The M1 label marks a product that has been tested in impartial third-party laboratory according to the M1 testing protocol and has under the test conditions fulfilled the criteria set for the M1 Classification. Only laboratory tests done by a laboratory approved by the Building Information are accepted.
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
| Parameter | Emission 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 2 | acceptable | acceptable |
1) does not include formaldehyde, 2) odour acceptance ≥ 0.0
Emissions of products falling into the categories small area (2 m2) and very small area (0.4 m2) can be assessed using reference room concentrations (see table below).
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 small and very small area products
| Parameter | |
| Total volatile organic compounds (TVOC) emissions [µg/m3] | ≤ 20 |
| Emissions of volatile organic compounds (VOC) [µg/m3] | ≤ EU-LCI |
| 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
M1 limit values for office chairs
| Parameter | ||||
| 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.