February 25, 2026 | Posted by MICRO
A Guide for MICRO Certified Inspectors and Remediators
As awareness of indoor air quality grows, more property owners, physicians, and attorneys are asking about mycotoxin testing in residential and commercial buildings. When laboratory reports reference LC-MS/MS analysis, many inspectors and remediators are asked:
- What does this test actually measure?
- Does it change the remediation scope?
- Is it required under IICRC S520?
- Does detection mean the building is unsafe?
For MICRO Certified Inspectors and Remediators, understanding the science behind LC-MS/MS mycotoxin testing is critical for maintaining professional credibility and defensible remediation decisions.
What Is LC-MS/MS Mycotoxin Testing?
LC-MS/MS stands for:
Liquid Chromatography – Tandem Mass Spectrometry
It is a highly sensitive laboratory method used to detect and quantify chemical compounds, including certain mycotoxins produced by mold species.
Unlike traditional mold testing methods such as:
- Spore trap air sampling
- Tape lifts
- Culture plates
- ERMI or HERTSMI-2 (DNA testing)
LC-MS/MS does not identify mold organisms.
It identifies chemical metabolites (toxins) that may be present in dust or building materials.
How LC-MS/MS Works (Simplified Explanation for Field Professionals)
1. Sample Collection
Environmental dust or bulk material is collected from the structure.
2. Chemical Extraction
Laboratory technicians use solvents to extract chemical compounds from the sample.
3. Liquid Chromatography (LC)
The extracted solution is passed through a column that separates compounds based on how they interact with the column material.
Each compound exits at a specific “retention time.”
4. Tandem Mass Spectrometry (MS/MS)
The compound is:
- Electrically charged (ionized)
- Separated by mass
- Fragmented into predictable pieces
- Confirmed by its molecular fingerprint
The result is highly specific identification at parts-per-billion (ppb) levels.
What Mycotoxins Are Commonly Tested?
LC-MS/MS environmental panels often test for:
- Ochratoxin A
- Aflatoxin B1
- Trichothecenes
- Gliotoxin
- Zearalenone
- Fumonisins
These compounds may be associated with certain mold genera under specific growth conditions.
Does LC-MS/MS Mycotoxin Detection Change Remediation Scope?
This is the most important question for remediation professionals.
According to ANSI/IICRC S520, remediation decisions are based on:
- Moisture source identification
- Visible or confirmed fungal contamination
- Condition 2 and Condition 3 material classification
- Engineering controls
- Source removal
- Verification of cleanliness
There are currently:
- No federal indoor exposure limits for mycotoxins
- No ANSI/IICRC S520 clearance thresholds for toxins
- No standardized environmental risk benchmarks
Therefore:
Detection of mycotoxins does not independently determine remediation scope.
If mold-contaminated materials are present, remediation is required regardless of toxin testing.
When Is Mycotoxin Testing in Buildings Appropriate?
Although not part of routine mold remediation, LC-MS/MS testing may be appropriate in certain professional situations:
Appropriate Scenarios
- Medical-sensitive occupant investigations
- Litigation or forensic documentation
- Failed prior remediation cases
- Persistent complaints after clearance
- High-value real estate disputes
- Physician-directed environmental evaluation
In these cases, mycotoxin dust testing may provide additional documentation, but it supplements — not replaces — contamination assessment.
When Mycotoxin Testing Is Not Appropriate
Routine mycotoxin testing is generally not recommended:
- As a screening tool in the absence of moisture or growth
- To determine whether mold remediation is necessary
- To define demolition scope
- As a substitute for proper moisture investigation
- As a standard clearance test under IICRC S520
Key Professional Principle: Remove the Reservoir
Mycotoxins are typically bound to:
- Mold spores
- Hyphal fragments
- Settled dust
- Contaminated porous materials
Proper remediation removes:
- The moisture source
- The contaminated materials
- The settled particulate reservoir
When the reservoir is removed through:
- Engineering controls
- HEPA vacuuming
- Damp wiping
- Source removal
- Post-remediation verification
The mycotoxin burden is typically reduced as well.
Why MICRO Certification Matters
MICRO Certified Inspectors and Remediators are trained to:
- Interpret laboratory data responsibly
- Avoid unnecessary scope expansion
- Follow science-based remediation standards
- Maintain defensible documentation
- Communicate clearly with clients and healthcare professionals
Understanding LC-MS/MS mycotoxin testing strengthens your ability to:
- Reduce liability
- Prevent fear-based remediation practices
- Maintain industry credibility
- Align with ANSI/IICRC S520 standards
Final Takeaway
LC-MS/MS is a powerful laboratory tool for detecting mycotoxins in environmental samples.
However:
- Detection does not equal exposure.
- Detection does not equal health outcome.
- Detection does not define remediation scope.
For MICRO Certified professionals, the remediation pathway remains consistent:
Control moisture.
Remove contamination.
Verify cleanliness.
Document thoroughly.
Advanced testing may support your documentation — but it does not replace sound remediation science.
