This document was  developed for  the Proposed Mandatory GHG Reporting Rule.
For the  final document, please visit the  final Mandatory  Reporting of
Greenhouse Gases  Rule.
Magnesium Production
                                                                                  United Slates
Proposed Rule: Mandatory Reporting of Greenhouse Gases                        Environmental Protection


Under the proposed Mandatory Reporting of Greenhouse Gases (GHGs) rule, owners or
operators of facilities that contain magnesium production processes (as defined below) and that
emit 25,000 metric tons of GHGs per year or more (expressed as carbon dioxide equivalents)
from stationary combustion, miscellaneous use of carbonates, and other source categories (see
information sheet on General Provisions) would report emissions from all other source
categories located at the facility for which emission calculation methods are defined in the rule.
Owners or operators would collect emission data; calculate GHG emissions; and follow the
specified procedures for quality assurance, missing data, recordkeeping, and reporting.

How Is This Source Category Defined?

Under the proposal, magnesium production and processing facilities are defined as any site where
magnesium metal is produced through smelting (including electrolytic smelting), refining, or remelting
operations, or any site where molten magnesium is used in alloying, casting, drawing, extruding, forming,
or rolling operations.

What GHGs Would Be Reported?

The proposal calls for each magnesium production facility would report total emissions at the facility
level for each of the following gases in kilograms (kg) and in metric tons of carbon dioxide equivalent
(CO2e) per year resulting from their use as cover gases or carrier gases in magnesium production or
processing:

       Sulfur hexafluoride (SF6)
    .   HFC-134a
       The fluorinated ketone FK5-1-12
       Carbon dioxide (CO2)
       Any other fluorinated GHG as defined in 40 CFR part 98, subpart A (General Provisions) of the
       rule

In addition, each facility would report GHG emissions for other source categories for which calculation
methods are provided in the rule. For example, facilities would report CO2, nitrous oxide (N2O), and
methane (CH4) emissions from each stationary combustion unit on site by following the requirements of
40 CFR part 98, subpart C (General Stationary Fuel Combustion Sources). Please refer to the relevant
information sheet for a summary of the proposal for calculating and reporting emissions from any other
source categories at the facility.

How Would GHG  Emissions Be Calculated?

Under the proposal, owners or operators of magnesium production facilities would calculate emissions of
each gas by monitoring the annual consumption of cover gases and carrier gases using one of three
methods:
March 2009                                   1                             EPA-430-F-09-033

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This document  was developed for the  Proposed Mandatory GHG Reporting Rule.
For  the  final  document,  please  visit the  final  Mandatory  Reporting  of
Greenhouse Gases Rule.

     Using a mass-balance approach that takes into account the following:
           o  Decrease in Inventory: The decrease in inventory of cover or carrier gases stored in
              containers from the beginning to the end of the year.
           o  Acquisitions: The amount of cover or carrier gas acquired through purchases or other
              transactions.
           o  Disbursements: The amount of cover or carrier gases disbursed to sources and locations
              outside the facility through sales or other transactions.
     Monitoring the changes in the masses of individual containers as the gases are used.
     Monitoring the mass flow of pure cover gas and carrier gas into the cover gas distribution system.

What Information Would Be Reported?

In addition to the information required by the General Provisions at 40 CFR 98.3(c), the proposal calls for
each annual report to include the following information:

     Total facility emissions of each GHG in kg and CO2e.
     Type of production process (e.g., primary, secondary, die casting).
     Magnesium production amount in metric tons for each process type.
     Cover gas flow rate and composition.
     Amount of CO2 used as a carrier gas during the reporting period.
     For any missing data, report the length of time the  data were missing, the method used to estimate
       emissions in their absence, and the quantity of emissions thereby estimated.
     Cover gas usage rate for the facility.
     If applicable, an explanation of any change greater than 30 percent in facility cover gas usage rate
       (e.g., installation of new melt protection technology or leak discovered in the cover gas delivery
       system that resulted in increased consumption).

For More Information

This  series of information sheets is intended to assist reporting facilities/owners in understanding key
provisions of the proposed rule. However, these information sheets are not intended to be a substitution
for the rule. Visit EPA's Web site (www.epa.gov/climatechange/emissions/ghgrulemaking.html) for more
information, including the proposed preamble and rule and additional information sheets on specific
industries, or go to  to access the rulemaking docket (EPA-HQ OAR-2008-0508).
For questions that cannot be answered through the Web site or docket, call 1-877-GHG-l 188.
March 2009                                    2                              EPA-430-F-09-033

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