Sampling for Mold in Air

The Air-O-Cell™ cassette (Product ID 8715301B) and similar cassettes, like the Allergenco-D cassette (Product ID 8715307B), are a single-use sampling devices designed for the rapid collection and analysis of a wide range of airborne particles. These include fungal spores, pollen, insect parts, skin cell fragments, fibers, and other organic and inorganic particulates.

The cassette is designed to operate at a flow rate of 15 LPM. Lower flow rates may result in a collection loss of some spores and the accumulation of others in a non-uniform manner. Therefore, it is critical to run the sampling pumps at the manufacturer’s recommended air flow rate.

Benefits

Useful for initial site testing, especially if fungal growth is not visible.
Quick and simple procedure.
Fast turn around times available.
Low chance of sample contamination.
Evaluate ambient air for contaminants around the sampling site.

Disadvantages

Fungi cannot be identified to species with this method. For species level identification use appropriate agar plates and impactors such as the VP-400 (Product ID 8709001).
Due to the similarities in spore morphology, some spores will be grouped together, i.e., Aspergillus sp. and Penicillium sp.
Spore viability cannot be assessed.

Sampling Procedure

Prior to sampling, calibrate your pump to 15 liters per minute via a rotameter. It is also recommended that the rotameter or sampling pump be periodically calibrated to a NIST primary standard. If using the Bio-Pump IAQ Lite (Product ID 8706002) use the specifically designed Air-O-Cell flow indicator. It cannot be used with any other type of pump.
Remove and retain tape seal covering inlet and outlet on the cassette.
Attach the outlet (round hole) to a standard 1/2” PVC tubing (for use with high volume pumps only).
Start the sampling pump and sample for an appropriate period of time (see recommendations below).
Remove Air-O-Cell from tubing and reseal with the original seals. Label sample.
Complete an EMSL Chain of Custody (COC), available at www.emsl.com, detailing client name and information, project name or number, sample number, description of sampling area, and volume of air collected.
To reduce shipping damage, it is recommended that the Air-O-Cell be placed in a corrugated box with padding to ensure safe arrival at the laboratory.

Sampling Duration

The sampling time is dependent on the density of particulate in the environment. It is important not to overload the sample, otherwise it will be impossible to accurately count the types of spores, pollen, or other particulates that are present. The following list represents typical sample times to attain a sharply defined trace with good dispersion of the spores:

Clean “office” or outdoors (no visible dust) = 10 minutes
Indoor environment, high activity and personnel = 5 minutes
Indoor environment, drywall renovation, or heavy industrial dust = 1 minute

Quality Control Recommendations

An effective interpretation is based on the comparison of indoor and outdoor samples. Outdoor samples will help determine whether spore amplification is occurring indoors.
Obtain a control sample from a non-complaint area for comparison.
Sending a blank cassette for analysis per project is a good practice.
Flow rate is critical for accurate results. Remember to calibrate and recalibrate the pump prior to all sampling (15 liters/minute).
Never use cassettes that are damaged or expired.

Sampling for Mold in Air