March 26, 1993

SUBJECT:  Error in CTC Report EPA-600/2-90-044, "Emission Factors
          for Iron Foundries -- Criteria and Toxic Pollutants"


     A significant error has been discovered in the report
entitled "Emission Factors for Iron Foundries -- Criteria and
Toxic Pollutants", EPA-600/2-90-044.  The error effects the values
in Table 3, page 16.  The error was in the conversion of the data
from the reference, which was in mg/cu. meter, to mg/Mg iron
produced.  The contractor, E.H. Pechan, multiplied the
concentration by the sampler flowrate instead of by the stack
flowrate.  The values presented in Table 3 need to be multiplied
by as much as 2,400 up to 12,000 times, depending on the sample
and stack flows in each test.

     The approximate error factors for each of the columns in
Table 3 are:

     Electric Arc Furnaces - 7,200

     Cupola - 6,400

     Inoculation - 2,400

     Pouring - 12,000

     Green Sand Shakeout - 7,000

For more information on this please call the CTC Hotline at (919)
541-0800.