Reconsideration of the National Ambient Air Quality Standards for Particulate Matter

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Environmental Protection Agency 40 CFR Parts 50, 53, and 58 [EPA-HQ-OAR-2015-0072; FRL-8635-02-OAR] RIN 2060-AV52 AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: Based on the Environmental Protection Agency's (EPA's) reconsideration of the air quality criteria and the national ambient air quality standards (NAAQS) for particulate matter (PM), the EPA is revising the primary annual PM 2.5 standard by lowering the level from 12.0 µg/m 3 to 9.0 µg/m 3 . The Agency is retaining the current primary 24-hour PM 2.5 standard and the primary 24-hour PM 10 standard. The Agency also is not changing the secondary 24-hour PM 2.5 standard, secondary annual PM 2.5 standard, and secondary 24-hour PM 10 standard at this time. The EPA is also finalizing revisions to other key aspects related to the PM NAAQS, including revisions to the Air Quality Index (AQI) and monitoring requirements for the PM NAAQS. DATES: This final rule is effective May 6, 2024. ADDRESSES: The EPA has established a docket for this action under Docket ID No. EPA-HQ-OAR-2015-0072. All documents in the docket are listed on the https://www.regulations.gov website. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are …