Surface Sampling – Mold Testing
A surface sample is useful when there is suspected visible mold growth on a surface, and a client wants to know information in regard to the suspected mold growth that is observed. One of the limitations of surface sampling mold growth is that a surface sample will only provide information for an approximate one square inch of surface where the surface sample is being collected. There may be a variety of different genus and species of mold present in a large mold growth colony.
A surface sample will answer the following questions: Is mold present where the surface sample for anticipated mold growth is collected? Surface sampling can also be useful in determining the genus type of mold that is present and perhaps it can be narrowed down to the species level of mold that is present depending of the type of surface sample that is collected.
SafeAir Certified Mold Inspection has two different types of surface sampling methods for mold growth available depending on the information that a client is requesting about a possible source of mold growth. The two surface sampling methods, for mold growth, that are available are tape lift samples and swab samples.
The first surface sampling method to determine if mold growth is present is called a tape lift sample. A tape lift sample is a sticky tape-like material that is approximately one square inch in size. To collect a tape lift sample, contact with the sticky side of the tape lift is made with the surface of suspected mold growth. A tape lift sample will determine the genus type of mold that is present. A tape lift sample will not provide information regarding the specific species of mold that is present. However, determining the species of mold that is present is generally not useful information in developing a plan to remove a mold problem, since all mold growth indoors is recommended to be removed, or to answer the question of; is there mold present on a specific surface? A tape lift sample is less expensive to process than a swab sample and a tape lift sample can be processed in the laboratory in as little as 3 hours.
If you want to know if a surface is free of mold growth or if you want to know if a suspected area of mold growth is the same genus type of mold spore that has been identified in a spore trap air sample, then a tape lift sample of the suspected area of mold growth is the recommended surface sample to collect.
The second type of surface sample for identifying mold growth on a surface is called a swab sample. We take a damp cotton swab and rub it on a one square surface area of suspected mold growth. We then deliver the swab sample to the laboratory, and grow the suspected mold growth in a petri dish that is then placed inside an incubator for approximately ten days, so that the mold can grow into a mature mold colony. Mold must to grow and develop into a mature mold colony in order to determine both genus and species of suspected mold that is collected.
A swab sample is more expensive to process than a tape lift sample and the approximate ten days it takes to process a swab sample is a much longer time frame than the three hours it can take to process a tape lift sample. However, a swab sample can provide more detailed information than a tape lift sample because both genus and species can be identified. If you want to know if a source of mold growth is a type of mold that is known to be a toxic mold or harmful mold for medical or legal purposes, then a swab sample is the preferred method of surface sample to collect for laboratory analysis.
It is important to understand that determining if a source of mold is a toxic mold or allergenic type mold is not necessary for determining a plan to remove a mold problem, because all mold growth located indoors is recommended to be remediated weather it is a toxic mold or just a type of mold that is commonly found in the outdoor environment. An additional reason that determining both genus and species of mold that is present is not necessary for developing a plan to remove the mold problem is that both the genus and species of mold that is on a surface can transform into a completely different genus and species of mold depending on a variety of factors such as changes in the environment as well as the length of time the mold colony has been present. The genus and species of mold present tends to become nastier, and a potentially more toxic mold type, as more time goes by and also as the level of moisture increases.