In T 958/90 the board mentioned that a known effect could not be novel for the sole reason that the patent provided the information that it was present to a hitherto unknown extent.

In T 279/93 a claim directed to the use of a first compound in a process for preparing a second compound was revoked by the opposition division for lack of novelty. In particular, the claims were directed to the use of the alkanolamines for reducing the formation of isomelamine impurities. According to the appellant, this purpose, even if it might have been inherently attained by following the teaching of a prior art document, should have rendered the subject matter of the claims novel, since, in application of the reasoning in decision G 2/88 (OJ 1990, 93), inherency did not destroy the novelty of the new use, which had to be regarded as a functional technical feature of the claims. In the board's judgment, the use of a compound in a process for preparing another compound in order to reduce the formation of impurities was not necessarily a functional technical feature within the meaning of decision G 2/88, and did not therefore in all circumstances confer novelty on the subject matter of a claim containing it. The facts of the case at issue differed significantly from those underlying decision G 2/88, since the claim did not appear to contain any new technical effect or technical purpose in the sense required by that decision. In the board's view, noticing that an old product had the property of containing fewer isomelamine impurities was a mere discovery. To convert this into a patentable invention, and to show the characteristics of a new technical effect, the use referred to in the claim would have to be some new use of the product which exploited the discovery that the isomelamine impurities were low for some new technical purpose.

In T 1855/06, the board held that novelty of a use of a known compound for the known production of a known product could not be deduced from a new property of that product. In such a case, the use of a compound to produce a product had to be interpreted as a process for producing the product with the compound and could be regarded as novel only if the production process as such was novel. Similarly, where its stated purpose was merely to improve an already known property of the product to be produced, the use could not be regarded as a new technical activity within the meaning of G 2/88 and G 6/88, unless the claim required that the improvement be exploited in some form. In line with T 279/93, the board held that a finding that a known product had a particular property was a mere discovery and could not establish novelty of a use claim.

In T 892/94 (OJ 2000, 1) the board noted that according to G 2/88, novelty within the meaning of Art. 54(1) EPC 1973 could be acknowledged for a claim directed to the use of a known substance for a hitherto unknown, i.e. new, non-medical purpose reflecting a newly discovered technical effect. However, a newly discovered technical effect did not confer novelty on a claim directed to the use of a known substance for a known non-medical purpose if the newly discovered technical effect already underlay the known use of the known substance. The disclosure in citation (1) was, in the board's judgment, prejudicial to the novelty of the claim in question. It was immaterial for the purposes of prejudice to novelty that the actual technical effect exhibited by "aromatic esters" in deodorising compositions was not described in the cited document. The ex post facto discovery that the deodorising effect of "aromatic esters" when used as an active ingredient in deodorising products could result from their capability of inhibiting esterase-producing micro-organisms might possibly be regarded as a (potentially surprising) piece of knowledge about the known use or application of such esters but could not confer novelty on a claim, since the latter would require that the newly discovered effect did indeed result in either a new technical application or use of the "aromatic esters", which was not necessarily correlated with the known application or use and could be clearly distinguished therefrom.

In T 706/95 the board held that the discovery that the same known means led to an additional effect when they are used for the same known purpose (i.e. known use) of reducing the concentration of nitrogen oxides in the same effluent could not confer novelty on this known use (see also T 934/04).

In T 189/95 the board ruled that a new property of a substance, i.e. a new technical effect, did not necessarily signal or give rise to a new use for that substance. For example, the new property might merely explain the mechanism behind the use already described in the prior art, as in T 892/94 (OJ 2000, 1). Here again the board ruled that discovering a new property or activity did not in itself render novel a claim for the use of a known substance for a known non-medical use, if the discovery only showed what formed the basis of the known use of the known substance.

In T 151/13 the board stated that the purpose of a particular reagent in a known chemical process is not a functional technical feature in the sense of G 2/88 and does not render said process novel.

On the issue of the discovery of a previously unknown property of a compound underlying a known use, see further T 1073/96, referring to T 254/93 (OJ 1998, 285). By contrast, it was found that there was a new use, e.g. in T 319/98, T 952/99, T 966/00, T 326/02 and T 1090/02.