Air Quality Testing San Francisco – Green Festival
For the two days we wore passive vapor monitor badges at the Green Festival-SF. This blog about Air Quality Testing San Francisco – Green Festival provides a summary of the air quality sampling methods, lab analysis, and lab results.
Air Quality Sampling Methods
Vapor monitors offer an inexpensive way to monitor air quality. Vapor monitors are small, lightweight, and easily affixed to an individual’s clothing or personal protective equipment. They are used most often for monitoring exposure levels in workplace settings. This sort of vapor monitor is known as a “passive” sampling method, because there is no active air pump required for sample collection.
It is generally recommended that vapor monitors be kept “in the breathing zone,” and allowed to run for 24-48 hours. Some vapor monitor badges are designed to quantify short-term exposures for as little as 15 minutes. There is often a cap (maximum allowable time) to how long you can leave them out before the results would be meaningless, so it’s important to know the sampling time limitations. There is also an optimum amount of time the sample should be collected, before which the results cannot be relied on for quantifying low-level exposures.
For air quality testing at the Green Festival we started the sample collection just before the gates opened on November 10th, 9:45 AM. We utilized two vapor monitors; “formaldehyde,” and “organic vapor” scan for 52 common indoor VOCs. Because the optimum run time was for 24-48 hours, and we wouldn’t be in the space for 24 hours for the weekend show, we had to leave the vapor monitors out overnight in the SF Concourse Exhibition Center. They were worn on my lapel during the rest of the Green Festival. Samples were sealed back up and sent to the lab immediately at the end of the show.
Air Quality Lab Analysis
Vapor monitoring badgest contain contain solid adsorbent material to which gases cling. At the lab, vapors are first desorbed and then run through a gas chromatograph to determine the type and concentrations of each analyte.
The formaldehyde vapor badge utilized 2,4-DNPH-coated high-purity silica gel as an adsorbent media. The “organic” vapor badge looks for more than 50 common indoor air contaminants, including: Acetone, Benzene, Chloroform, Ethyl Alcohol, Isobutyl Alcohol, Isopropyl Alcohol, Methylene Chloride, Pentane, Perchloroethylene, Styrene, Toluene, Trichloroethane, and Xylene.
Air Quality Testing Results
This is a teaser. More detailed results from the VOCs will follow.
Total VOCs at the Green Festival were below 300 ug/m3.
The method of analysis used to analyze VOCs only scanned for approximately 50 compounds. Here is the list of compounds we analyzed for:
Formaldehyde levels measured 0.005 ppm.
Soon we’ll be posting more details about what types of VOCs were detected, and air quality testing results from GreenBuild, so keep an eye out for an interesting comparison! Please peruse our website if you’re interested in Air Quality Inspections or Air Quality Testing.