Comparing Air Quality Results from Green Festival and GreenBuild San Francisco

For those curious about indoor air quality… we are comparing air quality results from Green Festival and GreenBuild San Francisco. This is a very limited sampling method and sample size, so take these results with a grain of salt. But you must admit it is interesting to see how these two “green” events stack up in terms of indoor air quality.

I’m pleased, and considerably relieved, to report neither venue had any major red flags. Of the chemicals we tested for – none were found above recommended health and safety thresholds established by regulatory agencies or the USGBC.

For both events I wore a personal vapor monitoring badge during the day, and clipped the badges somewhere inconspicuous overnight so the collection time would be between 24-48 hours. You may have wondered what those weird circular badges hanging from my lapel…

Air Sampling Monitoring Badge on Alex Stadtner’s Name Tag and Lapel

Healthy Building Science Booth
Air Quality Testing at Green Festival San Francisco

This is admittedly a very simplistic sampling method and very limited sample size (2 vapor monitor badges). These air quality results are merely for demonstration and only represent a single snapshot in time. The same method of sampling and lab analysis was used for testing air quality at the Green Festival one week before GreenBuild.

Here are several charts comparing air quality results from Green Festival and GreenBuild San Francisco:

Comparing Formaldehyde Results:

These results are so close it is a virtual tie, but the Green Festival (San Francisco Concourse Exhibition Center) was one part per billion (ppb) less than the GreenBuild venue (Moscone Center in San Francisco).

Comparing Formaldehyde Concentrations from GreenBuild and the Green Festival
Concentrations in Parts per Million (ppm)

Formaldehyde was detected, but it was measured at relatively low levels [0.006 ppm, or 6 parts per billion (ppb)]. It is worth noting that levels were below the Agency for Toxic Substances and Disease Registry’s Minimum Risk Level (MRL) for 365 days of exposure (8 ppb). The yellow column in the above charts represents 8 ppb.  The US EPA and American Lung Association recommend a maximum level of 0.1 ppm (100 ppb) formaldehyde in indoor air. The California Air Resources Board recommends 0.05 ppm (50 ppb). Both samples were and well below NIOSH RELs and OSHA PELs.

Comparing VOC Results:

Comparing Total Volatile Organic Compound (TVOC) measurements is an easy way to analyse these results.

TVOC Comparison between Green Festival and GreenBuild
Reported in micrograms per cubic meter (ug/m3)

There are no established regulatory limits for TVOCs indoors. However, the United States Green Building Council (USGBC) recommends a maximum of 500 micrograms per cubic meter (ug/m3) in LEED certified buildings. Using TVOC as a measuring stick – GreenBuild had slightly cleaner air than the Green Festival.

Comparing Detailed VOC Results:

And finally we dive into the specific volatile organic compounds (VOCs) found: Acetone, Benzene, Butane, D-Limonene, Ethyl Alcohol, Isopropyl Alcohol, 2-Methylbutane, Pentane and Toluene.

Detailed VOC Comparison
Reported in micrograms per cubic meter (ug/m3)

None of the chemicals tested for were found in concentrations above (or anywhere near) NIOSH, OSHA or ACGIH limits. Yes, some of these chemicals are nasty… but they were measured in very low concentrations and according to our regulatory agencies would not pose a threat to otherwise healthy individuals. This graph makes clear the higher levels of ethyl alcohol and isopropyl alcohol found at the Green Festival.

If you have any questions about the methods used for these air quality results, please check out a previous blog post entitled “Air Quality Testing San Francisco – Green Festival.” This method of air sampling is generally not our preferred approach, but it worked well for measuring my personal exposure over the course of my time at these two green events.