InterNACHI Mold Inspector flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Water activity (aw)

Measure of available water in a material; molds require aw ≥0.80 for growth. Xerophilic molds grow at aw 0.75–0.85, mesophilic at 0.85–0.90, hydrophilic at >0.90.

Stachybotrys chartarum

Slow-growing, cellulose-loving mold requiring chronic high moisture (aw >0.90). Produces mycotoxins (trichothecenes) and is an indicator of long-term water damage.

Mycotoxins

Toxic secondary metabolites produced by some molds (e.g., trichothecenes from Stachybotrys, aflatoxins from Aspergillus flavus). They are not volatile; exposure occurs via ingestion, dermal contact, or inhalation of spores.

MVOCs

Microbial volatile organic compounds produced by mold metabolism; cause musty odors and can irritate eyes, nose, and throat. Not reliable indicators of mold presence.

Thermal bridge

A building envelope component with higher thermal conductivity (e.g., metal studs, uninsulated corners) that creates cold spots, leading to condensation and mold growth.

Dew point

Temperature at which air becomes saturated and water vapor condenses. Condensation on surfaces occurs when surface temperature is below the dew point.

Category 3 water

Black water from sewage or floodwater containing pathogens; requires removal and disinfection. Mold can develop within 24–48 hours if materials remain wet.

Efflorescence

White mineral deposits on masonry surfaces indicating water movement through the material. Often a sign of moisture intrusion or rising damp.

Moisture meter

Device used to detect moisture in building materials. Pin-type measures electrical resistance; pinless measures capacitance. Confirm readings with invasive methods for accuracy.

Hypersensitivity pneumonitis

Allergic lung inflammation caused by repeated inhalation of organic dusts, including mold spores. Symptoms include cough, fever, and shortness of breath.

Immunocompromised individuals

Persons with weakened immune systems (e.g., from illness or medication) who are at higher risk of opportunistic mold infections, such as aspergillosis.

Occupant interview

Structured conversation to gather history of water damage, visible mold, odors, and health symptoms. Helps identify mold sources and address concerns.

Dose-response relationship

The relationship between exposure dose and health effect. For mold, no established dose-response exists, so airborne mold concentrations cannot be used to predict health outcomes.

Spore trap sampling

Air sampling method using a calibrated pump to impact spores onto a slide for direct microscopy. Reports spore types and concentrations in spores/m³.

Tape lift sampling

Surface sampling method using adhesive tape to collect visible mold for direct microscopy. Identifies genus but not viability; useful for confirming mold presence.

Outdoor control sample

Air sample collected outside the building to establish baseline spore concentrations. Essential for interpreting indoor results; indoor levels significantly higher suggest indoor amplification.

Chain of custody

Documentation tracking sample possession from collection to laboratory analysis. Includes sample ID, location, date, time, and collector signatures; ensures sample integrity.

Calibrated air pump

Device used for air sampling that must be calibrated before and after use to ensure accurate flow rate (e.g., 15 L/min) and sample volume.

Spore trap analysis

Laboratory method using direct microscopy to identify and count spores collected on a slide. Reports concentrations in spores/m³; semi-quantitative and does not indicate viability.

Culture analysis

Laboratory method that incubates samples on media to grow viable mold colonies. Reports colony-forming units (CFU); identifies species but slow-growing molds may be overgrown.

PCR analysis

DNA-based laboratory method that identifies mold species with high specificity. Does not indicate viability; results are reported as presence/absence or spore equivalents.

Indicator mold

Mold genus associated with specific moisture conditions (e.g., Stachybotrys for chronic water damage). Presence indoors is significant regardless of concentration.

AIHA-LAP accreditation

Laboratory accreditation program for mold analysis (EMLAP). Ensures labs meet quality standards; inspectors should use accredited laboratories for sample analysis.

Aspergillus/Penicillium

Common mold genera that are indistinguishable under direct microscopy due to similar spore morphology. Often reported together as a group in spore trap analysis.

IICRC S520

Standard for professional mold remediation, covering assessment, containment, remediation, and verification. Provides guidelines for mold cleanup and clearance.

Post-remediation verification

Inspection and sampling after remediation to confirm mold removal. Includes visual inspection, moisture readings, and air/surface sampling compared to outdoor controls.

Clearance criteria

Conditions that must be met after remediation: no visible mold, normal moisture levels, and indoor spore concentrations comparable to outdoor or control areas.

Containment

Physical barrier (e.g., plastic sheeting, negative air pressure) used during remediation to prevent mold spores from spreading to unaffected areas.

HEPA filtration

High-efficiency particulate air filtration that removes 99.97% of particles ≥0.3 microns, including mold spores. Used in remediation containment and air scrubbers.

Conflict of interest

Situation where an inspector has a personal or financial interest in the outcome. Inspectors should not perform remediation on properties they inspect to maintain objectivity.

InterNACHI Mold Inspector SOP

Standards of practice for mold inspections, requiring visual inspection, moisture assessment, and written report with limitations. Sampling is optional and must be requested.

Remediation report

Documentation of remediation scope, methods, verification results, and conclusions. Includes before/after photos, lab reports, and recommendations; retained for at least 5 years.