Commenters wishing to submit proprietary information for consideration must clearly distinguish such information from other comments and clearly label it as CBI. Send submissions containing such proprietary information directly to the following address, and not to the public docket, to ensure that proprietary information is not inadvertently placed in the docket: Attention: Mr. William Schrock; c/o OAQPS Document Control Officer (Room 740B); U.S. Environmental Protection Agency; 411 W. Chapel Hill Street; Durham, NC 27701. We will disclose information identified as CBI only to the extent allowed by the procedures set forth in 40 CFR part 2. If no claim of
confidentiality accompanies a submission when we receive it, the information may be made available to the public without further notice to the commenter.

Public Hearing. Persons interested in presenting oral testimony or inquiring as to whether a hearing is to be held should contact Ms. Maria Noell at least 2 days in advance of the public hearing. Persons interested in attending such a public hearing must also contact Ms. Noell to verify the time, date, and location of the hearing. The address, telephone number, and email address for Ms. Noell are listed in the preceding FOR FURTHER INFORMATION CONTACT section. If a public hearing is held, it will provide interested parties the opportunity to present data, views, or arguments concerning these proposed emission standards.

Docket. The docket is an organized and complete file of all the information considered by us in the development of this rulemaking. The docket is a dynamic file because material is added throughout the rulemaking process. The docketing system is intended to allow members of the public and industries involved to readily identify and locate documents so that they can effectively participate in the rulemaking process. Along with the proposed and promulgated standards and their preambles, the contents of the docket will serve as the record in the case of judicial review. (See section 307(d)(7)(A) of the CAA.) The regulatory text and other materials related to this rulemaking are available for review in the docket or copies may be mailed on request from the Air Docket by calling (202) 2607548. A reasonable fee may be charged for copying docket materials.

Worldwide Web (WWW). In addition to being available in the docket, an electronic copy of today's proposed rule will also be available on the WWW through the Technology Transfer Network (TTN). Following the Administrator's signature, a copy of the rule will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules http://www.epa.gov/ttn/oarpg. The TTN provides information and technology exchange in various areas of air pollution control. If more information regarding the TTN is needed, call the TTN HELP line at (919) 5415384.

Regulated Entities. Categories and entities potentially regulated by this action include those listed in the following table. [[Page 52167]]
Examples of Category SIC NAICS regulated entities Industry......................... 3089 326199 cellulose food casing operations. cellophane operations. cellulosic sponge operations. 2821 325211 cellulosic sponge operations. 2823 325221 rayon
2819 325188 operations. 2869 325199 cellulose ether operations.

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. To determine whether your process operation is regulated by this action, you should examine the applicability criteria in Sec. 63.5481 of the proposed rule. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Outline. The information presented in this preamble is organized as follows:
I. Background
A. What is the source of authority for development of NESHAP? B. What criteria are used in the development of NESHAP?
C. What is the history of the source categories?
D. What are the health effects associated with the pollutants emitted from cellulose products manufacturing operations?
II. Summary of the Proposed Rule
A. What source categories and subcategories are affected by this proposed rule?
B. What are the primary sources of HAP emissions and what are the emissions?
C. What is the affected source?
D. What are the emission limits, operating limits and other standards?
E. What are the testing and initial compliance requirements? F. What are the continuous compliance provisions?
G. What are the notification, recordkeeping and reporting
requirements?
III. Rationale for Selecting the Proposed Standards
A. How did we select the source categories?
B. How did we select any subcategories?
C. How did we select the affected source?
D. How did we determine the basis and level of the proposed standards for the Viscose Processes source category?
E. How did we determine the basis and level of the proposed standards for the Cellulose Ethers source category?
F. How did we select the form of the standards?
G. How did we select the alternative standards?
H. How did we select the standards for the Viscose Processes source category?
I. How did we select the standards for the Cellulose Ethers source category?
J. How did we select the testing and initial compliance
requirements?
K. How did we select the continuous compliance requirements? L. How did we select the notification, reporting, and recordkeeping requirements?
M. What is the relationship of this rule to other rules?
IV. Summary of Environmental, Energy and Economic Impacts
A. What are the air quality impacts?
B. What are the cost impacts?
C. What are the economic impacts?
D. What are the nonair health, environmental and energy impacts? V. Solicitation of Comments and Public Participation
VI. Administrative Requirements
A. Executive Order 12866, Regulatory Planning and Review
B. Executive Order 13132, Federalism
C. Executive Order 13084, Consultation and Coordination with Indian Tribal Governments
D. Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks
E. Unfunded Mandates Reform Act of 1995
F. Regulatory Flexibility Act (RFA), as amended by the Small Business Regulatory Enforcement Fairness Act of 1966 (SBREFA), 5 U.S.C. 601 et. Seq.
G. Paperwork Reduction Act
H. National Technology Transfer and Advancement Act of 1995 I. Background
A. What is the source of authority for development of NESHAP?

The CAA was enacted, in part, ``to protect and enhance the quality of the Nation's air resources so as to promote the public health and welfare and the productive capacity of its population * * *'' (section 101(b)(1) of the CAA). Section 112 of the CAA requires us to list categories and subcategories of major sources and area sources of HAP and to establish NESHAP for the listed source categories and subcategories. The categories of major sources covered by today's proposed NESHAP were listed on the following dates: Cellulose Food Casings, Rayon, Cellophane, Methyl Cellulose, Carboxymethyl Cellulose, and Cellulose EthersJuly 16, 1992 (57 FR 31576); and Cellulosic SpongesNovember 18, 1999 (64 FR 63026). Major sources of HAP are those that have the potential to emit greater than 10 ton/yr of any one HAP or 25 ton/yr of any combination of HAP.

B. What criteria are used in the development of NESHAP?

Section 112 of the CAA requires that we establish NESHAP for the control of HAP from both new and existing major sources. The CAA requires the NESHAP to reflect the maximum degree of reduction in emissions of HAP that is achievable. This level of control is commonly referred to as the MACT.

The MACT floor is the minimum control level allowed for NESHAP and is defined under section 112(d)(3) of the CAA. In essence, the MACT floor ensures that the standard is set at a level that assures that all major sources achieve the level of control at least as stringent as that already achieved by the bettercontrolled and loweremitting sources in each source category or subcategory. For new sources, the MACT floor cannot be less stringent than the emission control that is achieved in practice by the bestcontrolled similar source. The MACT standards for existing sources can be less stringent than standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the bestperforming 12 percent of existing sources in the category or subcategory (or the bestperforming 5 sources for categories or subcategories with fewer than 30 sources).

In developing MACT, we also consider control options that are more stringent than the floor. We may establish standards more stringent than the floor based on the consideration of cost of achieving the emissions reductions, any nonair quality health and environmental impacts, and energy requirements.
C. What is the history of the source categories?

1. Listing the Initial Source Categories

Section 112 of the CAA requires us to establish emission standards for categories of stationary sources that emit HAP. On July 16, 1992, we published an initial list of source categories to be regulated (57 FR 31576). Today's proposed rule groups the various cellulose products manufacturing industries included in the initial list with another industry recently added to the list and combines them to create two new source categories.

The initial source category list included separate source categories for various cellulose products manufacturing industries. These source categories are Cellulose Food Casings, Rayon, Cellophane, Methyl Cellulose, Carboxymethyl Cellulose, and Cellulose Ethers. The Cellulose Ethers source
[[Page 52168]]
category on the initial list included the hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose industries. 2. Adding Another Source Category

In developing this proposed rule, we identified another cellulose products manufacturing industry, cellulosic sponge manufacturing, that was not on the initial source category list. Based on information we obtained while gathering data for this proposed rule, we determined that the production of cellulosic sponges is similar to the production of some of the other cellulose products (cellulose food casings, rayon, and cellophane). We found similarities in raw materials, process operations, emission characteristics, and control device applicability. We added Cellulosic Sponges to the source category list under section 112(c) of the CAA on November 18, 1999 (64 FR 63026).

3. Reducing to Two Source Categories

In developing the proposed rule, we decided to combine the various cellulose products manufacturing source categories on the initial source category list with the Cellulosic Sponge source category that was listed November 18, 1999. Then we split out the Cellulose Food Casing, Rayon, Cellophane, and Cellulosic Sponge manufacturing industries and combined them to create a new source category named ``Viscose Processes.'' We split out the various cellulose ether industries (Methyl Cellulose, Carboxymethyl Cellulose, and Cellulose Ethers) and combined them to create a new source category named ``Cellulose Ethers.''

Within each new source category (Viscose Processes and Cellulose Ethers), we found similarities in raw materials, process operations, emission characteristics, and control device applicability. Based on these factors, we concluded that separate MACT standards were not warranted for each of the individual cellulose products source categories on the source category list.

Instead, we believe that it is technically feasible to regulate emissions from a variety of viscose process operations (or a variety of cellulose ether operations) by a single set of standards. Similar to the Hazardous Organic NESHAP (HON) for the Synthetic Organic Chemical Manufacturing Industry (SOCMI), we are proposing separate requirements for process vents, storage vessels, equipment leaks, and wastewater HAP emission points.

One set of standards for each of the two new source categories would ensure that process equipment with comparable HAP emissions and control technologies are subject to consistent emission control requirements. In addition, some of the cellulose ether operations are collocated within individual plants. Plants with collocated cellulose ether manufacturing operations could more easily comply with one set of standards than with individual standards for each of the collocated process operations.
D. What are the health effects associated with the pollutants emitted from cellulose products manufacturing operations?

Today's proposed rule protects air quality and promotes the public health by reducing emissions of some of the HAP listed in section 112(b)(1) of the CAA. Available emission data, collected as we developed this proposed rule, show that CS2, COS, and toluene are the HAP emitted in the greatest quantities from viscose process operations. Ethylene oxide, methanol, methyl chloride, and propylene oxide are the HAP emitted in the greatest quantities from cellulose ether operations. Exposure to these HAP has been demonstrated to cause adverse health effects.

This section describes the adverse health effects associated with the exposure to these specific HAP. The adverse health effects resulting from exposure to HAP can range from mild to severe. The severity of health effects resulting from HAP exposure depends on: (1) Concentrations of HAP in the area; (2) the amount of time a person is exposed; and (3) characteristics of exposed individuals (such as genetics, age, preexisting health conditions, and lifestyle) which vary significantly among the population. Exposure is also influenced by sourcespecific characteristics (such as emission rates and local meteorological conditions), as well as pollutantspecific

characteristics.

The HAP that this proposed rule would control are associated with a variety of adverse health effects. These adverse health effects include chronic health disorders (such as effects on the central nervous and reproductive systems) and acute health disorders (such as irritation of eyes, throat, and mucous membranes and narcotic effects). Three of the HAP have been classified as probable or possible human carcinogens. In general, these findings have only been shown with concentrations higher than those typically found in the ambient air.

We do not have the kind of current, detailed data on the operations covered by today's proposed rule (and the people living around the operations) that are necessary to determine the actual population exposures to the HAP emitted from these operations and the potential for resultant health effects. Therefore, we do not know the extent to which the adverse health effects described above occur in the populations surrounding these operations. However, to the extent the adverse effects do occur, this proposed rule will reduce emissions and subsequent exposures.
1. Health Effects Associated with HAP Emitted from Viscose Process Operations

Acute (shortterm) inhalation exposure of humans to CS2 has caused changes in breathing and chest pains. Nausea, vomiting, dizziness, fatigue, headache, mood changes, lethargy, blurred vision, delirium, and convulsions have also been reported in humans acutely exposed by inhalation. Neurologic effects, including behavioral and neurophysiological changes, have been observed in chronic (longterm) human and animal inhalation studies. Reproductive effects, such as decreased sperm count and menstrual disturbances, have been observed in humans exposed to CS2 by inhalation. Developmental effects, including birth defects, toxicity to the embryo, and functional and behavioral disturbances, have been observed in animal studies. We have not classified CS2 with respect to potential human carcinogenicity.

Acute (shortterm) inhalation of high concentrations of COS may cause narcotic effects in humans. Carbonyl sulfide may also irritate the eyes and skin in humans. No information is available on the chronic (longterm), reproductive, developmental, or carcinogenic effects of COS in humans. We have not classified COS with respect to potential human carcinogenicity.

Acute (shortterm) inhalation of toluene by humans may cause effects to the central nervous system (CNS), such as fatigue, sleepiness, headache, and nausea, as well as irregular heartbeat. Adverse CNS effects have been reported in chronic abusers exposed to high levels of toluene. Symptoms include tremors, decreased brain size, involuntary eye movements, and impaired speech, hearing, and vision. Chronic (longterm) inhalation exposure of humans to lower levels of toluene also causes irritation of the upper respiratory tract, eye irritation, sore throat, nausea, dizziness, headaches, and difficulty with sleep. Studies of
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children of pregnant women exposed by inhalation to toluene or to mixed solvents have reported CNS problems, facial and limb abnormalities, and delayed development. However, these effects may not be attributable to toluene alone.
2. Health Effects Associated with HAP Emitted from Cellulose Ether Operations

The acute (shortterm) effects of ethylene oxide in humans consist mainly of CNS depression and irritation of the eyes and mucous membranes. High concentrations of ethylene oxide produce weakness, nausea, bronchitis, pulmonary edema, emphysema, and death. Chronic (longterm) exposure to ethylene oxide in humans can cause irritation of the eyes, skin, and mucous membranes, and adversely affect the functioning of the brain and nerves. Limited evidence from animal and human studies indicates that inhalation exposure to ethylene oxide may result in adverse reproductive effects, such as an increased rate of miscarriages. Some limited human cancer data suggest an increase in the incidence of leukemia, stomach cancer, cancer of the pancreas, and Hodgkin's disease in workers exposed to ethylene oxide. Ethylene oxide has been shown to cause lung, gland, and uterine tumors in laboratory animals. We have classified ethylene oxide as a Group B1 (probable) human carcinogen.

Acute (shortterm) or chronic (longterm) exposure of humans to methanol by inhalation or ingestion may result in blurred vision, headache, dizziness, and nausea. No information is available on the reproductive, developmental, or carcinogenic effects of methanol in humans. Birth defects have been observed in the offspring of rats and mice exposed to methanol by inhalation. A methanol inhalation study using rhesus monkeys reported a decrease in the length of pregnancy and limited evidence of impaired learning ability in offspring. We have not classified methanol with respect to potential human carcinogenicity.

Acute (shortterm) exposure to high concentrations of methyl chloride in humans causes severe neurological effects, including convulsions, coma, and death. Methyl chloride also affects the heart rate, blood pressure, liver, and kidney function in humans. No information is available regarding chronic (longterm) systemic effects of methyl chloride in humans, but animal studies have reported effects to the liver, kidney, spleen, and CNS. No information is available concerning developmental or reproductive effects of methyl chloride in humans. Inhalation studies have demonstrated that methyl chloride causes reproductive effects in male rats, with effects such as testicular lesions and decreased sperm production. We have classified methyl chloride as a Group C (possible) human carcinogen on the basis of limited human data and animal studies that have reported kidney tumors in male mice.

Acute (shortterm) exposure of workers to propylene oxide may cause CNS effects, such as headache, weakness, loss of coordination, and coma. Propylene oxide also irritates the eyes and respiratory tract, causing coughing and difficulty in breathing, possibly leading to pulmonary edema and pneumonia. Health effects from chronic propylene oxide exposure in humans have not been reported. Chronic (longterm) animal studies have reported neurological disorders and inflammatory lesions of the nasal cavity, trachea, and lungs. We have classified propylene oxide as a Group B2 (probable) human carcinogen on the basis of nasal tumors observed in rodents exposed by inhalation.
II. Summary of the Proposed Rule
A. What source categories and subcategories are affected by this proposed rule?

Today's proposed rule applies to the Viscose Processes source category and the Cellulose Ethers source category. There are no subcategories.
B. What are the primary sources of HAP emissions and what are the emissions?

The primary sources of HAP emissions at cellulose products manufacturing operations are process vents, storage vessels, equipment leaks, and wastewater systems. Total baseline HAP emissions for all cellulose products manufacturing operations at the current level of control are 20,700 ton/yr. Baseline emissions from process vents account for most of the emissions, or approximately 92 percent of the total. Baseline emissions from wastewater, equipment leaks, and storage vessels account for approximately 4 percent, 3 percent, and 1 percent of the total, respectively.

C. What is the affected source?

The affected source for the Viscose Processes source category is the sum of all operations engaged in the production of cellulose food casing, rayon, cellophane, or cellulosic sponge. The affected source for the Cellulose Ethers source category is the sum of all operations engaged in the production of cellulose ethers.
D. What are the emission limits, operating limits and work practice standards?

As provided under the authority of CAA section 112(h), we are proposing the requirements of this rule in the form of emission limits (such as mass rate, percent reduction, and concentration emission limits), operating limits, and work practice standards. Work practice standards include design, equipment, work practices, and operational standards.

In establishing HAP emission limits for viscose process affected sources, we selected total sulfide emissions as a surrogate for HAP emissions of CS2 and COS. We are defining total sulfide emissions as the sum of all CS2, COS, and H2S emissions (reported as CS2). (Emissions of H2S are included because they are generated from byproducts of the CS2 reactions in the viscose process operation.) We are requiring owners and operators of cellulose food casing, rayon, cellophane, and cellulosic sponge operations at both new and existing viscose process affected sources to reduce the total sulfide emissions from their process vents by a specified percentage, which is unique to the type of viscose process operation.

We are requiring owners and operators of any of the three types of cellulose ether operations at both new and existing cellulose ether affected sources to reduce the total HAP emissions from their process vents by 99 percent. The HAP included in total HAP vary for each cellulose ether operation, depending on the cellulose ether product being manufactured.

We are requiring owners and operators of cellulose food casing, rayon, cellophane, and cellulosic sponge operations at both new and existing viscose process affected sources to control the CS2 emissions from their CS2 unloading and storage operations by complying with one of the following options: (1) Reducing
CS2 emissions by at least 83 percent using any compliance method, or (2) installing a nitrogen system for CS2 unloading and storage, or (3) obtaining an equivalent emission reduction from elsewhere in the viscose process (such as process vents).

We are requiring owners and operators of cellulose ether operations at both new and existing cellulose ether affected sources to reduce the HAP emissions from their wastewater by complying with the applicable process wastewater provisions in subpart G of 40 CFR part 63.

We are requiring owners and operators of cellulose ether operations at both new and existing cellulose ether
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affected sources to reduce the HAP emissions from equipment leaks by complying with the equipment leak provisions in subpart H of 40 CFR part 63. We are considering allowing owners or operators that can demonstrate that they are below a certain number of leaks an alternative to complying with the equipment leak provisions in subpart H; that is, they may comply with the equipment leak provisions in the proposed subpart F of 40 CFR part 65 (65 FR 57837, October 28, 1998) after it becomes final and we evaluate its requirements.

It is generally not cost effective for owners and operators of these affected sources to continuously test the emission control devices to ensure continuous compliance with the emission standards. Therefore, for the most likely control devices to be used, this proposed rule specifies operating parameters that can be monitored to demonstrate continuous compliance. This proposed rule also specifies operating limits for these parameters. We have established operating limits for carbon adsorbers, thermal oxidizers, condensers, biofilters, oil absorbers, wet scrubbers, and flares.

Owners and operators of affected sources that use a control device other than those listed in this proposed rule may establish operating limits for the appropriate operating parameters subject to prior written approval from the Administrator. The owners and operators must submit for approval a proposed sitespecific monitoring plan that includes a description of the alternative control device, test results verifying the performance of the control device, the appropriate operating parameters that will be monitored, and the frequency of measuring and recording to establish continuous compliance with the operating limits. The owners and operators of the affected sources must install, operate, and maintain the parameter monitoring system for the alternative control device in accordance with the monitoring plan approved by the Administrator. The owners and operators will also establish operating limits during the initial performance test based on the operating parameters for the alternative control device included in the approved monitoring plan.

Owners and operators of affected sources that use a control device listed in this proposed rule may establish operating limits for alternative operating parameters subject to prior written approval by the Administrator. The owner and operators must submit the application for approval of alternative operating parameters no later than the notification of the performance test. The application must include information justifying the request for alternative operating parameters (such as the infeasibility or impracticality of using the operating parameters in this proposed rule), a description of the proposed alternative control device operating parameters, the monitoring approach, the frequency of measuring and recording the alternative parameters, the averaging period for the operating limits, how the operating limits are to be calculated, and information documenting that the alternative operating parameters would provide equivalent or better assurance of compliance with the relevant emission limit. The owners and operators of the affected sources must install, operate, and maintain the alternative parameter monitoring systems in accordance with the application approved by the Administrator. The owners and operators will establish operating limits during the initial performance test based on the alternative operating parameters included in the approved application.
E. What are the testing and initial compliance requirements?

We are requiring owners and operators of all affected sources to conduct an initial performance test using specified EPA test methods to demonstrate initial compliance with the emission limits for process vents. The owner or operator would test at the inlet and outlet to the control device and at the stack(s) for the process operation and, using these results, calculate a percent reduction of emissions.

We are also requiring owners and operators of all viscose process affected sources to prepare a material balance that documents HAP usage and HAP emissions at the affected source. The material balance would be based on HAP emissions information from the initial performance test and HAP usage information from records at the affected source.

Prior to the initial performance test, owners and operators of affected sources are required to install the parameter monitoring equipment to be used to demonstrate compliance with the operating limits. During the initial test, the owners or operators would use the parameter monitoring equipment to establish operating parameter limits.

We are requiring owners and operators of cellulose food casing, rayon, cellophane, and cellulosic sponge operations at new and existing viscose process affected sources to demonstrate initial compliance with the emission limits and work practice standards for CS2 unloading and storage operations by: (1) Documenting an 85 percent reduction in emissions from CS2 unloading and storage operations; or (2) certifying that a nitrogen system is being used in CS2 unloading and storage operations to prevent emissions; or (3) complying with the initial compliance requirements for process vents at viscose process affected sources, such that the total emission reductions from process vents equals the required emission reductions from both process vents and CS2 unloading and storage operations.

We are requiring owners and operators of cellulose ether operations at new and existing cellulose ether affected sources to comply with the initial compliance provisions for process wastewater in subpart G of 40 CFR part 63.

We are requiring owners and operators of cellulose ether operations at new and existing cellulose ether affected sources to comply with the initial compliance provisions for equipment leaks in subpart H of 40 CFR part 63.

F. What are the continuous compliance provisions?

We are requiring owners and operators of all affected sources to monitor and record the operating parameters established during the initial performance test and calculate average operating parameter values averaged over the period of time specified in this proposed rule to demonstrate continuous compliance with the operating limits.

We are also requiring owners and operators of all viscose process affected sources to maintain the material balance documenting HAP usage and HAP emissions that they established as part of their initial compliance requirements. The owners and operators would use the HAP usage and HAP emissions information from the material balance to calculate the percent reduction in emissions and demonstrate continuous compliance with the emission limits.

We are requiring owners and operators of cellulose food casing, rayon, cellophane, and cellulosic sponge operations at new and existing viscose process affected sources to demonstrate continuous compliance with the emission limits and work practice standards for CS2 unloading and storage operations by: (1) Keeping a record documenting the 85 percent reduction in emissions; or (2) keeping a record certifying that a nitrogen system is being used; or (3) complying with the continuous compliance requirements for process vents at viscose process affected
[[Page 52171]]
sources, such that the total emission reductions from process vents equals the required emission reductions from both process vents and CS2 unloading and storage operations.

We are requiring owners and operators of cellulose ether operations at new and existing cellulose ether affected sources to comply with the continuous compliance provisions for process wastewater in subpart G of 40 CFR part 63.

We are requiring the owners and operators of cellulose ether operations at new and existing cellulose ether affected sources to comply with the continuous compliance provisions for equipment leaks in subpart H of 40 CFR part 63.
G. What are the notification, reporting, and recordkeeping requirements?

We are requiring owners and operators of all affected sources to submit initial notifications, notifications of performance tests, and notifications of compliance status by the specified dates in the proposed rule, which may vary depending on whether the affected source is new or existing.

We are also requiring owners and operators of all affected sources to submit semiannual compliance reports. In addition, if an owner or operator undertakes action that is inconsistent with their approved startup, shutdown, and malfunction (SSM) plan, then we are requiring that they submit SSM reports within 2 days of starting such action and within 7 days of ending such action.

We are requiring owners and operators of all affected sources to keep a copy of each notification and report, along with supporting documentation. Owners and operators of all affected sources also must keep records related to SSM, records of performance tests, and records for each continuous parameter monitoring system. Owners and operators of those viscose process affected sources that comply with the work practice standard for CS2 unloading and storage operations requiring installation of a nitrogen system must keep records certifying that a nitrogen system is being used. Owners and operators of all viscose process affected sources must keep records of all material balances and calculations documenting the percent reduction in HAP emissions.
III. Rationale for Selecting the Proposed Standards

A. How did we select the source categories?

Today's proposed rule applies to the Viscose Processes source category and the Cellulose Ethers source category. We are creating these two source categories by combining seven existing source categories based on the differences between the categories and the similarities within each category with regard to raw materials, process operations, emission characteristics, and control device applicability. 1. Raw Materials

Both viscose process operations and cellulose ether operations use cellulose and sodium hydroxide (NaOH) as raw materials to produce alkali cellulose. However, after the production of alkali cellulose, the viscose process operations and cellulose ether operations add different chemicals to the process. All of the viscose process operations use primarily CS2, while the cellulose ether operations use a variety of chemicals (such as propylene oxide, ethylene oxide, chloroacetic acid, and methyl chloride), depending upon the type of cellulose ether being produced. Some of the cellulose ether operations use the same chemicals. For example, both the methyl cellulose and hydroxypropyl methyl cellulose operations use methyl chloride, and both the hydroxypropyl methyl cellulose and hydroxypropyl cellulose operations use propylene oxide.

2. Process Operations

Although both operations produce alkali cellulose, the viscose process operations and cellulose ether operations are completely different in terms of the process steps and equipment used. For example, all of the viscose process operations include the following process steps: (1) production of alkali cellulose from cellulose and NaOH, (2) production of sodium cellulose xanthate from alkali cellulose and CS2 (xanthation), (3) production of viscose from sodium cellulose xanthate and NaOH solution, (4) regeneration of liquid viscose into solid cellulose, and (5) washing of the solid cellulose product.

The cellulose ether operations include mostly different process steps, as follows: (1) production of alkali cellulose from cellulose and NaOH, (2) reaction of the alkali cellulose with organic chemical(s) to produce a cellulose ether product, (3) washing and purification of the cellulose ether product, and (4) drying of the cellulose ether product.

3. Emission Characteristics

Viscose process operations emit primarily CS2, whereas cellulose ether operations do not use or emit CS2. Emissions from cellulose ether operations include ethylene oxide, methanol, methyl chloride, and propylene oxide. The type of emissions depends upon the type of cellulose ether produced. Some of the cellulose ether operations have the same type of emissions; for example, the methyl cellulose, hydroxypropyl methyl cellulose, and carboxymethyl cellulose operations all emit methanol as a byproduct of the reaction. 4. Control Device Applicability

All of the viscose process operations are subject to a permissible exposure limit (PEL) for CS2 from the U.S. Occupational Safety and Health Administration (OSHA) that requires owners or operators to reduce worker exposure to CS2 inside the buildings. The viscose process operations have been able to reduce worker exposure to CS2 by increasing gas flow rates (thereby reducing CS2 concentrations) and enclosing some processes. As a result, viscose process operations have lower HAP concentrations and higher gas flow rates compared to cellulose ether operations.

Because the viscose process operations and cellulose ether operations are different in terms of the type and concentration of HAP emitted as well as the gas flow rate, the types of control devices that are applicable to the viscose process operations and cellulose ether operations are also different. Cellulose ether operations are better able to apply certain types of control devices, such as condensers, that require highconcentration, lowflow gas streams to operate effectively. Control devices that are effective on lowconcentration, highflow gas streams, such as biofilters and carbon adsorbers, are the most viable options for reducing CS2 emissions from the viscose process operations.

Some control devices that cellulose ether operations have effectively employed on their organic HAP emissions cannot be as easily employed by viscose process operations on their CS2 emissions. For example, while wet scrubbers are effective control devices for cellulose ether operations, available data show them to have little effect on CS2 emissions at viscose process operations. Also, viscose process operations have special concerns regarding the flammability of CS2 that cellulose ether operations do not have to consider in selecting a control device. B. How did we select any subcategories?

1. Viscose Process Industry

We reviewed the available information on the viscose process [[Page 52172]]
industry and determined that the various viscose process operations should not be subcategorized. We found that viscose process operations are generally similar with respect to types of raw materials, emissions, initial process steps, and control device applicability.

We are establishing a single set of standards across the Viscose Processes source category in those areas (such as CS2 unloading and storage, wastewater emissions, and equipment leaks) where we have found important similarities between the various viscose process operations. For example, most viscose process operations use nitrogen or water displacement to unload the liquid CS2 from the railcar in order to control CS2 emissions during unloading, and they use nitrogen or water padding in the head space of the CS2 storage vessels in order to control CS2 emissions from the vessels.

Other similarities between the various viscose process operations include how they address wastewater emissions and equipment leaks. None of the viscose process operations take any measures to control the CS2 emissions from their wastewater, and none of the viscose process operations are subject to Federal or State leak detection and repair (LDAR) requirements to control the CS2 emissions from their equipment leaks.

However, we are establishing separate limits for the various viscose process operations (cellulose food casing, rayon, cellophane, and cellulosic sponge) in those areas (such as process vents) where we have found important differences between the various viscose operations. We found some differences between the various viscose process operations with respect to final process steps and final products. For example, some viscose process operations use different methods and equipment to complete the regeneration step. Cellulose food casing operations extrude viscose through a die, forming a tube, while rayon operations extrude viscose through spinnerets, forming thin strands. Cellophane operations extrude viscose through a long slit, forming a flat sheet, while cellulosic sponge operations feed a mixture of viscose and Glauber's salt into a sponge mold. Also, cellulose food casing, rayon, and cellophane operations use a hot acid solution in their regeneration step, while cellulosic sponge operations use either a hot salt solution or electricity.

The various viscose process operations produce a variety of products, such as cellulose food casings, rayon, cellophane, and cellulosic sponges, all of which compete in different economic markets. None of the viscose process operations produces more than one of these products. For example, a cellulose food casing operation does not also produce rayon or cellophane.

2. Cellulose Ether Industry

We reviewed the available information on the cellulose ether industry and determined that the Cellulose Ethers source category should not be subcategorized. We found that the various cellulose ether operations are sufficiently similar with respect to their process steps and control device applicability to justify keeping the various operations in one category. Therefore, we are establishing a single set of standards across the Cellulose Ethers source category.

C. How did we select the affected source?

In selecting the affected source for the Viscose Processes source category and the Cellulose Ethers source category, we included all equipment that emits HAP, such as process vents, storage vessels, wastewater treatment processes, and other components (such as pumps, valves, flanges, sampling connections, compressors, and pressure relief devices). In addition, because ``reconstruction,'' as defined in Sec. 63.2 of subpart A of 40 CFR part 63, is calculated based on the affected source, we also included other auxiliary equipment that is necessary to make the operation run but which may not emit HAP.

We are defining the affected source broadly to include the sum of all operations engaged in the production of the cellulose product (that is, cellulose food casing, rayon, cellophane, cellulosic sponge, or cellulose ethers). We defined the affected source broadly because emissions from the sum of all operations are better documented than emissions from individual process lines or emission points. In addition, by defining the affected source broadly, it is less likely that a change will trigger new source MACT. New source MACT would be triggered when the fixed capital cost of new components exceeds 50 percent of the fixed capital cost for all components that would be required to construct a comparable new affected source. Because emissions averaging takes place within the affected source, a broadly defined affected source would provide owners and operators with more flexibility in conducting any emissions averaging.
D. How did we determine the basis and level of the proposed standards for the Viscose Processes source category?

The following sections present the basis for determining the components of the MACT floor for equipment leaks, wastewater emissions, CS2 unloading and storage operations, and process vents for the Viscose Processes source category. The MACT floor for the category is the sum of the MACT floor components for each type of emission point present at a given affected source. The Viscose Processes source category has fewer than 30 process operations from which to establish existing source MACT floors for these emission points. If there are fewer than 30 sources in a category, the CAA states that the MACT floor for existing affected sources must be determined based on the average emission limitation achieved by the bestperforming five sources.

We have previously interpreted the ``average'' emission limitation as either the mean or median emission limitation. Where we had at least five process operations in a group of similar operations to establish a MACT floor (that is, equipment leaks, wastewater emissions, and CS2 unloading and storage operations), we used the median emission limitation to establish the MACT floor because it corresponds to the control level for an actual control technology. Where we had fewer than five operations in a group of similar operations to establish a MACT floor (that is, process vents), we used another approach, which is discussed below.

For new affected sources, the CAA states that the MACT floor must be determined based on the emission limitation achieved by the best performing similar source. In each case, we used this approach to determine the new source MACT floor.

1. MACT Floor for Equipment Leaks and Wastewater Emissions

Because none of the ten viscose process operations control CS2 emissions from equipment leaks or wastewater, the MACT floor for those emission points is no control.
2. MACT Floor for CS2 Unloading and Storage Operations

Most of the ten viscose process operations have taken steps to control CS2 emissions from unloading and storage operations by using nitrogen or water displacement to unload the liquid CS2 from the railcar and using nitrogen or water padding in the head space of the storage vessels. All of these CS2 control techniques reduce liquid CS2 contact with air. However, the water
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unloading and padding systems result in CS2contaminated water being sent to wastewater treatment, thereby generating gaseous CS2 emissions from wastewater. We have determined that using nitrogen unloading and storage systems reduces CS2 emissions by at least 85 percent relative to the water unloading and storage systems.

The MACT floor for CS2 unloading and storage operations at existing affected sources is the median CS2 emission reduction achieved by the top five viscose process operations. The median viscose process operation has a nitrogen system for both unloading and storage. Therefore, we established the MACT floor for CS2 unloading and storage operations at 85 percent CS2 control, which is the calculated control efficiency for nitrogen systems relative to water systems. Because the bestcontrolled viscose process operation also has a nitrogen system for CS2 unloading and storage operations, the MACT floor is the same for both new and existing affected sources.

3. MACT Floors for Process Vents

a. Methodology. We determined separate components of the viscose process operation MACT floor for each type of process vent used in a viscose process operation (that is, one MACT floor for cellulose food casing, one for rayon, one for cellophane, and one for cellulosic sponge). There are only three viscose process operations that include cellulose food casing process operations, two that include rayon process operations, one that includes cellophane process operation, and four that include cellulosic sponge process operations from which to establish the various process vent components of the MACT floor for viscose process operations. The CAA does not clearly address how to establish the MACT floor for existing affected sources when there are fewer than five process operations to determine the average emission limitation.

For the various viscose process operations (cellulose food casing, rayon, cellophane, and cellulosic sponge), we decided to use the MACT floor approach outlined in the preamble to the proposal for the Generic MACT NESHAP (63 FR 55178, October 14, 1998). According to the preamble to the Generic MACT NESHAP, the smaller the group of similar process operations, the less likely it is that the best control strategies have been implemented for the process operations in that group. Averaging the emission limitations from uncontrolled and wellcontrolled process operations in a small group would result in a low average emission limitation that is clearly below the emission limitation already demonstrated by at least one process operation in that group. Selecting the average emission limitation also could result in a control level with no corresponding control technology. Selecting the median process operation of the group, which would be uncontrolled, would also have little relevance to the determination of MACT.

As an alternative, the proposal preamble to the Generic MACT NESHAP outlined two basic scenarios where EPA can reasonably infer that the MACT floor requirements for small groups of similar process operations have been satisfied:

First, when the EPA intends to select a MACT standard that coincides with the level of control achieved by the bestcontrolled [process operation(s)] in a [group of similar process operations], it is selfevident that the MACT floor has been met, and it is clearly a waste of EPA resources to undertake a separate
quantitative MACT floor analysis based, in part, on control levels at the less wellcontrolled [process operations] * * *. Second, in those instances where the EPA will base its MACT standard for a small [group of similar process operations] (five or fewer [process operations]) on MACT standards previously established for a larger group of demonstrably similar [process operations] in other categories, it is also reasonable to infer MACT floor compliance without the need for a detailed new analysis.

The second scenario under which we would determine MACT floors based on MACT standards previously established for a larger group of similar process operations in other categories is not useful here. We found the cellulose food casing, rayon, cellophane, and cellulosic sponge process operations to be completely different from other industrial process operations in terms of the type and concentration of HAP emitted, gas flow rates, control device applicability, types of emission points, and special concerns regarding the flammability of CS2 that other industries do not have to consider.

Instead, we selected the first scenario under which we would determine process vent MACT floors based on the emission limitation of the bestperforming process operation for each type of viscose process operation (cellulose food casing, rayon, cellophane, and cellulosic sponge). The substantial emissions from viscose process vents (18,900 ton/yr nationwide for ten process operations) demonstrate the need for effective emission control for this emission point. In this case, the emission point is represented by the collection of process vents at each viscose process operation. For example, when we determined the bestperforming process operation for rayon process vents, we compared the overall reductions in process vent HAP emissions at the two rayon process operations, and the process operation with the higher overall reduction in process vent HAP emissions was considered to be the best performing rayon process operation.

We also determined the process vent MACT floors for new affected sources based on the bestperforming source for each type of viscose process operation. Consequently, the process vent MACT floors for viscose process operations at existing affected sources are the same as the process vent MACT floors for viscose process operations at new affected sources.

b. MACT Floor for Cellophane Process Vents. Because there is only one cellophane process operation, we established the MACT floor for the cellophane production process vents based on the current emission reductions achieved by that process operation. The process operation currently achieves between 85 and 90 percent control of total uncontrolled sulfide emissions (reported as CS2). The process operation accomplishes these reductions by using a CS2 recovery system. To take into account any variability, we established the MACT floor for cellophane production process vents at 85 percent control.

We also established the MACT floors for solvent coating process vents and toluene storage vessels at cellophane process operations based on the current emission reductions achieved by the cellophane process operation. The process operation currently achieves between 95 and 100 percent control of uncontrolled toluene emissions from these emission points. The process operation accomplishes these reductions by venting emissions from solvent coating process vents and toluene storage vessels to a solvent recovery system. To take into account any variability, we established the MACT floor for solvent coating process vents and toluene storage vessels at 95 percent control.

c. MACT Floor for Cellulose Food Casing Process Vents. Of the three cellulose food casing process operations, we have determined that the bestperforming process operation achieves between 25 and 30 percent control of total sulfide emissions (reported as CS2) from process vents at the MACT floor. The process operation accomplishes part of these sulfide emission reductions by using viscose process changes to reduce the amount of CS2 added to the process. The process
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operation accomplishes the remaining sulfide emission reductions by using caustic scrubbers to capture H2S emissions, which are generated from byproducts of the CS2 reactions in the viscose process operation. To take into account any variability, we established the MACT floor for cellulose food casing process vents at 25 percent control.

d. MACT Floor for Rayon Process Vents. Of the two rayon process operations, we have determined that the bestperforming process operation achieves between 55 and 60 percent control of total sulfide emissions reported as CS2. The process operation accomplishes these reductions by using a new rayon spinning technology, CS2 recovery operations (using condensers and oil absorbers), and caustic scrubbers (to capture the H2S generated from CS2). To take into account any variability, we established the MACT floor for rayon process vents at 55 percent control.

e. MACT Floor for Cellulosic Sponge Process Vents. Of the four cellulosic sponge process operations, we have determined that the two bestperforming process operations achieve similar CS2 reductions from process vents, between 75 and 85 percent overall. One of these two process operations reduces CS2 emissions by using a biofilter to remove the CS2 emissions from its spongemaking operations. The second process operation reduces CS2 emissions by using a carbon adsorber to recover the CS2 from the viscose production and regeneration operations and by using a thermal oxidizer to destroy the CS2 and H2S from the salt recovery operation. To take into account any variability, we established the MACT floor for cellulosic sponge process vents at the lower end of the range, that is, 75 percent control.

4. BeyondtheFloor Technology

The CAA states that MACT must be no less stringent than the MACT floor. Therefore, we also evaluate options more stringent than the MACT floor. When evaluating the more stringent options, we consider the costs, nonair quality health and environmental impacts, and energy requirements that accompany the expected emission reductions.

a. Beyondthefloor Technology for CS2 Unloading and Storage Operations. We did not consider any beyondthefloor requirements for CS2 unloading and storage operations at new or existing affected sources because no beyondthefloor technologies are available for that emission point.

b. BeyondtheFloor Technology for Equipment Leaks and Wastewater Emissions. We do not project any emission control beyond the MACT floor for equipment leaks and wastewater emissions at new or existing affected sources to be cost effective.

In order to control HAP emissions from equipment leaks, viscose process operations would be required to implement an LDAR program similar to the LDAR provisions in subpart H of 40 CFR part 63. However, the baseline HAP emissions from equipment leaks at viscose process operations account for less than 2 percent of total HAP emissions. Therefore, we do not project that any reduction in HAP emissions from equipment leaks would be worth the cost to implement the LDAR program.

In order to control HAP emissions from wastewater, viscose process operations would be required to implement requirements similar to the process wastewater provisions in subpart G of 40 CFR part 63. However, the baseline HAP emissions from wastewater at viscose process operations account for less than 5 percent of total HAP emissions. Therefore, we do not project that any reduction in HAP emissions from wastewater would be worth the cost to implement requirements similar to those in subpart G.

c. BeyondtheFloor Technology for Cellophane and Cellulosic Sponge Process Vents. We did not consider any beyondthefloor requirements for cellophane process vents and cellulosic sponge process vents at new or existing affected sources because no beyondthefloor technologies are available for those emission points.

d. BeyondtheFloor Technology for Cellulose Food Casing Process Vents. We are including beyondthefloor requirements for process vents in today's proposed rule for cellulose food casing operations at new viscose process affected sources. The arguments supporting the beyond thefloor requirements are presented below.

None of the existing cellulose food casing operations has achieved CS2 emission reductions from process vents significantly greater than the MACT floor level, which is 25 percent control of total sulfide emissions (reported as CS2). However, other viscose process operations (such as, rayon and cellulosic sponge) have achieved higher CS2 emission reductions using various CS2 control technologies (such as condensers, biofilters, and carbon adsorbers). Because of similarities in process vents among the various viscose process operations, we believe that cellulose food casing operations are also capable of reducing the CS2 emissions from their process vents.

We have reviewed information obtained from cellulose food casing operations on CS2 concentrations and gas flow rates for individual process machines. Based on this information, we found that the emission streams from the stack at cellulose food casing operations have relatively low CS2 concentrations and high air flows. The stack CS2 concentrations are typically around 100 parts per million (ppm), and the stack gas flow rates typically exceed 80,000 cubic feet per minute (cfm). We have determined that the cost to control these streams at stack conditions would be excessive. However, we also have determined that, if more concentrated emission streams from further back in the cellulose food casing process are segregated from the less concentrated emission streams and sent to a control device, then CS2 control technologies could be applied to the cellulose food casing operations more cost effectively.

Two of the four cellulosic sponge operations have achieved total sulfide emission reductions of at least 75 percent for the sum of their process vents by using either a carbon adsorber or a biofilter. We have determined that applying one of these CS2 control technologies (such as a carbon adsorber) to cellulose food casing process vents at new viscose process affected sources to achieve 75 percent control would be cost effective, with minimal nonair quality environmental and energy impacts. Therefore, we are including a beyond thefloor control requirement of 75 percent total sulfide control for cellulose food casing process vents at new viscose process affected sources in today's proposed rule.

The cost effectiveness of applying carbon adsorbers to the three existing cellulose food casing process operations to achieve 75 percent control ranges from $500 to $1,600 per ton of total sulfide (reported as CS2). The incremental cost effectiveness between the MACT floor requirement of 25 percent control and the beyondthefloor requirement of 75 percent control ranges from $500 to $700 per ton of total sulfide (reported as CS2). The low incremental cost effectiveness is based primarily on the larger emission reductions achieved beyond the floor. The high capital costs for this control technology ($3.9 to $5.8 million) and the economic status of the industry are the primary factors in our rejecting beyondthefloor requirements for cellulose food casing operations at existing viscose process affected sources. However, we project that capital costs and cost effectiveness for this control technology will be lower for cellulose food casing operations at new
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viscose process affected sources. The costs for the existing affected sources include retrofit costs which increased the capital costs by 50 percent. Retrofit costs will not be a factor for cellulose food casing operations at new viscose process affected sources.

The nonair quality impacts and energy requirements for cellulose food casing operations at new viscose process affected sources are expected to be comparable to those determined for operations at existing viscose process affected sources which are minimal. The energy requirements for applying carbon adsorbers to the three existing cellulose food casing operations range from 2,800 to 4,600 megawatt hours per year (MWh/yr), and the wastewater impacts range from 15 to 35 million gallons per year (gal/yr).
e. BeyondtheFloor Technology for Rayon Process Vents. We are including beyondthefloor requirements for process vents in today's proposed rule for rayon operations at new viscose process affected sources. The arguments supporting the beyondthefloor requirements are presented below.

One of the rayon operations has indicated that an emission control technology (fluidizedbed carbon adsorber) is available to increase their CS2 emission reductions from 60 to 80 percent. This emission control technology is similar to technology currently being

FOR FURTHER INFORMATION CONTACT For questions about the proposed rule, contact Mr. William Schrock; Organic Chemicals Group; Emission Standards Division (MD13); U.S. Environmental Protection Agency; Research Triangle Park, North Carolina, 27711; (919) 5415032; schrock.bill@epa.gov. For questions about the public hearing, contact Ms. Maria Noell; Organic Chemicals Group; Emission Standards Division (MD13); U.S. Environmental Protection Agency; Research Triangle Park, North Carolina 27711; (919) 5415673; noell.maria@epa.gov.