EPO clarifies: No reproducibility required for Prior Art status

In a landmark decision (G 1/23), the Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) has confirmed that a commercially available product constitutes prior art, even if its exact composition or internal structure could not be analysed or reproduced by a skilled person before the filing date.

What was decided?

The EBA ruled that:

1. A product placed on the market before a European patent application is filed cannot be excluded from the state of the art under Article 54(2) EPC merely because its structure or composition was not fully analysable or reproducible.
2. Any technical information made publicly available about that product before the filing date also qualifies as prior art, regardless of whether the skilled person could reverse-engineer it at that time.

In other words: public availability is the key factor. It is not necessary for the skilled person to understand exactly how the product works in order for it to destroy novelty.

Why does this matter?

This decision is highly relevant to:

• EPO opposition proceedings
• Revocation actions before the UPC and national courts
• Strategic patent filing timing.

Some practitioners have likened it to the U.S. "on-sale bar" concept: once a product is released to the market, even by a third party, it may count as novelty-destroying prior art if the invention is later claimed in a patent application.

Practical implications

• For novelty, it is now clear: any product that is made publicly available before the filing date is prior art, even if its technical details are difficult to determine.
• For inventive step, the (non-)reproducibility of the product might still play a role, but only as part of secondary indicia, not as a decisive factor.

An illustrative example from the ruling

The EBA used the example of Coca-Cola: although its recipe is secret, the taste is known to the public. So, modifying the taste slightly (e.g. adding lemon juice) would not automatically be inventive just because the original formula is not publicly available. The product’s properties can still be relevant to the prior art, even if its inner workings remain confidential.

Conclusion

The ruling in G 1/23 makes it clear that the threshold for what constitutes “state of the art” does not depend on reproducibility. A publicly available product may destroy novelty even if its composition is not fully understood.

For patent applicants, this highlights the importance of carefully considering the order of public disclosure and patent filing, particularly in situations where products may be demonstrated, sold or promoted prior to filing.

Not sure whether your invention is still “new” under G 1/23? Concerned about past public disclosures or product launches? Our European patent attorneys are happy to advise.