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G 1 /23 on the interpretation of G 1/92 has been issued – It is however not without problems

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EP 2 626 911 B1 relates to an encapsulating material for solar cell and a solar cell module.

Brief outline of the case

The opposition was rejected and the opponent appealed.

The board held that the granted patent fulfiled the requirements of sufficiency of disclosure.

The crucial question was whether the claims as granted lacked inventive step in view of the disclosure of document D1, particularly its Example 3 with the commercially available product ENGAGE® 8400.

The reproducibility of D1 was questioned by the proprietor with reference to opinion G 1/92.

The order of G 1/92

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

2. The same principle applies mutatis mutandis to any other product.

The referring decision

In T 438/19, the board referred the following questions 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 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 Art 54(2), 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 EBA’s argumentation

What can be derived from G 1/92

For the EBA, the answer in G 1/92 gave rise to two separate legal issues. It confirmed that properties of products will belong to the state of the art, also without any specific motivation to analyse a property. Additionally, it was interpreted in the case law as setting up the requirement that a product put on the market needs to be reproducible in order to be an item of the prior art. The present referral is directed at this second issue only.

The EBA’s answer in G 1/92 unambiguously calls for the analysis and reproduction of the product as a condition to be examined.

There is no pointer in either G 1/92 or the referring decision that the analysis and reproduction of the product would be hindered by anything other than the lack of knowledge required to analyse and reproduce the composition.

The product in question was a commercially available man-made product. It is not discussed in the appeal file whether the ENGAGE® 8400 polymer had still been commercially available at a later time, e.g. at the time of filing or even later.

For the referring decision these issues do not appear to play any role for the prior art status of ENGAGE® 8400.

The EBA further considered it to be undisputed that the ability to physically reproduce a physically existing product is meant where G 1/92 mentions the reproduction.

For the EBA, the term “reproduce” appears to cover two possibilities.

If a product has been available for a reasonable period of time and in reasonable quantities, it will normally open up for the skilled person the possibility to obtain the product again in its readily available form.

Alternatively, the skilled person would consider manufacturing the product themselves. In this case the skilled person would look for a suitable method of manufacture.

Both G 1/92 and the referring decision proceeds on the condition that the product has been put on the market, and that as such is physically available.

Different interpretations of G 1/92?

The referring decision considers that at least two different interpretations of G 1/92 are possible. Where the composition (and therefore the product) cannot be reproduced,

(1) the product itself (inevitably including its composition) is not part of the state of the art in its entirety for the purposes of Article 54(2) EPC, or

(2) only the composition of the product does not belong to the state of the art, but the product itself and its reproducible properties are part of the state of the art.

The polymer ENGAGE® 8400 was intentionally put on the market as a multi-purpose polymer, useful in various applications. The manufacturer made efforts to advertise it and to make it known for all potential customers.

It is another matter that the manufacturer at the same time may have made every effort to hide the production secrets from its competitors.

For the EBA, neither the first nor the second suggested interpretation of the referring board of G 1/92 can be brought into conformity with the Convention, given that they both lead to a manifestly absurd result.

The contradictions of an enablement requirement set up by G 1/92 disappear if the condition of reproducibility in the answer of G 1/92 can be interpreted as including the obtaining of the product from the market in its readily available form.

Even if, as argued by the proprietor, the product itself being non-reproducible but otherwise existing and commercially available does not belong to the state of the art leads to an absurd result.

The assumption that the skilled person would ignore non-reproducible products cannot hold. Rather, the opposite is true: the skilled person cannot achieve anything without non-reproducible, but otherwise available products.

Readily available products can thus not be excluded from the common general knowledge of the skilled person, hence also not from the state of the art within the meaning of Art 54(2).

Potential disappearance of the non-reproducible product

The patent proprietor argued at length that man-made non-reproducible products cannot be considered to be “available to the public” because they may disappear from the market or may change.

The EBA does not see why this undisputed fact would keep the product from becoming part of the state of the art. Taking into account the uncertain future availability of a product put on the market, e.g. a man-made product, would mean that a fundamentally new element would appear in the notion of the “state of the art” within the meaning of Art 54(2).

The prior art status of a disclosure will have to be decided not only on the basis of facts that all occurred before the filing date, but would have to include an element of prediction. Put differently, the term “made available to the public” would have to imply not only the access to the information possibly only once in the past, but an apparently long-term, if not permanent and everlasting availability of the source of the information, here the man-made or naturally occurring product.

The disappearance of the non-reproducible product may cause problems, but such problems are nothing new or unusual.

The “state of the art” is the information content, the abstract technical teaching, which does not disappear from the public domain as a question of legal principle once the technical teaching becomes part of the state of the art, i.e. enters the public domain. 

It is undisputed that the content of the technical teaching may be difficult to establish at a later time, as a question of proof. In most cases of public prior use, the latter has to be established by way of complicated evaluation of evidence.

This corresponds to the situation where a disclosure of some technical information was factually available to the public for a relatively short time only, but did not prevent the disclosure from becoming permanently part of the state of the art as a legal consequence of its temporary availability.

The order of the EBA

I. 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 Art 54(2) for the sole reason that its composition or internal structure could not be analysed and reproduced by the skilled person before that date.

II. 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 Art 54(2), irrespective of whether the skilled person could analyse and reproduce the product and its composition or internal structure before that date.

Comments

The EBA has confirmed G 1/92 and added that the mere fact of bringing a product to the market qualifies the product as prior art under Art 54(2), irrespective of whether the skilled person could analyse and reproduce the product and its composition or internal structure before that date.

If a marketed product is quoted in a piece of prior art under Art 54(2), then its composition or internal structure is considered as well belonging to the prior art.

The proposal of the EBA is in contradiction with existing case law

There appears to be an inherent contradiction in the EBA’s decision.

On the one hand, it may prima facie be admitted that any readily available product, be it reproducible or not forms part of the prior art under Art 54(2).

On the other hand, in its Summary, Point V, the EBA has specifiedEnablement within the meaning of Art 83 is not treated in this decision”.

The contradiction arises from the fact that there is a long line of case law of the boards to the effect that insufficient disclosure in the prior art cannot be upheld against a later application/patent. Such a document cannot be prior art under Art 54(2). See Case Law of the Boards, 10th Edition, I-C, 4.11.

This long line of case law should actually not become obsolete with G 1/23, since the EBA has clearly said G 1/23 does not deal with sufficiency in the meaning of Art 83. But then G 1/23 leads to an absurd result.

An insufficiently disclosed element in an application/patent is not capable of supporting the sufficiency of the latter, and after publication does it seem possible that such a published application or patent is part of the prior art under Art 54(2), see above.

Declaring on the one hand, that a non-reproducible prior art disclosure is part of the prior art under Art 54(2), but at the same time ignoring whether it is actually enabled in the meaning of Art 83, is logically incompatible.

In view of the existing case law, the problems caused by a product only defined by a trademark, whether temporarily available or not, does not seem as easily solved as the EBA makes out.

Some examples

In T 392/01, relating to self-adhesive wall-coverings, sufficiency was denied and the patent revoked. Thee only adhesive cited in the description, “Cascotak ADP 21/494″, cf. column 7, lines 29 to 36. The formulation of this adhesive was not disclosed in the patent.

This adhesive was, however, merely “a development product that evolved into WB 868“, and was thus not any longer available.  “Cascotak ADP 21/494″ was manifestly available at the filing date of the patent, but not later. The patent underlying T 392/01 was revoked for lack of sufficiency.

Claim 1 of AR4 in T 842/14, requires the “anti-foam reagent” to be selected from a group of anti-foam reagents designated by trademarks, namely “1520-US, AF, FG-10, 0-30, SE-15, and Antifoam B”.

The board held that in order to reproduce the claimed method, each one of the anti-foam reagents is essential and must be available during the whole lifetime of the patent. Whilst it is common ground between the parties that all of them were commercially available at the priority and filing dates of the patent, their availability up to the end of the patent term was disputed.

The chemical composition of the anti-foam reagents designated by trademarks was thus not directly and unambiguously derivable from any published documents, as the exact composition of these anti-foam emulsions or reagents was explicitly said to be “proprietary”.

Since the conditions set out in decision G 1/92 were not fulfilled, claim 1 of AR4 did not fulfil the requirements of Art 83.

A similar conclusion was reached in T 797/14.

In T 1293/13 claims 1 and 17 limit the determination of air permeability of a garment to a particular method “measured according to ASTM D737-96” and to a particular machine ”Frazier Low Pressure Air Permeability Machine 750”.

The machine ‘Frazier Low Pressure Air Permeability Machine 750’ was not any longer available, so that this machine could not any longer be used for the determination of the claimed values of air permeability.

In T 1293/13 the machine used to determine the values of air permeability was a clear limitation of the claim.

The board held that, regardless of whether the number “750” is a serial number or a model number, no evidence was provided that the skilled person could carry out the invention, since the invention is defined for a single machine only namely the claimed machine “750

The invention could therefore not be carried out, and the patent was revoked for lack of sufficiency.

In T 522/14, the copolymer mentioned in the example is a commercially available material called “Durotak 387-2510”, but the description contained the disclosure of its composition, so that there was no problem of sufficiency.

In T 2020/13, in a piece of prior art, the catalysts used were disclosed by their trademarks, but their composition was known from documents of the manufacturer itself and had been added to the Chemical Abstracts database. They were thus known.   

G 1/23 is not exempt from critics

Even if the question of sufficiency was not part of the referral, in view of the existing case law, the later availability of ENGAGE® 8400, should not have been ignored.  

As far as prior art or applications/patents are concerned, sufficiency of disclosure or prior art under Art 54(2) should not be treated differently.

The comparison with a public prior use for the availability of a product is an interesting point of view, but does not follow, in view of the existing case law, that a product ought merely to be available at the filing date, but also during the whole life of the patent. There is no guarantee that a public prior use is enabled. If, for any reason, a public prior use is not enabled, it cannot be part of the prior art under Art 54(2).

Some facts about ENGAGE™ 8400

Even if the question of sufficiency was not part of the referral, in view of the existing case law, the later availability of ENGAGE™ 8400 cannot be ignored.

In D1 at stake in the referring decision, filed on 19.09.2007, ENGAGE™8400 has been used to encapsulate solar cells.

In the more recently available information on ENGAGE® 8400, the use of ENGAGE™ 8400 is recommended for “Airbag Covers, Bumper Fascia and Panels, Consoles and Trim”, i.e. for the automotive industry. No word about the suitability for encapsulating solar cells.

One would therefore logically conclude that, the use of ENGAGE™ 8400 for encapsulating solar cells, is not any longer advised by the proprietor of D1 and the manufacturer of ENGAGE™ 8400. For both it is the Dow Company.

I have therefore great difficulties understanding that according G 1/23, D1 and ENGAGE™ 8400 are part of the prior art under Art 54(2).

A pragmatic solution only in appearance

Inasmuch G 1/22 and G 2/22 can be held as a pragmatic solution of the problems linked to the validity of priority, G 1/23, by ignoring the case law about enablement of prior art, cannot be considered as giving a pragmatic solution to the problem raised in D1.

G 1/23

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12 replies on “G 1 /23 on the interpretation of G 1/92 has been issued – It is however not without problems”

francis hagelsays:

The decision relies on a commonsense line of reasoning. According to G 1/23, the interpretation of G 1/92 at issue leads to absurd results. Assuming that the product available on the market is complex, its manufacturer makes use of components provided by suppliers. What matters, for the product to be reproductible, is just the availability of the components on the market. The manufacturer does not need to investigate how the components are obtained by its suppliers.

Avatar photoDaniel X. Thomassays:

Mr Hagel,

Common general knowledge is without any doubt part of the patent world. I did not know that common sense was also part of it. Thanks for adding this notion to the patent world.

The problem with G 1/23 is that a product only known by a trademark can disappear from the market or that the composition of such a product remains “proprietary”. This is however in flagrant contradiction with existing case law as I have shown in my blog.

Does this mean that sufficiency of disclosure is automatically acquired if a product, known only by a trademark, is on the market on the day of filing, but its availability is not guaranteed until the end of the patent life and/or its composition remains secret?

This is however a conclusion which can be derived from G 1/23.
This conclusion appears as absurd as stating that G 1/92 can lead to absurd results.

I would allow myself to say that common sense should not be confused with oversimplification.

Anonymoussays:

I don’t think there has to be complete symmetry between article 83 and 54. It seems fair that article 83’s requirements are not bounded to any specific point in time and a proprietor’s patent should be sufficient throughout its life because there is no reference to a date in article 83. Article 54 clearly does involve a time so there is an inherent asymmetry between the articles and if the state of the art is held to include things that had been available at any point before the priority date rather than things that were available on the priority date, this does not seem unreasonable to me from a policy perspective or from the wording of the articles.

Much case law may now be obsolete but as you sometimes say, this is part of life’s rich tapestry. I am yet to be convinced that this is a bad thing because the existing law led to some strange results.

Avatar photoDaniel X. Thomassays:

@ Anonymous,

I beg to disagree with you when you think it “fair that article 83’s requirements are not bounded to any specific point in time”. The contrary is true: sufficiency has to be given at the filing date and throughout the life of a patent.

I do also not agree when you state that “there is no reference to a date in article 83”.

I quote here G 1/03, Reasons 2.5.3: “Such a contribution is not present as long as the person skilled in the art is not able to carry out the invention. Therefore, the decisive date for fulfilling the requirement has to be the date of filing or priority, as the case may be. Deficiencies in this respect cannot be remedied during the proceedings before the EPO.”

Sufficiency of disclosure is to be assessed on the basis of the application as filed supplemented with common general knowledge at the filing date.

Only for those two reasons, it does not appear right to state that Art 83 can do without a date.

If, in order to implement an invention, you absolutely need a product only known by a trade mark, this can have dear consequences.

Even if the composition of a product only know under a trademeark is known at the filing date, you will not be allowed to add this information in the description or in the claims, as this amendment would infringe Art 123(2).

It is also to be kept in mind that an objection under Art 83 or under Art 56 depends on the formulation of the claim.

I refer here to G 1/03, Reasons 2.5.2, last §, and T 2001/12, Headnote.

If an effect is claimed but cannot be obtained, then the objection an objection under Art 83 has to be raised.

If an effect is not claimed, but irrespective of what may be asserted in the description, the effect cannot be obtained, then an objection under Art 56 has to be raised.

I see here a further reason to object to your statement that there is no reference to a date in Art 83.

We should all be weary of not oversimplifying situations as this could lead to results which are not reasonable.

The way we look at G 1/23 will also depend on our status as party.

It will be interesting to see how boards will interpret G 1/23.

Anonymoussays:

You have disagreed with my statement that “fair that article 83’s requirements are not bounded to any specific point in time” by saying “The contrary is true: sufficiency has to be given at the filing date and throughout the life of a patent”. Perhaps I was unclear, but that is exactly the point I was making: the EPC itself does not dictate any specific time when sufficiency has to be given and from a policy perspective, it is fair to assume that you only fulfil your side of the patent bargain if you truly make your invention available to the public forever. I do not think our opinions differ at all here.

On the other hand, your statement that “I do also not agree when you state that “there is no reference to a date in article 83″” is difficult to follow. “The European patent application shall disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art”. Here, date is not mentioned so I do not understand how you can disagree. How the enlarged board previously chose to interpret article 83’s requirements is a separate question to my original comment on the wording of the EPC

In situations like this where the case law of the boards has got too complex with diverging approaches and the enlarged board has been asked to weigh in, it is instructive to refer to the original text of the law and the underlying intentions and to ignore the masses of case law that led us to needing the question to be clarified. My comment was on the wording of the EPC and not its interpretation in the case law.

francis hagelsays:

Mr Thomas,

Common sense is welcome, including in the field of patents. Patent law makes great use of legal fictions; common sense is far from useless as guardrail against overly unrealistic or complex applications of these fictions.

The GCR showed common sense in its decision by considering as state of the art a commercially available product, without taking into account whether its composition or properties are publicly available. The GCR’s reasoning is convincing in that it finds relevance in the real-life situation of a company which routinely procures components from suppliers.

Moreover, the decision dismisses the application of a condition inspired by Article 83 to the definition of state of the art according to Article 54, which would have opened up a Pandora’s box and created complications and uncertainties detrimental to both the EPO and the concerned parties.

You refer to products mentioned in the description in relation to the implementation of the invention that are only known by a trademark. But the issue is not how a product is designated in the description. What matters is whether it has been commercially available or not. Referring to a trademark to identify a commercial product is a convenient shorthand in the drafting of an application, as trademark names are generally familiar to specialists in the relevant field; however, this is not in itself evidence that the product has actually been marketed.

Looking at the product at issue in the referring decision T 438/19 (“ENGAGE 8400”), it does not seem to examplify a product only known by a trademark name, judging from the detailed information available on the internet.

Avatar photoDaniel X. Thomassays:

Mr Hagel,

As such, I have nothing against common sense. It helps in lots of situations.

I have well understood that for G 1/23 what “matters is whether it [“ENGAGE 8400”] has been commercially available or not”.

Referring to a trademark to identify a commercial product might be a “convenient shorthand in the drafting of an application”. It means that at least when the application has been filed, the product was available on the market, but nothing more.

As far as “ENGAGE 8400” is concerned, there are indeed lots of information on the parameters it fulfils available, but there is no information about its actual composition, be it before the filing date of D1 nor presently.

In D1, filed on 19.09.2007, “ENGAGE 8400” has been used to encapsulate a solar cell. In the more recently available information on “ENGAGE 8400”, the use of “ENGAGE 8400” is recommended for “Airbag Covers, Bumper Fascia and Panels, Consoles and Trim”, i.e. for the automotive industry. No word about the suitability for encapsulating solar cells.

I would therefore logically conclude that the use of “ENGAGE 8400” for encapsulating solar cells is not any longer advised by the proprietor of D1 and the manufacturer of “ENGAGE 8400”, for both it is the Dow Company.

The EBA might have found a pragmatic solution for the time of filing, but failed to consider what has happened with a product only known under its trademark during the life of the patent in which it has been mentioned. D1, which has a EP family member, is nearing its active life as it has lapsed in most of the EPC member states.

I maintain that, as long as the product is available during the life time of a patent, then there is no problem with enablement, but once the product disappears from the market, or like in the present case the manufacturer does not even advise the use of its product for encapsuling solar cells, some reasonable doubts are permitted about the enablement of D1.

If the composition of a product only known by a trademark is known as such from the manufacturer or from other reliable sources, then there is no problem with the availability of the product, even after the filing date. See for example T 522/14 or T 2020/13, I have quoted in my comments.

The solution proposed by the EBA actually leads to more problems that it is meant to solve. The availability of the product at the filing date is nothing more than a snapshot. If I am not completely mistaken, enablement should be given over the whole scope claimed and the whole life time of a patent.

In T 1293/13, Claims 1 and 17 limit the determination of air permeability of the garment to a particular method “measured according to ASTM D737-96” and to a particular machine ”Frazier Low Pressure Air Permeability Machine 750”. The machine ‘Frazier Low Pressure Air Permeability Machine 750’ no longer exists, such that this machine could not be used for determination of the claimed values. As the machine was not any longer available, the board held that the requirements of Art 83 were not fulfilled, and confirmed the revocation o the patent.

This situation is similar to that in T 392/01, T 842/14 and T 797/14 I quoted in my comments where the products were only known by their trademarks.

I do not think that the result of all those decisions was absurd.

Comparing the availability of “ENGAGE 8400” with that of a public prior use is at best somehow short-sighted from the side of the EBA.

What about a public prior use if it turns out that it is not enabling? Then the whole theory of the EBA is falling apart like a card house.

Avatar photoDaniel X. Thomassays:

@ Anonymous of 07 Jul. 2025

The tone and the style of the comment remind me of a “good friend” of mine: Proof of Pudding which could also be called Moon Sailor.

You were not only unclear, you were also playing “I know it better”. You may have your opinion, but you should refrain from saying I know it better and to coclude with a sweeping statement that vast parts of case law have to be binned.

At best, you make yourself look preposterous.

Contrary to what you allege, the case law of the boards in matters of enablement has not gone too complex. The contrary is true.
As far as Art 83 is concerned, thee case law of the board is very coherent.

I will therefore continue to strongly disagree with you.

For the surplus, I refer you to my last comments to Mr Hagel.

Avatar photoDaniel X. Thomassays:

@ Anonymous of 07 and 11. Jul. 2025,

I have previously announced that I could delete comments. I don’t enjoy it, on the contrary, it’s not pleasant.

Contrary to most blogs, comments on the present blog do not undergo any approbation before publication.
This should not change, but it’s not a licence for discussions that don’t serve the matter at stake.

Only comments which contribute to the discussion will remain.

I have deleted your comment dated 11. Jul. 2025.

You did not even try to comment the decisions quoted in the blog and in the comments.
You merely maintained your apodictic attitude.

Whether you like it or not, enough is enough.

If you want to demonstrate that you know it better, then start your own blog.

I just wish to share a practical consideration. This decision may discourage filing a patent application claiming a non-reproducible product, but just keep it as trade secret. Minimal cost, no 20 year term, and if a a third party files a patent application after my sale, I can not only rely on the pre-use limits, but the sale qualifies as prior art under Art 54(2)

Avatar photoDaniel X. Thomassays:

Ganesh,

I would be a bit more weary when it comes to trade-secrets. In view of the nowadays reverse engineering possibilities, your product might, in the end, not be as secret as you think, and then G 1/92 fully applies.

In the case leading to G 1/23, the product ENGAGETM 8400 was, according to the opponent, not reproducible, which allowed the proprietor to claim 1 was not prior art under Art 54(2). Now with G 1/23, ENGAGETM 8400 is part of the prior art under Art 54(2) and D1 is part of said prior art, but it does not change anything to the fact that it is not an enabling disclosure. But on the other hand, according to the case law of the boards on sufficiency, a non-enabled prior art cannot be held against a patent/application.

Your practical consideration only comes into play, when your product is actually not reproducible. In such a situation, according to G 1/23, this product is part of the prior art under Art 54(2).

Your practical consideration shows all the difficulties which will occur if sufficiency of disclosure is given as soon as a product, manifestly not reproducible, is put on the market.

In view of the long line of case law on sufficiency, any third party filing an application and using the non-reproducible product will be faced with an objection of lack of sufficiency, although the product is meant, as such, to be part of the prior art under Art 54(2).

This explains the difficulty to transform an objection of lack of sufficiency in an objection of lack of N or IS which is what G 1/23 has tried to do.

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