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Mold Test Kit Review

Air vs. Surface Sampling Techniques

Reviews of Various Mold Tests


Note on Mold Testing:

Mold tests by themselves cannot give you the full picture of the mold problem in your house or building. When combined with other evaluation methods (such as those listed at: "Signs of a Mold Problem") you can better determine the extent of the problem.

Since they can be expensive, and usually tell you only what you already know, it is usually best to find the source of excessive moisture and to try fixing it before resorting to a mold test (Finding Mold, Preventing Mold, Cleaning Up Mold).

Some techniques identify what species of molds are present. This can be helpful since some mold species pose a greater health risk than others.

Air vs. Surface Sampling Techniques

Mold tests can be divided into two categories: air and surface. If you find it necessary to perform a mold test (e.g. for legal purposes), then it would be advisable to take at least one surface sample and one air sample. 

The reason is, in some situations, you may have mold growing on surface, yet it has not reached a point where it is releasing very many mold spores into the air. In which case, air sampling alone would provide results that did not accurately portray the extent of mold growth.

Or, you may have a situation where, in your random surface sampling, you did not sample a surface where mold was growing (or at least not at a significant level), but mold colonies throughout other parts of the home had reached a point where they were releasing substantial amounts of mold spores into the air. In this case, your surface sampling would not give you and accurate picture of the problem.


Reviews of Various Mold Tests

Anderson N-6 Bioaerosol Sampler:

This is a single stage petri plate impacter that consists of an aluminum device held together by 3 spring clamps and is sealed with O-ring gaskets. A high volume of air is drawn through the sampler causing multiple jets of air to direct airborne particles toward the surface of the agar collection plate. This will lead to biological growth if any microorganisms are present in the air that is sampled. A short collection period (3-5 minutes @ 28.3 lpm) should be used to prevent the plates from being overgrown by microorganisms. The sampler should be disinfected with isopropyl alcohol between each use and you don not want to use media thatís expired, has visible cracks, or possible contamination.
Pros: Results relate directly to airborne exposures; qualitative and quantitative results; it is possible to speciate; specific organisms can be targeted since various types of media are available; results can be compared to bulk, tape, or swab results in order to find amplification sites.
Cons:
Expensive; time consuming for sampling and analysis; only isolates viable (living) organisms; some fungi may overgrow others leading to an unclear picture about what is present; media has a short shelf-life; and the samples are perishable if not handled properly and carefully.

Spore Trap:

This indoor air quality sampler is a particulate sampling cassette, Zefon Air-O-Cell Cassette, designed for rapid collection and analysis of a wide range of airborne aerosols including mold spores, pollen, insect parts and skin fragments. These types of samples are used to detect for total spore counts. It is useful for rapid analysis of airborne contaminants in IAQ testing, allergy testing and flood restoration monitoring.
Pros: Media is easy to store and has a long-shelf life; results are semi-quantitative and relates directly to airborne exposure; rapid analysis of results.
Cons: Differentiation between viable and non-viable organisms is difficult; canít sample for bacteria; there is large lab to lab variation in analysis of results; and cannot speciate.

Bulk/Surface Samples:

These types of sample are applicable when there is visible contamination of building materials such as drywall, flooring, insulation, wood, etc. Materials are collected then sent directly to a lab for microbial identification. Bulk/ surface sampling is useful in verification of remediation.
Pros: Inexpensive; rapid spore count identification; can be quantitative; able to differentiate between viable and non-viable microorganisms; possible to culture and then speciate.
Cons: Destructive of building materials; may expose occupants during collection; results do not relate directly to airborne exposures; may not be the source of contamination.

Wallchecks: 

Wallchecks evaluate concealed spaces without being destructive.
Pros: Results are qualitative and quantitative; media is easy to store and has a long shelf-life, results relate directly to spacial contamination and to the contamination of the air behind the wall, cabinet space, etc; rapid analysis of results.
Cons: Differentiation between viable and non-viable is difficult; cannot collect samples for bacteria; lab to lab variation in results is great; cannot speciate; the lack of dilution ventilation may cause high levels for results that are not representative of the problem.

Swab/Tape Sampling for Building Surfaces:

A swab sample is collected with a sterile cotton ďQ-tipĒ applicator that has been moistened with sterile growth media. The area to be swabbed should be performed by a person wearing sterile latex, surgical gloves and the cotton head of the applicator is broken off into the growth solution vial.  The vial and swabbed applicator sent to a lab for plate culturing and counting.
Pros: Inexpensive; non-destructive; rapid analysis for spore counts; results can be quantitative and cultured for speciation; sampling can be performed on irregular surfaces.
Cons: Results do not relate directly to airborne exposures; fungal structures may be damaged during collection causing identification of the mold to be less accurate; spores may germinate before lab analysis; may miss presence of organisms in porous materials; and sample collection does not work well on dry surfaces.

The ProLab Mold Test Kit: 

Offers three (3) different types of sampling methods, depending on your application needs:

Method 1: taking a sample from a visual growth area. The same as bulk/surface sampling (covered above).

Method 2: taking a 10 minute grab air sample of the HVAC system. This is done by placing a petri dish over a register, closing all other registers, and turning the HVAC system fan on and sampling for 10 minutes. Close the plate up and allow it to incubate for a couple of days.

Method 3: taking an air sample using a settling plate technique. This is simply done by placing an open petri dish somewhere in a room for like an hour, closing it up, and allowing the plate to incubate for a couple of days.

Pros: Results may relate to airborne exposures; qualitative results; it is possible to speciate; results can be compared to bulk, tape, or swab results in order to find amplification sites: Methods 2 & 3 are beneficial for finding mold in the HVAC system. 

Cons: Time consuming for analysis; only isolates viable (living) organisms; some fungi may overgrow others leading to an unclear picture about what is present; and the samples are perishable if not handled properly and carefully; would not be quantitative since it does not employ using a specified flow rate, therefore you cannot calculate a quantity in a sample of air.


Signs of Mold - 22 signs that you may have a potential mold problem in your home or building.

How to Find Mold - Where to look and ways to uncover mold growth in your home or building.

Signs of Mold  |  Finding Mold  |  Prevention Tips  |  Mold Clean Up

Mold Background  |  Mold Health Effects  |  Mold Species  |  About TBMIC

Humidity Sensor Buying Guide  |  Dehumidifier Buying Guide | Mold Test Review  Articles 

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