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  • Where can I download hourly emissions data from continuous monitoring?

    Hourly emissions data files are available from the Clean Air Markets Division of EPA, collected as part of 40 CFR Part 75. The download location has changed in February, 2023. The new location is https://campd.epa.gov/data/bulk-data-files . Once on this new site, use the menu (at the left) and the Keyword…

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  • Where can I find older NEI data (prior to 2008)?

    The raw data and summaries that are still available (dating back to 1990) can be obtained from the web page https://www.epa.gov/air-emissions-inventories/pollutant-emissions-summary-files-earlier-neis . Starting with 2001 data, a more limited selection of summary files are available.

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  • How do the different parts of particulate matter (PM) fit together?

    The various parts of PM in the NEI are related as follows. PM10-FIL > PM25-FIL because PM10-FIL includes PM25-FIL PM25-PRI = PM25-FIL + PM-CON This equation only applies at the process level. Because some sources only can report PM2.5 (due to test method differences), this equation does not apply to…

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  • How does PM2.5 relate to PM species such as EC, OC, SO4, NO3, PMFINE, and DIESEL-PM25?

    Primary PM2.5 estimates are speciated into the five PM species in the NEI: elemental (black) carbon (EC), organic carbon (OC), nitrate (NO3), sulfate (SO4), and the remainder of PM25-PRI (PMFINE). Diesel engine PM25-PRI and PM10 emissions are also labeled as DIESEL-PM25 and DIESEL-PM10 for mobile source diesel engines. For all…

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  • Why are industries exempt under OSHA's PSM subject to RMP?

    The Program 3 prevention program requirements under 40 CFR Part 68 are almost identical to the requirements of OSHA's process safety management (PSM) standard. OSHA exempts certain industries from the PSM standard. Why does EPA not exempt those same industries from the CAA §112(r) risk management program requirements? EPA and…

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  • What if the quantity in the process fluctuates?

    What if the quantity in the process fluctuates? I may not have a threshold quantity now, but I will intermittently exceed the threshold quantity. You do not need to comply with the rule and file an RMP unless you have more than threshold quantity in a process; however, once you…

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  • Process identification and distance between vessels

    How far apart do separate vessels have to be to be considered different processes? There is no hard and fast rule for how great this distance should be before you do not need to consider the vessels as part of one process. Two vessels at opposite ends of a large…

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  • What does "same industrial group" mean?

    Operations at a site that belong to the same three-digit North American Industry Classification System (NAICS) code prefix (which has replaced the old SIC codes) belong to the “same industrial group. In addition, where one or more operations at the site serve primarily as support facilities for the main operation…

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  • Updating RMP if EPA lists a new substance

    What if EPA lists a new substance? You will have three years from the date on which the new listing is effective to come into compliance for any process that is covered because EPA has listed a new substance.

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  • Should tank capacity be considered when determining thresholds?

    When determining whether a threshold amount of a regulated substance is present in a process (e.g., a tank), must the owner or operator of a stationary source consider the total capacity of the process, or the actual amount of regulated substance contained in the process? The threshold determination is based…

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  • Does the chlorine listing apply only to gaseous forms of chlorine?

    There is no qualifier attached to the listing for chlorine (40 CFR §68.130). The listing, therefore, applies to chlorine (CAS number 7782-50-5), regardless of physical state.

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  • If laboratory chemicals are stored outside the laboratory, are they exempt from threshold determination?

    Under 40 CFR Part 68, for the purpose of determining whether more than a threshold amount of a regulated substance is present at a stationary source, certain exemptions may apply. One such exemption is provided for "activities in laboratories" (40 CFR §68.115(b)(6)). If laboratory chemicals are stored outside the laboratory…

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  • Calculating thresholds for toxic substances with concentration qualifiers

    Several toxic substances are listed as regulated substances under 40 CFR §68.130 with concentration qualifiers (e.g., "conc 37% or greater"). What does this concentration mean? When determining whether a threshold amount of these substances exists in a process, should I consider the weight of the entire solution, or simply the…

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  • Is there an exemption for the atmospheric storage of flammables?

    Under OSHA's Process Safety Management Standard, an exemption is provided for atmospheric storage of flammables. Has EPA included this exemption under the risk management program regulations? No. There is no exemption from the risk management program requirements for atmospheric storage of flammable substances because the list of regulated flammable substances…

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  • How did the January 6, 1998, final rule affect the definition of stationary source?

    How did the January 6, 1998, final rule ( 63 FR 640 ) affect the definition of stationary source, as it relates to the transportation exemption? The January 6, 1998 final rule amended the regulatory definition of stationary source by removing previous references to "active shipping papers" and "temporary storage"…

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