Technical FAQ for Regulations 5.20, 5.21 and 5.22
Here are technical frequently asked questions, with answers, for the large point source component of the STAR Program described in Regulations 5.20, 5.21 and 5.22.
Do you have a question that is not answered below? Send us your STAR Program question.
Question: (3/23/2007) In general, an automobile body repair facility would be an exempt stationary source. (Regulation 5.01 section 1.7.2.) However, the definition of "exempt stationary source" (Regulation 5.01 section 1.7) excludes a stationary source that has a permitted process or process equipment other than a cold cleaner subject to Regulation 6.18. If an auto body repair facility that had a Federally Enforceable District Origin Operating Permit (FEDOOP) was also regulated under Regulation 6.31/7.59 (miscellaneous metal parts and products surface coating operations), would only the processes or process equipment subject to Regulation 6.31/7.59 be subject to the STAR Program requirements (Regulation 1.06 enhanced emissions reporting and Regulation 5.21 environmental acceptability) or would all of the processes and process equipment at the stationary source be subject to these STAR Program requirements?
Response: If an automobile body repair shop was also subject to Regulation 6.31/7.59, then it would not be an exempt stationary source. Thus, all of the processes and process equipment at the stationary source would be subject to the STAR Program requirements applicable to a FEDOOP company (Regulation 1.06 enhanced emissions reporting and Regulation 5.21 environmental acceptability).
Question: (6/27/2007) If compliance with one or more environmental acceptability (EA) goals will not be achieved, may the submitted compliance plan pursuant to Regulation 5.21 section 4.4 include a request for modification of the applicable EA goals? If a request for modification is included in the submittal (along with any other necessary compliance plans and schedules), will the company be deemed in compliance with section 4.4? If the request for modification of an EA goal is subsequently denied, will the company be allowed additional time to submit the required compliance plan and schedule?
Response: If a company is not in compliance with the applicable EA goals, the submittal pursuant to Regulation 5.21 section 4.4 may include a request for modification of one or more EA goals. To be deemed in compliance with the requirement for submittal of the needed compliance plans and schedules, the company must submit an administratively complete request for modification, addressing all of the modification request requirements in Regulation 5.21 section 2.3 or section 2.6, as applicable. If a request for modification of an EA goal is subsequently denied, regardless of whether the request was submitted as part of the section 4.4 compliance plan package or separately, the District will, in the written denial letter, include a deadline for submittal of a compliance plan and schedule that demonstrates compliance with the EA goal.
Question: If a company is a Group 2 stationary source only because it has 25 tons emission of a criteria pollutant, but is not a FEDOOP or Title V, is it subject to the modification demonstration requirements of Regulation 5.21 Section 3 immediately?
Response: Yes, Regulation 5.21 Section 3 applies to Group 1 and 2 stationary sources and Regulation 5.01 section 1.9.2 would include such a stationary source in the definition of Group 2 stationary source.
Question: When would a facility be required to demonstrate environmental acceptability for the single and multiple TAC scenarios for the entire facility if a modification occurs?
Response: Each construction permit application subject to Regulation 5.21 Section 3 would be required to include a demonstration of compliance with Regulation 5.21 section 2.2.2 (all new or modified (N/M) processes or process equipment (P/PE), HQ of 1.0 for each TAC individually) and section 2.2.3 (all N/M P/PE, risk of 3.8 x 10-6 for all applicable carcinogens). Regulation 5.21 section 2.4 includes the phrase "taking into account the compliance schedule for the various categories of TACs in section 4.5." If the construction permit is issued before the submittal of the stationary source-wide demonstration of environmental acceptability is submitted or due, whichever occurs first, then the cumulative risk from the construction permit at hand would not be required to address existing P/PE, although the EA goals in sections 2.5.2 or 2.5.3 shall not be exceeded unless a modification of the EA goal is approved. If the construction permit is not issued before the stationary source-wide demonstration of environmental acceptability is submitted or due, whichever occurs first, then the construction permit at hand would be required to include a new demonstration of the EA goals in sections 2.5.2 and 2.5.3.
Question: The 7.5 x 10-6 risk EA goal for carcinogens applies to all the emission points for a single TAC from the entire facility. How is the risk from new or modified equipment added to that?
Response: [Please note that the 7.5 x 10-6 risk EA goal for carcinogens (Regulation 5.21 section 2.5.3) applies to the cumulative risk from all applicable carcinogenic TACs at the stationary source, not to a single carcinogenic TAC as stated in the question.] The 7.5 x 10-6 risk EA goal includes existing P/PE and any future N/M P/PE. Thus, the addition of additional carcinogenic risk would be required to fit within this amount to meet the EA goal. This could mean a reduction in the risk from either the N/M P/PE or existing P/PE.
Question: (12/4/2006) How should the emissions from the combustion of natural gas be treated for the December 31, 2006, (due date) environmental acceptability demonstrations for Category 1 TACs from Title V Sources?
Response: [See Update at the end of this response.] Treating all emissions from the combustion of natural gas as de minimis was approved on November 8, 2006, by the Strategy Committee of the Louisville Metro Air Pollution Control Board to undergo the formal Public Review process. The 30-day public comment period began on November 8, 2006, and the public hearing will be held on December 13, 2006. However, this provision does not take effect until adopted by the Board.
Based upon the broad support from the various members of the STAR Implementation Advisory Group, the District anticipates that the added de minimis provision, proposed Regulation 5.01 section 1.6.7, will be approved by the Board unless unexpected, significant concern is expressed during the formal Public Review process. However, the District cannot legally waive the application of the existing regulation without action by the Board to amend this regulation as proposed. Until a final action is taken by the Board, the District intends to use enforcement discretion and, presuming the indicated, expected outcome, will likely not deem the lack of submittal of a demonstration of environmental acceptability for emissions from the combustion of natural gas to be a violation of the December 31, 2006, due date for the submittals required of Title V companies for Category 1 toxic air contaminants (TACs).
However, the District notes that it has determined that a process with a heat input capacity, or enforceable limit, of no more than 70.4 million Btu per hour would qualify as de minimis pursuant to section 1.6.4 of Regulation 5.01, the definition of de minimis related to the benchmark ambient concentrations (toxicity) of the emissions. Thus, a Title V company may, in its December 31, 2006, (due date) submittal of environmental acceptability for a process or process equipment combusting natural gas, identify, with respect to the emissions from the combustion of natural gas, the process or process equipment as de minimis pursuant to Regulation 5.01 section 1.6.4, if the heat input capacity is no more than 70.4 million Btu per hour or request that an enforceable limit of no more than 70.4 million Btu per hour be included in the company’s Title V operating permit. For a new or modified process or process equipment, as defined in Regulation 5.21 section 1.6, the BAC-based heat input de minimis level for the combustion of natural gas determined by the District is 61.5 million Btu per hour.
Update: On January 17, 2007, the Board adopted a revision to the definition of “de minimis emission” that added a new section 1.6.7 that treats all emissions from the combustion of natural gas as de minimis. This provision further specifies: “This includes all of the emissions from a process or process equipment for which the only emissions are the products of combustion of natural gas, such as from a natural gas-fired boiler or turbine, but does not include the other emissions from a process or process equipment that are not the products of combustion of natural gas.”
The District notes that even though the combustion of natural gas is de minimis as a category, Regulation 5.21 section 4.1 states: “If the emission of an applicable TAC is de minimis pursuant to Regulation 5.01 section 1.6, then the submittal shall indicate the specific applicable provision of section 1.6 for the process or process equipment, ...” Thus, a natural gas-burning process would still need to be included in the environmental acceptability demonstration submittal and the section 1.6.7 de minimis status identified.
Question: What are the environmental acceptability goals for the following situations?
Note: The following responses relate to the specific situation identified. The statement that there is no separate goal established for the specific situation does not invalidate a goal that could include the specific situation. For example, the absence of a separate goal that would apply to multiple carcinogens from a single new or modified process or process equipment does not invalidate the 3.8 x 10-6 cancer risk goal that applies to multiple carcinogens from all new or modified processes or process equipment.
Question: Single TAC from a single piece of existing equipment ...
||1.0 x 10-6
||Reference: Regulation 5.21 section 2.5.1|
|Chronic noncancer risk:
||1.0 Hazard Quotient (HQ)
||Reference: section 2.5.1|
Question: Single TAC from all existing pieces of equipment at a single facility (stationary source) ...
Response: There is no separate goal for just all existing processes and process equipment at a single stationary source. Sections 2.5.2 and 2.5.3 apply to all processes and process equipment, including new or modified processes and process equipment.
Question: Multiple TACs from a single piece of existing equipment ...
Response: There is no separate cancer risk goal for multiple carcinogens from a single existing process or process equipment. There is not a goal established for the cumulative chronic noncancer risks of multiple TACs. Note, in general, each TAC is treated separately for chronic noncancer risks.
Question: Multiple TACs from all pieces of existing equipment from a single facility ...
Response: There is no separate cancer risk goal for multiple carcinogens from all existing processes and process equipment at a single stationary source. There is not a goal established for the cumulative chronic noncancer risks of multiple TACs. Sections 2.5.2 and 2.5.3 apply to all processes and process equipment, including new or modified processes and process equipment.
Question: Single TAC from a single piece of new or modified equipment ...
||1.0 x 10-6
||Reference: Regulation 5.21 section 2.2.1|
|Chronic noncancer risk:
||Reference: Regulation 5.21 section 2.2.1|
Question: Single TAC from all new or modified pieces of equipment at a facility ...
Response: There is no separate cancer risk goal for a single carcinogen from all new or modified processes and process equipment at a stationary source. Section 2.2.3 establishes a cumulative cancer risk goal of 3.8 x 10-6 for all applicable carcinogens.
|Chronic noncancer risk:
||Reference: Section 2.2.2|
Question: Multiple TACs from a single piece of new or modified equipment ...
Response: There is no separate cancer risk goal for multiple carcinogens from a single new or modified process or process equipment. There is not a goal established for the cumulative chronic noncancer risks of multiple TACs.
Question: Multiple TACs from all pieces of new or modified equipment from a single facility ...
||3.8 x 10-6
||Reference: Regulation 5.21 section 2.2.3|
Response: There is not a goal established for the cumulative chronic noncancer risks of multiple TACs.
Question: Multiple TACs from a single piece of existing plus new or modified equipment ...
Response: There is no separate cancer risk goal for multiple carcinogens for this situation. There is not a goal established for the cumulative chronic noncancer risks of multiple TACs.
Question: Multiple TACs from all pieces of existing plus all new or modified equipment from a single facility ...
||7.5 x 10-6
||Reference: Regulation 5.21 section 2.5.3|
Response: There is not a goal established for the cumulative chronic noncancer risks of multiple TACs.
Question: How are the adjustment factors, established in Regulation 5.21 section 2.9, applied to the modeling receptors with coordinates on industrial property and public roadways?
Response: If, as determined through modeling, the risk exceeds an applicable environmental acceptability (EA) goal at a receptor that is located on industrial property or a public roadway, then the EA goal is multiplied by the applicable (section 2.9) factor and a determination made if the risk exceeds the increased EA goal.
Question: With respect to fugitive emissions from equipment leaks, what are the acceptable methods for modeling these emissions? Are fugitive emissions to be considered an area source, volume source, or process emissions as defined in the STAR program? If process emissions, how would the de minimis levels apply to equipment leak fugitives? If area or volume source, what methodology will be required to apportion them throughout a facility?
Response: The EPA guidance for the various models provide guidance on the treatment and modeling protocols for fugitive emissions. De minimis determinations are made on a pounds-per-hour and pounds-per-averaging-period basis for an individual process or process equipment. Fugitive emissions related to that process or process equipment would be included in the total hourly and averaging period emissions. Individual circumstances should be discussed with the District staff.
Question: What acceptable methods are there for modeling TAC emissions from wastewater treatment operations like aeration, biotreatment, and clarification?
Response: The EPA guidance for the various models provide guidance on the treatment and modeling protocols for fugitive emissions. Individual circumstances should be discussed with the District staff.
Modeling - General
Question: Which UTM coordinate system will the District use for the STAR program, NAD27 or NAD83? If these two are mixed (e.g., a company submits modeling that uses one NAD convention and the District uses another for its validation modeling and county-wide cumulative risk analysis), the coordinates for the maximum receptor concentration will be different. This means LMAPCD would not be able to "add up" max concentrations from different sources using different NAD coordinate systems. In addition, the locations of max concentrations may be significantly different for the same source (e.g., on industrial property using one NAD system and on public or private property using the other system), thus affecting the allowable EA numbers as well.
Response: Before making a determination that the cumulative risk from multiple stationary sources exceeds an environmental acceptability goal, the District will perform modeling using a consistent coordinate system. Individual companies are not required, pursuant to Regulation 5.21, to evaluate the cumulative risk from other stationary sources.
Question: Why is the District not considering the effects of elevated terrain in modeling for the STAR Program? The consideration of elevated terrain is part of the protocol for the ISC3 and AERMOD models and terrain elevations are readily available for and can be imported into both models.
Response: For the purpose of the STAR Program, the District considers that the terrain in Jefferson County is generally relatively flat in relation to the horizontal distance from a point of emission to the point of maximum concentration. Therefore, the District does not believe that consideration of the differences in terrain to be necessary and is not requiring the models to be run using the elevated terrain features. Modeling protocols for the STAR Program do not change the EPA-required modeling protocols for other programs.
Question: How is the STAR defining public roadway? Where does the public roadway start and end from the pavement? Also, does the District want us to put discrete receptors along each public road bordering an industrial property?
Response: In general, the District would consider a public roadway to be the portion of a road that is improved, designed, or ordinarily used for vehicular travel and which is open to the public for vehicular travel. In general, the District will not require that discrete receptors on a public road bordering an industrial property be added. However, if the maximum concentration occurs on a public roadway, then the grid spacing must be fine enough to reasonably define the maximum ambient air concentration not on a public roadway.
Question: How is a downtown area stack emission point surrounded by buildings taller than the exhaust point, with no additional land owned by the source, to be modeled?
Response: Special cases like this should be discussed with the District staff.
Question: Regulation 5.22 Procedures for Determining the Maximum Ambient Concentration of a Toxic Air Contaminant section 1.2 allows an average emission rate to be used to determine the maximum ambient concentration when a process or process equipment has an intermittent emission, provided that there is a legally enforceable limitation on the hours of production. There is, however, a 10% minimum floor (876 hours) for reducing the average emission rate. If the average rate for an intermittent emission is less that 10% of the maximum hourly rate, then a rate of 10% of the maximum hourly rate may be used, not the actual average emission rate. The U.S. Environmental Protection Agency (EPA) recognized that emergency generators operate far fewer hours, establishing a default 500-hour limit for calculating the potential to emit. Could this limit on operating hours be used for modeling emergency generators for demonstrating environmental acceptability for the STAR Program?
Response: Yes. In calculating the potential to emit for emergency generators, the EPA allows, pursuant to a guidance memorandum (Calculating Potential to Emit (PTE) for Emergency Generators, John S. Seitz memo, September 6, 1995), a reasonable and realistic “worst-case” estimate of the number of hours that power would be expected to be unavailable from the local utility to be used for the purpose of estimating the PTE for an emergency generator. The EPA “defines” an “emergency generator” as a generator whose sole function is to provide back-up power when electric power from the local utility is interrupted. This memorandum explains why the EPA concluded that the constraint on the hours of operation is in fact “inherent.” The EPA recommended that the PTE be determined based upon an estimate of the maximum amount of hours power would be expected to be unavailable and the number of hours for maintenance and operator training. The EPA stated that it believes that 500 hours per year is an appropriate default assumption for estimating the number of hours that an emergency generator could be expected to operate under worst-case conditions, although recognizing that an alternative cap could be justified on a case-by-case basis.
Based upon the EPA’s treatment of emergency generators regarding this inherent limitation on their potential to emit, the District believes that it is acceptable to make an exception, applicable only to emergency generators, to the 10% intermittent minimum for demonstrating environmental acceptability pursuant to Regulations 5.22 and 5.21 Environmental Acceptability for Toxic Air Contaminants. Use of an exception provision would require that the hours of operation of the emergency generator be limited by a legally enforceable permit condition. The District believes that either the EPA’s default 500 hours per year limitation or a site-specific limitation, justified to the satisfaction of the District, could be used. The District will recommend that Regulation 5.22 explicitly provide for this modeling exception for emergency generators.
In supporting the modeling exception for emergency generators, the District is not revisiting the intermittent provision of Regulation 5.22 section 1.2 relative to other processes or process equipment.
Question: What is the point at which the risk from all TACs from all P/PEs from an entire facility be determined? Regulation 5.21 Section 2.2 Note 3 defines "maximum concentration" as the concentration at the "point of maximum risk of all applicable emissions from all applicable processes." The introductory sentence of Note 3 states the Rc is the "sum of the cancer risks at a single point." Not all TACs are emitted by the same emission points throughout a facility and each TAC will have a different maximum receptor location.
Response: The point of maximum risk may be determined using a Tier 4 model by simultaneously modeling all points of emissions of applicable carcinogens taking into account the relative differences in the benchmark ambient concentrations (BACs). This can be accomplished by adjusting the emission rates by the relative differences in BACs and determining the point with the highest adjusted concentration (i.e., risk). The risk of an individual emission of a TAC is calculated using the concentration of that emission at the location of the highest adjusted concentration (and the BAC for that TAC). The cumulative risk is the summation of each risk thus calculated.
Question: What meteorological (met) data will be approved and/or required to be used for ISC3 or AERMOD modeling?
Response: The District has posted met data files for 1990 to 1994 on the District’s web site at "http://www.louisvilleky.gov/APCD/STAR/MetData.htm". The District has confirmed that these files will run in the ISC3 model, and will use these 1990 to 1994 met data files when using the ISC3 model. The District has evaluated the significance of using the 1986 to 1990 five-year met data set that was submitted by a local consulting firm. In general, this 1986 to 1990 met data set resulted in similar, but slightly higher, concentrations than were calculated using the 1990 to 1994 met data set posted on the District’s web page. Thus, the District approves the use of this specific 1986 to 1990 met data set. The use of any other met data set for modeling submitted to the District will require evaluation and approval by the District. The District will be working with the Kentucky Division for Air Quality and EPA Region 4 to develop a five-year met data set that is formatted for use in AERMOD.
Question: EPA has announced they plan to replace ISC with AERMOD in the next couple of months as the reference model for impacts 50 km or less from a source. Will the District allow the use of AERMOD?
Response: Yes, Regulation 5.22 section 5.1.1 as adopted specifically identifies AERMOD as an acceptable model.
Question: May ISC Prime be used for modeling instead of ISC3?
Question: Pursuant to Regulation 5.20 Methodology for Determining Benchmark Ambient Concentration of a Toxic Air Contaminant section 2.1.1 and section 2.1.3, ethyl acrylate is determined to be a carcinogen. However, the National Toxicology Program (NTP) has removed ethyl acrylate from its "reasonably anticipated to be a human carcinogen" list. Can this action by the NTP be taken into consideration if an emission of ethyl acrylate does not meet an environmental acceptability goal?
Response: Yes. As stated in the question, ethyl acrylate is determined to be a carcinogen because it is listed as a carcinogen, with a unit risk estimate established by at least one of the information sources identified in sections 3.3.1 to 3.3.3 of Regulation 5.20. Additionally, even if ethyl acrylate were not thus identified by at least one of those information sources, ethyl acrylate is listed as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC). Thus, regardless of the action by the NTP, an emission of ethyl acrylate is required to demonstrate compliance with the applicable environmental acceptability (EA) goals of Regulation 5.21. If compliance for ethyl acrylate, whether as an individual chemical or contributing to a cumulative risk exceeding an EA goal, is not demonstrated, the owner or operator of the stationary source may request a modification of the applicable EA goal.
However, as part of the process of requesting a modification of an EA goal pursuant to Regulation 5.21 section 22.214.171.124, the owner or operator of the stationary source may include information relating to "other factors" for consideration by the District. Such other factors could include information relating to the action taken by the NTP. Section 2.6.3 requires the District to consider information submitted with the modification request addressing other factors.
See May a submitted compliance plan pursuant to Regulation 5.21 section 4.4 include a request for modification of the applicable EA goals?
Question: (1/9/2006) The draft Regulation 1.06 reporting forms refer to a “Process ID.” The District has not previously established process IDs for grouping process equipment at stationary sources. What is intended by the request to identify “Process ID”?
Response: For the 2006 submittal of the stack and fugitive emission release parameters, a Title V company may use any of the following for Process ID:
- The same grouping of process equipment as is used in the Title V permit, referred to as "Emission Unit."
- The same grouping of process equipment as is used in the District’s emissions inventory system, referred to as "Point ID."
- A grouping scheme proposed by the company for the grouping of process equipment as a process.
The District recognizes that the separation of process equipment into process groupings could include a single process step or a series of related process steps and thus is subject to a determination as to what appropriately is included as a single process. Insight into the District’s intent of grouping is provided by the definition "process or production unit" that is found in District Regulation 5.16: "any collection of structures and equipment that processes, assembles, applies, or otherwise uses material inputs to produce or store an intermediate or final product. A single stationary source may contain more than one process or production unit." While an automobile assembly plant produces a finished automobile, there are logical "processes" within the overall series of operations, such as a prime coat line, primer surfacer line, topcoat line, etc. Additionally, the EPA considers separate boilers to be individual emission units even if multiple boilers are located in a common "powerhouse" building or vented to a common stack. While the District intends to provide consistency in grouping process equipment to determine the scope of the process, the District believes that individual circumstances can also be taken into consideration.
Because the grouping of process equipment into processes may be different than groupings used previously, the District will add a section to the Regulation 1.06 stack and fugitive emission release parameters forms for the company to identify what process equipment is included in each process, along with an indication whether this grouping is the same as the Title V permit "Emission Unit" grouping, the District’s emission inventory system "Point ID" or is a proposed grouping scheme.
Question: (1/20/2006) In completing the Form SAM 82, are TACs that are de minimis required to be listed in the last column of Page 3 of the form under TACs emitted (and subsequent pages on which a list of TACs is required)?
Response: No. Regulation 1.06 section 3.7 specifies that the “related stack and fugitive emission release parameters” information that is applicable only to de minimis emissions is not required to be submitted. A listing of a TAC that is de minimis would be information that is “applicable only to de minimis emissions” and is thus not required. Only the applicable TACs (Category 1 and 2) that are greater than de minimis are required to be listed.
Question: (2/24/2006) If a company has no Category 1 TAC emission or each Category 1 TAC emission is de minimis, what is required to be reported for Form SAM 82?
Response: If a company has no Category 1 TAC emission or each Category 1 TAC emission is de minimis (note that the Regulation 5.01 section 1.6.4 definition of de minimis is based on allowed emissions, not actual emissions), then the company should complete Form SAM 82 Page 1 and Certification Page, indicating that the number of processes for which a report is being filed is “0.” Additionally, the company should attach a plot plan drawn to scale showing the following: property line, fences, scale, north arrow, buildings and other structures, height of buildings and other structures (if buildings have tiers, profile building tiers), and UTM coordinates for the corners of property, fences, and buildings. The plot plan need not include the location of processes and process equipment, location and identification of points of emission, or UTM coordinates for points of emission (although if a company already has a plot plan drawn that includes this additional information, it may be submitted).
Question: (2/24/2006) May attachments be used instead of filling out the forms?
Response: Yes, consistent with the procedures and requirements of the District’s emission inventory reporting requirements. The following is taken from Form SAM 2A, general instructions:
Attachments may be included with your completed forms. If you decide to use attachments, then please affix them securely to the appropriate forms. Identify each attachment page with your company name, plant identification number (EIS number) and the SAM form to which it pertains. Also, indicate on the appropriate document that there is an attachment. Include enough information on the form and attachment alike to make re-attachment possible, should they become disjoined during handling and processing.
Although the District does not specify that the format of an attachment must be identical to the SAM form, the attachment must be consistent enough so that the same information is submitted, and in a format that makes the required information readily identifiable.
Question: (2/27/2006) A company may not have accurate information concerning fenceline location. Would a company need to have its property surveyed to accurately place fencelines on the required plot plan?
Response: No, fencelines may be estimated on the required plot plan. If the location is estimated, please indicate on the plot plan that the fenceline location is estimated. In the formal comment/response document, the District indicated that, in general, the District intended not to make a distinction between fenceline and property line unless there is an area between the property line and the fenceline to which the public is invited, such as a park or playground. If such an area exists and the location of the fenceline on the plot plan is estimated, the District may require, after written notification, the submittal of accurate fenceline information. However, with the availability of GPS equipment, it is not likely that a formal survey would be necessary.
Question: (1/10/2006) On December 19, 2005 (70 FR 75047), the EPA removed methyl ethyl ketone (MEK) from the list of hazardous air pollutants (HAPs). What is the status of MEK for the STAR Program, given that it was listed because it was a HAP?
Response: The District intends to undergo rulemaking to propose the removal of MEK from the Category 4 TAC list in Regulation 5.23. [Note, the District will also propose the removal of MEK from the HAP list in Regulation 5.14.] If the proposed removal is adopted by the Board, MEK would no longer be subject to the STAR Program as a Category 4 TAC. Until a final action is taken by the Board, the District intends to use enforcement discretion and not consider MEK to be subject to the STAR Program as a Category 4 TAC.
Question: (2/24/2006) The Material Safety Data Sheet (MSDS) for Stoddard solvent (CAS No. 8052-41-3) used by a company identifies that the composition is 100% aliphatic hydrocarbons. Additional information from the supplier indicates that the material is typically a mixture of 50-60% paraffinic hydrocarbons, 30-40% naphthenic hydrocarbons (cycloparaffins) with less than 1% aromatics, and the olefin content is less than 0.01% (100 ppm). Additional information is that neither benzene nor toluene is detected (50 ppb detection level), xylene is 30-60 ppm, ethylbenzene is 5-15 ppm, and isopropylbenzene (cumene) is 30-60 ppm. Does Stoddard solvent, and its components, need to be reviewed for a new or modified process or process equipment (review of Categories 1, 2, 3, and 4 TACs)?
Response: No. The District believes that it is acceptable to treat the use of Stoddard solvent (CAS No. 8052-41-3) as de minimis, based upon the MSDS provision, Regulation 5.01 section 1.6.1 (carcinogen TACs less than 0.1% by weight, "noncarcinogen" TACs less than 1.0% by weight). The information submitted by the supplier is consistent with other information the District has seen regarding Stoddard solvent.
The following information was taken from the Agency for Toxic Substances and Disease Registry (ATSDR) web page (http://www.atsdr.cdc.gov/toxprofiles/tp79-c4.pdf) regarding Stoddard solvent :
Stoddard solvent is a chemical mixture containing hydrocarbons that range from C7 to C12 with the majority of hydrocarbons in the C9-C11 range (Air Force 1989b; Rothman and Emmett 1988). The hydrocarbons composing Stoddard solvent are 30-50% alkanes, 30-40% cycloalkanes, and l0-20% aromatics (Air Force 1989b; McDermott 1975). Stoddard solvent is considered to be a form of mineral spirits, white spirits, and naphtha; however, not all forms of mineral spirits, white spirits, or naphtha are considered to be Stoddard solvent. Stoddard solvent is produced from straight-run distillate of paraffinic or mixed base crude oil (Air Force 1989b; Rothman and Emmett 1988) and must meet the specifications of the American Society for Testing and Materials designation for Type I mineral spirits (Stoddard solvent) (ASTM 1988, 1992).
Although the ATSDR identifies 10-20% aromatics, the information is based on 1975 and 1989 reports, which predated the 1990 Clean Air Act list of hazardous air pollutants. The District’s review of several MSDSs for Stoddard solvent is much more recent. Based on this recent review, the District believes that treating the use of Stoddard solvent as de minimis, for STAR Program purposes, is acceptable. If the District reviews new information that contradicts this determination, the District will revise this FAQ.
The newest question is at the top.
- May a submitted compliance plan pursuant to Regulation 5.21 section 4.4 include a request for modification of the applicable EA goals?
- If an auto body repair facility that had a FEDOOP was also regulated under Regulation 6.31/7.59, would only the processes or process equipment subject to Regulation 6.31/7.59 be subject to the STAR Program requirements?
- How should the emissions from the combustion of natural gas be treated for the December 31, 2006 environmental acceptability demonstrations for Category 1 TACs from Title V Sources?
- Would a company need to have its property surveyed to accurately place fencelines on the required plot plan?
- In completing the Form SAM 82, are TACs that are de minimis required to be listed in the last column of Page 3 of the form under TACs emitted?
- What is the status of methyl ethyl ketone (MEK) for the STAR Program, given that it was listed because it was a HAP?
- What is intended by the request to identify “Process ID” in the draft Regulation 1.06 reporting forms?
Do you have a question about the STAR program that is not answered here? If so, you can e-mail it to us, call us at (502) 574-6000, or write to the address below.
Louisville Metro Air Pollution Control District
850 Barret Avenue
Louisville, Kentucky 40204-1745