The M1 emission classification is a Finnish voluntary classification system that assesses the chemical emissions of building materials and furniture into indoor air. An M1 classified product has been scientifically proven to be low-emission and meets strict limits for volatile organic compounds (VOC), formaldehyde, and ammonia emissions, among others. Additionally, the product must have an acceptable odour. The classification supports healthy indoor air and sustainable construction, and it has been in use in Finland since 1996. An M1 classified product supports the objectives of the EU taxonomy.
In this article:
Principles and background of the classification
Multidisciplinary expertise and impartiality as the basis of the classification activity
M1 is both a national and international emission classification
Applying for the classification and its validity
The right to use the classification mark is company- and product-specific
Supervision of the classification and manufacturer’s obligations
Significance and use of the M1 classification
Most building materials fall under the M1 emission classification
An M1 classified product supports the objectives of the EU taxonomy
Principles and background of the classification
Multidisciplinary expertise and impartiality as the basis of the classification activity
The emission classification of building materials is owned by Rakennustietosäätiö RTS sr and the classification activity is operated by Rakennustietosäätiö RTS’s owned Rakennustieto Oy. The classification activity is guided and developed by the main committee Indoor Climate (PT 41) appointed by Rakennustietosäätiö RTS, which includes representatives from the building product industry, developers, designers, and research institutes. Classification applications and matters related to classification decisions are handled confidentially in a separate impartial classification working group. The classification activity is based on the Indoor Climate Classification 2018 document, the classification rules, and the classification criteria and principles in force at the time of the classification decision. There are two levels in the emission classification of building materials: M1 and M2. Hardly any classifications have been granted for the higher emission level, M2, so the classification is typically referred to as the M1 emission classification.
M1 is both a national and international emission classification
There is no statutory obligation in Finland to test the indoor air emissions of building materials or furniture, but it is known that high emissions from building materials negatively affect indoor air quality. The Finnish solution to this challenge is based on a voluntary classification system, and the M1 classification has been developed taking into account the Finnish perception of good indoor air. Good indoor air does not smell, so M1 classification requires an acceptable odour in addition to chemical low emissions from building materials. The Finnish M1 classification is more comprehensive than other European emission classifications, which typically focus only on VOC and formaldehyde emissions. This has also been recognised in other Nordic countries and the Baltics, where M1 classification is widely used to demonstrate a product’s low emissions. When comparing the criteria of different emission classifications, it should be noted that different classifications may use different measurement and calculation methods, so numerical values are not directly comparable.
M1 classification is part of a larger whole
The voluntary emission classification of building materials is part of a broader Indoor Climate Classification developed by the Indoor Air Association and Rakennustietosäätiö RTS. The Indoor Climate Classification serves building and building services design, contracting, and equipment and material manufacturing to create higher quality and more comfortable buildings.
Good indoor climate requires consideration of indoor air issues at all stages of design, construction, and use. When using low-emission building materials, good quality indoor air can be achieved with more moderate ventilation than when using high-emission materials. However, even though the use of low-emission building materials helps create a pleasant indoor environment, errors made in the design and implementation of structures and ventilation cannot be corrected by good building materials.
Applying for the classification and its validity
The classification is applied for with an application
Only Rakennustieto can grant the emission classification for building materials. In addition to laboratory tests, a classification application is always required to grant the classification. Additional instructions for applying for the classification can be found in the section Applying for the classification and different application types.
M1 classification is valid for three (3) years
The validity period of the M1 emission classification and the right to use the classification mark is three (3) years from the granting of the classification. If the product’s composition and manufacturing process have remained unchanged during the first classification period, the product’s classification can be extended for one additional 3-year period without new testing. After the product has been classified for six years (3+3), it must be retested. The validity of renewal and reapplication periods continues from where the previous classification period ended, so an applicant does not lose anything by applying for an extension or renewal before the classification period expires, but neither do they gain anything by applying late. Renewal and reapplication can be requested 6 months before the classification expires. The M1 classification does not include annual fees or audits, and the classification fee is the same regardless of the application type.
The right to use the classification mark is company- and product-specific
The M1 classification mark is a registered trademark of Rakennustietosäätiö RTS sr, which may be used in product marketing only if the product has a valid M1 classification granted by Rakennustieto. The M1 classification is granted for three (3) years at a time. During this period, the company has the right to mark the classified product with the classification mark and use it in product marketing. Only the company whose product has been approved for M1 classification may use the classification mark in its marketing. The classification mark can only be used for those products that have been granted the classification, and it cannot be used to refer to the entire company. Detailed instructions on the use of the classification mark are provided in the general rules of the emission classification.
All M1 classified products are published in the Rakennustieto M1 database, where products can be searched either by company or product name and according to the Talo 2000 classification. If a product is not found in the search service, it has either not been classified at all or the classification has expired. Each M1 classification is also accompanied by a classification certificate, the distribution of which is the responsibility of the classification holder. Information about the product’s M1 classification can also be reported in Rakennustieto’s Product Information database as part of other product information, and if a contractor uses the Product Information management service, the information about the product’s M1 classification also becomes part of the contract documentation.
Supervision of the classification and manufacturer’s obligations
The quality control and assurance of classified products is the responsibility of the classification holder. The quality of classified products is monitored annually by Rakennustieto Oy through a spot check procedure. A product whose spot check results do not meet the M1 classification criteria is removed from the classified products database and the right to use the classification mark ends. In cases of misuse or if it becomes evident that the requirements for granting the classification are no longer met, Rakennustieto Oy may revoke the emission classification and the right to use the classification mark.
The classification holder is obliged to notify Rakennustieto Oy in advance of any changes affecting the product’s manufacturing methods, composition, or other properties if these changes may affect the product’s emissions. The classification working group will assess the need for retesting the product or product group based on the notification provided.
The manufacturer is also responsible for providing sufficient instructions for the use and maintenance of their product:
- how the product should be stored
- the types of applications and compatible products with which the product is suitable for use
- how the product should be maintained and serviced
- which cleaning methods are suitable for the product
Significance and use of the M1 classification
An M1 classified product is verifiably low-emission
The M1 classification focuses on emissions from building materials and furniture into indoor air, setting limit values for volatile organic compounds (VOC), formaldehyde, and ammonia emissions, as well as for odour acceptability. The M1 classification criteria are set for long-term emissions (i.e., specific emissions of the product) that are significant for indoor air, not for rapidly evaporating primary emissions (e.g., evaporation of solvents and other auxiliaries during drying and film formation processes). For this reason, the emission tests required by the M1 classification are conducted after a 28-day ageing period (except for office chairs, whose emissions are tested after 3 days). The M1 classification mark on a product indicates that the product is low-emission and supports good indoor air quality. The M1 classification mark is a type I environmental label according to standard EN ISO 14024:2018, limited to the product’s indoor air emissions.
The M1 classification process does not include factory audits, but the company applying for the classification must have an acceptable quality assurance system in place. Composition analyses do not provide information about a product’s indoor air emissions, so product composition is not tested in the M1 classification. An M1 classified product is assumed to meet the statutory and mandatory requirements set for the product type (e.g., CE marking and REACH), but these are not reviewed as part of the classification process. The M1 classification does not consider emissions during product installation nor does it address occupational safety issues, but when classifying chemical building materials (e.g., paints, varnishes, and fillers), the product must have an up-to-date safety data sheet.
Most building materials fall under the M1 emission classification
The M1 classification is a voluntary emission classification that a manufacturer or importer can apply for their products. The emission classification of building materials is primarily intended for building materials and furniture used in typical residential, living, and work spaces. The classification covers:
- building materials (e.g., floor coverings, building boards, paints and varnishes, adhesives, mortars and fillers, and insulation)
- factory-made composite products (e.g., windows, doors, movable walls, and acoustic products)
- fixed furniture (e.g., kitchen and bathroom cabinets, furniture doors, and worktops)
- non-upholstered loose furniture (e.g., chests of drawers, shelves, cupboards, and desks)
- upholstered and non-upholstered office and auditorium chairs (covered with fabric or faux leather)
The emission classification of building materials does not cover, for example, electrical devices, interior textiles, HVAC products, or sports equipment (e.g., basketball hoops). Ventilation products fall under the ventilation product cleanliness classification.
Indoor Climate Classification 2018 defines a group of naturally low-emission materials that can be equated with M1 classified products when planning spaces. These include uncoated brick, natural stone, glass and metal, ceramic tiles, and untreated boards and logs made from aspen, birch, spruce, or pine. The VOC emissions of untreated board and log products may exceed the M1 class limits when fresh, but the emissions level out to a lower level over time. Products designated as naturally low-emission may not be marketed as M1 classified unless they have a valid M1 classification granted by Rakennustieto.
An M1 classified product supports the objectives of the EU taxonomy
According to the EU taxonomy, building materials must meet certain chemical and emission requirements to be classified as environmentally sustainable. This relates to the section on Prevention and Reduction of Environmental Pollution and its DNSH criteria in the EU taxonomy. These requirements include restrictions on emissions of carcinogenic, mutagenic, and reproductive toxic (CMR) substances as well as formaldehyde emissions.
It is possible to combine the M1 classification with a voluntary emission limit assessment of building materials, for example, to verify compliance with the EU taxonomy or SINTEF indoor air emission criteria. Depending on the application, two different scopes of limit assessments can be chosen:
1. formaldehyde emission < 60 µg/m³ and carcinogenic substances emission < 1 µg/m³ (scope required solely for taxonomy reporting)
2. formaldehyde emission < 60 µg/m³, carcinogenic substances emission < 1 µg/m³, and total volatile organic compounds (TVOC) emission < 300 µg/m³ (scope suitable for taxonomy and SINTEF reporting)
According to the EU taxonomy requirements, building materials must meet these emission limits to be classified as environmentally sustainable. This means that manufacturers and suppliers of building materials must ensure that their products comply with these requirements before marketing them as compliant with taxonomy requirements. The EU taxonomy emission limits for CMR substances and formaldehyde apply to both new building construction and the repair or renovation of existing buildings.
In Finland, emission classifications of building materials, such as the M1 classification, support these requirements. It is possible to combine the M1 classification with a voluntary emission limit assessment of building materials to verify compliance with the EU taxonomy (or SINTEF) indoor air emission criteria.
As a rule, testing of all valid M1 classified products can be used as a basis for the limit assessment. The limit assessment can be ordered both as part of the normal classification process and during the classification period. The limit assessment is included in the M1 classification certificate of the product or product group, whereby the certificate:
- verifies that the product is M1 classified, low-emission, and supports good indoor air quality
- provides emission information required for taxonomy reporting in a standardised, unambiguous, and accurate form
- the reported emission data is verified by an impartial third party
- removes the need to share complex test reports with third parties
Classified products must be used and maintained correctly
An M1 classified product is low-emission only when stored, installed, and used correctly. A low-emission material can become high-emission, for example, by storing the product in damp conditions, using incompatible products, neglecting product maintenance, or using incorrect cleaning methods. For this reason, it is always important to follow the manufacturer’s instructions for product storage, installation, and use. Classified products must only be used in their intended applications and conditions: for example, products intended for dry spaces must not be used in damp spaces.