Since the adoption of the SEAC opinion, the operator of the plant in which full substitution is envisaged by 2025 has entered into a binding agreement with the authorities of the Member State concerned with a view to guaranteeing the gradual substitution of diaphragms containing chrysotile by a non-asbestos alternative material from 2014 on and achieving full substitution at the latest by 30 June 2025. Therefore it is appropriate that the duration of the exemption granted by Member States to permit the use of diaphragms containing chrysotile and of chrysotile fibres used exclusively in their maintenance is limited to 30 June 2025 at the latest.