58.The sulphur limits prescribed by section 57 for heavy fuel oil, coal, coke and pitch do not apply if
(1) part of the sulphur that would otherwise be emitted in the form of sulphur dioxide in the combustion gases is collected and blended with a raw material or product coming into contact with the gases;
(2) part of the sulphur that would otherwise be emitted in the form of sulphur dioxide in the combustion gases is collected and treated in a scrubber; or
(3) in a petroleum refinery, another low sulphur fossil fuel is used simultaneously.
Despite the first paragraph, the quantity of sulphur dioxide emitted into the atmosphere during fossil fuel combustion must not exceed the quantity emitted when burning fuel that has a calorific value of 42.6 MJ/kg and a sulphur content
(1) meeting the requirements of section 57 that apply in the case of subparagraphs 1 and 2 of the first paragraph of this section;
(2) of 1% (mass/mass) by weight in the case of subparagraph 3 of the first paragraph of this section.