Penicillium /Aspergillus – the most common mold species to appear in indoor air samples. The majority of the hundreds of sub-species are allergenic; only a few are toxic. This group of species only grows with the humidity in the air as its water source.
Cladosporium – the most common mold species and is considered to be an allergenic.
Curvularia – another common allergenic mold
Chaetomium – a common water marker that usually indicates wet paper and/or drywall.
Stachybotrys – the most common toxic mold species, but not all sub-species are toxic. These species need a direct water source to grow.
Memnoniella – a sister mold to Stachybotrys. The two species will grow together; also considered toxic.
Because mold spore species and levels differ within each state, agreements are hard to come by with analysts and scientists. A comparison to an outdoor air sample is usually used as the rule of thumb. The following mold spore ranges use the spore/m3 number and not the raw count for each species when interpreted in a lab’s “Air Sample Report”.
0-50 spores – these trace levels are not an issue. Even Stachybotrys is not considered an issue if the sample does not also contain water markers like Chaetomium and Fusarium or high levels of Penicillium/Aspergillus.
50-200 spores – still very low levels; the toxic mold species Stachybotrys and Memnoniella are the only species to be considered an issue at this level.
200-500 spores – the most common species (Penicillium/Aspergillus, Cladosporium and Curvularia) are not an issue and stay within the normal range.
500-1500 spores – sometimes the Penicillium/Aspergillus & Cladosporium levels are in this range and do not require remediation. If water intrusion or mold was not found during the, these levels can be caused by normal life in an enclosed environment.
1500-3000 spores – this point indicates that an issue may be apparent, unless a corresponding number in the outdoor sample exists. If water intrusion or mold issue wasn’t found, these levels can be achieved by a dusty home or A/C system.
3000-10,000 spores – without a corresponding number in the outdoor sample, some remediation is necessary. A perimeter clean-up is needed if a mold spore source has been identified. If water intrusion or mold issue wasn’t found, the home may need to be cleaned and the duct system should be evaluated.
10,000-25,000 spores – without a corresponding number in the outdoor sample, a mold spore source is usually identified and remediation is needed. If no water intrusion or mold issue was found, the duct system may need to be cleaned and a general cleaning of the residence.
25,000-75,000+ spores – a mold issue will be easy to identify. Clean up will be required and should be performed by a Professional Mold Remediator.
75,000-1,000,000+ spores – mold issue will be evident. Remediation will be required and needs to be performed by a Professional Mold Remediator, like United Water Restoration Group, Inc.