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When is the composition of a product on the market prior art?

G1/23 – EPO Enlarged Board of Appeals of the EPO “available” (referral from T 0438/19)

Under which circumstances can the public prior use of a product constitute prior art for novelty or inventive step[s], specifically if the composition or internal structure of the product can only be analysed and or reproduced with difficulty? The Technical Board of Appeals in T 0438/19 recently referred corresponding questions to the Enlarged Board of Appeals. This question becomes relevant where reengineering of products can be burdensome, such as in the Life Sciences and chemical industries. 

Article 54(2) EPC holds that “the state of the art shall be held to comprise everything made available to the public (…) by use, or in any other way, before the date of filing of the European patent application.”

The key word in this provision is “available”, and the key question is therefore one of an appropriate threshold for something having been made “available” to the public. This question, which might seem academic, is sometimes difficult to answer in practice. 

The underlying case

In the case at hand, the patent proprietor claimed a polymer coating composition. The opponent relied on the public prior use of a product named ENGAGE 8400. It was undisputed that such product was “available” per se at the priority date. However, the patent proprietor argued that the composition of ENGAGE 8400 could not be analyzed without undue burden and thus the product would fail the test for admissible prior art (and thus must be disregarded in its entirety).

The legal test as set out by G1/92

The question of what is “available” to the public is actually not asked for the first time by the technical board of appeals of chamber 3.3.3 in T0438/19. It has been before the Enlarged Board of Appeals for decision already in G1/92, and has been discussed by the Enlarged Board of Appeals in G2/88 and G6/88 (sections 8, 10, respectively thereof) and in plenty of decisions of the technical boards of appeals before and after.

What is it that has to be available?

If there is any consensus among all of the decisions (and also between the parties at dispute in the underlying case to T0438/19), then that the availability standard shall be applied to a technical teaching. 

But it is actually this reference to “teaching” that renders the question of actual availability difficult to be answered, if a physical product is concerned. As opposed to a written statement (eg a patent), a product cannot actively teach anything. There is no explanation, but just the product. So what is the technical teaching thereof? Certainly – and this is again consensus – there is analysis required to identify the technical teaching comprised by a product.

While G1/92 brought clarification regarding the question, whether there is a requirement of motivation for analysis to have a product teach its properties and make them available, once it is in the public domain, G1/91 also brought some (further) ambiguity.

The three step test according to G1/92

The headnote of G1/92 is crisp and – apparently – crystal clear, in stating that: 

“The chemical composition of a product is state of the art when the product as such is available to the public and can be analyzed and reproduced by the skilled person, irrespective of whether or not particular reasons can be identified for analysing the composition.”

Thus, there is a three-step test of availability. 

(a) First, whether the product “as such” is available, which essentially corresponds to the “publication date” of such product being before the relevant date. 
(b) Second, whether the skilled person can analyse the product
(c) Third, whether the skilled person can reproduce the product.

While the first step is self-explanatory, the second is perfectly understandable: an analysis must be possible (otherwise there would be no teaching). However, G1/92 also introduces the requirement of reproducibility as a third step of the test. At first glance, this requirement is superfluous, because after analysis the teaching would be revealed and there is no need for reproduction. However, there are many properties and parameters of a product that can be analysed. Many may have been successfully analysed, and still a specific teaching of the product may still not have been revealed. Therefore, reproduction is required to ensure that every physical and structural aspect of the product has been understood.
The headnote of G1/92 does not provide any further constraints, as to time, effort etc. It may require to effect such analysis and reproduction. Thus, if it can be anyhow shown that a product could be analysed and reproduced at the priority date, it was part of the prior art. However, section 1.4 of the very same decision then states that:
“Where it is possible for the skilled person to discover the composition or the internal structure of the product and to reproduce it without undue burden, then both the product and its composition or internal structure become state of the art.”
Thus, while the headnote did not mention this explicitly, the decision reasoning added another requirement, which said that the analysis and reproduction must be possible without undue burden.

The referral

In the case of T0438/19 the patent proprietor based on the case law of G1/92 argued that the prior use had to be disregarded given an analysis of the product was not possible without undue burden. It is likely correct, that no actual polymer composition that would fall within the scope of the claims at issue can be analyzed and reproduced easily. The complexity and variability of such polymer compositions results in a tremendous effort that would be required to analyse every parameter that may be required to enable true reproduction thereof. But is this undue burden as it was meant by the enlarged board in G1/92?

Departing therefrom, the technical board of appeal raised the following set of questions:

  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 (eg 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?


The second question in particular appears too strict. It takes the “undue burden” requirement to the extreme and questions whether written evidence on individual features of a product can be deemed “enabled” (ie actually disclosed), if such product cannot be reproduced via reverse-engineering from analysis. 

If such question would be answered in the negative, this could be translated into a general skepticism on written product information as prior art for products that cannot be reverse-engineered by analysis (and there are many, particularly in biotech, pharma and chemistry).

Even though the question at hand in the underlying case is rather specific and technical, the departing legal question and particularly the implications of the answers to the questions are fundamental.

Considering the enlarged board would answer the first question in the positive (and particularly with no constraints), this would mean that in many areas of science a huge amount of “new” inventions would become possible, because the prior art that they would have to be tested against, would – over night – lose substantial amounts of disclosure.