The Cleanliness Classification of Ventilation Products

M1 Cleanliness Classification of Ventilation Products has helped Finns to achieve fresh incoming air for more than 20 years. The M1 Cleanliness Classification, introduced in 2001, was created to promote the development and use of clean and odourless ventilation products.

A good indoor environment requires consideration of indoor air issues in all stages of planning, construction and use. Part of this process is clean ventilation products that help achieve good indoor air quality. Read more about the M1 Cleanliness Classification here.

What is M1 Cleanliness Classification?

The M1 Cleanliness Classification was created to promote the development and use of clean and odourless ventilation products.


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Classification process

The Cleanliness Classification of Ventilation Products can only be granted by Rakennustieto. In addition to laboratory tests, an application for classification is always required.

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Apply for a Cleanliness Classification

The application must include both the test report and the requested information about the product(s). Classification applications are submitted for processing through the application portal.

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Upcoming classification meetings

Upcoming meeting dates can be found on the front page of the application portal.

The application must be submitted no later than four (4) working days before the meeting, so that it can be added to the agenda of the meeting. If the application requires additional information, it will only be processed by the classification committee when all the necessary information has been submitted. All applications must be submitted for processing via the application portal, applications submitted by email or post cannot be processed. As a general rule, decisions and classification documents related to applications are delivered to the applicant within two (2) weeks of the meeting where the application was processed.

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The classification system is based on multidisciplinary expertise and impartiality

The Cleanliness Classification of Ventilation Products is owned by Rakennustietosäätiö RTS sr and operated by Rakennustietosäätiö RTS’s subsidiary Rakennustieto Oy. The classification is overseen and developed by the principal committee Indoor Environment (PT 41) appointed by Rakennustietosäätiö RTS sr, in which representatives include construction products industry, developers, designers,and research institutes. Classification applications and matters related to classification decisions are handled confidentially by a separate impartial classification committee. The classification decisions are based on the document Classification of Indoor Environment 2018 (Sisäilmastoluokitus 2018), the general rules of the classification and the classification criteria.

The scope of the M1 Cleanliness Classification includes ventilation ducts and terminal equipment

The M1 Cleanliness Classification is a unique Finnish innovation. The voluntary M1 Cleanliness Classification has been developed considering the Finnish perception of good indoor air. Good indoor air is clean and doesn't smell, so these things should also be demanded from the ventilation products. Importers and manufacturers can apply for the M1 Cleanliness Classification for products covered by the classification:

  • ventilation ducts and their parts as well as closing, adjusting and fire dampers
  • air filters
  • silencers
  • ventilation terminals

Currently, the scope of the Cleanliness Classification does not include e.g. coating materials for ductwork and self-supporting mineral wool ductwork. Rakennustieto is looking to develop the Cleanliness Classification, so that one day these product types would also be included in the scope of the M1 Cleanliness Classification. Insulating materials, sealants, and other building materials belong in the scope of Emission Classification of Building Materials.

M1 Classification needs to be applied for

The Cleanliness Classification of Ventilation Products can only be granted by Rakennustieto. In addition to laboratory tests, an application for classification is always required. Further instructions on how to apply for M1 Classification can be found in the section Classification process.

The M1 Classification is valid for three (3) years

The M1 Cleanliness Classification and the validity of the right to use the classification label is three (3) years from the date of granting the classification. If the composition and manufacturing process of the product have remained unchanged during the first classification period, one 3-year continuation of the product's classification can be applied for without further testing.

After the product has been classified for six (3+3) years, the product must be tested again. The validity of the continuation and renewal periods of the classification continues from where the previous classification period ends. I.e., the applicant does not lose out by applying for a continuation or renewal of the classification before the end of the classification period, nor wins anything by applying for an extension late. Continuation and renewal applications can be submitted six (6) months before the classification expires. The M1 Classification does not include annual fees or audits. The classification fee is the same regardless of the type of application (new, continuation or renewal application).

The right to use the classification label is company- and product-specific

The M1 label is a registered trademark of the Rakennustietosäätiö RTS sr., which may only be used in the marketing of a product 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 label and use it in the marketing of the product.

The M1 label can only be used by the company who has applied for the M1 Classification. A company can only use the M1 label for their M1-classified products, and the classification label cannot refer to the company as a whole. More detailed instructions on the use of the classification label are given in the general rules of the Cleanliness Classification.

All M1-classified products are published in Rakennustieto’s M1 database, where products can be searched either by company or product name and according to the Talo 2000 classification. If a product cannot be found in the database, it is either not classified or the classification has expired. Each M1-classified product also has a classification certificate which may be distributed by the classification holder.

Quality assurance and obligations of the manufacturer 

The quality control and assurance of the classified product shall be 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 random check results do not meet the M1 criteria will be removed from the M1 database and the right to use the classification label is revoked. In case of misconduct or if it turns out that the requirements for granting the classification are no longer met, Rakennustieto Oy may revoke the M1 Classification.

The classification holder is obligated to notify Rakennustieto in advance any changes concerning the manufacturing methods, composition, or other properties of the product, if the changes may have an impact on the emissions of the product. Based on the notification, the classification committee assesses the need for retesting of the product or product group.

The manufacturer also has the responsibility to provide adequate instructions for the use and maintenance of the product:

  • how the product should be stored
  • suitable applications and compatible materials for the product
  • how the product should be serviced and maintained

The Cleanliness Classification of Ventilation Products is part of the Classification of Indoor Environment

The voluntary Cleanliness Classification of Ventilation Products is part of the broader Classification of Indoor Environment (Sisäilmastoluokitus) developed by the Finnish Society of Indoor Air Quality and Climate and Rakennustietosäätiö RTS sr.

The Classification of Indoor Environment was published for the first time in 1995 and has since been updated in 2001, 2008 and 2018. The Classification of Indoor Environment is used by architects, designers, contractors, and manufacturers when building healthier and more comfortable buildings.