1. (a) For sulfur dioxides, the maximum allowable particulate matter emission rate from non-ferrous foundries, smelters, or investment casting operations shall be calculated by the applicable equation in (b) through (d), below, where:

   1. (1) “X” means the total sulfur, CAS number 7704-34-9, burned in the smelter in pounds per hour; and
   2. (2) “Y” means the emission of sulfur dioxide, CAS number 7446-09-5, in pounds per hour;

2. (b) For copper from smelters, CAS number 7440-50-8, multiply X by 0.2, as shown in the formula below:

   Y = 0.2X

3. (c) For zinc from smelters, CAS number 7440-66-6, raise X to the 0.85 power and multiply the result by 0.564, as shown in the formula below:

   Y = 0.564 X^0.85

4. (d) For lead from smelters, CAS number 7439-92-1, raise X to the 0.77 power, and multiply the result by 0.98, as shown in the formula below:

   Y = 0.98 X^0.77

Source. #10315, eff 4-23-13 (from Env-A 2405.02); ss by #13694, eff 7-22-23