The 2008 revision of the Declaration of Helsinki (Declaration) includes a new paragraph dealing specifically with the standards of informed consent required for research involving identifiable human tissue samples and/or data. In cases where obtaining consent would be impossible or unduly burdensome, researchers may now proceed without it, following approval of the project by an ethics committee. This is a significant development in the Declaration, yet so far it has received little attention. We examine the implications of paragraph 25, and assess its role in the debates on proper sample handling. In particular, we question whether the use of the term "identifiable" weakens the paragraph, as its meaning depends on national context. Relying on this term to designate samples that could be traced to the donor, and therefore carry risk for that donor, is impossible if its meaning is not universally accepted. The Declaration of Helsinki is now entering a new revision phase. In order to protect sample donors, paragraph 25 should be enhanced, and the remit of the Declaration strengthened, by a more precise description of which samples and data count as identifiable.