Subpart T – Magnesium Production

This page provides resources for subpart T reporters, including implementation information as well as supporting documents for relevant rulemakings.

Summary

The magnesium (Mg) production source category is defined as consisting of any process where Mg metal is produced through smelting (including electrolytic smelting), refining, or remelting operations (including primary production facilities that extract Mg from its ore and secondary production facilities that recover Mg from scrap), or any process where molten Mg is used in alloying, casting, drawing, extruding, forming, or rolling operations.

Reporter Resources

Subpart T Regulatory History

40 CFR Part 98.200
Federal Register DateCitationActionDescriptionFirst reporting year impacted
12/11/201479 FR 73750Final RuleAdds chemical-specific and default global warming potentials (GWPs) for fluorinated greenhouse gases (F-GHGs) and fluorinated heat transfer fluids (F-HTFs) to the general provisions of the Greenhouse Gas Reporting Rule, makes conforming changes to subpart I (Electronics Manufacturing) and subpart L (Fluorinated Gas Production), amends certain provisions of subpart L, and establishes confidentiality determinations for certain reporting requirements of subpart L.
Correction Notice (12/11/2014) (pdf) (1 p, 230 KB)
Final Preamble and Rule (12/11/2014) (pdf) (48 pp, 796 KB)
Response to Comments (12/11/2014)
Fact Sheet: Addition of Global Warming Potentials to the General Provisions and Amendments and Confidentiality Determinations for Fluorinated Gas Production (pdf) (44.97 KB, Nov 2014)
Proposed Preamble and Rule (1/10/2012) (pdf) (19 pp, 222 KB)
Proposed Preamble and Rule (9/11/2013) (pdf) (31 pp, 550 KB)
Proposed Rule (11/19/2013) (pdf) (24 pp, 400 KB)
Proposed Preamble and Rule (7/31/2014) (pdf) (21 pp, 370 KB)
Notice of Data Availability (04/05/2103) (pdf) (6 pp, 251 KB)		2014
11/29/201378 FR 71904Final RuleUpdates global warming potentials (GWPs) to reflect IPCC AR4 values, and amends 27 subparts to improve and clarify reporting requirements. Establishes confidentiality determinations for new and revised data elements.
Final Preamble and Rule (11/2013) (pdf) (79 pp, 935 KB)
Correction Notice (11/2013) (pdf) (2 pp, 248 KB)
Response to Comments (11/2013)
Fact Sheet: 2013 Revisions and Confidentiality Determinations (pdf) (37.58 KB, Nov 2013)
Memorandum: Table of Final 2013 Revisions to the Greenhouse Gas Reporting Rule (pdf) (1.02 MB, Sept 2013)
Proposed Preamble and Rule (4/2/2013) (pdf) (77 pp, 909 KB)		2014
11/29/201176 FR 73866Final RuleAmends subparts A, W, FF, II, OO, RR, and TT to clarify reporting requirements and correct technical and editorial errors.
Final Preamble and Rule (11/2011) (pdf) (25 pp, 341 KB)
Response to Comments (11/2011)
Fact Sheet: 2011 Technical Corrections, Clarifying, and Other Amendments to Certain Provisions of the Mandatory Reporting of Greenhouse Gases Rule (pdf) (48.02 KB, Nov 2011)
Proposed Preamble and Rule (8/4/2011) (pdf) (30 pp, 427 KB)
More Information on Technical Corrections		2011
05/26/201176 FR 30782Final RuleFinalizes confidentiality determinations for 34 subparts for data elements that are not inputs to emissions equations. Finalizes amendments to 40 CFR 2 governing CBI obtained under 40 CFR 98.
Final Preamble and Rule (5/2011) (pdf) (37 pp, 330 KB)
Correction Notice (10/2011) (pdf) (6 pp, 167 KB)
Response to Comments (5/2011)
Fact Sheet: Final Confidentiality Determinations for Data Collected Under the Greenhouse Gas Reporting Program and Amendments to Special Rules Governing Certain Information Obtained Under the Clean Air Act (pdf) (43.28 KB, May 2011)
Final Data Category Assignments and Confidentiality Determinations for Part 98 Reporting Elements (pdf) (1.76 MB)
Proposed Preamble and Rule (7/27/2010) (pdf) (4 pp, 164 KB)
Proposed Preamble and Rule (7/07/2010) (pdf) (40 pp, 366 KB)
CBI Powerpoint Presentation (pdf) (95.58 KB) 		2011
07/12/201075 FR 39736Final RuleAdds the following subparts to 40 CFR Part 98: T (Magnesium Production), FF (Underground Coal Mines), II (Industrial Wastewater Treatment), and TT (Industrial Waste Landfills); also finalizes harmonizing changes to subpart A.
Final Preamble and Rule (7/2010) (pdf) (43 pp, 372 KB)
Response to Comments (7/2010)
Withdrawal Notice (4/2010) (pdf) (133 KB)
Direct Final Rule (3/16/2010) (pdf) * (8 pp, 165 KB)
Proposed Preamble and Rule (3/16/2010) (pdf) (140 KB)
Proposed Mandatory Reporting of Greenhouse Gases Rule (pdf) (3.03 MB)
Subpart T Technical Support Document- Magnesium Production (pdf) (48.24 KB, 2/10/2009)
More Information on Subparts FF, II, TT
* The direct final rule received adverse comment and was subsequently withdrawn.		2011

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Last updated on August 6, 2025