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

The firm has tapped a local patent trio to establish a foothold in the market and broaden its national presence
New Asia-Pacific IP head Jonathan Chu is eyeing opportunities arising from Chinese technology licensing, overseas enforcement and increasingly IP-heavy cross-border deals
Europe’s largest intellectual property convention and trade fair is back: IP Service World 2026 takes place in Munich from November 23–25 – the 16th edition, with 1,400-plus attendees from 55-plus nations, 100-plus speakers, and 100-plus exhibitors. Three days. Two focused areas. One IP marketplace.
Mehmet Gün and Uğur Aktekin discuss four decades of change in Türkiye’s legal market, the firm’s commitment to independence and the challenge of building an institution that can outlast its founders
Boehringer Ingelheim has instructed a team from Kirkland, while Teva is being represented by Pinsent Masons
The Delhi High Court’s latest directions offer an opportunity to move beyond remedies against bad-faith registrations and address how suspicious applications are identified in the first place, says Fatima Baig at Lexlinc
Camilla Hamrin describes how the acquisition by Acapo Onsagers will impact Bergenstråhle’s trademark practice – and reflects on changes she has seen over 30 years in IP
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
Gift this article