Changes to Council Directive 77/576/EEC of 25 July 1977 on the approximation of the laws, regulations and administrative provisions of the Member States relating to the provision of safety signs at places of work
EU Directive 1977/576
Made by Commission Directive 79/640/EEC of 21 June 1979 amending the Annexes to Council Directive 77/576/EEC on the approximation of the laws, regulations and administrative provisions of the Member States relating to the provision of safety signs at places of work
From legislation.gov.uk's record of changes, the official one: see it there.