Changes to Council Directive 78/631/EEC of 26 June 1978 on the approximation of the laws of the Member States relating to the classification, packaging and labelling of dangerous preparations (pesticides)
EU Directive 1978/631
Made by Commission Directive 84/291/EEC of 18 April 1984 adapting Council Directive 78/631/EEC on the approximation of the laws of the Member States relating to the classification, packaging and labelling of dangerous preparations (pesticides)
From legislation.gov.uk's record of changes, the official one: see it there.