In most cases, if there is visible mold growth, sampling is not necessary. Because no federal or EPA limits have been established for mold or mold spores, sampling cannot be used to verify a building's compliance with federal mold regulations. Surface sampling can be useful in determining if an area has been properly cleaned or remediated. Mold sampling should be performed by professionals who have specific experience in designing mold sampling protocols, sampling methods and interpretation of results.
Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Government Industrial Hygienists (ACGIH), or other professional organizations. It may be hard to swallow the idea that mold testing is, in most cases, superfluous, but the EPA supports the concept. He argues that when there is visible mold growth, sampling is “unnecessary”; mold should simply be removed. It then goes into detail about the circumstances in which you might want to use a behavior mold test, but these are few (we'll discuss them below).
If your home has mold problems or you are thinking of buying a moldy home, here are some things to consider before paying for a mold evaluation. My first house had obvious mold, so I had a professional evaluation of mold. When the inspector finished evaluating my home, they provided me with an extensive report showing the various strains and concentrations of mold. While it was a relief to learn that it didn't have the infamous toxic black mold, Stachybotrys chartarum, the conclusion that the house was full of mold came as no surprise.
However, what was valuable was the evaluation of water. The mold inspector walked through the house from top to bottom with a humidity sensor, and he showed me exactly where the water was infiltrating the frame of the house and causing mold and rot. It turned out that, in addition to a problem with the water in the basement, rainwater seeped around both chimneys and through invisible leaks in the roof. As we inspected the house together, I was also able to determine that it was structurally sound.
Knowing that my problem had more to do with cleaning than with carpentry helped me to calm down. In recent years, advertising about “toxic mold” has turned mold inspection and remediation into a hugely profitable industry. It has also paved the way for many scams designed to scare you into paying big bucks for unnecessary tests or incomplete “remediation plans”. Environmental Protection Agency Recommends Common Sense Approach to Mold: If You Can See Visible Mold Growth, No Mold Inspection Necessary.
Since there are no federal standards for mold levels, there is no way to “pass” or “fail” an inspection, although after the project is completed, it may be helpful to test to find out if everything has been cleaned. There are no established sanitary standards for acceptable levels of biological agents in indoor air. We do not recommend routine air sampling for mold with building air quality assessments. This is because mold concentrations in the air cannot be interpreted with regard to hazards for.
Mold tests provide the means for the detection of toxic molds. If you can really see mold, do you still have to try mold? Yes. Surprisingly, unlike simple mathematics, most mold inspectors and other poorly trained consultants attempt to deduce the arithmetic mean of their samples. An arithmetic mean would be appropriate if the data showed a Gaussian distribution.
However, most mold inspectors never determine the distribution, and there is no reason to believe that the distribution is Gaussian or anything other than lognormal. Mr. Connell is a member of the American Industrial Hygiene Association (AIHA), the American Conference of Government Industrial Hygienists (ACGIH), the Property Care Association (England) and the Occupational Hygiene Society of Ireland, and currently serves on three international standards committees, including ASTM D22.08 Indoor Air (whose task is to develop and write internally accepted indoor and building mold evaluation standards); ASTM E50 Committee (Environmental Assessment & Risk Management) and ASTM E30.05 Forensic Science Committee. Connell serves as an expert on industrial hygiene for the federally funded Inter-Agency Board (sub-group on health, safety of medical responders).
Both the EPA and experts such as Moldman suggest that a mold inspection is not necessary if mold can be seen. You can proceed directly to the remediation step. You don't need to pay a professional inspector to tell you what you already know. However, the remediation process will usually involve the contractor determining the extent of the problem, which is effectively a mold inspection.
Mold is a serious problem, and spotting mold contamination before it gets out of control can save you thousands of dollars. He has been qualified as an expert witness in the Federal Court (Philadelphia), 81 for the lack of scientific validity of common mold samples and tests used by certified mold inspectors. It's helpful to think of air sampling as a single tool in the tool belt when inspecting a home for mold problems. In fact, once there is visible mold, the same Mold Remediation Principles mentioned above are followed to remove it regardless of color, species, etc.
Investigating hidden mold problems can be difficult and will require caution when research involves disturbing potential mold growth sites. Virtually ALL of the hundreds of samples that FACT has reviewed over the years collected by home inspectors and certified mold remediators or certified mold inspectors were useless or meaningless (or both), and always unnecessary. Studies and research conducted by this author (Connell), consistent with other researchers, have not observed a correlation between mold hidden in walls and a degradation of indoor air quality or a correlation between mold hidden in walls and an increase in the spore count in occupied spaces. A typical mold inspection involves the inspector talking to the property owner about any areas where they have seen mold or where there have been moisture problems or water damage in the past.
However, following review of the studies, air monitoring in such cases was generally poorly and inadequately performed and simply increased visual inspections, and in no case was hidden mold discovered that otherwise would not have been found by a normal visual inspection by a researcher experienced. The cost of mold inspection may vary slightly from region to region, but the difference is generally quite small. Do-it-yourself mold tests on the market, such as the EPA ERMI kit and the IAQ Pro 5-minute home mold test, are misleading and cannot be used to determine if a home has a problem. If mold contamination exceeds 10 square feet, EPA recommends calling a contractor experienced in mold remediation.
Even then, knowing the genus or species of a mold is usually worthless, since the genus or species of mold does not alter any subsequent decision. . .