Do the mold test kits work that we see at the hardware stores? Are they really dependable.
The over the counter mold tests are poor at best.
The test normally is a petri dish that the mold spores settle on when left open. The customer (at their expense) then has to send the sample to a lab that analizes the type of mold or molds that grow or are culturable. Mold is everywhere all the time, it is only when there is an elevated spore count that a potential problem may exist. Any petri dish left open will have culturable mold spores.
Mold spores are either viable (will grow or reproduce) or non-viable (unable to reproduce). Both viable and non-viable mold spores present a potential health risk, as the mycotoxins are mainly in the shell or outer covering of the spore.
Without trying to become to long or technical, the first problem is that not all mold spores are viable and the spores that grow (cultured) are only a small portion of the total airborne old spore count. Viable tesing (petri dish) is used to determine the actual species of the mold and used in conjunction with air sampling that is taken in a cassette to establish the total airborne spore counts. Viable type tests must be shipped cold and be sent overnight for valid analysis.
Another problem is that when performing mold testing, all of the samples must be of the same volume or size. Professionals use an air pump for a set time period so each sample can be compared equally for the same type of molds and quantity's of mold spores.
Mold testing starts with taking an outside air sample to establish a baseline or normal environment, and then samples are taken of suspect areas/rooms, of the interior. Along with the air samples, additional samples may be taken with swabs, tape lifts, or vacuum cassettes to determine a settled mold spore count or what is a history of mold spores that have settled out of the air onto surfaces.
When using over the counter tests, even if a petri dish is placed outside, the air movement outside will be different than the air movement inside, so the volume will not be consistent. A baseline of the normal environment can not be correctly established so any sample taken of the interior will be bias or in-valid, and not all airborne mold spores will be determined.
The companies that sell these home kits have a network of mold inspectors that they refer the public to after the home tests are analized. The lab often times send the results along with a letter stating there may be a problem or additional testing is recommended, and include a list of professionals in the area that are in their network of certified mold inspectors for that additional testing. Many times these professionals are home inspectors who do mold testing as a sideline to their inspection business, and have only had a two (2) day on-line training course.
Instead, always use a professional to start with. It will save time and money in the long run.
Jay Hoffman, Owner