Harmonised standard

# Harmonised standard A harmonised standard is a European standard developed in response to a European Commission standardisation request and cited in the Official Journal of the European Union. Applying a harmonised standard gives a manufacturer a legal presumption that the product meets the essential requirements of the corresponding EU legislation that the standard covers. ## Key facts - Harmonised standards are EN standards adopted by CEN, CENELEC or ETSI following a Commission standardisation request. - Citation in the Official Journal of the EU is what makes a standard "harmonised" in the legal sense. - Using a harmonised standard is voluntary, but it confers a presumption of conformity with the essential requirements it covers. - Presumption of conformity is the simplest and most common route to CE marking for many product categories. - Standards are reviewed and can be withdrawn; only the cited version gives presumption of conformity. - Harmonised standards exist across directives and regulations, from toys (EN 71) to radio equipment (EN 300 328). - Manufacturers may use alternative technical solutions, but then they must demonstrate conformity without the presumption. ## How a standard becomes harmonised European standards are developed by the three European standardisation organisations: CEN for most sectors, CENELEC for electrotechnical products, and ETSI for telecommunications. The process starts when the European Commission issues a standardisation request, historically called a mandate, asking the organisations to develop standards supporting specific EU legislation. Technical committees with experts from industry, national standards bodies, consumer organisations and regulators draft the standard by consensus. Once adopted as an EN standard, each member state transposes it as a national standard, so the same technical content exists as, for example, DIN EN in Germany, BS EN in the United Kingdom and NF EN in France, with conflicting national standards withdrawn. The final legal step is citation: the Commission publishes a reference to the standard in the Official Journal of the European Union, listing the legislation it supports. Only from the date of that citation does the standard give presumption of conformity. The Commission maintains public lists of harmonised standards per directive and regulation, and these lists are updated as standards are added, superseded or withdrawn. ## Presumption of conformity and what it means in practice Presumption of conformity is the central legal effect of a harmonised standard. When a manufacturer applies a cited standard in full, market surveillance authorities must presume the product satisfies the essential requirements covered by that standard. The burden of proof effectively shifts: an authority challenging the product must demonstrate non-compliance rather than the manufacturer having to prove compliance from first principles. This matters most during conformity assessment. For many CE marking directives, the internal production control module allows the manufacturer to self-declare conformity, and applying harmonised standards is what makes that self-declaration robust. For higher-risk products where a notified body must be involved, harmonised standards define the test methods and limit values the notified body will use, which makes certification faster and more predictable. Presumption of conformity is limited to what the standard actually covers. A standard may address only certain essential requirements, for example the mechanical safety of a toy but not its chemical safety, and the manufacturer must address the remaining requirements through other standards or its own technical solutions. The citation in the Official Journal sometimes notes restrictions, such as clauses of a standard that do not give presumption, and these notes must be read carefully. ## Voluntary use and alternative routes Applying harmonised standards is voluntary. EU product legislation sets mandatory essential requirements, usually expressed as safety objectives, and leaves the technical means of meeting them open. A manufacturer may demonstrate conformity through any technically valid route, including its own design solutions, other standards or a combination. Choosing an alternative route has consequences. Without the presumption of conformity, the manufacturer must document in the technical file exactly how each essential requirement is met, and a market surveillance authority may scrutinise that reasoning more closely. For some conformity assessment modules, particularly those involving EU type examination by a notified body, deviating from harmonised standards typically means the notified body examines the technical design in greater depth, which increases time and cost. In practice, the vast majority of manufacturers follow harmonised standards because they represent the consensus of experts, are recognised by test laboratories worldwide and simplify dealings with customers and regulators. Alternative routes are mainly used for innovative products where no suitable standard exists yet, or where a standard does not reflect the product's technology. ## Finding and tracking the right standards The starting point for any product is identifying the applicable EU legislation, then consulting the Commission's list of harmonised standards for that legislation. Each entry shows the standard number and title, the date of citation and, where relevant, the date on which a superseded version ceases to give presumption of conformity. Transition periods between an old and a new version are common, and products must comply with the current cited version by the end of the transition. Because standards are copyrighted documents, the full texts must be purchased from national standards bodies or their distributors. The titles, scopes and citation lists are public. Many manufacturers subscribe to standards update services so they are alerted when a standard they rely on is revised or withdrawn, since continuing to apply a withdrawn version silently removes the presumption of conformity. Test laboratories play a central role: most manufacturers have their products tested against the applicable harmonised standards by accredited laboratories, and the resulting test reports become the core evidence in the technical documentation supporting the EU Declaration of Conformity. | Concept | Meaning for manufacturers | |---|---| | EN standard | European standard adopted by CEN, CENELEC or ETSI and transposed nationally | | Standardisation request | Commission request that triggers development of standards for specific legislation | | OJEU citation | Publication that gives the standard its legal presumption of conformity | | Presumption of conformity | Legal assumption that essential requirements covered by the standard are met | | Superseded standard | Older version with a transition period after which it no longer gives presumption | | Restricted citation | Citation noting that certain clauses do not confer presumption of conformity | ## Common pitfalls A frequent mistake is assuming that any EN standard gives presumption of conformity. Only standards cited in the Official Journal for the relevant legislation do, and the citation must be current. Another is applying a standard partially while claiming full presumption; presumption only follows from applying the standard in full for the requirements it covers. Manufacturers sometimes overlook the date on which a superseded standard ceases to give presumption. Products placed on the market after that date must meet the new version. Because product development cycles are long, engineering teams should track draft revisions and plan transitions early. Language is another trap. The reference version of a harmonised standard is usually the English text, and translations can lag. In disputes, the reference language version prevails, so compliance decisions should be checked against it. Finally, harmonised standards do not cover every legal duty. Labelling, traceability, documentation and market surveillance cooperation obligations come from the legislation itself, not from the standards, and must be handled separately. ## Frequently asked questions Is it mandatory to apply harmonised standards for CE marking? No. They are voluntary. What is mandatory are the essential requirements of the applicable legislation. Harmonised standards are simply the easiest way to demonstrate compliance because they carry presumption of conformity. Where do I find the list of harmonised standards for my product? The European Commission publishes lists of cited harmonised standards per directive and regulation. Identify your applicable legislation first, then consult the corresponding list and check the citation dates and any restrictions. What happens when a harmonised standard is updated? The Commission cites the new version and sets a date on which the old version ceases to give presumption of conformity. Products placed on the market after that date should comply with the new version. Plan the transition during the overlap period. Can I use an ISO or IEC standard instead of a harmonised standard? Many harmonised standards are adoptions of ISO or IEC standards, published as EN ISO or EN IEC. A pure ISO or IEC standard that has not been adopted as a cited EN standard does not give presumption of conformity under EU law, though it can still be useful technical evidence. Do harmonised standards apply outside the EU? Legally, presumption of conformity is an EU concept. In practice, EN standards are widely used and recognised internationally, and many countries adopt identical national versions, so testing to them often supports market access elsewhere too. Who writes harmonised standards? Technical committees of CEN, CENELEC or ETSI, with experts nominated through national standards bodies. Industry, SMEs, consumer and environmental organisations and regulators can all participate, and decisions are made by consensus or weighted vote. ## Sources - EU harmonised standards overview - New Legislative Framework building blocks - EU market surveillance framework