What it is
Nigrospora is predominantly an outdoor mold - when it shows up indoors, it usually drifted in rather than colonized.
Where it grows
Outdoor air, occasionally indoor on damp wood or fabric.
Health impact
Mild allergic reactions. Not generally associated with major health effects.
This species does not typically produce mycotoxins, though it can still cause allergic reactions and respiratory irritation.
Property risk
Low risk indoors. Often shows up in air samples as background outdoor signal.
When to test
If you see what looks like nigrospora in your home - or if a lab report flagged it in your air samples - testing the affected area against an outdoor baseline is the most useful next step. The decision about remediation depends on:
- How much is present (spore count per cubic meter, or visible square footage)
- What's beneath it (porous materials like drywall and insulation usually need removal; hard surfaces can often be cleaned)
- Whether the moisture source is identifiable and fixable
Our approach
For confirmed indoor nigrospora colonies, our process is the same as for any mold species: identify and stop the moisture source, contain the work area, remove what's compromised, HEPA-filter and HEPA-vacuum the surrounding area, dry everything, and verify with a post-remediation clearance test against the outdoor baseline.