(74)The technical specifications drawn up by public purchasers need to allow public procurement to be open to competition as well as to achieve objectives of sustainability. To that end, it should be possible to submit tenders that reflect the diversity of technical solutions standards and technical specifications in the marketplace, including those drawn up on the basis of performance criteria linked to the life cycle and the sustainability of the production process of the works, supplies and services. Consequently, technical specifications should be drafted in such a way as to avoid artificially narrowing down competition through requirements that favour a specific economic operator by mirroring key characteristics of the supplies, services or works habitually offered by that economic operator. Drawing up the technical specifications in terms of functional and performance requirements generally allows that objective to be achieved in the best way possible. Functional and performance-related requirements are also appropriate means to favour innovation in public procurement and should be used as widely as possible. Where reference is made to a European standard or, in the absence thereof, to a national standard, tenders based on equivalent arrangements should be considered by contracting authorities. It should be the responsibility of the economic operator to prove equivalence with the requested label. To prove equivalence, it should be possible to require tenderers to provide third-party verified evidence. However, other appropriate means of proof such as a technical dossier of the manufacturer should also be allowed where the economic operator concerned has no access to such certificates or test reports, or no possibility of obtaining them within the relevant time limits, provided that the economic operator concerned thereby proves that the works, supplies or services meet the requirements or criteria set out in the technical specifications, the award criteria or the contract performance conditions.