The Enlarged Board of Appeal of the European Patent Office (EPO) today issued its decision in case G1/23. This pivotal decision, arising from a case involving the commercially available polymer “ENGAGE® 8400”, directly addresses a critical question: Can a product on the market be excluded from the state of the art (within the meaning of Article 54(2) EPC) solely because its composition or internal structure can’t be reproduced by a person skilled in the art?
Background
T 0438/19 of 27 June 2023 (“the Referring Decision”) is an appeal against the decision of the Opposition Division rejecting the opposition filed against European patent no. 2 626 911 (“the patent in suit”).
The patent in suit relates to a solar cell encapsulating material. The core dispute revolved around whether the commercially available polymer “ENGAGE® 8400” should be considered prior art. ENGAGE® 8400 is a complex polymer. Certain properties of ENGAGE® were demonstrated by various pieces of technical documentation. However, the method for manufacturing it exactly was not in the public domain and the exact reproduction of a complex polymer is not a straightforward exercise (even if the final product is available for analysis).
The patent proprietors (Mitsui Chemical, Inc., and Mitsui Chemicals ICT Materia, Inc.) argued that ENGAGE® 8400 had not been made available to the public within the meaning of Article 54(2) EPC, having regard to the rationale of the opinion of the Enlarged Board of Appeal in G1/92, because it could not be exactly reproduced. Conversely, the opponent (Borealis GmbH) contended that publicly available information and properties of the commercial product should be considered prior art, irrespective of reproducibility.
This led the Technical Board of Appeal 3.3.03 to refer three questions of law to the Enlarged Board of Appeal on the conditions for a product to form part of the state of the art within the meaning of Article 54(2) EPC.
The three questions referred to the Enlarged Board of Appeal
The referring Board of Appeal, grappling with the interpretation of G1/92 and its “reproducibility requirement”, posed the following questions of law:
Question 1
Is a product put on the market before the date of filing of a European patent application 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?
Question 2
If the answer to question 1 is no, is technical information about said product which was made available to the public before the filing date (e.g. by publication of technical brochure, non-patent or patent literature) state of the art within the meaning of Article 54(2) EPC, irrespective of whether the composition or internal structure of the product could be analysed and reproduced without undue burden by the skilled person before that date?
Question 3
If the answer to question 1 is yes or the answer to question 2 is no, which criteria are to be applied in order to determine whether or not the composition or internal structure of the product could be analysed and reproduced without undue burden within the meaning of opinion G 1/92? In particular, is it required that the composition and internal structure of the product be fully analysable and identically reproducible?
Decision of the Enlarged Board of Appeal
After considering various submissions, the Enlarged Board of Appeal provided the following definitive answers in its decision:
Answer to Question 1 is: NO
The Enlarged Board of Appeal ruled that 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.
The Enlarged Board of Appeal analysed the different interpretations of the “reproducibility requirement” set out in G1/92 and clarified that the term “reproduce” must be understood in a broader sense, namely as the ability of the skilled person to obtain and possess the physical product.
For the purposes of Question 1, the Enlarged Board of Appeal considered that a treatment of analysability independently from the reproducibility was not required.
Answer to Question 2 is: YES
The Enlarged Board of Appeal ruled that 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.
This means that if the product is available for analysis, the results of such an analysis, and any other publicly available information about it (e.g., in technical brochures), will be prior art. The Enlarged Board of Appeal reaffirmed the principle from G1/92 that “direct and unambiguous access to some particular information is possible, which make the latter available, whether or not there is any reason for looking for it”.
The Enlarged Board of Appeal also clarified that the potential disappearance of a non-reproducible product from the market does not prevent it from becoming part of the state of the art. The “state of the art” refers to the abstract technical teaching, which, once made public, does not disappear as a matter of legal principle. Practical problems of later proving prior use or content remain for legal proceedings, but they do not negate its legal status as prior art.
Answer to Question 3: Not required (moot)
Given the answers to Questions 1 and 2, the Enlarged Board of Appeal considered Question 3 moot.
Key takeaways
The Enlarged Board of Appeal’s decision in G1/23 provides long-awaited clarity on the interpretation of Article 54(2) EPC, confirming that a product made available on the market cannot be excluded from the state of the art solely because its composition or internal structure cannot be reproduced by the skilled person. By adopting a broader understanding of the “reproducibility requirement” from G1/92, focusing on the ability to obtain and possess the product rather than replicate it, the Board has resolved longstanding legal uncertainty and aligned the law with practical realities in the fields involving complex materials.
This decision reinforces the principle that public availability, not technical replicability, is the key criterion for determining state of the art, and it will have far-reaching implications for novelty and inventive step assessments across a wide range of technologies.
Our previous article(s) on the referral: