemical manufacturing production process 

unit, or CMPU, is used in §§63.132 through 63.148, the phrase “a 

process unit whose primary product is a product produced by a 

source category subject to this subpart” shall apply, for the 

purposes of this subpart.

(3) Owners and operators of affected sources are not 

required to comply with §63.132(b)(1) and (d) and §63.138(c). 

Further, owners and operators are exempt from all requirements 

in §§63.132 through 63.148 that pertain solely and exclusively 

to organic HAP listed in Table 8 of subpart G of this part.

(4) When the determination of equivalence criteria in 

§63.102(b) is referred to in §§63.132, 63.133, and 63.137, the 

alternative nonopacity emission standard provisions in §63.6(g) 

shall apply, for the purposes of this subpart.

(5) When the HON storage vessel requirements for internal 

floating roofs contained in §63.119(b) are referred to in 

§63.133(a)(2)(ii), the requirements in §63.1063(a)(1)(i), (2), 

and (b) shall apply, for the purposes of this subpart.

(6) When the HON storage vessel requirements for external 

floating roofs in §§63.119(c) and 63.120(b)(5) and (6) are 

referred to in §63.133(a)(2)(iii) and (d), the requirements in 

§63.1063(a)(1)(ii), (2), and (b) shall apply, for the purposes 

of this subpart.
Page 131 of 197

(7) For the purposes of this subpart, §63.1063(c)(2)(iv) 

shall apply instead of §63.133(e).

(8) When §§63.143(c), (d), (e)(3) and 63.146(a) require the 

submission of a request for approval to monitor alternative 

parameters according to the procedures specified in §63.151(f) 

or (g), the owner or operator requesting to monitor alternative 

parameters shall follow the procedures specified in §63.1108(c) 

or as specified in a referenced subpart.

(9) When §63.147(d) requires the owner or operator to keep 

records of the daily average value of each continuously 

monitored parameter for each operating day as specified in 

§63.152(f), the owner or operator shall keep records of each 

continuously monitored parameter for each operating day as 

specified in §63.998(b).

(10) When §63.132(a) and (b) refer to the “applicable dates 

specified in §63.100 of subpart F of this part,” the applicable 

compliance dates specified in §63.1102 shall apply, for purposes 

of this subpart.

(11) Where §63.152(b) and/or the Notification of Compliance 

Status is referred to in §§63.132 through 63.148, the 

Notification of Compliance Status requirements contained in 

§63.1110(a)(3) shall apply, for purposes of this subpart.

(12) Where §63.152(c) and/or the Periodic Report 

requirements are referred to §§63.132 through 63.148, the 
Page 132 of 197

Periodic Report requirements contained in §63.1110(a)(4) shall 

apply, for purposes of this subpart.

(13) When Method 18 of appendix A to part 60 of this 

chapter is specified in §63.139(e)(1)(ii), §63.145(d)(4), or 

§63.145(i)(2), either Method 18 or Method 25A may be used. The 

use of Method 25A of appendix A to part 60 of this chapter shall 

comply with paragraphs (a)(13)(i) and (a)(13)(ii) of this 

section.

(i) The organic HAP used as the calibration gas for Method 

25A of appendix A of part 60 of this chapter shall be the single 

organic HAP representing the largest percent by volume of the 

emissions.

(ii) The use of Method 25A of appendix A of part 60 of this 

chapter is acceptable if the response from the high-level 

calibration gas is at least 20 times the standard deviation of 

the response from the zero calibration gas when the instrument 

is zeroed on the most sensitive scale.

(14) When the HON recordkeeping requirements for by-pass 

lines in §63.118(a)(3) is referred to in §63.148(f), the 

requirements in §63.998(d)(1)(ii)(A) shall apply, for the 

purposes of this subpart.

(15) When the Initial Notification requirements in 

§63.182(b) are referred to in §63.148(j), the requirements in 

§63.1110(c) shall apply, for the purposes of this subpart.
Page 133 of 197

(16) For the purposes of this subpart, §63.148(k) shall not 

apply.

(b) Maintenance wastewater. The owner or operator of each 

affected source shall comply with the HON maintenance wastewater 

requirements in §63.105. When terms used in §63.105 are defined 

in §63.1101, the definition in §63.1101 shall apply, for the 

purpose of this subpart. For terms used in §63.105 that are not 

defined in §63.1101, the definitions in §§63.101 and 63.111 

shall apply.

(c) Liquid streams in open systems. The owner or operator 

shall comply with the provisions of Table 35 of subpart G of 

this part for each item of equipment meeting the criteria 

specified in paragraphs (c)(1) through (3) of this section and 

either paragraph (c)(4)(i) or (ii) of this section, with the 

exceptions provided in paragraphs (c)(5) and (6) of this 

section.

(1) The item of equipment is one of the types of equipment 

identified in paragraphs (c)(1)(i) through (vii) of this 

section.

(i) Drain or drain hub;

(ii) Manhole (including sumps and other points of access to 

a conveyance system);

(iii) Lift station;

(iv) Trench;
Page 134 of 197

(v) Pipe;

(vi) Oil/water separator; and

(vii) Tanks with capacities of 38 m3 or greater.

(2) The item of equipment is part of an affected source 

that is subject to this subpart.

(3) The item of equipment is controlled less stringently 

than in Table 35 of subpart G of this part, and the item of 

equipment is not otherwise exempt from the provisions of this 

subpart, or a referenced subpart.

(4) The item of equipment:

(i) Is a drain, drain hub, manhole, lift station, trench, 

pipe, or oil/water separator that conveys water with a total 

annual average concentration greater than or equal to 10,000 

parts per million by weight of Table 9 compounds (as defined 

under this subpart) at any flow rate; or a total annual average 

concentration greater than or equal to 1,000 parts per million 

by weight of Table 9 compounds (as defined under this subpart) 

at an annual average flow rate greater than or equal to 10 

liters per minute.

(ii) Is a tank that receives one or more streams that 

contain water with a total annual average concentration greater 

than or equal to 1,000 parts per million by weight of Table 9 

compounds (as defined under this subpart) at an annual average 

flow rate greater than or equal to 10 liters per minute. The 
Page 135 of 197

owner or operator shall determine the characteristics of the 

stream as specified in paragraphs (c)(4)(ii)(A) and (B) of this 

section.

(A) The characteristics of the stream being received shall 

be determined at the inlet to the tank.

(B) The characteristics shall be determined according to 

the procedures in §63.144(b) and (c).

(5) When terms used in Table 35 of subpart G of this part 

are defined in §63.1101, the definition in §63.1101 shall apply, 

for the purpose of this subpart. For terms used in Table 35 of 

subpart G of this part that are not defined in §63.1101, the 

definitions in §63.101 and §63.111 shall apply.

(6) When Table 35 of subpart G of this part refers to 40 

CFR 63.119(e)(1) or (e)(2) in the requirements for tanks, the 

requirements in §63.982(a)(1) shall apply, for purposes of this 

subpart.

(d) The compliance date for the affected sources subject to 

the provisions of this section is specified in §63.1102.

§63.1107 Equipment leaks: applicability assessment procedures 

and methods.

(a) Each piece of equipment within a process unit that can 

reasonably be expected to contain equipment in organic HAP 

service is presumed to be in organic HAP service unless an owner 

or operator demonstrates that the piece of equipment is not in 
Page 136 of 197

organic HAP service. For a piece of equipment to be considered 

not in organic HAP service, it must be determined that the 

percent organic HAP content can be reasonably expected not to 

exceed the percent by weight control applicability criteria 

specified in §63.1103 for an affected source on an annual 

average basis. For purposes of determining the percent organic 

HAP content of the process fluid that is contained in or 

contacts equipment, Method 18 of 40 CFR part 60, appendix A 

shall be used.

(b) An owner or operator may use good engineering judgment 

rather than the procedures in paragraph (a) of this section to 

determine that the percent organic HAP content does not exceed 

the percent by weight control applicability criteria specified 

in §63.1103 for an affected source. When an owner or operator 

and the Administrator do not agree on whether a piece of 

equipment is not in organic HAP service, however, the procedures 

in paragraph (a) of this section shall be used to resolve the 

disagreement.

(c) If an owner or operator determines that a piece of 

equipment is in organic HAP service, the determination can be 

revised after following the procedures in paragraph (a) of this 

section, or by documenting that a change in the process or raw 

materials no longer causes the equipment to be in organic HAP 

service.
Page 137 of 197

(d) Samples used in determining the percent organic HAP 

content shall be representative of the process fluid that is 

contained in or contacts the equipment.

(e) Requirements for pressure relief devices. For acrylic 

and modacrylic fiber production affected sources and 

polycarbonate production affected sources, except as specified 

in paragraph (e)(4) of this section, the owner or operator must 

comply with the requirements specified in paragraphs (e)(1) and 

(2) of this section for pressure relief devices in organic HAP 

gas or vapor service. Except as specified in paragraph (e)(4) of 

this section, the owner or operator of an acrylic and modacrylic 

fiber production affected source or polycarbonate production 

affected source must also comply with the requirements specified 

in paragraph (e)(3) of this section for all pressure relief 

devices in organic HAP service.

(1) Operating requirements. Except during a pressure 

release event, operate each pressure relief device in organic 

HAP gas or vapor service with an instrument reading of less than 

500 ppm above background as detected by Method 21 of 40 CFR part 

60, appendix A.

(2) Pressure release requirements. For pressure relief 

devices in organic HAP gas or vapor service, comply with 

paragraph (e)(2)(i) or (ii) of this section, as applicable.
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(i) If the pressure relief device does not consist of or 

include a rupture disk, conduct instrument monitoring, as 

detected by Method 21 of 40 CFR part 60, appendix A, no later 

than 5 calendar days after the pressure relief device returns to 

organic HAP service following a pressure release to verify that 

the pressure relief device is operating with an instrument 

reading of less than 500 ppm above background. After 5 calendar 

days, an instrument reading of 500 ppm above background or 

greater is a violation.

(ii) If the pressure relief device consists of or includes 

a rupture disk, install a replacement disk as soon as 

practicable after a pressure release, but no later than 5 

calendar days after the pressure release. The owner or operator

must also conduct instrument monitoring, as detected by Method 

21 of 40 CFR part 60, appendix A, no later than 5 calendar days 

after the pressure relief device returns to organic HAP service 

following a pressure release to verify that the pressure relief 

device is operating with an instrument reading of less than 500 

ppm above background. After 5 calendar days, an instrument 

reading of 500 ppm above background or greater is a violation.

(3) Pressure release management. Except as specified in 

paragraph (e)(4) of this section, the owner or operator must 

comply with the requirements specified in paragraphs (e)(3)(i) 

and (ii) of this section for all pressure relief devices in 
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organic HAP service. Any pressure release from such a pressure 

relief device is a violation.

(i) The owner or operator must equip each pressure relief 

device in organic HAP service with a device(s) or parameter 

monitoring system that is capable of identifying and recording 

the time and duration of each pressure release and of notifying 

operators immediately that a pressure release is occurring. The 

device or monitoring system may be either specific to the 

pressure relief device itself or on an associated process system 

or piping sufficient to indicate a pressure release to the 

atmosphere. Examples of these types of devices and systems 

include, but are not limited to, a rupture disk indicator, 

magnetic sensor, motion detector on the pressure relief valve 

stem, flow monitor, or pressure monitor. Regardless of the 

methodology chosen, when the device or monitoring system 

indicates that a pressure release has occurred, it shall be 

directly enforceable as a release from the pressure relief 

device. If this instrument is capable of measuring the 

concentration of leaks through the pressure relief device, then 

the owner or operator may use this instrument to meet the 

requirements of paragraph (e)(2) of this section.

(ii) If any pressure relief device in organic HAP service 

releases to atmosphere as a result of a pressure release event, 

the owner or operator must calculate the quantity of organic HAP 
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released during each pressure release event and report this 

quantity as required in paragraph (g) of this section. 

Calculations may be based on data from the pressure relief 

device monitoring alone or in combination with process parameter 

monitoring data and process knowledge.

(4) Pressure relief devices routed to a control device or 

process. If a pressure relief device in organic HAP service is 

designed and operated to route all pressure releases through a 

closed vent system to a control device or process, the owner or 

operator is not required to comply with paragraphs (e)(1), (2), 

or (3) (if applicable) of this section. Both the closed vent 

system and control device (if applicable) must meet the 

requirements of § 63.1034 of this part.

(f) Recordkeeping requirements. For acrylic and modacrylic 

fiber production affected sources and polycarbonate production 

affected sources, for pressure relief devices in organic HAP 

service, keep records of the information specified in paragraphs 

(f)(1) through (5) of this section, as applicable.

(1) A list of identification numbers for pressure relief 

devices that the owner or operator elects to equip with a 

closed-vent system and control device, under the provisions in 

paragraph (e)(4) of this section.
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(2) A list of identification numbers for pressure relief 

devices subject to the provisions in paragraph (e)(1) of this 

section.

(3) A list of identification numbers for pressure relief 

devices equipped with rupture disks, under the provisions in 

paragraph (e)(2)(ii) of this section.

(4) The dates and results of the monitoring following a 

pressure release for each pressure relief device subject to the 

provisions in paragraph (e)(1) and (2) of this section. The 

results shall include:

(i) The background level measured during each compliance 

test.

(ii) The maximum instrument reading measured at each piece 

of equipment during each compliance test.

(5) For pressure relief devices in organic HAP service 

subject to paragraph (e)(3) of this section, keep records of 

each pressure release to the atmosphere, including the following 

information:

(i) The source, nature, and cause of the pressure release.

(ii) The date, time, and duration of the pressure release.

(iii) An estimate of the quantity of total HAP emitted 

during the pressure release and the calculations used for 

determining this quantity.

(iv) The actions taken to prevent this pressure release.
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(v) The measures adopted to prevent future such pressure 

releases.

(g) Periodic reports. For owners or operators of an acrylic 

and modacrylic fiber production affected source or polycarbonate 

production affected source subject to paragraph (e) of this 

section, Periodic Reports must include the information specified 

in paragraphs (f)(1) through (3) of this section for pressure 

relief devices in organic HAP service.

(1) For pressure relief devices in organic HAP service 

subject to paragraph (e) of this section, report confirmation 

that all monitoring to show compliance was conducted within the 

reporting period.

(2) For pressure relief devices in organic HAP gas or vapor 

service subject to paragraph (e)(2) of this section, report any 

instrument reading of 500 ppm above background or greater, more 

than 5 days after the relief device returns to organic HAP gas 

or vapor service after a pressure release.

(3) For pressure relief devices in organic HAP service 

subject to paragraph (e)(3) of this section, report each 

pressure release to the atmosphere, including the following 

information:

(i) The source, nature, and cause of the pressure release.

(ii) The date, time, and duration of the pressure release.
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(iii) An estimate of the quantity of total HAP emitted 

during the pressure release and the method used for determining 

this quantity.

(iv) The actions taken to prevent this pressure release.

(v) The measures adopted to prevent future such pressure 

releases.

§63.1108 Compliance with standards and operation and maintenance 

requirements.

(a) Requirements. The requirements of paragraphs (a)(1), 

(2), and (5) of this section apply to all affected sources 

except acrylic and modacrylic fiber production affected sources 

and polycarbonate production affected sources. The requirements 

of paragraph (a)(4) of this section apply only to acrylic and 

modacrylic fiber production affected sources and polycarbonate 

production affected sources. The requirements of paragraphs 

(a)(3), (6), and (7) of this section apply to all affected 

sources.

(1) Except as provided in paragraph (a)(2) of this section, 

the emission limitations and established parameter ranges of 

this part shall apply at all times except during periods of 

startup, shutdown, malfunction, or non-operation of the affected 

source (or specific portion thereof) resulting in cessation of 

the emissions to which this subpart applies. However, if a 

startup, shutdown, malfunction or period of non-operation of one 
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portion of an affected source does not affect the ability of a 

particular emission point to comply with the specific provisions 

to which it is subject, then that emission point shall still be 

required to comply with the applicable provisions of this 

subpart and any of the subparts that are referenced by this 

subpart during startup, shutdown, malfunction, or period of nonoperation.

(2) If equipment leak requirements are referenced by this 

subpart for a subject source category, such requirements shall 

apply at all times except during periods of startup, shutdown, 

or malfunction, process unit shutdown (as defined in §63.1101), 

or non-operation of the affected source (or specific portion 

thereof) in which the lines are drained and depressurized 

resulting in cessation of the emissions to which the equipment 

leak requirements apply.

(3) For batch unit operations, shutdown does not include 

the normal periods between batch cycles; and startup does not 

include the recharging of batch unit operations, or the 

transitional conditions due to changes in product.

(4)(i) For acrylic and modacrylic fiber production affected 

sources and polycarbonate production affected sources, the 

emission limitations and established parameter ranges of this 

part shall apply at all times except during periods of nonoperation of the affected source (or specific portion thereof) 
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resulting in cessation of the emissions to which this subpart 

applies. Equipment leak requirements shall apply at all times 

except during periods of non-operation of the affected source 

(or specific portion thereof) in which the lines are drained and 

depressurized resulting in cessation of the emissions to which 

the equipment leak requirements apply.

(ii) General duty. At all times, the owner or operator must 

operate and maintain any affected source, including associated 

air pollution control equipment and monitoring equipment, in a 

manner consistent with safety and good air pollution control 

practices for minimizing emissions. The general duty to minimize 

emissions does not require the owner operator to make any 

further efforts to reduce emissions if levels required by the 

applicable standard have been achieved. Determination of whether 

a source is operating in compliance with operation and 

maintenance requirements will be based on information available 

to the Administrator, which may include, but is not limited to, 

monitoring results, review of operation and maintenance 

procedures, review of operation and maintenance records, and 

inspection of the source.[Reserved]

(5) During startups, shutdowns, and malfunctions when the 

emission standards of this subpart and the subparts referenced 

by this subpart do not apply pursuant to paragraphs (a)(1) 

through (43) of this section, the owner or operator shall 
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implement, to the extent reasonably available, measures to 

prevent or minimize excess emissions. The measures to be taken 

shall be identified in the startup, shutdown, and malfunction 

plan (if applicable), and may include, but are not limited to, 

air pollution control technologies, recovery technologies, work 

practices, pollution prevention, monitoring, and/or changes in 

the manner of operation of the affected source. Back-up control 

devices are not required, but may be used if available. 

Compliance with an inadequate startup, shutdown, and malfunction 

plan developed pursuant to §63.1111 is not a shield for failing 

to comply with good operation and maintenance requirements.

(6) Malfunctions shall be corrected as soon as practical 

after their occurrence.

(7) Operation and maintenance requirements established 

pursuant to section 112 of the Act are enforceable, independent 

of emissions limitations or other requirements in relevant 

standards.

(b) Compliance assessment procedures —(1) Parameter 

monitoring: compliance with operating conditions. Compliance 

with the required operating conditions for the monitored control 

devices or recovery devices may be determined by, but is not 

limited to, the parameter monitoring data for emission points 

that are required to perform continuous monitoring. For each 

excursion except for excused excursions (as described in 
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§63.998(b)(6)(ii)), and as provided for in paragraph (b)(2) of 

this section the owner or operator shall be deemed to have 

failed to have applied the control in a manner that achieves the 

required operating conditions.

(2) Parameter monitoring: Excursions. An excursion is not a 

violation in cases where continuous monitoring is required and 

the excursion does not count toward the number of excused 

excursions (as described in §63.998(b)(6)(ii)), if the 

conditions of paragraph (b)(2)(i) or (ii) of this section are 

met, except that the conditions of paragraph (b)(2)(i) of this 

section do not apply for acrylic and modacrylic fiber production 

affected sources and polycarbonate production affected sources. 

Nothing in this paragraph shall be construed to allow or excuse 

a monitoring parameter excursion caused by any activity that 

violates other applicable provisions of this subpart or a 

subpart referenced by this subpart.

(i) During periods of startup, shutdown, or malfunction 

(and the source is operated during such periods in accordance 

with §63.1111(a)), or

(ii) During periods of non-operation of the affected source 

or portion thereof (resulting in cessation of the emissions to 

which the monitoring applies).

(3) Operation and maintenance procedures. Determination of 

whether acceptable operation and maintenance procedures are 
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being used will be based on information available to the 

Administrator. This information may include, but is not limited 

to, monitoring results, review of operation and maintenance 

procedures (including the startup, shutdown, and malfunction 

plan under §63.1111), review of operation and maintenance 

records, and inspection of the affected source, and alternatives 

approved as specified in §63.1113.

(4) Applicability and compliance assessment procedures. 

Applicability and compliance with standards shall be governed 

by, in part, but not limited to, the use of data, tests, and 

requirements according to paragraphs (b)(4)(i) through (iii) of 

this section. Compliance with design, equipment, work practice, 

and operating standards, including those for equipment leaks, 

shall be determined according to paragraph (b)(5) of this 

section.

(i) Applicability assessments. Unless otherwise specified 

in a relevant test method required to assess control 

applicability, each test shall consist of three separate runs 

using the applicable test method. Each run shall be conducted 

for the time and under the conditions specified in this subpart. 

The arithmetic mean of the results of the three runs shall apply 

when assessing applicability. Upon receiving approval from the 

Administrator, results of a test run may be replaced with 

results of an additional test run if it meets the criteria 
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specified in paragraphs (a)(4)(i)(A) through (D) of this 

section.

(A) A sample is accidentally lost after the testing team 

leaves the site; or

(B) Conditions occur in which one of the three runs must be 

discontinued because of forced shutdown; or

(C) Extreme meteorological conditions occur;

(D) Other circumstances occur that are beyond the owner or 

operator's control.

(ii) Performance test. The Administrator may determine 

compliance with emission limitations of this subpart based on, 

but not limited to, the results of performance tests conducted 

according to the procedures specified in §63.997 of this part, 

unless otherwise specified in this subpart or a subpart 

referenced by this subpart. For acrylic and modacrylic fiber 

production affected sources and polycarbonate production 

affected sources, performance tests shall be conducted under such 

conditions as the Administrator specifies to the owner or 

operator based on representative performance of the affected 

source for the period being tested. Representative conditions 

exclude periods of startup and shutdown unless specified by the 

Administrator or an applicable subpart. The owner/operator may 

not conduct performance tests during periods of malfunction. The 

owner operator must record the process information that is 
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necessary to document operating conditions during the test and 

include in such record an explanation to support that such 

conditions represent normal operation. Upon request, the owner 

or operator shall make available to the Administrator such 

records as may be necessary to determine the conditions of 

performance tests.

(iii) Operation and maintenance requirements. The 

Administrator may determine compliance with the operation and 

maintenance standards of this subpart by, but not limited to, 

evaluation of an owner or operator's conformance with operation 

and maintenance requirements, including the evaluation of 

monitoring data, as specified in this subpart or a subpart 

referenced by this subpart.

(5) Design, equipment, work practice, or operational 

standards. The Administrator may determine compliance with 

design, equipment, work practice, or operational requirements 

by, but is not limited to, review of records, inspection of the 

affected source, and by evaluation of an owner or operator's 

conformance with operation and maintenance requirements as 

specified in this subpart, and in the subparts referenced by 

this subpart.

(c) Finding of compliance. The Administrator may make a 

finding concerning an affected source's compliance with an 

emission standard or operating and maintenance requirement as 
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specified in, but not limited to, paragraphs (a) and (b) of this 

section, upon obtaining all of the compliance information 

required by the relevant standard (including the written reports 

of performance test results, monitoring results, and other 

information, if applicable) and any information available to the 

Administrator to determine whether proper operation and 

maintenance practices are being used. Standards in this subpart 

and methods of determining compliance are in metric units 

followed by the equivalents in English units. The Administrator 

will make findings of compliance with the numerical standards of 

this subpart using metric units.

(d) Compliance time. All terms that define a period of time 

for completion of required tasks (e.g., weekly, monthly, 

quarterly, annually), unless specified otherwise in the section 

or subsection that imposes the requirement, refer to the 

standard calendar periods.

(1) Notwithstanding time periods specified for completion 

of required tasks, time periods may be changed by mutual 

agreement between the owner or operator and the Administrator, 

as specified in §63.1110(h). For each time period that is 

changed by agreement, the revised period shall remain in effect 

until it is changed. A new request is not necessary for each 

recurring period.
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(2) When the period specified for compliance is a standard 

calendar period, if the initial compliance date occurs after the 

beginning of the period, compliance shall be required according 

to the schedule specified in paragraph (d)(2) (i) or (ii) of 

this section, as appropriate.

(i) Compliance shall be required before the end of the 

standard calendar period within which the compliance deadline 

occurs, if there remain at least 3 days for tasks that must be 

performed weekly, at least 2 weeks for tasks that must be 

performed monthly, at least 1 month for tasks that must be 

performed each quarter, or at least 3 months for tasks that must 

be performed annually; or

(ii) In all other cases, compliance shall be required 

before the end of the first full standard calendar period after 

the period within which the initial compliance deadline occurs.

(3) In all instances where a provision requires completion 

of a task during each of multiple successive periods, an owner 

or operator may perform the required task at any time during the 

specified period, provided the task is conducted at a reasonable 

interval after completion of the task during the previous 

period.

§63.1109 Recordkeeping requirements.

(a) Maintaining notifications, records, and reports. Except 

as provided in paragraph (b) of this section, the owner or 
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operator of each affected source subject to this subpart shall 

keep copies of notifications, reports and records required by 

this subpart and subparts referenced by this subpart for at 

least 5 years, unless otherwise specified under this subpart.

(b) Copies of reports. If the Administrator has waived the 

requirement of §63.1110(g)(1) for submittal of copies of 

reports, the owner or operator is not required to maintain 

copies of the waived reports. This paragraph applies only to 

reports and not the underlying records that must be maintained 

as specified in this subpart and the subparts referenced by this 

subpart.

(c) Availability of records. All records required to be 

maintained by this subpart or a subpart referenced by this 

subpart shall be maintained in such a manner that they can be 

readily accessed and are suitable for inspection. The records of 

the remaining 3 years, where required, may be retained offsite. 

Records may be maintained in hard copy or computer-readable form 

including, but not limited to, on paper, microfilm, computer, 

computer disk, magnetic tape, or microfiche.

(d) Control applicability records. Owners or operators 

shall maintain records containing information developed and used 

to assess control applicability under §63.1103 (e.g., combined 

total annual emissions of regulated organic HAP).

§63.1110 Reporting requirements.
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(a) Required reports. Each owner or operator of an affected 

source subject to this subpart shall submit the reports listed 

in paragraphs (a)(1) through (8) of this section, as applicable.

Each owner or operator of an acrylic and modacrylic fiber 

production affected source or polycarbonate production affected 

source subject to this subpart shall submit the reports listed 

in paragraph (a)(9) of this section, as applicable.

(1) A Notification of Initial Startup described in 

paragraph (b) of this section, as applicable.

(2) An Initial Notification described in paragraph (c) of 

this section.

(3) [Reserved]

(4) A Notification of Compliance Status report described in 

paragraph (d) of this section.

(5) Periodic Reports described in paragraph (e) of this 

section.

(6) Application for approval of construction or 

reconstruction described in §63.5(d) of subpart A of this part.

(7) Startup, Shutdown, and Malfunction Reports described in 

§63.1111 of this subpart (except for acrylic and modacrylic 

fiber production affected sources and polycarbonate production 

affected sources).
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(8) Other reports. Other reports shall be submitted as 

specified elsewhere in this subpart and subparts referenced by 

this subpart.

(9) Electronic reporting. Within 60 days after the date of 

completing each performance test (as defined in § 63.2), the 

owner or operator must submit the results of the performance 

tests, including any associated fuel analyses, required by this 

subpart according to the methods specified in paragraph 

(a)(9)(i) or (ii) of this section.

(i) For data collected using test methods supported by the 

EPA-provided software, the owner or operator shall submit the 

results of the performance test to the EPA by direct computerto-computer electronic transfer via EPA-provided software, 

unless otherwise approved by the Administrator. Owners or 

operators, who claim that some of the information being 

submitted for performance tests is confidential business 

information (CBI), must submit a complete file using EPAprovided software that includes information claimed to be CBI on 

a compact disc, flash drive, or other commonly used electronic 

storage media to the EPA. The electronic media must be clearly 

marked as CBI and mailed to U.S. EPA/OAPQS/CORE CBI Office, 

Attention: WebFIRE Administrator, MD C404-02, 4930 Old Page Rd., 

Durham, NC 27703. The same file with the CBI omitted must be 
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submitted to the EPA by direct computer-to-computer electronic 

transfer via EPA-provided software.

(ii) For any performance test conducted using test methods 

that are not compatible with the EPA-provided software, the 

owner or operator shall submit the results of the performance 

test to the Administrator at the appropriate address listed in §

60.4.

(b) Notification of initial startup —(1) Contents. An owner 

or operator of an affected source for which a notice of initial 

startup has not been submitted under §63.5, shall send the 

Administrator written notification of the actual date of initial 

startup of an affected source. This paragraph does not apply to 

an affected source in existence on the effective date of this 

rule.

(2) Due date. The notification of the actual date of 

initial startup shall be postmarked within 15 days after such 

date.

(c) Initial Notification. Owners or operators of affected 

sources who are subject to this subpart shall notify the 

Administrator of the applicability of this subpart by submitting 

an Initial Notification according to the schedule described in 

paragraph (c)(1) of this section. The notice shall include the 

information specified in paragraphs (c)(2) through (7) of this 

section, as applicable. An application for approval of 
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construction or reconstruction required under §63.5(d) of 

subpart A of this part may be used to fulfill the initial 

notification requirements.

(1) The initial notification shall be postmarked within 1 

year after the source becomes subject to this subpart.

(2) Identification of the storage vessels subject to this 

subpart.

(3) Identification of the process vents subject to this 

subpart.

(4) Identification of the transfer racks subject to this 

subpart.

(5) For equipment leaks, identification of the process 

units subject to this subpart.

(6) Identification of other equipment or emission points 

subject to this subpart.

(7) As an alternative to the requirements specified in 

paragraphs (c)(1) through (3) and (c)(5) of this section, 

process units can be identified instead of individual pieces of 

equipment. For this alternative, the kind of emission point in 

the process unit that will comply must also be identified.

(d) Notification of Compliance Status —(1) Contents. The 

owner or operator shall submit a Notification of Compliance 

Status for each affected source subject to this subpart 

containing the information specified in paragraphs (d)(1)(i) and 
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(d)(1)(ii) of this section. For pressure relief devices subject 

to the requirements of § 63.1107(e)(3), the owner or operator of 

an acrylic and modacrylic fiber production affected source or 

polycarbonate production affected source shall submit the 

information listed in paragraph (d)(1)(iii) of this section in 

the Notification of Compliance Status within 150 days after the 

first applicable compliance date for pressure relief device 

monitoring.

(i) The Notification of Compliance Status shall include the 

information specified in this subpart and the subparts 

referenced by this subpart. Alternatively, this information can 

be submitted as part of a title V permit application or 

amendment.

(ii) The Notification of Compliance Status shall include a 

statement from the owner or operator identifying which subpart 

he or she has elected to comply with, where given a choice, as 

provided for in §63.1100(g).

(iii) For pressure relief devices in organic HAP service, a 

description of the device or monitoring system to be 

implemented, including the pressure relief devices and process 

parameters to be monitored (if applicable), and a description of 

the alarms or other methods by which operators will be notified 

of a pressure release.
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(2) Due date. The owner or operator shall submit the 

Notification of Compliance Status for each affected source 240 

days after the compliance date specified for the affected source 

under this subpart, or 60 days after completion of the initial 

performance test or initial compliance assessment, whichever is 

earlier. Notification of Compliance Status reports may be 

combined for multiple affected sources as long as the due date 

requirements for all sources covered in the combined report are 

met.

(e) Periodic Reports. The owner or operator of an affected 

source subject to monitoring requirements of this subpart, or to 

other requirements of this subpart or subparts referenced by 

this subpart, where periodic reporting is specified, shall 

submit a Periodic Report.

(1) Contents. Periodic Reports shall include all 

information specified in this subpart and subparts referenced by 

this subpart.

(2) Due date. The Periodic Report shall be submitted no 

later than 60 days after the end of each 6-month period. The 

first report shall cover the 6-month period after the 

Notification of Compliance Status report is due. The first 

report shall be submitted no later than the last day of the 

month that includes the date 8 months (6 months and 60 days) 

after the Notification of Compliance Status report is due.
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(3) Overlap with title V reports. Information required by 

this subpart, which is submitted with a title V periodic report, 

need not also be included in a subsequent Periodic Report 

required by this subpart or subpart referenced by this subpart. 

The title V report shall be referenced in the Periodic Report 

required by this subpart.

(f) General report content. All reports and notifications 

submitted pursuant to this subpart, including reports that 

combine information required under this subpart and a subpart 

referenced by this subpart, shall include the information 

specified in paragraphs (f)(1) through (4) of this section.

(1) The name, address and telephone number (fax number may 

also be provided) of the owner or operator.

(2) The name, address and telephone number of the person to 

whom inquiries should be addressed, if different than the owner 

or operator.

(3) The address (physical location) of the reporting 

facility.

(4) Identification of each affected source covered in the 

submission and identification of the subparts (this subpart and 

the subparts referenced in this subpart) that are applicable to 

that affected source. Summaries and groupings of this 

information are permitted.
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(g) Report and notification submission —(1) Submission to 

the Environmental Protection Agency. All reports and 

notifications required under this subpart shall be sent to the 

appropriate EPA Regional Office and to the delegated State 

authority, except that request for permission to use an 

alternative means of emission limitation as provided for in 

§63.1113 shall be submitted to the Director of the EPA Office of 

Air Quality Planning and Standards, U.S. Environmental 

Protection Agency, MD–10, Research Triangle Park, North 

Carolina, 27711. The EPA Regional Office may waive the 

requirement to submit a copy of any reports or notifications at 

its discretion.

(2) Submission of copies. If any State requires a notice 

that contains all the information required in a report or 

notification listed in this subpart, an owner or operator may 

send the appropriate EPA Regional Office a copy of the report or 

notification sent to the State to satisfy the requirements of 

this subpart for that report or notification.

(3) Method of submission. Wherever this subpart specifies 

“postmark” dates, submittals may be sent by methods other than 

the U.S. Mail (e.g., by fax or courier). Submittals shall be 

sent on or before the specified date.
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(4) Submission by electronic media. If acceptable to both 

the Administrator and the owner or operator of an affected 

source, reports may be submitted on electronic media.

(h) Adjustment to timing of submittals and review of 

required communications —(1)Alignment with title V submission. 

An owner or operator may submit Periodic Reports required by 

this subpart on the same schedule as the title V periodic report 

for the facility. The owner or operator using this option need 

not obtain prior approval, but must ensure that no reporting 

gaps occur. The owner or operator shall clearly identify the 

change in reporting schedule in the first report filed under 

this paragraph. The requirements of paragraph (f) of this 

section are not waived when implementing this change.

(2) Establishment of a common schedule. An owner or 

operator may arrange by mutual agreement (which may be a 

standing agreement) with the Administrator a common schedule on 

which periodic reports required by this subpart shall be 

submitted throughout the year as long as the reporting period is 

not extended. Procedures governing the implementation of this 

provision are specified in paragraphs (h)(3) through (7) of this 

section.

(3) Submission requirements. Except as allowed by paragraph 

(h)(1) of this section, until an adjustment of a time period or 

postmark deadline has been approved by the Administrator under 
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paragraphs (h)(5) and (6) of this section, the owner or operator 

of an affected source remains strictly subject to the required

submittal deadlines specified in this subpart and subparts 

referenced by this subpart.

(4) Request for adjustment of reporting schedule. Except as 

allowed by paragraph (h)(1) of this section, an owner or 

operator shall request the adjustment provided for in paragraphs 

(h)(5) and (6) of this section each time he or she wishes to 

change an applicable time period or postmark deadline specified 

in this subpart or subparts referenced by this subpart. A 

request for a change to the periodic reporting schedule need 

only be made once for every schedule change and not once for 

every semiannual report submitted.

(5) Alteration of time periods or deadlines. 

Notwithstanding time periods or postmark deadlines specified in 

this subpart for the submittal of information to the 

Administrator by an owner or operator, or the review of such 

information by the Administrator, such time periods or deadlines 

may be changed by mutual agreement between the owner or operator 

and the Administrator. An owner or operator who wishes to 

request a change in a time period or postmark deadline for a 

particular requirement shall request the adjustment in writing 

as soon as practical before the subject activity is required to 

take place. The owner or operator shall include in the request 
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whatever information he or she considers useful to convince the 

Administrator that an adjustment is warranted.

(6) Approval of request for adjustment. If, in the 

Administrator's judgment, an owner or operator's request for an 

adjustment to a particular time period or postmark deadline is 

warranted, the Administrator will approve the adjustment. The 

Administrator will notify the owner or operator in writing of 

approval or disapproval of the request for an adjustment within 

15 calendar days of receiving sufficient information to evaluate 

the request.

(7) Notification of delay. If the Administrator is unable 

to meet a specified deadline, he or she will notify the owner or 

operator of any significant delay and inform the owner or 

operator of the amended schedule.

§63.1111 Startup, shutdown, and malfunction.

(a) Startup, shutdown, and malfunction plan. The 

requirements of this paragraph (a) apply to all affected sources 

except for acrylic and modacrylic fiber production affected 

sources and polycarbonate production affected sources.—

(1) Description and purpose of plan. The owner or operator 

of an affected source shall develop a written startup, shutdown, 

and malfunction plan that describes, in detail, procedures for 

operating and maintaining the affected source during periods of 

startup, shutdown, and malfunction. This plan shall also include 
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a program of corrective action for malfunctioning process and 

air pollution control equipment used to comply with relevant 

standards under this subpart. The plan shall also address 

routine or otherwise predictable CPMS malfunctions. This plan 

shall be developed by the owner or operator by the affected 

source's compliance date under this subpart. The requirement to 

develop this plan shall be incorporated into the source's title 

V permit. This requirement is optional for equipment that must 

comply with subparts TT or UU under this subpart. It is not 

optional for equipment equipped with a closed vent system and 

control device subject to this subpart and subpart SS of this 

part. The purpose of the startup, shutdown, and malfunction plan 

is described in paragraphs (a)(1)(i) and (ii) of this section.

(i) To ensure that owners or operators are prepared to 

correct malfunctions as soon as practical after their 

occurrence, in order to minimize excess emissions of regulated 

organic HAP; and

(ii) To reduce the reporting burden associated with periods 

of startup, shutdown, and malfunction (including corrective 

action taken to restore malfunctioning process and air pollution 

control equipment to its normal or usual manner of operation).

(2) Operation of source. During periods of startup, 

shutdown, and malfunction, the owner or operator of an affected 

source subject to this subpart YY shall operate and maintain 
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such affected source (including associated air pollution control 

equipment and CPMS) in a manner consistent with safety and good 

air pollution control practices for minimizing emissions to the 

extent practical. The general duty to minimize emissions during 

a period of startup, shutdown, or malfunction does not require 

the owner or operator to achieve emission levels that would be 

required by the applicable standard at other times if this is 

not consistent with safety and good air pollution control 

practices, nor does it require the owner or operator to make any 

further efforts to reduce emissions if levels required by the 

applicable standard have been achieved. Determination of whether 

such operation and maintenance procedures are being used will be 

based on information available to the Administrator which may 

include, but is not limited to, monitoring results, review of 

operation and maintenance procedures (including the startup, 

shutdown, and malfunction plan required by this section), review 

of operation and maintenance records, and inspection of the 

source.

(3) Use of additional procedures. To satisfy the 

requirements of this section to develop a startup, shutdown, and 

malfunction plan, the owner or operator of an affected source 

may use the affected source's standard operating procedures 

(SOP) manual, or an Occupational Safety and Health 

Administration (OSHA) or other plan, provided the alternative 
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plans meet all the requirements of this section and are made 

available for inspection when requested by the Administrator.

(4) Revisions to the plan. Based on the results of a 

determination made under §63.1108(b)(3), the Administrator may 

require that an owner or operator of an affected source make 

changes to the startup, shutdown, and malfunction plan for that 

source. The Administrator may require reasonable revisions to a 

startup, shutdown, and malfunction plan if the Administrator 

finds that the plan is inadequate as specified in paragraphs 

(a)(4)(i) through (iv) of this section:

(i) Does not address a startup, shutdown, and malfunction 

event of the CPMS, the air pollution control equipment, or the 

affected source that has occurred; or

(ii) Fails to provide for the operation of the affected 

source (including associated air pollution control equipment and 

CPMS) during a startup, shutdown, and malfunction event in a 

manner consistent with good air pollution control practices for 

minimizing emissions to the extent practical; or

(iii) Does not provide adequate procedures for correcting 

malfunctioning process and air pollution control equipment as 

quickly as practicable; or

(iv) Does not provide adequate measures to prevent or 

minimize excess emissions to the extent practical as specified 

in §63.1108(a)(5).
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(5) Additional malfunction plan requirements. If the 

startup, shutdown, and malfunction plan fails to address or 

inadequately addresses an event that meets the characteristics 

of a malfunction but was not included in the startup, shutdown, 

and malfunction plan at the time the owner or operator developed 

the plan, the owner or operator shall revise the startup, 

shutdown, and malfunction plan within 45 days after the event to 

include detailed procedures for operating and maintaining the 

affected source during similar malfunction events and a program 

of corrective action for similar malfunctions of process or air 

pollution control equipment or CPMS.

(b) Startup, shutdown, and malfunction reporting 

requirements. The requirements of the paragraph (b) apply to all 

affected sources except for acrylic and modacrylic fiber 

production affected sources and polycarbonate production 

affected sources.—

(1) Periodic startup, shutdown, and malfunction reporting 

requirements. If actions taken by an owner or operator during a 

startup, shutdown, and malfunction of an affected source, or of 

a control device or monitoring system required for compliance 

(including actions taken to correct a malfunction) are 

consistent with the procedures specified in the affected 

source's plan, then the owner or operator shall state such 

information in a startup, shutdown, and malfunction report. 
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During the reporting period, reports shall only be required for 

startups, shutdowns, and malfunctions during which excess 

emissions, as defined in §63.1108(a)(5), occur during the 

reporting period. A startup, shutdown, and malfunction report 

can be submitted as part of a Periodic Report required under 

§63.1110(a)(5), or on a more frequent basis if specified 

otherwise under this subpart or a subpart referenced by this 

subpart or as established otherwise by the permitting authority 

in the affected source's title V permit. The startup, shutdown, 

and malfunction report shall be delivered or postmarked by the 

30th day following the end of each calendar half (or other 

calendar reporting period, as appropriate), unless the 

information is submitted with the Periodic Report. The report 

shall include the information specified in paragraphs (b)(1)(i) 

through (b)(1)(iv) of this section.

(i) The name, title, and signature of the owner or operator 

or other responsible official certifying its accuracy.

(ii) The number of startup, shutdown, and malfunction 

events and the total duration of all periods of startup, 

shutdown, and malfunction for the reporting period if the total 

duration amounts to either of the durations in paragraphs 

(b)(1)(ii)(A) or (B) of this section. Records of the number of 

CPMS startup, shutdown, and malfunction events and the total 

duration of all periods of startup, shutdown, and malfunction 
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for the reporting period are required under §63.998(c)(1)(ii)(C) 

and (D) of this section.

(A) Total duration of periods of malfunctioning of a CPMS 

equal to or greater than 5 percent of that CPMS operating time 

for the reporting period; or

(B) Total duration of periods of startup, shutdown, and 

malfunction for an affected source equal to or greater than 1 

percent of that affected source's operating time for the 

reporting period.

(iii) Records documenting each startup, shutdown and 

malfunction event as required under §63.998(c)(1)(ii)(F).

(iv) Records documenting the total duration of operating 

time as required under §63.998(c)(1)(ii)(H).

(2) Immediate startup, shutdown, and malfunction reports. 

Notwithstanding the allowance to reduce the frequency of 

reporting for startup, shutdown, and malfunction reports under 

paragraph (b)(1) of this section, any time an action taken by an 

owner or operator during a startup, shutdown, or malfunction 

(including actions taken to correct a malfunction) during which 

excess emissions occur is not consistent with the procedures 

specified in the affected source's plan, the owner or operator 

shall report the actions taken for that event within 2 working 

days after commencing actions inconsistent with the plan, 

followed by a letter delivered or postmarked within 7 working 
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days after the end of the event. The immediate report required 

under this paragraph shall contain the name, title, and 

signature of the owner or operator or other responsible official 

who is certifying its accuracy, explaining the circumstances of 

the event, the reasons for not following the startup, shutdown, 

and malfunction plan, and whether any excess emissions and/or 

parameter monitoring exceedances are believed to have occurred. 

Notwithstanding the requirements of the previous sentence, after 

the effective date of an approved permit program in the State in 

which an affected source is located, the owner or operator may 

make alternative reporting arrangements, in advance, with the 

permitting authority in that State. Procedures governing the 

arrangement of alternative reporting requirements under this 

paragraph are specified in §63.1110(h).

(3) [Reserved](c) Malfunction recordkeeping and reporting. 

The requirements of this paragraph (c) apply only to acrylic and 

modacrylic fiber production affected sources and polycarbonate 

production affected sources.

(1) Records of malfunctions. The owner or operator shall 

keep the records specified in paragraphs (c)(1)(i) through (iii) 

of this section.

(i) In the event that an affected unit fails to meet an 

applicable standard, record the number of failures. For each 

failure record the date, time, and duration of each failure.
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(ii) For each failure to meet an applicable standard, 

record and retain a list of the affected sources or equipment, 

an estimate of the volume of each regulated pollutant emitted 

over any emission limit, and a description of the method used to 

estimate the emissions.

(iii) Record actions taken to minimize emissions in 

accordance with § 63.1108(a)(4)(ii), and any corrective actions 

taken to return the affected unit to its normal or usual manner 

of operation.

(2) Reports of malfunctions. If a source fails to meet an 

applicable standard, report such events in the Periodic Report. 

Report the number of failures to meet an applicable standard. 

For each instance, report the date, time and duration of each 

failure. For each failure the report must include a list of the 

affected sources or equipment, an estimate of the volume of each 

regulated pollutant emitted over any emission limit, and a 

description of the method used to estimate the emissions.

§63.1112 Extension of compliance, and performance test, 

monitoring, recordkeeping and reporting waivers and 

alternatives.

(a) Extension of compliance —(1) Extension of compliance 

with emission standards. Until an extension of compliance has 

been granted by the Administrator under this paragraph, the 

owner or operator of an affected source subject to the 
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requirements of this subpart shall comply with all applicable 

requirements of this subpart.

(2) Extension of compliance for early reductions and other 

reductions. (i) Early reductions. Pursuant to section 112(i)(5) 

of the Act, if the owner or operator of an existing source 

demonstrates that the source has achieved a reduction in 

emissions of hazardous air pollutants in accordance with the 

provisions of subpart D of this part, the Administrator will 

grant the owner or operator an extension of compliance with 

specific requirements of this part, as specified in subpart D of 

this part.

(ii) Other reductions. Pursuant to section 112(i)(6) of the 

Act, if the owner or operator of an existing source has 

installed best available control technology (BACT) (as defined 

in section 169(3) of the Act) or technology required to meet a 

lowest achievable emission rate (LAER) (as defined in section 

171 of the Act) prior to the promulgation of an emission 

standard in this part applicable to such source and the same 

pollutant (or stream of pollutants) controlled pursuant to the 

BACT or LAER installation, the Administrator will grant the 

owner or operator an extension of compliance with such emission 

standard that will apply until the date 5 years after the date 

on which such installation was achieved, as determined by the 

Administrator.
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(3) Request for extension of compliance. Paragraphs (a)(4) 

through (7) of this section concern requests for an extension of 

compliance with a relevant standard under this part (except 

requests for an extension of compliance under paragraph 

(a)(2)(i) of this section will be handled through procedures 

specified in subpart D of this part).

(4) Requests for extensions of compliance for section 112 

standards. (i) Section 112(d) standards. (A) The owner or 

operator of an existing source who is unable to comply with a 

relevant standard established under this part pursuant to 

section 112(d) of the Act may request that the Administrator 

grant an extension allowing the source up to 1 additional year 

to comply with the standard, if such additional period is 

necessary for the installation of controls. The owner or 

operator of an affected source who has requested an extension of 

compliance under this paragraph and who is otherwise required to 

obtain a title V permit shall apply for such permit or apply to 

have the source's title V permit revised to incorporate the 

conditions of the extension of compliance. The conditions of an 

extension of compliance granted under this paragraph will be 

incorporated into the affected source's title V permit according 

to the provisions of part 70 or Federal title V regulations in 

this chapter (42 U.S.C. 7661), whichever are applicable.
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(B) Any request under this paragraph for an extension of 

compliance with a relevant standard shall be submitted in 

writing to the appropriate authority not later than 12 months 

before the affected source's compliance date (as specified in 

§63.1102) for sources that are not including emission points in 

an emissions average, or not later than 18 months before the 

affected source's compliance date (as specified in §63.1102) for 

sources that are including emission points in an emissions 

average. Emission standards established under this part may 

specify alternative dates for the submittal of requests for an 

extension of compliance if alternatives are appropriate for the 

source categories affected by those standards, e.g., a 

compliance date specified by the standard is less than 12 (or 

18) months after the standard's effective date.

(ii) Section 112(f) standards. The owner or operator of an 

existing source unable to comply with a relevant standard 

established under this part pursuant to section 112(f) of the 

Act may request that the Administrator grant an extension 

allowing the source up to 2 years after the standard's effective 

date to comply with the standard. The Administrator may grant 

such an extension if he/she finds that such additional period is 

necessary for the installation of controls and that steps will 

be taken during the period of the extension to assure that the 

health of persons will be protected from imminent endangerment. 
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Any request for an extension of compliance with a relevant 

standard under this paragraph shall be submitted in writing to 

the Administrator not later than 15 days after the effective 

date of the relevant standard.

(5) Requests for extensions of compliance for BACT or LAER. 

The owner or operator of an existing source who has installed 

BACT or technology required to meet LAER (as specified in 

paragraph (a)(2)(ii) of this section) prior to the promulgation 

of a relevant emission standard in this part may request that 

the Administrator grant an extension allowing the source 5 years 

from the date on which such installation was achieved, as 

determined by the Administrator, to comply with the standard. 

Any request for an extension of compliance with a relevant 

standard under this paragraph shall be submitted in writing to 

the Administrator not later than 120 days after the promulgation 

date of the standard. The Administrator may grant such an 

extension if he or she finds that the installation of BACT or 

technology to meet LAER controls the same pollutant (or stream 

of pollutants) that would be controlled at that source by the 

relevant emission standard.

(6) Contents of request. (i) The request for a compliance 

extension under paragraph (a)(4) of this section shall include 

the following information:
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(A) A description of the controls to be installed to comply 

with the standard;

(B) A compliance schedule, including the date by which each 

step toward compliance will be reached. At a minimum, the list 

of dates shall include:

(1) The date by which contracts for emission control 

systems or process changes for emission control will be awarded, 

or the date by which orders will be issued for the purchase of 

component parts to accomplish emission control or process 

changes;

(2) The date by which on-site construction, installation of 

emission control equipment, or a process change is to be 

initiated;

(3) The date by which on-site construction, installation of 

emission control equipment, or a process change is to be 

completed; and

(4) The date by which final compliance is to be achieved.

(C) A description of interim emission control steps, that 

will be taken during the extension period, including milestones 

to assure proper operation and maintenance of emission control 

and process equipment; and

(D) Whether the owner or operator is also requesting an 

extension of other applicable requirements (e.g., performance 

testing requirements).
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(ii) The request for a compliance extension under paragraph 

(a)(5) of this section shall include all information needed to 

demonstrate to the Administrator's satisfaction that the 

installation of BACT or technology to meet LAER controls the 

same pollutant (or stream of pollutants) that would be 

controlled at that source by the relevant emission standard.

(7) Additional advice. Advice on requesting an extension of 

compliance may be obtained from the Administrator.

(8) Approval of request for extension of compliance. 

Paragraphs (a)(9) through (14) of this section concern approval 

of an extension of compliance requested under paragraphs (a)(4) 

through (6) of this section.

(9) General. Based on the information provided in any 

request made under paragraphs (a)(4) through (6) of this 

section, or other information, the Administrator may grant an 

extension of compliance with an emission standard, as specified 

in paragraphs (a)(4) and (5) of this section.

(10) Contents of extension. The extension will be in 

writing and will—

(i) Identify each affected source covered by the extension;

(ii) Specify the termination date of the extension;

(iii) Specify the dates by which steps toward compliance 

are to be taken, if appropriate;
Page 179 of 197

(iv) Specify other applicable requirements to which the 

compliance extension applies (e.g., performance tests); and

(v)(A) Under paragraph (a)(4) of this section, specify any 

additional conditions that the Administrator deems necessary to 

assure installation of the necessary controls and protection of 

the health of persons during the extension period; or

(B) Under paragraph (a)(5)of this section, specify any 

additional conditions that the Administrator deems necessary to 

assure the proper operation and maintenance of the installed 

controls during the extension period.

(11) Progress reports. The owner or operator of an existing 

source that has been granted an extension of compliance under 

paragraph (a)(10) of this section may be required to submit to 

the Administrator progress reports indicating whether the steps 

toward compliance outlined in the compliance schedule have been 

reached. The contents of the progress reports and the dates by 

which they shall be submitted will be specified in the written 

extension of compliance granted under paragraph (a)(9) of this 

section.

(12) Notifications to owners and operators regarding 

compliance extensions for section 112(d) standards. (i) The 

Administrator will notify the owner or operator in writing of 

approval or intention to deny approval of a request for an 

extension of compliance within 30 days after receipt of 
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sufficient information to evaluate a request submitted under 

paragraph (a)(4)(i) or (a)(5) of this section. The 30-day 

approval or denial period will begin after the owner or operator 

has been notified in writing that his/her application is 

complete. The Administrator will notify the owner or operator in 

writing of the status of his/her application, that is, whether 

the application contains sufficient information to make a 

determination, within 30 days after receipt of the original 

application and within 30 days after receipt of any 

supplementary information that is submitted.

(ii) When notifying the owner or operator that his/her 

application is not complete, the Administrator will specify the 

information needed to complete the application and provide 

notice of opportunity for the applicant to present, in writing, 

within 30 days after he/she is notified of the incomplete 

application, additional information or arguments to the 

Administrator to enable further action on the application.

(iii) Before denying any request for an extension of 

compliance, the Administrator will notify the owner or operator 

in writing of the Administrator's intention to issue the denial, 

together with—

(A) Notice of the information and findings on which the 

intended denial is based; and
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(B) Notice of opportunity for the owner or operator to 

present in writing, within 15 days after he/she is notified of 

the intended denial, additional information or arguments to the 

Administrator before further action on the request.

(iv) The Administrator's final determination to deny any 

request for an extension will be in writing and will set forth 

the specific grounds on which the denial is based. The final 

determination will be made within 30 days after presentation of 

additional information or argument (if the application is 

complete), or within 30 days after the final date specified for 

the presentation if no presentation is made.

(13) Notifications to owners and operators regarding 

compliance extensions for section 112(f) standards. (i) The 

Administrator will notify the owner or operator in writing of 

approval or intention to deny approval of a request for an 

extension of compliance within 30 days after receipt of 

sufficient information to evaluate a request submitted under 

paragraph (a)(4)(ii) of this section. The 30-day approval or 

denial period will begin after the owner or operator has been 

notified in writing that his/her application is complete. The 

Administrator will notify the owner or operator in writing of 

the status of his/her application, that is, whether the 

application contains sufficient information to make a 

determination, within 15 days after receipt of the original 
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application and within 15 days after receipt of any 

supplementary information that is submitted.

(ii) When notifying the owner or operator that his/her 

application is not complete, the Administrator will specify the 

information needed to complete the application and provide 

notice of opportunity for the applicant to present, in writing, 

within 15 days after he/she is notified of the incomplete 

application, additional information or arguments to the 

Administrator to enable further action on the application.

(iii) Before denying any request for an extension of 

compliance, the Administrator will notify the owner or operator 

in writing of the Administrator's intention to issue the denial, 

together with—

(A) Notice of the information and findings on which the 

intended denial is based; and

(B) Notice of opportunity for the owner or operator to 

present in writing, within 15 days after he/she is notified of 

the intended denial, additional information or arguments to the 

Administrator before further action on the request.

(iv) A final determination to deny any request for an 

extension will be in writing and will set forth the specific 

grounds on which the denial is based. The final determination 

will be made within 30 days after presentation of additional 

information or argument (if the application is complete), or 
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within 30 days after the final date specified for the 

presentation if no presentation is made.

(14) Termination of extension. The Administrator may 

terminate an extension of compliance at an earlier date than 

specified if any specification under paragraphs (a)(10)(iii) or 

(iv) of this section is not met.

(15) [Reserved]

(16) Administrator's authority. The granting of an 

extension under this section shall not abrogate the 

Administrator's authority under section 114 of the Act.

(b) Waiver of performance tests —(1) Applicability of this 

section. Until a waiver of a performance testing requirement has 

been granted by the Administrator under this paragraph, the 

owner or operator of an affected source remains subject to the 

requirements of this section.

(2) General. Individual performance tests may be waived 

upon written application to the Administrator if, in the 

Administrator's judgment, the source is meeting the relevant 

standard(s) on a continuous basis, or the source is being 

operated under an extension of compliance, or the owner or 

operator has requested an extension of compliance and the 

Administrator is still considering that request.

(3) Request to waive a performance test. (i) If a request 

is made for an extension of compliance under paragraph (a) of 
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this section, the application for a waiver of an initial 

performance test shall accompany the information required for 

the request for an extension of compliance. If no extension of 

compliance is requested or if the owner or operator has 

requested an extension of compliance and the Administrator is 

still considering that request, the application for a waiver of 

an initial performance test shall be submitted at least 60 days 

before the performance test if a site-specific test plan is not 

submitted.

(ii) If an application for a waiver of a subsequent 

performance test is made, the application may accompany any 

required compliance progress report, compliance status report, 

or excess emissions and continuous monitoring system performance 

report, but it shall be submitted at least 60 days before the 

performance test if a site-specific test plan is not submitted.

(iii) Any application for a waiver of a performance test 

shall include information justifying the owner or operator's 

request for a waiver, such as the technical or economic 

infeasibility, or the impracticality, of the affected source

performing the required test.

(4) Approval of request to waive performance test. The 

Administrator will approve or deny a request for a waiver of a 

performance test made under paragraph (b)(3) of this section 

when he/she—
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(i) Approves or denies an extension of compliance under 

paragraph (a) of this section; or

(ii) Approves or disapproves a site-specific test plan; or

(iii) Makes a determination of compliance following the 

submission of a required compliance status report or excess 

emissions and continuous monitoring systems performance report; 

or

(iv) Makes a determination of suitable progress towards 

compliance following the submission of a compliance progress 

report, whichever is applicable.

(5) Administrator's authority. Approval of any waiver 

granted under this section shall not abrogate the 

Administrator's authority under the Act or in any way prohibit 

the Administrator from later canceling the waiver. The 

cancellation will be made only after notice is given to the 

owner or operator of the affected source.

(c) Use of an alternative monitoring method —(1) General. 

Until permission to use an alternative monitoring method has 

been granted by the Administrator under this paragraph, the 

owner or operator of an affected source remains subject to the 

requirements of this section and the relevant standard.

(2) Alternatives to monitoring methods. After receipt and 

consideration of written application, the Administrator may 
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approve alternatives to any monitoring methods or procedures of 

this part including, but not limited to, the following:

(i) Alternative monitoring requirements when installation 

of a CMS specified by a relevant standard would not provide 

accurate measurements due to liquid water or other interferences 

caused by substances within the effluent gases;

(ii) Alternative monitoring requirements when the affected 

source is infrequently operated;

(iii) Alternative monitoring requirements to accommodate 

CEMS that require additional measurements to correct for stack 

moisture conditions;

(iv) Alternative locations for installing CMS when the 

owner or operator can demonstrate that installation at alternate 

locations will enable accurate and representative measurements;

(v) Alternate methods for converting pollutant 

concentration measurements to units of the relevant standard;

(vi) Alternate procedures for performing daily checks of 

zero (low-level) and high-level drift that do not involve use of 

high-level gases or test cells;

(vii) Alternatives to the American Society for Testing and 

Materials (ASTM) test methods or sampling procedures specified 

by any relevant standard;

(viii) Alternative CMS that do not meet the design or 

performance requirements in this part, but adequately 
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demonstrate a definite and consistent relationship between their 

measurements and the measurements of opacity by a system 

complying with the requirements as specified in the relevant 

standard. The Administrator may require that such demonstration 

be performed for each affected source; or

(ix) Alternative monitoring requirements when the effluent 

from a single affected source or the combined effluent from two 

or more affected sources is released to the atmosphere through 

more than one point.

(3) Conflicts between alternative and required methods. If 

the Administrator finds reasonable grounds to dispute the 

results obtained by an alternative monitoring method, 

requirement, or procedure, the Administrator may require the use 

of a method, requirement, or procedure specified in this section 

or in the relevant standard. If the results of the specified and 

alternative method, requirement, or procedure do not agree, the 

results obtained by the specified method, requirement, or 

procedure shall prevail.

(4)(i) Request to use alternative monitoring method. An 

owner or operator who wishes to use an alternative monitoring 

method shall submit an application to the Administrator as 

described in paragraph (c)(4)(ii) of this section. The 

application may be submitted at any time provided that the 

monitoring method is not used to demonstrate compliance with a 
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relevant standard or other requirement. If the alternative 

monitoring method is to be used to demonstrate compliance with a 

relevant standard, the application shall be submitted not later 

than with the site-specific test plan required, or with the 

site-specific performance evaluation plan (if requested), or at 

least 60 days before the performance evaluation is scheduled to 

begin.

(ii) The application shall contain a description of the 

proposed alternative monitoring system and a performance 

evaluation test plan, if required. In addition, the application 

shall include information justifying the owner or operator's 

request for an alternative monitoring method, such as the 

technical or economic infeasibility, or the impracticality, of 

the affected source using the required method.

(iii) The owner or operator may submit the information 

required in this paragraph well in advance of the submittal 

dates specified in paragraph (c)(4)(i) of this section to ensure 

a timely review by the Administrator in order to meet the 

compliance demonstration date specified in this section or the 

relevant standard.

(5) Approval of request to use alternative monitoring 

method. (i) The Administrator will notify the owner or operator 

of approval or intention to deny approval of the request to use 

an alternative monitoring method within 30 days after receipt of 
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the original request and within 30 days after receipt of any 

supplementary information that is submitted. Before disapproving 

any request to use an alternative monitoring method, the 

Administrator will notify the applicant of the Administrator's 

intention to disapprove the request together with—

(A) Notice of the information and findings on which the 

intended disapproval is based; and

(B) Notice of opportunity for the owner or operator to 

present additional information to the Administrator before final 

action on the request. At the time the Administrator notifies 

the applicant of his or her intention to disapprove the request, 

the Administrator will specify how much time the owner or 

operator will have after being notified of the intended 

disapproval to submit the additional information.

(ii) The Administrator may establish general procedures and 

criteria in a relevant standard to accomplish the requirements 

of paragraph (c)(5)(i) of this section.

(iii) If the Administrator approves the use of an 

alternative monitoring method for an affected source under 

paragraph (c)(5)(i) of this section, the owner or operator of 

such source shall continue to use the alternative monitoring 

method until he or she receives approval from the Administrator 

to use another monitoring method as allowed by this subpart or a 

subpart referenced by this subpart.
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(6) Alternative to the relative accuracy test. An 

alternative to the relative accuracy test for CEMS specified in 

a relevant standard may be requested as follows:

(i) Criteria for approval of alternative procedures. An 

alternative to the test method for determining relative accuracy 

is available for affected sources with emission rates 

demonstrated to be less than 50 percent of the relevant 

standard. The owner or operator of an affected source may 

petition the Administrator under paragraph (c)(6)(ii) of this 

section to substitute the relative accuracy test in section 7 of 

Performance Specification 2 with the procedures in section 10 if 

the results of a performance test conducted according to the 

requirements specified in this subpart or subpart referenced by 

this subpart demonstrate that the emission rate of the pollutant 

of interest in the units of the relevant standard is less than 

50 percent of the relevant standard. For affected sources 

subject to emission limitations expressed as control efficiency 

levels, the owner or operator may petition the Administrator to 

substitute the relative accuracy test with the procedures in 

section 10 of Performance Specification 2 if the control device 

exhaust emission rate is less than 50 percent of the level 

needed to meet the control efficiency requirement. The 

alternative procedures do not apply if the CEMS is used 

continuously to determine compliance with the relevant standard.
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(ii) Petition to use alternative to relative accuracy test. 

The petition to use an alternative to the relative accuracy test 

shall include a detailed description of the procedures to be 

applied, the location and the procedure for conducting the 

alternative, the concentration or response levels of the 

alternative relative accuracy materials, and the other equipment 

checks included in the alternative procedure(s). The 

Administrator will review the petition for completeness and 

applicability. The Administrator's determination to approve an 

alternative will depend on the intended use of the CEMS data and 

may require specifications more stringent than in Performance 

Specification 2.

(iii) Rescission of approval to use alternative to relative 

accuracy test. The Administrator will review the permission to 

use an alternative to the CEMS relative accuracy test and may 

rescind such permission if the CEMS data from a successful 

completion of the alternative relative accuracy procedure 

indicate that the affected source's emissions are approaching 

the level of the relevant standard. The criterion for reviewing 

the permission is that the collection of CEMS data shows that 

emissions have exceeded 70 percent of the relevant standard for 

any averaging period, as specified in the relevant standard. For 

affected sources subject to emission limitations expressed as 

control efficiency levels, the criterion for reviewing the 
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permission is that the collection of CEMS data shows that 

exhaust emissions have exceeded 70 percent of the level needed 

to meet the control efficiency requirement for any averaging 

period, as specified in the relevant standard. The owner or 

operator of the affected source shall maintain records and 

determine the level of emissions relative to the criterion for 

permission to use an alternative for relative accuracy testing. 

If this criterion is exceeded, the owner or operator shall 

notify the Administrator within 10 days of such occurrence and 

include a description of the nature and cause of the increased 

emissions. The Administrator will review the notification and 

may rescind permission to use an alternative and require the 

owner or operator to conduct a relative accuracy test of the 

CEMS as specified in section 7 of Performance Specification 2.

(d) Waiver of recordkeeping or reporting requirements. (1) 

Until a waiver of a recordkeeping or reporting requirement has 

been granted by the Administrator under this paragraph, the 

owner or operator of an affected source remains subject to the 

recordkeeping and reporting requirements of this subpart and any 

subparts referenced by this subpart.

(2) Recordkeeping or reporting requirements may be waived 

upon written application to the Administrator if, in the 

Administrator's judgment, the affected source is achieving the 

relevant standard(s), or the source is operating under an 
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extension of compliance, or the owner or operator has requested 

an extension of compliance and the Administrator is still 

considering that request.

(3) If an application for a waiver of recordkeeping or 

reporting is made, the application shall accompany the request 

for an extension of compliance under paragraph (a) of this 

section, any required compliance progress report or compliance 

status report required under this part or in the source's title 

V permit, or an excess emissions and continuous monitoring 

system performance report required under §63.999(c) or another 

subpart referenced by this subpart, whichever is applicable. The 

application shall include whatever information the owner or 

operator considers useful to convince the Administrator that a 

waiver of recordkeeping or reporting is warranted.

(4) The Administrator will approve or deny a request for a 

waiver of recordkeeping or reporting requirements under this 

paragraph when he/she—

(i) Approves or denies an extension of compliance under 

paragraph (a) of this section; or

(ii) Makes a determination of compliance following the 

submission of a required Notification of Compliance Status 

report or excess emissions and continuous monitoring systems 

performance report; or
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(iii) Makes a determination of suitable progress towards 

compliance following the submission of a compliance progress 

report, whichever is applicable.

(5) A waiver of any recordkeeping or reporting requirement 

granted under this paragraph may be conditioned on other 

recordkeeping or reporting requirements deemed necessary by the 

Administrator.

(6) Approval of any waiver granted under this section shall 

not abrogate the Administrator's authority under the Act or in 

any way prohibit the Administrator from later canceling the 

waiver. The cancellation will be made only after notice is given 

to the owner or operator of the affected source.

§63.1113 Procedures for approval of alternative means of 

emission limitation.

(a) Alternative means of emission limitation. An owner or 

operator of an affected source may request a determination of 

alternative means of emission limitation to the requirements of 

design, equipment, work practice, or operational standards of 

this subpart or of a subpart referenced by this subpart. If, in 

the judgment of the Administrator, an alternative means of 

emission limitation will achieve a reduction in HAP emissions at 

least equivalent to the reduction in emissions from that source 

achieved under any design, equipment, work practice, or 

operational standards (but not performance standards) in this 
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subpart, the Administrator will publish in the Federal Register 

a notice permitting the use of the alternative means for 

purposes of compliance with that requirement.

(1) The notice may condition the permission on requirements 

related to the operation and maintenance of the alternative 

means.

(2) Any such notice shall be published only after public 

notice and an opportunity for a hearing.

(b) Content of submittal. (1) In order to obtain approval, 

any person seeking permission to use an alternative means of 

compliance under this section shall collect, verify, and submit 

to the Administrator information showing that the alternative 

means achieves equivalent emission reductions. An owner or 

operator of an affected source seeking permission to use an 

alternative means of compliance who has not previously performed 

testing shall also submit a proposed test plan. If the owner or 

operator seeks permission to use an alternative means of 

compliance based on previously performed testing, they shall 

submit the results of testing, a description of the procedures 

followed in testing or monitoring, and a description of 

pertinent conditions during testing or monitoring.

(2) The owner or operator who requests an alternative means 

of emissions limitation shall submit a description of the 

proposed testing, monitoring, recordkeeping, and reporting that 
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will be used and the proposed basis for demonstrating 

compliance.

(3) For storage vessels, the owner or operator shall 

include the results of actual emissions tests using full-size or 

scale-model storage vessels that accurately collect and measure 

all regulated HAP emissions using a given control technique, and 

that accurately simulate wind and account for other emission 

variables such as temperature and barometric pressure, or an 

engineering analysis that the Administrator determines to be an 

accurate method of determining equivalence.

(4) For proposed alternatives to equipment leak 

requirements referenced by this subpart, the owner or operator 

shall also submit the information specified in and meet the 

requirements for alternate means of emission limitation 

specified in the referenced subparts.

§63.1114 Implementation and enforcement.

(a) This subpart can be implemented and enforced by the 

U.S. Environmental Protection Agency (EPA), or a delegated 

authority such as the applicable State, local, or tribal agency. 

If the EPA Administrator has delegated authority to a State, 

local, or tribal agency, then that agency has the authority to 

implement and enforce this subpart. Contact the applicable EPA 

Regional Office to find out if this subpart is delegated to a 

State, local, or tribal agency.
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(b) In delegating implementation and enforcement authority 

of this subpart to a State, local, or tribal agency under 40 CFR 

part 63, subpart E, the authorities contained in paragraphs 

(b)(1) through (5) of this section are retained by the EPA 

Administrator and are not transferred to the State, local, or 

tribal agency.

(1) Approval of alternatives to the nonopacity emissions 

standards in §63.1103(a)(3), (b)(3) through (5), (c)(3), (d)(3), 

(e)(3), (f)(3), (g)(3) and (4), and (h)(3) under §63.6(g). 

Follow the requirements in §63.1113 to request permission to use 

an alternative means of emission limitation. Where these 

standards reference another subpart, the cited provisions will 

be delegated according to the delegation provisions of the 

referenced subpart.

(2) [Reserved]

(3) Approval of major changes to test methods under 

§63.7(e)(2)(ii) and (f) and as defined in §63.90.

(4) Approval of major changes to monitoring under §63.8(f) 

and as defined in §63.90.

(5) Approval of major changes to recordkeeping and 

reporting under §63.10(f) and as defined in §63.90.