What is a Mold Assessment?
I once again raise this question because I’ve been called in to provide yet another second opinion of a mold inspection that consisted of nothing more than the collection of a few air samples for mold spores. I assure you that a correct mold assessment in accordance with the only industry standard of practice does not involve the random sampling of mold. The only industry standard of practice is the ASTM D-7338 Assessment of Fungal Growth in Buildings.
The question of just what is a mold assessment is a frustrating and surprisingly hard question for many industry professionals to answer. That’s right; many mold professionals just don’t know their own industry well enough to know the prevailing standard of practice. When I’m asked to provide a second opinion on a mold inspection, I always want to talk with the original mold assessors. Given the chance, I will always take the opportunity to try to raise the awareness of the original mold assessor and inform them of the ASTM D-7338 and the process of providing a valuable mold assessment and report. I feel that this is best for our industry and for the consumer.
So just what is it that many mold assessors believe is a mold inspection? Many believe that a mold assessment is simply testing for mold. There is plenty of guidance on the value of mold sampling but if the ill-informed mold assessor isn’t aware of the industry standard of practice, the ASTM D-7338, there is little chance that they will be aware of the very public opinion of mold sampling.
Let’s just review the industry position on mold sampling. Ten years ago, the ACGIH concluded that air testing provided a "snap shot" of conditions at the exact time and place of the sampling, but nothing more. The Center for Disease Control, CDC's current position is that air sampling for mold is nothing more than a snap shot and that such a snap shot is not reliable, representative or worth the cost. The CDC states very clearly that “Any claim based solely on air sampling results is inherently suspect.” The CDC goes on to state that “There is no reason to respond to questionable testing by conducting more of it. I believe that is a very clear position from a reputable source.
What does the laboratory say about the interpretation of the collected mold samples?
- The client is solely responsible for the use and interpretation
- Note: Interpretation is left to the company and/or persons who conducted the field work.
- The “Lab” shall have no liability to the client or the client's customer with respect to decisions or recommendations made, actions taken or courses of conduct implemented by either the client or the client's customer as a result of or based upon the Test Results.
The mold assessor that collected the mold samples is the laboratory’s client not the property owner. That is something that the mold sampler seems to not understand.
Let’s look a bit further. When the following governmental and industry organizations were asked if mold testing is necessary, this is what they had to say.
- American Industrial Hygiene Association, AIHA There are no standards for “acceptable” levels of mold in the indoor environment. If you know you have a mold problem, it is more important to spend time and resources solving the moisture problem and getting rid of the mold than to spend it on sampling.
- US Environmental Protection Agency, EPA If you know you have a mold problem, it is more important to spend time and resources solving the moisture problem and getting rid of the mold than to spend it on sampling. If visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards.
- Occupational Health and Safety Administration, OSHA In most cases, if visible mold growth is present, sampling is unnecessary. Your first step should be to inspect for any evidence of water damage and visible mold growth.
- U.S. Department of Labor There are no standards for acceptable levels of mold in buildings, and the lack of a definitive correlation between exposure levels and health effects makes interpreting the data difficult, if not impossible.
- Center for Disease Control, CDC There are no accepted standards for mold sampling in indoor environments or for analyzing and interpreting the data in terms of human health. Molds are ubiquitous in the environment, and can be found almost anywhere samples are taken. It is not known, however, what quantity of mold is acceptable in indoor environments with respect to health. CDC does not recommend routine sampling for molds. Generally, it is not necessary to identify the species of mold growing in a building. Measurements of mold in air are not reliable or representative. If mold is seen or smelled, there is a potential health risk; therefore, no matter what type of mold is present, you should arrange for its removal.
- The Florida Department of Health, The Florida Department of Health does not recommend mold testing or sampling to see if you have a mold problem, or to see what kind of mold might be growing.
- NYC Guidelines on Assessment and Remediation of Fungi in Indoor Environments, The Department of Health, DOH, should continue to emphasize in its public education materials that sampling for airborne mold is unlikely to provide reliable information for decision-making in damp or moldy buildings.
So, should you sample for mold? No, never for the purpose of mold investigation. Why? There are too many variables impacting the results and the sample size is too small for air testing for mold to be reliable. The type of mold will not change the necessary mold remediation. The genus of mold is just not relevant or necessary unless you are trying to frighten a client into believing that they have “Toxic” mold. Mold spore trap air samples do not have the ability to establish the presence of any mycotoxins. Air sampling's lack of utility in determining the level of mold found in indoor air may be a surprise to some, given the frequent references to these tests and mold litigation. Unfortunately, those that reference mold testing in mold litigation are never directly involved in mold litigation or they would know what the reality is, mold sampling to the genus level is worthless in court.
Mold assessors should bear in mind that samples provide information about a site as it existed at the time tested. However, the findings may not represent conditions at a time in the past or future, even the relatively recent past or near future. Changes in the kinds, concentrations, and proportions of biological agents in the air can be rapid and substantial. Bioaerosols: Assessment and Control, Section 184.108.40.206.
ASTM D7338 Standard Guide for Assessment of Fungal Growth in Buildings 7.1 The most important requirement of an assessment for fungal growth is an on-site inspection of the subject building. It is very important to remember that the ASTM D-7338 is the only recognized standard for mold assessment. According to the ASTM D-7338 the parts of a mold assessment include:
- the collection of background information,
- the formulation of a hypothesis or hypotheses,
- on-site inspection including moisture dynamics,
- an evaluation of the HVAC system,
- hypothesis testing,
- site documentation and written report.
The scope of work defines the problem and, just as importantly, which part of the basic assessment and which of the procedures are to be performed. The scope of work will define the inspection boundaries. The ASTM D-7338 clearly states that “Within the inspection boundary, all surfaces should be inspected to the extent feasible, including
- above suspended ceilings and
- inside pipe chases,
- attics, and
The exterior of the building and adjacent grounds should also be inspected for moisture intrusion sites and air leaks.”
The mold inspector that only samples for mold and provides nothing more than a laboratory report will attempt to exclude virtually all areas of a building from his responsibility. Below is an excerpt from a peer reviewed mold inspection report “Disclaimer”. It is a remarkable example of how some mold inspectors attempt to alleviate themselves form the responsibility of the very job that they were hired to perform.
Certain areas are considered inaccessible and impractical to inspect including, but not limited to,
the interiors of walls and inaccessible areas below; areas beneath wood floors over concrete; areas concealed by floor coverings; and areas to which there is no access without defacing or tearing out lumber, masonry, roofing or finished workmanship; structures; portions of the attic concealed or made inaccessible by insulation, belongings, equipment or ducting; portions of the attic or roof cavity concealed due to inadequate crawl space; areas of the attic or crawl space made inaccessible due to construction; interiors of enclosed boxed eaves; portions of the sub area concealed or made inaccessible by ducting or insulation; enclosed bay windows; portions of the interior made inaccessible by furnishings; areas where locks prevented access; areas concealed by appliances; areas concealed by stored materials; and areas concealed by heavy vegetation.
There is no economically practical method to make these areas accessible. However, they may be subject to attack by microbial organisms. No opinion is rendered concerning the conditions in these aforementioned or other inaccessible areas. Furthermore, mold grows. As such, the inspection and report produced by Mold Assessor is not a guarantee that mold does not exist.
As a courtesy Mold Assessor may point out conditions that contribute to mold growth but such comments are not part of the bargained for report, protocol, or supplemental information. The protocol is not intended to be either exhaustive or inclusive of all pertinent requirements, methods or procedures that might be appropriate on a particular mold remediation project.
Anyone using this document should understand the limitations with its use, and rely on his or her own independent judgment, or as appropriate, seek the advice of competent professionals in determining the exercise of reasonable care in any given situation.
This type of disclaimer is an example of how some mold inspectors are intent on limiting their area of responsibility. What exactly are property owners that hire this mold inspector paying for? What exactly is the value provided by the mold assessor? Most importantly, why the need to limit the area of responsibility in direct contradiction to the ASTM D-7338? The answer is that this mold assessor, like many, had no idea that the ASTM D-7338 even existed. This mold assessor, like many, felt that the simple collection of air samples for mold was a mold inspection in direct contradiction to the government and industry positions sited above.
As with any industry the mold industry has a standard of practice that must be followed to provide a property owner with necessary and relevant information regarding any possible mold issue within their property. Mold sampling will never have the ability to provide any of that necessary and relevant information
A mold inspection in accordance with the ASTM D-7338 will provide the property owner with a wealth of necessary and relevant information.
The ASTM D-7338 states in Section 7.5.3 Identification of Current Water Damage and Suspect Fungal Growth
- All surfaces within the inspection boundary should be systematically evaluated for indicators of moisture damage and fungal growth.
Exposed surfaces (including building materials, furnishings, and contents) should be examined for past and ongoing damage including:
(1) suspect fungal growth,
(2) standing water
(3) water stains,
(4) dampness to touch, and
(5) blistering, warping, de-lamination, or other deterioration.
The ASTM D-7338 states in Section 7.5.4 Identification of Potentials for Fungal Growth
The inspection should identify moisture sources and moisture pathways, including:
(1) sites where condensation may occur,
(2) equipment or activities which may release water,
(3) pathways for water movement and
(4) areas where leakage is likely.
- Staining patterns are often useful in identifying moisture sources.
The ASTM D-7338 states in Section 7.5.5 Presence of Odors
Detection of musty odors should always be noted.
(1) Sources of such odors should be located.
(2) If the source is not apparent, intrusive investigation may be required.
The ASTM D-7338 states in Section 7.5.6 Classification of Inspection Observations
Classify each distinct area or area of interest within the inspection boundary as one of the following categories:
(1) no apparent fungal growth and no apparent water damage;
(2) water damage having no visually suspect or confirmed fungal growth,
(3) visually suspect or confirmed fungal growth having no apparent water damage, &
(4) water damage having visually suspect or confirmed fungal growth.
The ASTM D-7338 states in Section 7.5.8 HVAC Inspection, if applicable per the scope of work
The interiors of HVAC equipment in contact with ventilation air should be inspected for indicators of excessive moisture or suspect fungal growth.
Such areas may include intake and return plenums, filters, coils, condensate pans, fans, housing insulation, and supply ducts immediately downstream from the coils.
The ASTM D-7338 states in Section 7.6.1 Site Map—A site/floor plan should be prepared showing each inspection classification, as determined in 7.5.6.
The plan should be sufficiently detailed to allow each area of interest to the assessment to be unambiguously located.
The ASTM D-7338 states in Section 7.6.2 Documentation of Suspect Fungal Growth—Wherever suspect or confirmed fungal growth is identified during the inspection, documentation should include:
(1) extent (for example, approximate square footage of suspect growth),
(2) severity (for example, relative darkness or continuity of stain), growth pattern (for example, light versus heavy growth and spotty versus continuous growth), and
(3) clues to apparent cause (for example, exterior wall, condensation near a HVAC vent, associated with water staining).
The ASTM D-7338 states in Section 7.6.3 Documentation of Moisture Damage—In addition to documenting the location of moisture damage, as above, further documentation should include:
(1) apparent sources of leaks and other moisture sources, and
(2) apparent timing and duration (for example, whether the moisture has been resolved, active (currently wet) or the moisture source is likely to reoccur
The ASTM D-7338 states in Section 7.6.4 Visual Documentation—Photographs or videotapes are often helpful in documenting building conditions. Captions should note location, timing, and context.
The ASTM D-7338 states in Section 7.6.5 Additional Detail—Start and stop time, temperature, humidity, occupancy, condition, and housekeeping of the property.
With a clearly written standard of practice for mold assessment, it’s truly hard to believe that there are so many mold assessors that provide a client little more than a few air samples for mold and call it a mold inspection. Worse yet is when these mold inspectors call the simple collection of air samples for mold air quality samples. Both are perfect examples of over selling and under delivering.
More importantly, I would stress that a mold assessment is NOT the collection of mold samples or testing for mold. It may include the collection of mold samples but the collection of mold samples is NOT, on its own, a mold assessment.
If you hire a licensed mold assessor you should receive a written report in accordance with the ASTM D-7338 signed by the licensed mold assessor that performed the assessment. Not by someone in another location that never visited your home or office. When you hire a licensed mold assessor you should receive the written report signed by the licensed mold assessor that performed the assessment and never be required to pay an additional fee for a written report.
That’s ridicules, what are you paying for if you aren’t receiving a written mold assessment report from your licensed assessor.
So what should the written mold assessment report include?
As the ASTM D-7338 clearly states. A detailed evaluation of data obtained from a building history and inspection to formulate an initial hypothesis about the
- identity, location,
- and extent of amplification of mold growth
The written report can then be provided to licensed mold remediators that can then provide you with a written estimate for the remediation.
Finally, I close with questions you should ask your mold assessor before you hire them.
- Are you licensed by the State of Florida? Verify a License https://www.myfloridalicense.com/wl11.asp?mode=0&SID=
- Will you be performing the mold assessment in accordance with the ASTM D-7338 Standard Guide for Assessment of Fungal Growth in Buildings?
- What qualifications do you have to perform mold inspection and/or testing?
- What certifications do and your company have?
- Are you familiar with the IICRC S-520?
- Will I be getting a written report from you or the laboratory?
- Will you be conducting a visual inspection or just mold testing?
- How do you interpret the laboratory results?
o (Tip: You're looking for conflicts of interest here. If they also perform remediation, they have a vested interest in finding mold to clean up.)
- Do you have references from clients within the past year that I can call to ask how the inspection went?
o (Tip: Be cautious of anyone new to the business and doesn't have references.)
- Do you perform mold remediation?
Please, as a take away, always ask if your mold assessor is Licensed and aware of the ASTM D-7338
John P. Lapotaire, CIEC
Indoor Air Quality Solutions, IAQS
Indoor Air Quality Association, IAQA President