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

IP experts gathered in San Francisco last week to discuss the changing global SEP landscape and new licensing models for AI infrastructure
SKW Schwarz partner Daniel Kendziur explains how new green claims rules are changing his workload and bringing him into direct contact with marketing, PR and government affairs teams
The government is targeting earlier resolution of SEP disputes while ruling out a standalone IPEC rate determination track and restrictions on injunctions
Ana Castedo, who brings a strong focus on patent litigation, is due to help build the firm’s IP litigation offering in Madrid
A former scientist, inventor and now a patent practice leader, Hanane Fathi Roswall shares her views on leadership, diversity, the rise of AI and the promise of the UPC
With rumours that a third IP judge could yet join the England and Wales High Court, we run through some potential names while practitioners outline the importance of a well-stocked bench
Speaking to Managing IP at Via’s Bridge Summit in San Francisco, president Kevin Mack explains why the AI infrastructure boom is forcing a rethink of traditional SEP licensing and FRAND models
Law firms continue to sell clients on international footprints, but sprawling office networks count for little if financial structures discourage internal collaboration
Via's Qi pool expands its footprint in Asia with the addition of Chinese smartphone giant and Japanese auto company
Matthew Cassie becomes the tenth partner to join the firm’s London outpost, and the second since it opened its new headquarters in May this year
Gift this article