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Regulations last checked for updates: Jun 16, 2025
Title 40 - Protection of Environment last revised: Nov 16, 2025
All Titles
Title 40
Chapter I - CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
Part 50 [§ 50.1 - § 50.21] - PART 50—NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS
Part 51 [§ 51.1 - § 51.1403] - PART 51—REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS
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