Jeffery Trolinger

Aerosol Research and Engineering Laboratories Inc.

Introduction: Ensuring indoor air quality, especially in environments sensitive to contamination, like hospitals and laboratories, demands precise and reliable monitoring tools. ARE Labs is at the forefront of characterizing devices aimed at monitoring to ensure accuracy in these critical environments.  Testing to establish detector response for various microorganisms, stability, repeatability, interferants response and limits-of-detection are critical for validating bioaerosol and gas detectors.  Here are ARE Labs we can challenge a range of microorganisms (bacteria, virus, spores and yeast) and can establish stable concentration ranges from 0.01 to over 1,000,000 cfu/pfu per liter to fully evaluate a detectors performance.

Testing Overview: The environment consists of airborne particles that can be nonorganic or biologically related to living organisms, such as bacteria, fungi, and viruses. Their monitoring is crucial for assessing air quality and managing health risks in various environments. The ability to accurately detect and quantify these particles and differentiate between non-biological particulate and bioaerosol allows for better control and prevention of airborne diseases.

Key Components of Testing: Testing Species: ARE Labs has access to a wide variety of microorganisms ranging from bacteria and viruses to mold spores that can be used for air monitor challenges, including the surrogates for the ESKAPE pathogens that are a significant concern in the healthcare industry. Some organisms that have been used for detector testing in the past are:  

·       Staphylococcus epidermidis

·       Klebsiella aerogenes

·       Pseudomonas fluorescens

·       Bacillus subtilis

·       Mycobacterium

·       Aspergillus brasiliensis

·       Candida albicans

·       RNA virus MS2

·       DNA virus Phi-X174

·       Enveloped RNA virus phi6

Testing Environment: The testing chambers at ARE Labs are equipped to adjust to a wide range of environmental conditions depending on the environment the client chooses to simulate. This environmental control allows for the most accurate representation of how the device would perform in a real-world scenario when conducting a test. Test chambers range from 1m3 to 30m3 sizes.

Testing Environment: The testing chambers at ARE Labs are equipped to adjust to a wide range of environmental conditions depending on the environment the client chooses to simulate. This environmental control allows for the most accurate representation of how the device would perform in a real-world scenario when conducting a test. Test chambers range from 1m3 to 30m3 sizes.

Testing Methodology

Background Sampling: Before a test is run, the background particulate level of the chamber is measured using an aerodynamic particle sizer. This ensures the background is as low as possible before testing and accounts for any preexisting particles in final calculations.

Device Exposure: Depending on the device, the device may be sealed inside the test chamber during exposure, with sampling done through a 3/8-inch stainless steel sample probe from outside the chamber during the test trials. The method for the dispersal of the organism can be chosen by the study sponsor before testing. Two of the main methods used during this testing have been:

• Constant dispersal of the organism: This method is ideal for keeping the testing environment at the same concentration throughout each trial for consistency.

•  Single dispersal with the organism dispersed at the beginning of each trial: This method can be instituted when testing aims to track the decline of organism concentration over time within the space establishing detector response.

Trial Repetition and Conditions Control: Multiple trials are conducted at varying concentrations and environmental settings to assess the devices' responsiveness and accuracy under different conditions. This rigorous approach helps in understanding how each system performs in dynamic environments.