SO2
as defined in Directive (EU) 2016/2284 of the European Parliament and of the Council of 14…, Article 3, point (5) (Definitions)
all sulphur compounds expressed as sulphur dioxide, including sulphur trioxide (SO3), sulphuric acid (H2SO4), and reduced sulphur compounds such as hydrogen sulphide (H2S), mercaptans and dimethyl sulphides;