Directive 2009/148/EC of the European Parliament [19. article 3.part]

The register referred to in paragraph 2 and the medical
records referred to in the fourth subparagraph of Article 18(2)
shall be kept for at least 40 years following the end of exposure,
in accordance with national laws and/or practice.

Source: Directive 2009/148/EC of the European Parliament and of the Council of 30 November 2009 on the protection of workers from the risks related to exposure to asbestos at work (Text with EEA relevance)