# National Emission Standards for Hazardous Air Pollutants for Source Categories: Aerospace Manufacturing and Rework; Reopening of the Public Comment Period > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A94-28842 ## Record - **Collection:** Federal Register - **Document type:** Uncategorized Document - **Published:** November 22, 1994 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 63 [AD-FRL-5110-9] RIN 2060-AE02 National Emission Standards for Hazardous Air Pollutants for Source Categories: Aerospace Manufacturing and Rework; Reopening of the Public Comment Period AGENCY: Environmental Protection Agency (EPA). ACTION: Reopening of the public comment period. ----------------------------------------------------------------------- SUMMARY: On June 6, 1994, EPA proposed standards to regulate the emissions of certain organic hazardous air pollutants from aerospace manufacturing and rework facilities which are part of major sources under Section 112 of the Clean Air Act as amended in 1990. The period for receiving public comment on the proposed rule ended on September 15, 1994. This action announces the reopening of the comment period to take comments on several amendments to the proposed rulemaking and other issues raised during the original comment period; clarification of the intent of a proposed requirement; and a correction of a typographical error. DATES: Comments: Comments must be received on or before January 6, 1995. ADDRESSES: Comments: Comments should be submitted (in duplicate, if possible) to: Air and Radiation Docket and Information Center (6102), Attn: Docket No. A-92-20, U.S. Environmental Protection Agency, 401 M Street SW, Washington, DC 20460. Docket: All information used in the development of this action is contained or referenced in the preamble below. Docket No. A-92-20 contains the supporting information for the original NESHAP and is available for public inspection and copying between 8:30 am and 5:00 pm, Monday through Friday, at the EPA's Air and Radiation Docket and Information Center, Waterside Mall, Room M- 1500, 1st floor, 401 M Street SW, Washington, DC 20460, or by calling (202) 260-7548 or FAX (202) 260-4400. A reasonable fee may be charged for copying. FOR FURTHER INFORMATION CONTACT: Ms. Mary Tom Kissell at (919) 541- 4516, Standards Development Branch, Emission Standards Division (MD- 13), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. SUPPLEMENTARY INFORMATION: I. Background On June 6, 1994 (59 FR 29216), national emission standards for hazardous air pollutants for the aerospace manufacturing and rework source category were proposed. Since that time, the EPA has received information on several aspects of the proposed rule which has led to the amendments being proposed in this notice for the following sections of the proposed subpart GG of 40 CFR part 63: Secs. 63.742, 63.745, 63.747, 63.749, 63.751, and 63.752. These sections deal with definitions, standards for primer and topcoat application operations, standards for chemical milling maskant application operations, compliance determinations, monitoring requirements, and recordkeeping requirements, respectively, for the NESHAP for aerospace manufacturing and rework facilities. This notice announces the reopening of the comment period for the aerospace NESHAP. However, only comments limited to the subjects listed below will be considered. (1) Correction of a typographical error regarding a request for comments for commercial exterior primers; (2) Proposal of a more stringent inorganic HAP emission control requirement for new primer and topcoat application operations and proposal of definition of high efficiency particulate air filter; (3) Proposal to eliminate the exemption for chemical milling maskant application operations for use with Type I chemical milling etchants; (4) Clarification of the intent of the proposed requirement for control devices used to control emissions from coating application operations; (5) Proposal of reduced recordkeeping requirements to encourage the use of a low VOC primer; (6) Request for comment on depainting for private, corporate, and small commuter aircraft; (7) Request for comment on use and efficiency of control devices for depainting operations using HAP-containing chemicals; and (8) Request for comment on determining the appropriate length of the rolling material balance period for liquid-liquid material balances for carbon adsorbers used as control devices for solvent recovery systems. These actions are further discussed in Part III of this preamble. As indicated in the preamble to the proposed rule at 59 FR 29217, the EPA traditionally issues a draft CTG containing recommended control levels for public comment. Rather than issue a separate draft CTG in this case, the EPA used the notice of proposed rulemaking to request public comment on draft best available control measures (BACM), which is the same as the proposed maximum achievable control technology (MACT) for coatings and solvents. Comments on the proposed rule and on the proposed amendments in this document will also be considered in formulating a final BACM. The proposed regulatory text is not included in this Federal Register notice, but is available in Docket No. A-92-20 or by written or telephone request from the Air and Radiation Docket and Information Center (see ADDRESSES). This notice with the proposed regulatory language is also available on the Technology Transfer Network (TTN), one of EPA's electronic bulletin boards. The TTN provides information and technology exchange in various areas of air pollution control. The service is free, except for the cost of a phone call. Dial (919) 541- 5742 for up to a 14,400 bps modem. If more information on TTN is needed, call the HELP line at (919) 541-5384. II. Summary of and Rationale for Changes to the Proposed Rule and Request for Public Comments A. Correction: Request for Comments on Commercial Exterior Primers Section II.B.2.a of the preamble to the proposed rule requested comments concerning whether the proposed organic HAP and VOC limits for commercial exterior topcoats represents demonstrated technology. This section should have referenced commercial exterior primers rather than topcoats. Consequently, the specific paragraph in this section (see 59 FR 29224, middle column) should read as follows: The EPA has received information indicating that the organic HAP and VOC content limits for primers do not represent demonstrated technology for exterior commercial primers. Consequently, the EPA is soliciting comments on whether a separate category should be developed for exterior commercial primers with organic HAP and VOC content levels higher than the proposed levels for primers. These comments should provide a technical justification for a higher limit, including why currently available commercial primers cannot be used by all sources. B. Amendment: New Source Requirements for Inorganic HAP Emissions from Coating Operations The EPA has received information that at least one facility is controlling inorganic HAP emissions from coating operations to a greater degree than that required in the proposed rule. This facility is using high efficiency particulate air (HEPA) filters in addition to the filtration methods required in the proposed rule. Consequently, the EPA is proposing that Sec. 63.745 require new primer and topcoat application operations to use HEPA filters in addition to the requirements specified in the rule proposed on June 6, 1994. Finally, the EPA is proposing that these sources keep records of documentation supplied by the filter manufacturer that the filter being used meets the HEPA filter requirements specified in the definition in Sec. 63.742 being proposed by this notice. C. Amendment: Inclusion of Chemical Milling Maskant Application Operations for Use With Type I Chemical Milling Etchants As proposed on June 6, 1994, the rule would apply only to those chemical milling maskant application operations in which Type II chemical milling etchants are subsequently used. This was based on information the EPA received showing that no facilities had implemented controls (either low VOC product substitutions or control devices) on chemical milling maskant application operations for use with Type I chemical milling etchants. Since proposal, the EPA has received comment that there is at least one chemical milling maskant application operation for use with Type I chemical milling etchants (which are not currently covered in the proposed rule) with reduced organic HAP and VOC content levels. The information supplied to the EPA, however, did not detail the applicability of this chemical milling maskant to all Type I etchant operations. The MACT floor for chemical milling maskant application operations, as determined by the average of the best performing 12 percent of sources for which the EPA had emission information, included the use of control devices (e.g., carbon adsorbers) as well as low organic HAP and VOC content chemical milling maskants. As mentioned above, the applicability of the low organic HAP and VOC content chemical milling maskant for which the EPA received comment is unknown. However, the use of the same control device technology as used for Type II chemical milling operations is applicable to Type I chemical milling operations. Consequently, the EPA is proposing to eliminate the exemption in Sec. 63.747 for chemical milling maskants used with Type I etchants and require them to meet the same requirements as chemical milling maskants for use with Type II etchants. This will allow the use of any low organic HAP and VOC content chemical milling maskant that meets the 160 grams per liter (1.3 pounds per gallon) organic HAP and VOC content limits or the use of control devices as specified in the proposed rule. D. Amendment: Requirement for the Capture of All Emissions by Control Devices The proposed rule required that whenever a control device is used to meet the emission limitations specified, the owner or operator must meet two provisions in order to demonstrate compliance. The first is that the overall control efficiency, taking into account capture and control efficiency, must be at least 81 percent. The second provision, as specified in Secs. 63.745(c)(1), 63.747(d)(1), 63.749(d)(4)(ii)(A), and 63.749(g)(3)(ii)(A) of the proposed rule, requires that all of the emissions from the respective operations be captured and controlled by the control device. In addition, the latter two paragraphs specify that all emissions must be controlled other than ``incidental emissions that may escape the capture system.'' The EPA has reviewed these provisions based on comments that have been received concerning their enforceability. Based on this review, the EPA has concluded that the provision specifying an overall control efficiency is adequate to ensure application of MACT. The additional language only added confusion to the proposed rule without any added environmental benefit. The EPA, therefore, is deleting from the proposed rule the four paragraphs referenced above concerning the capture of all emissions from coating operations. E. Amendment: Reduced Recordkeeping Requirements for Low Organic HAP and VOC Content Primer The EPA has received information that a low organic HAP and VOC content (approximately 250 grams VOC per liter (2.1 pounds per gallon) less water and exempt solvents) military waterborne primer has been qualified according to military specification MIL-P-85582A, Type I, Class II. While this primer may not represent demonstrated technology for all types of uses, the EPA wishes to encourage the use of low organic HAP and VOC content coatings. Consequently, the EPA is proposing to amend the recordkeeping requirements of Sec. 63.752 of the proposed rule to require that only annual purchasing records be maintained on the use of any primer that contains a maximum of 250 grams organic HAP per liter (2.1 pounds per gallon) less water as applied and 250 grams VOC per liter (2.1 pounds per gallon) less water and exempt solvents as applied. This significantly reduces the recordkeeping from the monthly records required for coatings with higher organic HAP and VOC contents. F. Request for Comments: Depainting Requirements for Private, Corporate, and Small Commuter Aircraft The EPA has received comments that the proposed standards for depainting do not represent demonstrated technology for private, corporate, and small commuter aircraft. Specifically, the commenters stated that depainting of these aircraft cannot be accomplished through the use of non-HAP chemical strippers or media blasting methods. One commenter also stated that the physical characteristics of the coatings typically used on the exterior of private and corporate aircraft cannot be removed by the non-HAP chemical strippers currently on the market. Another comment concerned the use of a control device, such as carbon absorbers followed by a catalytic incinerator, to reduce emissions from depainting operations where HAP-containing chemical strippers are used as an alternative means of compliance. In order to obtain additional and more specific information on this sector of the aerospace rework industry, the EPA is requesting data and information on the following specific issues: 1. One commenter stated that to achieve the finish quality demanded by private and corporate aircraft purchasers, the aircraft manufacturers are using coatings that have a cross-linked polymer structure. According to the commenter, the structure of these coatings does not allow the non-HAP chemical strippers to penetrate the coating in order to break the bond between the coating and substrate. The EPA requests information on whether non-HAP chemical strippers have been shown to be effective on this type of coating. Commenters are requested to provide as many details as possible of non-HAP chemical depainting processes such as type and number of aircraft depainted, specific type of primer and topcoats removed, VOC content (as applied, less water and exempt solvents) of the primer and topcoat removed, and method of disposal of the waste stripper. Information on the cross-linked polymer coatings (e.g., VOC content, manufacturer) and its finish characteristics are also requested. In addition, the EPA requests comments on whether coatings other than cross-linked polymers can be used on private and corporate aircraft. Information requested includes: whether substitute coatings can be used to achieve similar finishes; whether these other coatings are easier to strip; VOC content (as applies, less water and exempt solvents) of these other coatings; application methods; whether changing coatings or not painting aircraft would affect aircraft safety; and the economic impacts of changing coatings or not painting aircraft. 2. Another commenter focused on the thin exterior skin panels of private, corporate, and small commuter aircraft. The commenter said that since weight is a critical parameter for these aircraft, very thin exterior skin panels, that are very susceptible to damage from blast depainting methods, are typically used. The commenter states that as a consequence, no rework facilities are currently using blast depainting methods on these aircraft. Information on this topic is requested from any facility that has evaluated or is currently using any blast depainting method or non- chemical means to remove coatings from the exterior of private, corporate, or small commuter aircraft. Specifically, the information should document both successful and unsuccessful applications of blast or mechanical depainting methods for these aircraft, or any other aircraft with similarly thin exterior skin panels. Any information on the generation and control of emissions from blast or mechanical depainting operations (of any type of aircraft) would also be beneficial. G. Request for Comment: Control Devices for Depainting Operations Using HAP-Containing Chemicals Another commenter recommended that conventional chemical strippers (containing HAPs) be allowed when emissions are reduced through the use of a control device. The commenter stated that a combination of a carbon adsorber and catalytic incinerator can achieve greater than 99 percent removal efficiency, and would be essentially equal to the depainting standard of no HAP emissions. Information submitted on this topic should address the feasibility of installing such a control system, including cost and ability to achieve greater than 99 percent removal efficiency on a dilute airstream. Also, since some portion of the volatile HAP content of conventional strippers will be retained in the waste sludge produced from the operation, commenters should detail the ultimate fate of emissions from the volatile HAPs in the waste stream. For example, a conventional waste treatment system may aerate the waste stream as an initial processing step, emitting the volatile HAPs at that point. However, other waste treatment methods may destroy HAPs before the aeration step. Comments are also requested on whether a standard allowing the use of control devices to reduce emissions from depainting operations should apply only to the depainting of private, corporate, and small commuter aircraft, or if it should apply to military and commercial aircraft as well. H. Request for Comment: Appropriate Length of Rolling Material Balance Period for Liquid-Liquid Material Balances for Carbon Adsorbers Used as Control Devices on Solvent Recovery Systems The EPA proposed Method 309, ``Method to Determine Length of Rolling Period for Liquid/Liquid Material Balance Method'' to determine the length of the rolling material balance period for the liquid-liquid material balance for carbon adsorbers used as control devices on solvent recovery systems. Several comments have been received concerning whether Method 309 is the most appropriate method for the aerospace industry in all instances. Therefore, the EPA is requesting comment on alternatives to Method 309. Information in support of alternatives to Method 309 should include how the length of the balance period is determined; discussions of operations that make an alternate determination of length appropriate; discussions concerning how compliance is indicated and ensured with the alternative determination; whether the alternative determination has been approved by state or local air pollution agencies in permits or other documents; and why Method 309 does not allow for the alternative determination. III. Administrative Requirements A. Paperwork Reduction Act The changes detailed in this notice will have the following effects on the information collection burden (recordkeeping, reporting, and monitoring requirements) of the proposed rule: (1) The request for comments concerning commercial exterior primers does not affect the information collection burden of the proposed rule; (2) New sources would be required to use HEPA filter and to maintain records documenting that the filters used meet the requirements of HEPA filters, but this would not significantly increase the recordkeeping burden; (3) The inclusion of Type I chemical milling maskants would require the same recordkeeping and reporting requirements as specified for Type II chemical milling maskants. Since the EPA has no information on which to base an estimate of the number of facilities currently using Type I chemical milling etchants, the magnitude of the effect on the information collection burden cannot be made; (4) The deletion of the requirement to capture and control all of the emissions from coating operations does not affect the information collection burden of the proposed rule; and (5) Reducing the recordkeeping requirements for low organic HAP and VOC content primers will result in a decrease in the information collection requirements for those facilities that use these primers. However, the EPA has no information on which to base an estimate of the number of facilities that will use the low organic HAP and VOC content primers. Therefore, the magnitude of the effect on the information collection request burden cannot be made. Even though the effect on the information collection burden cannot be completely quantified, the EPA believes that it will not significantly change. Therefore, the Information Collection Request document developed for the proposed rule has not been revised. B. Executive Order 12866 Review This rule was classified as ``non-significant'' under Executive Order 12866 and, therefore, was not reviewed by the Office of Management and Budget. List of Subjects in 40 CFR Part 63 Environmental protection, Air pollution control, Hazardous substances, Reporting and recordkeeping requirements. Dated: November 14, 1994. Mary D. Nichols, Assistant Administrator for Air and Radiation. [FR Doc. 94-28842 Filed 11-21-94; 8:45 am] BILLING CODE 6560-50-P --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-28842. Public record. Not legal advice.