Changes 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)
EU Directive 1984/291
Made 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)
From legislation.gov.uk's record of changes, the official one: see it there.