OTEC Präzisionsfinish v STEROS GPA Innovative (CoA, 7 November 2025)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By an order of 7 November 2025 (UPC_CoA_579/2025), the Court of Appeal set aside the order of the Hamburg Local Division of 16 June 2025, rectified on 11 August 2025, which had prohibited OTEC Präzisionsfinish from manufacturing and marketing an electrolytic medium for electropolishing at the request of STEROS GPA Innovative, exclusive licensee of EP 4 249 647. The application for provisional measures was rejected and STEROS was ordered to bear the costs at both instances.

The interest of the order lies in claim interpretation: experimental data not disclosed in the patent specification are, as a general rule, not relevant to construing the claim (paragraph 43). A party cannot therefore fix the meaning of a feature through tests carried out for the purposes of the dispute.

Facts and procedure

STEROS applied on 26 March 2025 for provisional measures based on claim 1. The Hamburg Local Division, measuring separately the conductivity of each phase of the emulsion present in the attacked product, found that the non-conductive fluid was present and granted the injunction. OTEC appealed. Its application for suspensive effect was rejected by order of 10 July 2025. The hearing took place on 15 September 2025 before a panel including two technically qualified judges.

The applicable law

The claims are the decisive basis for the scope of protection (Art. 69 EPC and its Protocol on Interpretation). The description and drawings serve as explanatory aids, not only to resolve ambiguity (paragraph 22). In provisional measures proceedings, infringement must be shown to be more likely than not. Rule 222.2 of the Rules of Procedure governs new evidence on appeal.

Question

How should the feature of a « non-conductive fluid immiscible in the conductive solution » be assessed where that fluid is an emulsion, and can tests performed by the applicant on an example in the patent inform that construction?

Decision

The description and claim 8 show that an emulsion may form the non-conductive fluid: its conductivity is assessed as a whole, the continuous phase being decisive, and not ingredient by ingredient as the Local Division had done (paragraphs 25 to 35). Absent any other value in the patent, the fluid must have a conductivity of no more than 10 µS/cm, the threshold that feature 1.1.2 assigns to the particles. STEROS’s relative reading was rejected (paragraphs 36 to 39), and its new evidence would not change this, whether or not admissible (paragraph 40).

Table 10 of the patent gives compositions only. STEROS’s measurements, not disclosed in the specification, are in principle irrelevant to construction, since the skilled person works from what the patent discloses (paragraphs 41 to 43). Non-conductivity is assessed in the final electrolytic medium, after combination with the particles, not at an earlier stage of preparation (paragraphs 44 to 47).

STEROS’s own analyses put the liquid surrounding the particles above 400 µS/cm and OTEC measured 340 µS/cm: feature 1.2.2 is not met and infringement is not more likely than not (paragraphs 48 to 51). The court did not need to address validity or the other requests (paragraph 52). The order was set aside, the application rejected and STEROS ordered to pay the costs at both instances (paragraph 53 and order).

Key points for practice

• Tests carried out for the dispute cannot be used to construe a claim, which must rest on what the specification discloses.
• Where a claimed fluid is an emulsion, its conductivity is assessed as a whole, not phase by phase, unless the patent indicates otherwise.
• A functional feature with no numerical threshold may be read in the light of a threshold set elsewhere in the claim.
• Practical point: a party seeking provisional measures must prove that each feature is present in the product as used, with measurements taken on the final medium.

Provisions applied

Rules of Procedure

Rules 206, 221, 222, 223, 225, 226, 236 and 238

European Patent Convention

Art. 69 and Protocol on Interpretation

Case law cited

NanoString v 10x Genomics, Court of Appeal, 26 February 2024, OTEC Präzisionsfinish v Steros GPA Innovative, Court of Appeal, 10 July 2025

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.