Many of the cooking recipes in this blogger’s private collection end with „salt, pepper“ without indicating quantities. The skilled houseman or housewife will clearly be able to determine the quantities depending on his or her personal taste and would not contemplate adding ineffective amounts like 5 ppm.
This does, however, not apply to the famous person skilled in the art in its interpretation as applied by the EPO.
In the decision T 1009/12 discussed here and here, the claim at issue looked very much like a recipe for a composition, wherein the ingredient distinguishing the claim from the prior art was “an oxidant being selected from nitro aromatic compounds”.
The specification did neither mention any effects of this ingredient nor did the claim specify any minimum amount or maximum thereof to be used. The quantity was left completely open.
The BoA did not consider this feature for the assessment of inventive step:
According to this open definition the presence of a very small amount of e.g. 5 ppm of said oxidant is sufficient to meet the condition of claim 1 of the first auxiliary request. However, the Board considers that such a low concentration will not cause any effect in view of the common general knowledge of a chemist and the intended purpose of an oxidant. Particularly in the light of the most general range of the oxidant of from 0.1-25 g/l (corresponding to 100-25000 ppm) disclosed in the present application […] it is not reasonable to expect any effect of the nitro aromatic compound in such a low concentration.
And further below:Therefore claim 1, which does not specify any concentration ranges of the four components at all, is considered to cover embodiments where the mere presence of the nitro aromatic oxidant compound will not produce any effect at all.
The implication for the practice is that giving minimum (and maximum) values as well as the associated effects for any ingredient of a composition in the specification and claims as originally is highly recommendable. Failure to do so might result in the feature being completely disregarded in the assessment of inventive step.Since process claim 1 includes silver plating compositions including unspecified, therefore also ineffective concentrations of the nitro aromatic oxidant (see points [2.3.3] and [2.4] above) this feature can only be considered as an arbitrary feature, because it is not credible that it contributes to the solution of the underlying technical problem. The Board therefore does not further consider it. (emphasis added)
The full text of the decision can be found here.