1. Any measure implementing this Chapter, as regards workers, shall cover all benefits under occupational social security schemes derived from periods of employment subsequent to 17 May 1990 and shall apply retroactively to that date, without prejudice to workers or those claiming under them who have, before that date, initiated legal proceedings or raised an equivalent claim under national law. In that event, the implementation measures shall apply retroactively to 8 April 1976 and shall cover all the benefits derived from periods of employment after that date. For Member States which acceded to the Community after 8 April 1976, and before 17 May 1990, that date shall be replaced by the date on which Article 141 of the Treaty became applicable in their territory.

2. The second sentence of paragraph 1 shall not prevent national rules relating to time limits for bringing actions under national law from being relied on against workers or those claiming under them who initiated legal proceedings or raised an equivalent claim under national law before 17 May 1990, provided that they are not less favourable for that type of action than for similar actions of a domestic nature and that they do not render the exercise of rights conferred by Community law impossible in practice.

3. For Member States whose accession took place after 17 May 1990 and which were on 1 January 1994 Contracting Parties to the Agreement on the European Economic Area, the date of 17 May 1990 in the first sentence of paragraph 1 shall be replaced by 1 January 1994.