New referral to EPO over hidden internal structure or composition in prior art

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2026

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Cookies Settings

New referral to EPO over hidden internal structure or composition in prior art

Sponsored by

inspicos-400px recrop.jpg
molecules-3713741.jpg

Edward Farrington of Inspicos reports that guidance is being sought from the EPO Enlarged Board of Appeal three decades after a decision on the analysis of complex products

Patentees and patent applicants before the EPO are occasionally faced with prior art – for example, products which have been put on the market – the internal structure or composition of which is not clear without further investigation. In mechanical fields, such products might be devices or apparatuses which have to be disassembled or broken up to determine the contents. In the chemical field, such products might be polymers or similar chemical compositions, which are difficult or impossible to analyse.

Enlarged Board decision G 1/92 (OJ EPO May 1993) considered what “hidden properties” such products actually disclosed. Decision G 1/92 found that “[t]he 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… 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.”

Although decision G 1/92 is regularly relied upon by parties before the EPO, it did not clearly explain the meaning of the phrases “reproduce without undue burden”, “available to the public”, and “can be analysed”. Divergent case law has developed since G 1/92: some decisions requiring a high level of certainty when analysing hidden properties, others requiring a less complete analysis, and still other decisions excluding such disclosures from the state of the art altogether.

The Enlarged Board of Appeal (EBA) has therefore been asked to clarify some of the issues remaining after G 1/92 in a new referral, G 1/23.

In particular, the EBA will consider whether a marketed product can be excluded from the prior art if its composition or internal structure cannot be analysed. It will also consider whether technical information about a marketed product is state of the art, regardless of whether the composition or internal structure of the product can be analysed. The EBA is also being asked to clarify which criteria apply in determining whether the composition or internal structure of a product could be analysed and reproduced without undue burden.

It is hoped that decision G 1/23 will provide guidance as to which level complex products such as polymers must be analysed if they are to be considered state of the art.

more from across site and SHARED ros bottom lb

More from across our site

On a recent trip to the French capital, we learned that the UPC is squeezing domestic litigation while firms are chasing senior talent, experimenting with AI and considering new ways of organising their practices
Daniel Law says a string of lateral hires and broader expansion plans will strengthen its position to capitalise on Brazil’s burgeoning IP and patent litigation market
Jason Raeburn’s arrival will expand the firm’s London footprint in AI, copyright and tech disputes
The firm is shaping its AI strategy around partnerships with Harvey and Legora alongside internally developed tools from its legal technology company, Eltemate
A dispute Down Under shows why trademark lawyers cannot afford to wait on the sidelines when a rival brand gathers momentum
The Third Circuit’s decision in Thomson Reuters v ROSS marks the first appellate-level decision addressing AI and fair use, prompting copyright counsel to consider arguments around potential licensing markets
Injunctions for HandsFree Labs and Align Technology come as the Court of Appeal warns that busy teams must have the staffing and resources to meet UPC deadlines
The chief technology officer remit, which has been created as the firm is building its litigation team, will include expanding the use of AI in patent and legal work and automating manual processes
Former Hoyng Rokh Moneiger partner Laura Alonso, who brought her team to ECIJA in March, discusses plans to expand further and why ECIJA’s ‘IP DNA’ is helping broaden her work
Amita Haylock discusses building an integrated Asia practice as clients increasingly demand that firms combine IP, technology and data expertise
Gift this article