August 2021

1. Description

Formaldehyde, the most important aldehyde, is perhaps the most common toxic substance in indoor environments. Under normal conditions of temperature and pressure, formaldehyde occurs as a gas, with a pungent, intense and penetrating odor. It is water soluble and highly volatile.
It is a substance widely used in industry as an adhesive, biocide, preservative, degreaser, disinfectant, solvent, hardener, fungicide, waterproofing agent, cleaner, lubricant, microbiocide, pesticide, wood preservative, or even as a refrigerant. It is widely present in building interiors, due to building materials - chipboard and other wood-based materials, equipment, hygiene and cosmetic treatments or products, exhaust fumes and tobacco smoke - as a result of slow combustion.

2. Recommended levels

The limits established in Spain for short-term occupational exposures (VLA-EC) are 0.6 ppm or 740 µg/m³. On the other hand, the daily exposure limits (VLA-ED) are set at 0.3 ppm or 370 µg/m³.
There is no reference value for residential interiors.
The technical standard for measurement in Bioconstruction SBM2015 includes the following indicative values for rest areas for formaldehyde concentration in indoor air:

3. My inBiot Ranks

The ranges of values used in the MICA device as indicators are based on the SBM values for resting areas, as well as on the values above which allergic and sensitizing reactions occur:

4. Unit of measurement

Formaldehyde concentration in air is measured in µg/m³, ppm or ppb (parts per billion). MICA collects the values in µg/m³.
The conversion between µg/m³ and ppm/ppb - like other common concentration units - depends on the type of compound and the conditions of the indoor environment. For a typical inhabited room, with a temperature around 20 °C:

  • 0.1 ppm ~ 0.125 mg/m³ or 100 ppb ~ 125 µg/m³

5. Sources

Formaldehyde is commonly detected in building interiors (offices, dwellings). On the one hand, it is a compound widely used in the wood-based particleboard manufacturing industry in the form of glues and adhesives, for furniture, equipment and building boards. It is also frequently used in finishing products (glues, adhesives, laminates), as well as in hygiene, cleaning and cosmetic products. As a highly volatile gas, it is easily emitted into indoor air.
It is also naturally present in solid wood, although in very low concentrations compared to particleboard or other products.

‍6. Benefits of optimum levels

We spend between 80 and 90% of our time indoors. Our interrelationship with factors such as temperature, humidity, air renewal or the presence of pollutants such as formaldehyde characterize an adequate indoor environment and condition our health.
An indoor environment without the presence of formaldehyde will be an indoor environment focused on health, or at least, with the absence of one of the most frequent indoor pollutants. The quality of the overall indoor environment and the presence of other pollutants and health risk factors should be evaluated.

7. Risks of inadequate levels

Formaldehyde can cause allergies, headaches, irritation of mucous membranes, itchy nose, red eyes, coughing, hair loss, etc. It is also a substance included in the ISTAS black list due to its classification as:

  • Carcinogenic 1B according to RD 1272/2008 and group I IARC
  • Mutagen, grade 2, according to RD 1272/2008
  • Neurotoxic level 2
  • Sensitising according to RD 1272/2008
  • Allergen, according to REACH

8. Recommendations for improvement

  • Adequate air renewal
  • Elimination of the polluting source
  • Use of formaldehyde-free products
  • Contaminant source sealing - with expert advice to avoid secondary contamination by VOCs and/or isocyanates:
    - Formaldehyde sealant varnish.
    - Sealing of open edges or holes by gluing, aluminum adhesive tape, silicone, etc.

Share it on

Linkedin Twitter Facebook