Written by: Frederik Bernstorff, aera and John Carlund, Rouse
On 2 July 2025, the Enlarged Board of Appeal of the European Patent Office (EPO) issued decision G 1/23, holding that a product made publicly available before the filing date of a patent application constitutes prior art under Article 54(2) EPC, even if its composition or internal structure could not be analysed or reproduced.
Case Law Background
This decision departs from the earlier interpretation established in G1/92, which had set out that both public availability and reproducibility were necessary for a product to form part of the state of the art.
G1/92 introduced a limitation on what could be seen as forming a part of the state of the art by requiring that “the chemical composition of a product can only form a part of the state of the art when the product as such is A) available to the public and B) can be analysed and reproduced by the skilled person”.
G1/23 addresses point B) above by addressing the question of whether “a product put on the market before the date of filing of a European patent application is to be excluded from the state of the art within the meaning of Article 54 (2) EPC for the sole reason that its composition or internal structure could not be analysed and reproduced without undue burden by the skilled person before that date”.
Decision and reasoning
The Enlarged Board considered two interpretations of G1/92 regarding irreproducible products:
- (1) the product itself (inevitably including its composition) is not part of the state of the art in its entirety for the purposes of Article 54(2) EPC, or
- (2) only the composition of the product does not belong to the state of the art, but the product itself and its reproducible properties are part of the state of the art.
The Enlarged Board states in G1/23 that both interpretations were found to lead to a “manifestly absurd result”, one of these being that virtually all materials would be excluded from being prior art as every product ultimately relies on irreproducible starting materials such as natural chemical elements (described in reasons 56-60 of the decision).
Instead, the Enlarged Board put forth in reason 73 of the G1/23 decision a broader interpretation of “reproduce”, namely that simply obtaining the product in its readily available form from the market satisfies the reproducibility requirement set out in G1/92 (point B above), and thus the product constitutes prior art under Article 54(2) EPC.
Outcome of the Enlarged Board
The Enlarged Board summarised its decision as follows:
- A product put on the market before the date of filing of a European patent application cannot be excluded from the state of the art within the meaning of Article 54(2) EPC for the sole reason that its composition or internal structure could not be analysed and reproduced by the skilled person before that date.
- Technical information about such a product, which was made available to the public before the filing date, forms part of the state of the art within the meaning of Article 54(2) EPC, irrespective of whether the skilled person could analyse and reproduce the product and its composition or internal structure before that date.
Conclusion
As with any Enlarged Board of Appeal decision, it is likely to have wide ranging implications for patent applicants, proprietors, and others. In particluar, the outcome of G1/23 reinforces the need to secure patent protection before making a product publicly available, since such disclosure can now destroy novelty even if the product is non-reproducible. To this end, G1/23 enhances the need for caution with any confidential and potentially patentable matter (such as during commercialisation, prototyping, demonstrating, and providing sales samples).
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
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