Building Biology Standard:
Biological Pollutants
1 Molds
2 Yeasts
3 Bacteria
4 Dust mites and allergens
1 Molds and their spores and metabolites
Anomaly
Area of mold growth
Mold hyphae, sporulating fruiting bodies, spores as seen under a microscope
Extreme
> 5,000
Excessive
The number of mold spores/metabolites in the indoor air should be similar to or lower than the number in the outdoor air or in an uncontaminated reference room.
Particularly serious types of mold, such as toxic molds (e.g. Stachybotrys chartarum) or allergenic molds (e.g. Aspergillus), or those that thrive at 37°C body temperature, should be undetectable or only minimally detectable in the indoor air, on surfaces, in materials, or in house dust.
Indoor air or indoor surfaces shall not be contaminated with metabolites of molds (mycotoxins, MVOCs, glucans).
Additional assessment tools: Guideline on the Prevention, Detection and Remediation of Mould in Buildings by the German Federal Environment Agency (UBA)
cm2
/cm2
No
0
None
Slight
0–20
Sparse
Severe
20–5,000
Many
2 Yeasts and their metabolites
Yeasts should be undetectable or only minimally detectable in the indoor air, on surfaces, in materials, or in laundry, beds, bathrooms, kitchens, and hygiene and food storage areas.
This is especially true for critical yeasts such as Candida or Cryptococcus.
3 Bacteria and their metabolites
The number of bacteria in the indoor air should be similar to or lower than the number in the outdoor air or in an uncontaminated reference room.
Particularly serious types of bacteria, such as certain species of Pseudomona, Legionella, Actinomycetes or Actinobacteria, should be undetectable or only minimally detectable in the indoor air, on surfaces, in materials, in drinking water, or in hygiene areas such as bathrooms or kitchens.
Indoor air or indoor surfaces shall not be contaminated with metabolites of bacteria (endotoxins, MVOCs).
4 Dust mites and other allergens
Building biology guideline values for dust mites and allergens are not yet available.
For the assessment of dust mites and allergens, reference ranges from analytical laboratories or allergists should be consulted.