StacksVerified U.S. regulatory reference

40 CFR §98.66

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
In addition to the information required by § 98.3(c), you must report the following information at the facility level:
  1. (a)[Reserved]
  2. (b)Type of smelter technology used.
  3. (c)The following PFC-specific information on an annual basis:
    1. (1)Perfluoromethane emissions and perfluoroethane emissions from anode effects in all prebake and all Søderberg electrolysis cells combined.
    2. (2)Anode effect minutes per cell-day (AE-mins/cell-day), anode effect frequency (AE/cell-day), anode effect duration (minutes). (Or anode effect overvoltage factor ((kg CF4/metric ton Al)/(mV/cell day)), potline overvoltage (mV/cell day), current efficiency (%)).
    3. (3)Smelter-specific slope coefficients (or overvoltage emission factors) and the last date when the smelter-specific slope coefficients (or overvoltage emission factors) were measured.
  4. (d)Method used to measure the frequency and duration of anode effects (or overvoltage).
  5. (e)The following CO2-specific information for prebake cells:
    1. (1)Annual anode consumption if using the method in § 98.63(g).
    2. (2)Annual CO2 emissions from the smelter.
  6. (f)The following CO2-specific information for Søderberg cells:
    1. (1)Annual paste consumption if using the method in § 98.63(g).
    2. (2)Annual CO2 emissions from the smelter.
  7. (g)[Reserved]
  8. (h)Exact data elements required will vary depending on smelter technology (e.g., point-feed prebake or Søderberg) and process control technology (e.g., Pechiney or other).