New Referral to the Enlarged Board of Appeal (G 1/23)

On the face of it, novelty should be straightforward to assess; either something was known on a particular date, or it wasn’t. However, this latest referral to the EPO’s Enlarged Board of Appeal (EBA) concerns an interesting paradox whereby a chemical compound was simultaneously known and not known, depending on how the case law should be applied.

Article 54(2) EPC (novelty) defines the prior art as “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”. For chemical compounds, there is an additional caveat that a compound is only “made available to the public” if the skilled person could have been able to analyze and reproduce the product, following earlier EBA decision G 1/92[1].

The Board of Appeal dug into this issue when considering T0438/19[2], concerning solar panels. The case at issue, EP 2626911 owned by Mitsui Chemicals, was upheld as granted by the Opposition Division. The Appellant, Borealis AG, sought to overturn this decision on Appeal.

EP 2626911 relates to polymers for coating and protecting solar cells in solar panels. Claim 1 as granted relates to a material for encapsulating a solar cell, comprising a polymer having various properties.

The Appellant argued that polymer ENGAGE® 8400, described in Example 3 of D1, was the most appropriate starting point for assessing inventive step. The Appellant provided evidence to show that ENGAGE® 8400 had all of the properties of the polymers of claim 1 of the Patent, with the exception of the aluminum content. Altering the aluminum content was considered by the Board of Appeal to constitute an obvious modification. 

The Patentee did not dispute that ENGAGE® 8400 was disclosed in leaflets prior to the effective date of the Patent, but argued that this polymer had not been “made available” to be public in the sense of G 1/92 and thus could not constitute prior art. In particular, the Patentee argued that it would be an undue burden for the skilled person to reverse engineer ENGAGE® 8400 and then to select the specific catalysts and reaction conditions necessary for manufacture of the product. 

It is clear that both sides are heavily reliant on the definition of the skilled person to support their position, a view supported by G 1/92. G 1/92 ultimately created a “test” for assessing whether a commercially available product is prior art:

1. one member of the public must be able to access the product;
2. the skilled person must be able analyze product; and
3. the skilled person must be able to reproduce the product (even if they have no reason to do so).

Therefore, where it is possible for the skilled person to analyze and reproduce the product without undue burden, then the product becomes state of the art. “Undue burden” has been interpreted as “using normal means of investigation” (see e.g., T969/90, T953/90 & T301/94).

Following the above “test” from G1/92, if it is not possible to analyze and reproduce a product without undue burden, then the product should not be part of the state of the art. However, in this referring case, the Board of Appeal identified divergent case law. Some decisions agreed that the product and its internal composition/structure should not be part of the prior art (see e.g., T946/04, T1666/16), while others found that only the internal composition of the product should be excluded from the prior art (see e.g., T370/02, T2045/09, T1833/14, and T0023/11).

The referring Board recognizes the semantics here, but notes the wider implications for inventive step, particularly in the referring case which hinges on this concept of “made available to the public”.

The Board also considered how strictly the requirement to “analyze” and “reproduce” the alleged prior art compound should be interpreted. Does this, for example, require a full analysis of all features of a product and reproduction of an identical copy? Again, the referring Board found divergent case law. Certain decisions suggest that exact replication is not required (see e.g., T952/92 & T1540/21), while others require duplication (see e.g., T977/93 & T1833/14).   

This has led to the following questions being referred[3] to the EBA:

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?
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 analyzed 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 analyzed 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 analyzable and identically reproducible?

While the referring case is concerned with chemical subject-matter, like all EBA decisions, the outcome will have implications for all technical areas. If you have any questions on how this referral may impact your European applications and patents, please contact Maeve O’Flynn or Victoria Barker.

Endnotes

[1] https://new.epo.org/en/boards-of-appeal/decisions/g920001ep1.html

[2] https://new.epo.org/en/boards-of-appeal/decisions/t190438ex1.html

[3] https://www.epo.org/law-practice/case-law-appeals/communications/2023/20230629.html