Air Quality – Research Testing
Date:
Tech: Donna N. Lynch, MT(ASCP)
Equipment Used:
Nalgene
Aerosol Spray Bottles
RCS Plus
Air Sampler
Electromedia
Model 50C, a smaller version of the 100C
Brief Explanation of
Testing:
0.5 McFarland saline suspensions of E.coli ATCC 25922, S. aureus ATCC 25923, and C.albicans ATCC 66027 were made and placed in separate Nalgene aerosol spray bottles (Cat. No. 2430-0200). A .001 ml calibrated loopful of these suspensions was transferred to blood agar plates for colony count (should be > 100,000 CFU/ml). Next two TSA strips per test organism were labeled with the organism name, date of testing, and “pre” or “post” depicting when the air sample was taken (before the air filtration unit was turned on or after). The size of the room used was approximately 127 square feet. The 50C air filtration system was placed on a platform, at 5 ft. above the floor. A 500L/min air sample was taken of the room before any testing began or any equipment was turned on (background reading). The aerosol bottle containing E.coli was then sprayed for 1 second, directly towards the front of the filtration unit. The bottle was held 4 feet above the floor and 3ft. away from the unit. A 500 L/min air sample was immediately taken. The 50C was then turned on to full capacity and left running for 1 hour. Another 500 L/min air sample was taken. The unit was then turned off for 30 minutes. The aerosol bottles containing S.aureus and, after another full cycle of the above mentioned procedure, C.albicans, were both sprayed and tested.
Future Testing:
With the use of Mycobacterium bovis ATCC 35732, the same procedure as above will be followed. Afterwards, the main filter on the 50C will be cut up into four pieces and cultured for growth of E.coli, S.aureus, C.albicans, and M.bovis.
Results:
|
Organism |
Original Suspension
(Growth Results) |
Air Sample (Before
50C On) |
Air Sample (After
50C On) |
|
Escherichia coli ATCC 25922 |
>= 100,000 CFU/ml |
72 CFU/m³ |
6 CFU/m³ |
|
Staphylococcus aureus ATCC 25923 |
>= 100,000 CFU/ml |
14 CFU/m³ |
0 CFU/m³ |
|
Candida albicans ATCC 66027 |
>= 100,000 CFU/ml |
18 CFU/m³ |
8 CFU/m³ |
|
Mycobacterium bovis |
To Be Tested |
To Be Tested |
To Be Tested |
Calculations:
Air Sampling: 500 L/min
1000 L = 1 m³ = 35.3 ft³
1 ft³ = 28.3 L
CFU / m³ = CFU / ft³
35