Pursuant to Art. 24(1) EPC, members of the boards of appeal or of the Enlarged Board of Appeal may not take part in a case in which they have any personal interest, or if they have previously been involved as representatives of one of the parties, or if they participated in the decision under appeal. Art. 24(3) EPC additionally provides that members of a board of appeal may be objected to by any party for one of the reasons mentioned in Art. 24(1) EPC, or if suspected of partiality. According to Art. 3(3) RPBA 2007 and Art. 4(3) RPEBA there shall be no further proceedings in the case before a decision on the exclusion of the member is taken. For the purposes of taking this decision, the member objected to is replaced (Art. 24(4) EPC).
While there are no provisions comparable to Art. 24 EPC that are applicable to members of the departments of first instance, the established case law of the boards of appeal has determined that the basic requirement of impartiality applies also to them (see G 5/91, OJ 1992, 617; see also in this chapter III.J.1.6. below).
According to the Enlarged Board in G 2/08 of 15 June 2009 date: 2009-06-15, Art. 24 EPC envisages two different situations: exclusion and objection. The first, under paragraph 1, is exclusion ex officio of a member of the boards of appeal for specific reasons, primarily for having a personal interest or having been involved in the decision under appeal. The second, under paragraph 3, is objection by a party if it suspects a member of a board of partiality. In other words, under "Exclusion and objection" the legislator distinguishes between, on the one hand, an irrefutable presumption of law consisting in those compelling grounds for exclusion (see in this chapter III.J.5.1.) that must apply ex officio, and may therefore be raised by anyone, i.e. the parties, the board or a third person, without their having to justify any personal interest as of right, and, on the other hand, the grounds for objection (see in this chapter III.J.5.2.) that may be raised by any party to the proceedings if it suspects partiality of a member of a board of appeal or of the Enlarged Board of Appeal, since said party enjoys a personal and legitimate interest in the proceedings and is entitled to due process of law in respect of said interest. In such a case the burden of proof lies with the party who raises the objection, since board members, including those of the Enlarged Board of Appeal, are a priori presumed to be impartial (see in this chapter III.J.1.4.). This distinction is also reflected in Art. 112a(2)(a) EPC, which provides as a ground of petition for review that a member of a board of appeal took part in the decision in breach of Art. 24(1) EPC or despite having been excluded pursuant to a decision under Art. 24(4) EPC. In other words, whereas the grounds under Art. 24(1) EPC are considered to be peremptory due to the violation of the legal principle that nobody should be a judge in his own cause, the ground which could have justified an objection for suspicion of partiality is not directly envisaged as constituting a priori (i.e. unless proven and decided by the board; see also R 20/09) a cause of review (Art. 24(3) EPC).