G1/23: What is available to the public in the sense of G1/92?

G1/23 is the first case this year to be referred to the EPO’s Enlarged Board of Appeal. The Enlarged Board is the ultimate arbiter for questions concerning the legal interpretation of the European Patent Convention (EPC), so its decisions are important for all Patent practitioners.

The case is concerned with the interpretation of a much older Enlarged Board of Appeal case, G1/92, and the correct application of its conclusions. The Board of Appeal in the referring case, T0438/19, identified what they consider to be divergent interpretations of G1/92 regarding what can and cannot be determined from the analysis of a commercially available product.

The EPC defines the “state of the art” as:

The state of the art shall be held to comprise everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application.      

Anything that falls within the state of the art is not novel so cannot be the subject of a valid patent claim. Similarly, anything which is obvious, having regard to the state of the art, cannot be patented. The definition and extent of the state of the art is thus of fundamental importance.

The case before G1/92 concerned the composition of a product. The Enlarged Board concluded that this composition could be considered to have been "made available to the public" when the product (itself) has been made available to the public and can be analysed and reproduced by the skilled person. The test under G1/92 can be expressed in three parts:

1. Was the relevant product freely available?
2. Could the composition of the product be determined by analysis?
3. Can the skilled person reproduce the product using her/his general knowledge and without an undue burden?

T0438/19 concerns a polymer suitable as a protective coating for a solar cell. In the claims, the polymer is defined by some of its physical properties (density, hardness etc.) and also by its aluminium content, which stems from the catalyst used in its manufacture.

The opponent raised an inventive step objection based on a commercial polymer product called ENGAGE^® 8400 and provided documentary evidence showing that it had all of the physical properties recited in the claims. Experimental evidence was provided to show that the aluminium content of ENGAGE^® 8400 was below the claim limit, which the opposition division considered suitable to establish an inventive step. The Board in T0438/19 disagreed with the opposition division and suggested that were ENGAGE^® 8400 to be taken to be the closest prior art, the claimed invention would be obvious. The question of whether ENGAGE^® 8400 was ‘made available to the public’ is thus critical.

The patentee’s position is that even if the second G1/92 test is met (the first test is uncontested), the third test is not so that ENGAGE^® 8400 cannot be considered to be part of the state of the art. And if ENGAGE^® 8400 is not part of the state of the art, it cannot be used as the closest prior art for inventive step. The Board analysed the case law developed since G1/92 and the historical documents which led to the establishment of the EPC (the ‘Traveaux Preparatoires’), and questioned whether the third test, often referred to as the requirement for an ‘enabling’ disclosure, is actually applicable, or if it is, how far should it extend? Should it be enough for the composition of the product to be obtainable through analysis, or is it necessary that the skilled person must also be able to reproduce exactly the commercial product? Is it that case that all compositional features be obtainable through analysis or only those mentioned in the claims? If the skilled person is deemed to have to be able to reproduce the product, does this mean that all features of the product have to be reproducible, or is reproduction of only those features which are claimed sufficient?  The Board distilled these into three questions which they have referred to the Enlarged Board in G1/23:

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?
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?
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?

Although this case relates to polymers and their compositions and synthesis, G1/92 makes it clear that in principle, the same considerations should apply in all technical areas. The outcome of G1/23 will thus be of interest not just to those who deal with chemical subject matter, but to all practitioners with an interest in EPO proceedings.