in the case of existing industrial establishments using the sulphate process:

1. (i)
   as regards dust, discharges shall be reduced by 31 December 1993 to a value of not more than 50 mg/nm³ 13 from major sources and not more than 150 mg/nm³ 13 from any other source14;
2. (ii)

   as regards S0_x, discharges arising from digestion and calcination steps in the manufacture of titanium dioxide shall be reduced by 1 January 1995 to a value of not more than 10 kg of SO₂ equivalent per tonne of titanium dioxide produced;

3. (iii)

   Member States shall require means to be installed for preventing the emission of acid droplets;

4. (iv)
   plants for the concentration of waste acid shall not discharge more than 500 mg/nm³ SO_x calculated as SO₂ equivalent15;
5. (v)

   plants for the roasting of salts generated by the treatment of waste shall be equipped with the best available technology not entailing excessive costs in order to reduce SO_x emissions;

in the case of existing industrial establishments using the chlorine process:

1. (i)
   as regards dust, discharges shall be reduced by 15 June 1993 to a value of not more than 50 mg/nm³ 16 for major sources and not more than 150 mg/nm³ 16 from any other source17;
2. (ii)
   as regards chlorine, discharges shall be reduced by 15 June 1993 to a daily average concentration of not more than 5 mg/nm³ 18 and not more than 40 mg/ng3 at any time.