Claims for products defined in terms of a process of manufacture are allowable only if the products as such fulfil the requirements for patentability, i.e. inter alia that they are new and inventive. A product is not rendered novel merely by the fact that it is produced by means of a new process. A claim defining a product in terms of a process is to be construed as a claim to the product as such. The claim may for instance take the form "Product X obtainable by process Y". Irrespective of whether the term "obtainable", "obtained", "directly obtained" or an equivalent wording is used in the product-by-process claim, it is still directed to the product per se and confers absolute protection upon the product.
As regards novelty, when a product is defined by its method of manufacture, the question to be answered is whether the product under consideration is identical to known products. The burden of proof for an allegedly distinguishing "product-by-process" feature lies with the applicant, who has to provide evidence that the modification of the process parameters results in another product, for example by showing that distinct differences exist in the properties of the products. Nevertheless, the examiner needs to furnish reasoned argumentation to support the alleged lack of novelty of a product-by-process claim, especially if this objection is contested by the applicant.
The EPO applies option GL/ISPE A5.26 of the Appendix to Chapter 5 of the ISPE Guidelines.