G 1/23 - EPO no longer requires products to be enabled to form prior art

Rechtsprechung | 21.07.2025

On July 2, 2025, the Enlarged Board of Appeal published the decision G 1/23 “Solar Cell”, in which HOFFMANN EITLE was heavily involved as representative of our long-standing client Mitsui Chemicals, Inc. The Enlarged Board ruled that a product put on the market cannot be excluded from the state of the art solely because its composition or internal structure could not be analysed and reproduced by a skilled person, and that also all technical information about such a product belongs to the state of the art.

This represents a major change in the case law that issued over the past 25 years following the issuance of the opinion G 1/92, where the Enlarged Board previously held that that only where it is possible for a skilled person to discover the composition or the internal structure of a product and to reproduce it without undue burden, both the product and its composition or internal structure become state of the art. In the present decision, the Enlarged Board considered the reproducibility criterion of G 1/92 to be redundant and that a product is prior art if a skilled person can obtain and possess the physical product, regardless of any aspect of reproducibility. 

This decision will have wide implications for opposition and opposition appeal proceedings. Further, it will remain to be seen whether the established case law on written disclosures, which are generally only treated as prior art if their teaching is reproducible, will be maintained, in particular in case of written disclosures relating to products that are not merely hypothetical but which were clearly in physical existence.

Further, the present decision also highlights that even though products are prior art regardless of their reproducibility, this does not mean that such a product is necessarily relevant prior art. Depending on the circumstances, a product may be pertinent with regard to novelty but may not be suitable as a starting point for an inventive step assessment, as a skilled person´s inability to reproduce the product may be relevant information that has to be considered in the  selection of the closest prior art. It is thus to be expected that this aspect may be subject to discussion in particular in opposition proceedings, so that arguments in relation to reproducibility may not fully disappear from opposition proceedings before the EPO.

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