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How to Report Mold Levels in Mold Test Samples of Surfaces in Buildings
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• How to report mold levels in buildings
• Mold test & reporting procedures

This article discusses how to report levels of mold in buildings in order to promote consistent use of surface particle mold test adhesive tape sample descriptive language among microbiology lab and field investigation professionals. Here we define levels of significance of mold findings in test results. The definitions that follow are a work in progress and need support by example lab photomicrographs and quantitative study.

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When we examine surface test samples collected in buildings, properly obtained by following a visual inspection of the building and by using a clear, consistent sampling procedure, then we can report the following Non-Quantitative Particle or Mold Levels Based on Samples

Our mold level terms "Significant/Dominant, Present, Incidental" are defined below. Others may use similar terms such as "heavy, medium, light", or "high, moderate, low. "

1. Particles not detected in a sample means that the particle named was below the detection limit of the inspection, sampling, and examination methods used in the field and laboratory. It does not mean that none of these particles are present in the building.
2. Particles Incidental in a sample means that we found only occasional, or low-levels of fungal spores in the sample provided-below the level we usually find in indoor air samples in buildings where there has been a history of leaks, flooding, or known mold contamination.
   
   This is a positive description of the quality of indoor air insofar as fungal spores are concerned, but one cannot unequivocally conclude that there is no possible health hazard present because:
   1. individual exposure, sensitivity, and health status vary widely;
   2. even a zero count does not guarantee that a particle is not present in the building. It means only that that particle was not in the sample provided. A careful, expert look at the building may disclose particles that an occupant or inspector was unable to recognize and thus did not send to the laboratory for determination.

Type we Errors - missing a problem that's present: Occasional occurrences of certain mold genera in samples might suggest a hidden or un-noticed mold problem in the building somewhere other than at the spot from which the sample was collected. This is particularly true if the sample was collected by someone who is not expert at building science, indoor air quality, mycology, and related disciplines.

Type II Errors - asserting that a problem is present when it is not: Conversely, occasional occurrences of certain mold in samples might also seem to point a problem in a building where in fact none is present. This is a greater risk where mold "counts" are used in air sampling than it surface sampling combined with visual inspection. Occupant indoor air or environment-related complaints or a building history of leaks would suggest that additional investigation is in order.

To avoid both Type I and Type II errors in measuring toxic or allergenic mold exposure the building consultant needs to understand mycology (e.g. what mold is likely to grow in buildings), the significance of the particles found (e.g. Pen/Asp spore chains vs. individual spores), the history, construction, and materials in the building and the details of the inspection itself when interpreting the importance of low levels of mold in building samples.

3. Particles Present in a sample means that these particles were frequently present in the sample. They are less likely to be of significance to occupants of the building than "Significant/Dominant" particles except when particles named 1. are particularly allergenic or toxic 2. suggest an undiscovered building problem. If the building has a history of leaks, water entry, or other hidden moisture problems, the presence of even a few toxic or allergenic spores which are not often found in outdoor air samples may indicate a hidden problem. If control samples from outdoors or from non-complaint areas of a building do not show the presence of these particles, further investigation is in order to determine if there is a significant presence elsewhere in the building than from where this sample was taken.
4. Particles Significant/dominant in a sample means that within the sample these particles were the most-frequent particle in the sample or that the particle was present in most or all sample focal fields under the microscope at 400x or higher magnification. Problematic mold or allergenic particles listed in this category are likely to be of significance to occupants in the building. Where the particle is a mold genera or species capable of growing indoors a finding at this level makes it likely that there is one (or more) mold reservoir or mold colony in the building. This term refers to the sample content itself. A visual inspection of the property is needed to determine if the mold is present in extensive or large areas in the building. When the significant/dominant particle(s) present is/are allergenic or toxic mold or an allergen, building investigation to find and clean/remove the problem source is needed

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MOLD ACTION GUIDE - WHAT TO DO ABOUT MOLD
MOLD AGE - Old is the Mold?
MOLD APPEARANCE - WHAT MOLD LOOKS LIKE
MOLD APPEARANCE - STUFF THAT IS NOT MOLD
MOLD ATLAS & PARTICLES INDEX
MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD
MOLD REMEDIATION CLEARANCE INSPECTION
MOLD DETECTION & INSPECTION GUIDE
MOLD EXPERT, WHEN TO HIRE
MOLD GROWTH on SURFACES
MOLD INSPECTORS & MOLD TESTERS
MOLD EXPOSURE STANDARDS
  MOLD CONTAMINATION LEVELS
  MOLD TOXICITY VARIATION
  MOLD STANDARDS - GOVERNMENT
  MYCOTOXIN EFFECTS of MOLD EXPOSURE
  MOLD CONTAMINATION LEVELS, SPECIFIC
MOLD EXPOSURE RISK LEVELS
  L1: Very-Low Mold Risk
  L2: Low Mold Risk
  L3: High Mold Risk
  L4: Contaminated
MOLD LEVEL IN AIR, VALIDITY
MOLD LEVEL REPORTS
  ACCEPTABLE MOLD LEVEL
  ACCURACY OF AIRBORNE MOLD SPORE COUNTS
  MOLD CLASSES, HAZARD LEVELS
  MOLD CULTURE PLATE TEST ERRORS
  MOLD LEVEL IN AIR, VALIDITY
  MOLD LEVELS on SURFACES
MOLD LEVELS on SURFACES   Mold Reporting Errors
MOLD PREVENTION GUIDE
MOLD RELATED ILLNESS GUIDE
MOLD RELATED ILLNESS SYMPTOMS
MOLD TEST KITS

MOLD CLASSES, LEVELS - Mold Hazard levels, Mold Spore Count Validity, Interpreting Mold Counts, and Classes of Mold

• Airborne Mold Spore Counts: Airborne Mold Spore Counts - are indoor fungal spore counts valid?
• Mold Exposure Standards: Exposure Standards for Mold, Levels of Severity of Indoor Mold Contamination - Various Published Standards of Permissible Mold Exposure Limits: at what level is toxic or allergenic mold a problem? - What does your "spores per cubic meter of air" or "spore count" really mean - if anything?
• MOLD EXPOSURE RISK LEVELS: How to Determine Mold Contamination Probability or Mold Exposure Risk Levels in Buildings Based on Visual Inspection
• MOLD LEVEL IN AIR, VALIDITY: Mold Spore Counts - are indoor fungal spore counts valid?
• Mold Hazard Levels: Mold Classes, Levels of what types of cosmetic, allergenic, or toxic mold are a problem? Can mold be cleaned-up successfully?
• MOLD CLASSES, LEVELS - the full text article on this topic.
• Mold Level Reporting: How to Report Mold Levels in Mold Test Samples of Surfaces in Buildings
• MOLD LEVEL IN AIR, VALIDITY: airborne density counts of mold spores per cubic meter of air - how to interpret low mold spore trap count results

MOLD REPORTS - Mold and IAQ Investigation Reports

• Indoor Air / Toxic Mold Field Investigation & Lab Reports - what to look for in a toxic mold field investigation report and mold test laboratory report ©
• Indoor Air / Toxic Mold Test Lab Reports - what to look for in a toxic mold test laboratory report ©
• How to Report Mold Levels in Mold Test Samples of Surfaces in Buildings - suggested non-quantitative definitions
• Sick House Investigation Questionnaire used to collect occupant and Building information that may aid the investigator ©

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Books, Complete List of Environmental Inspection, Diagnosis, Cleanup, Air Quality & Design, Inspection, Repair Books at the InspectAPedia Bookstore
• Environmental Health & Investigation Bibliography - our own technical library on indoor air quality inspection, testing, laboratory procedures, forensic microscopy, etc. Factors contributing to mold growth in buildings are discussed in-depth at
  Mold Standards: Levels on Surfaces in Buildings provides information about allergenic, infectious, and levels of toxic mold in residential buildings - at what point does the amount of mold in a building prove likely to be a problem for the occupants?
  Mold Testing: Bulk Samples and Their Interpretation - a quick tutorial  
  Mold Testing: Air Samples and their interpretation - a quick tutorial describes air sampling, its uses & shortcomings
  Mold Testing: Validity of Cultures (settlement plates or swabs) to find toxic mold in buildings describes the shortcomings of these approaches which are invalid when used alone.
  Mold Spore Counts in Buildings: are indoor fungal spore counts valid?
  Mold Classes in Buildings: cosmetic, allergenic, or toxic mold in buildings
  Mold Investigation Reports and Mold Test Lab Reports: What to Look For outlines a professional, useful mold investigation report.
  Mold Risk Levels in Buildings Based on Visual Inspection
  and our Mold Information Center: What to Do About Mold in Buildings provides a list of key resources about indoor environmental concerns with mold.
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The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

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