The M1 label marks a product, which has been tested in neutral third-party laboratory and which under the test conditions fulfills the M1-certification criteria. In M1 classification limit values are set for the chemical emission and odour deriving from the product in to the indoor air.

The only criteria concerning the substance content of building materials is set for leveling compounds, putties, screeds, mortars, fillers and plasters. These type of products must be free of casein. Fungicide treatment of fabrics or padding is not allowed in M1-certified products.

Classified products

The classification sets requirements for building materials, fixture and furniture in office and residential buildings with respect to good indoor air quality.

There is another set of criteria for upholstered office chairs, which has some minor difference with the criteria for building material and furniture with hard surfaces.

Wood, glass, metal, stone and ceramic products have a special status

The document “Classification of Indoor Environment 2018 ” places no restrictions on the use of following products:

  • brick
  • natural stone
  • ceramic tile
  • glass
  • metal

and construction board and log surfaces made of unprocessed wood (excluding hardwood). The VOC emissions of fresh wood may nevertheless exceed the limit value of emission class M1.

However the classification is not granted for products without test results. If a company wants to use the M1 label on its product, the product must always be tested and an application made.

Limit values

ParameterEmission class M1 Emission class M2
Total volatile organic compounds (TVOC) emissions [mg/m2h]≤ 0.2≤ 0.4
Emissions of volatile organic compounds (VOC) [µg/m3] 1≤ EU-LCI≤ EU-LCI
Formaldehyde emissions [mg/m2h]≤ 0.05≤ 0.125
Ammonia emissions [mg/m2h]≤ 0.03≤ 0.06
Emissions of CMR compounds (category Carc. 1A or 1B in Annex VI to Regulation (EC) No 1272/2008) [mg/m3] 1≤ 0.001≤ 0.001
Odour 2acceptableacceptable

1) does not include formaldehyde,  2) odour acceptance  ≥ 0.0

The emissions of the products falling into the category small areas (2 m2) and very small areas (0.4 m2) can be assessed also as model room concentrations. The M1 limit values [mg/m3] for such products are: TVOC 0.02, formaldehyde and ammonia 0.01, and CMR compounds 0.001. Also emissions of VOCs [µg/m3] must be EU-LCI and the product shall be odourless.

Products in category small areas are e.g. doors, windows, wooden beams and tiling grout and very small areas e.g. sealants ans some adhesives .

M1 limit values for office chairs

Total volatile organic compounds (TVOC) emissions [µg/m3] ≤ 20
Emissions of volatile organic compounds (VOC) [µg/m3]≤ EU-LCI / ≤ 10
Formaldehyde emissions [µg/m3] ≤ 10
Ammonia emissions [µg/m3] ≤ 10
Emissions of CMR compounds (category Carc. 1A or 1B in Annex VI to Regulation (EC) No 1272/2008) [µg/m3] 1 ≤ 1
Odour 2 acceptable

 1) does not include formaldehyde,  2) odour acceptance  ≥ 0.0  

The classified product can be upholstered either with textile or artificial leather. The chairs are group to product groups according their surface material. The grouping is always verified in the technical working group, which also select the products to tested.

In office chairs classification the emission are measured after three days ageing period.

Additional information:

  • Fungicide treatment of the chairs fabric/surface material is prohibited
  • LCI values µg/m3, see. EU-LCI Values.
  • The assembly date of the chair must be reported, newly manufactured components must be used

Classified products must be applied and maintained according to manufacturers’ instructions

M1 criteria does not include any requirements for emissions during installation. Issues related to occupational health and safety must be checked from the manufacturer’s instructions and Material Safety Data Sheets if available. Classified products must be applied on sites and under the conditions they are designed for. For example, products designed for dry areas must not be used in wet areas.

Furthermore, wrong maintenance practices may lead to deterioration of materials and degeneration of the indoor air quality. Instructions for installation and use of products can be obtained directly from manufacturers and retailers. Design and implementation mistakes of structural elements or ventilation systems cannot be compensated by using low-emission building materials.