In many cases the ability to recognise a technical teaching such as the internal structure or composition of a product in prior use presupposes analysis of the product embodying this technical teaching. Whether it is technically feasible to analyse a product that is available on the open market is an issue that the boards have considered on a number of occasions.
In T 952/92, OJ 1995, 755, the board stated that information as to the composition or internal structure of a prior sold product is made available to the public and becomes part of the state of the art if direct and unambiguous access to such information is possible by means of known analytical techniques which were available for use by a skilled person before the relevant filing date (see also T 2/09). The board also stated that the likelihood or otherwise of a skilled person analysing such a prior sold product, and the degree of burden (i.e. the amount of work and time involved in carrying out such an analysis), is in principle irrelevant to the determination of what constitutes the state of the art. The novelty of a claimed invention is destroyed by the prior disclosure (by any means) of an embodiment which falls within the claim. The possibility of a complete analysis of a prior sold product is not necessary. The novelty of a claim is destroyed if an analysis of a prior sold product is such as to inform the skilled person of an embodiment of the product which falls within the claim.
In G 1/92 (OJ 1993, 277) the Enlarged Board of Appeal held that the chemical composition of a product forms part of the state of the art when the product as such is available to the public and can be analysed and reproduced by the skilled person, irrespective of whether or not particular reasons can be identified for analysing the composition. The same principle applies mutatis mutandis to any other product. It also stated that "An essential purpose of any technical teaching is to enable the person skilled in the art to manufacture or use a given product by applying such teaching. Where such teaching results from a product put on the market, the person skilled in the art will have to rely on his general technical knowledge to gather all information enabling him to prepare the said product. Where it is possible for the skilled person to discover the composition or the internal structure of the product and to reproduce it without undue burden, then both the product and its composition or internal structure become state of the art."
In T 472/92 (OJ 1998, 161) the board referred to G 1/92 and concluded that the printability characteristic of the material was not a property that became available to the public by their mere delivery, since this was clearly an extrinsic characteristic requiring interaction with specifically chosen outside conditions. Thus, such characteristic could not be considered as already having been made available to the public (see also T 267/92).
In T 390/88 the board rejected the argument that a film had not been made available to the public because its existence had only been announced at a press conference three weeks before the priority date, and hence it would have been impossible in that short time for a person skilled in the art to determine the film's composition.
In T 301/94 the board decided that the skilled person would have been able to reproduce the green glass without undue burden and that this was sufficient to meet the requirement of reproducibility set out in G 1/92. A skilled person must be able to prepare the product without undue burden on the basis of his general technical knowledge and knowing the composition or internal structure of the product, whatever the scale of production (laboratory, pilot or industrial scale). The board held that when a commercially available product could be analysed by the analytical methods known on the priority date and could also be reproduced, its chemical composition formed part of the state of the art even if a skilled person could not have recognised a priori (i.e. before performing an analysis), on the basis of the common general knowledge on the priority date that at least one component was present in the product, or was present in an "unusual small" amount (referring to T 952/92, OJ 1995, 755; T 406/86 OJ 1989, 302; T 390/88; G 1/92; see also T 370/02).
In T 947/99 the alleged public prior use concerned a visit to an ice-cream factory. Although it had not been established that a feature of the manufacturing process had been explicitly explained to the visitors, the board decided that information about the procedure had been publicly disclosed. The board observed that, in accordance with the principles set out in G 1/92, it was the fact that direct, unlimited and unambiguous access to any particular information regarding the manufacturing processes known per se was possible which made these processes available to the public within the meaning of Art. 54(2) EPC 1973, whether or not there was any reason to look or ask for such information.
In T 969/90 and T 953/90 the board had ruled that the internal structure of a product in prior use had been made available to the public because a skilled person relying on the normal means of investigation available to him would have been able to analyse the product.
In T 461/88 (OJ 1993, 295) the board ruled that a control program stored on a microchip had not been made available to the public if the analysis of the program would require an expenditure of effort on a scale which could only be reckoned in man-years and if, for economic reasons, it was highly improbable that the sole purchaser of the machine controlled by the program had carried out such an analysis (see obiter dictum ruling in T 969/90, see also T 212/99).