58. A sulphite, bisulphite or dissolving grade sulphite pulp plant must not emit a quantity of sulphur dioxide into the atmosphere in excess of 6 kg/t of pulp produced, assuming that the pulp has a water content not exceeding 10%.
The standard in the first paragraph does not include an emission from a spent cooking liquor incinerator. Such an incinerator must not emit a concentration of sulphur dioxide into the atmosphere in excess of 400 ppm.