A patent claim needs to be novel and comprise an inventive step in view of what was public “prior art” before the filing date (or priority date) of the patent application. Therefore, the “prior art” sets a key yardstick for whether or not a patent claim is valid.
In the recent landmark decision G 1/23, the Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) addressed under what conditions a product put on the market qualifies as prior art under Article 54(2) EPC.
This major decision overhauls the standard set more than three decades ago by the EBA in decision G 1/92.
1. General principles set out by G 1/92
Previously, G 1/92 had set out a test for the “availability to the public”. It found that the chemical composition of a product is state of the art when the following three criteria are met:
the product as such is available to the public and
can be analyzed by the skilled person (irrespective of the difficulty of the analysis) and
can be reproduced by the skilled person without undue burden, irrespective of whether particular reasons can be identified for analyzing the composition.
That generally meant that, if a product is on the market, but it cannot be reproduced by the skilled person “without undue burden”, the product could still be patented later on (if the patent application describes the details on how to reproduce it).
2. Case underlying G 1/23
The appeal proceedings concerned the decision of the Opposition Division rejecting the opposition against European patent EP 2 626 911. Claim 1 is directed at a material that is suitable for encapsulating a solar cell and comprises a specific polymer defined by its chemical composition including the aluminum content and its physical properties.
In the referring decision, the Board determined that the assessment of inventive step for the subject matter of claim 1 depends on whether the product ENGAGE® 8400 was “made available to the public” within the meaning of Article 54(2) EPC. While the product was publicly available, its exact composition and manufacturing process were not disclosed, raising questions about whether it could be considered part of the prior art under Article 54(2) EPC. In particular, the question arose to which extent the product’s commercial availability resulted in it being “made available to the public” in light of G 1/92.
The Referring Board referred three legal questions to the EBA, focusing on whether reproducibility is a prerequisite for a product to qualify as prior art:
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 analyzed 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 a 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 analyzed and reproduced without undue burden by the skilled person before that date?
