CHAS,

Re: air quality monitoring in organic laboratory

A variety of inexpensive air quality monitors are available and easy to use (some are capable of data logging.) I've used both CO2 and VOC/H2CO/PM2.5 monitors in my home and when traveling.

During the COVID pandemic, when we realized that CO2 was a proxy for fresh air, I bought a $40 pocket size CO2 monitor. I've observed CO2 > 1500 ppm routinely on airplanes, trains, and buses; can approach 3000 ppm during deplane and also in crowded bars and nightclubs. CO2 > 1200 ppm can make people drowsy, i.e., students in a classroom.

Two years ago, I recommended that my local library get a VOC/H2CO/PM2.5 monitor (and separate CO2 monitor) and I used it to confirm unhealthy PM2.5 concentrations during the Canadian wildfires. The state has outdoor air quality monitors (including NOx, ozone, etc) but I'm concerned about my indoor air quality. (I have a Corsi-Rosenthal box fan filter on 24 hr/day, essentially for dust control; my house has hot water heat, so no furnace filters.)

I have a gas stove and when on CO2 increases from indoor ambient 500-600 ppm to ~1000 ppm, but not so much VOC or H2CO or PM2.5. NO2 is another matter, I'm not aware of any inexpensive real time monitors, but film badge devices and I've observed high NO2 when the stove/oven is on, via 24 hr period of heavy cooking vs no cooking. (The action level for NO2 is much lower than for carbon monoxide.)

Just my opinion, but every classroom should have a CO2 monitor. I know people who have installed commercial heat exchangers in their house to bring in fresh air and retain heat (or AC.) I read a paper a few years ago that showed increased PM2.5 during high student traffic on carpets (enter and exit classrooms.) Laboratories need other monitors, especially if solvent use and/or Bunsen burners. Sadly, some people (not on this list) feel that if you don't measure it, it's not a problem. For ~$250 you can get reliable monitors, but having them in your local library of things is also a good idea.

I add that I'm a member of CES and in 2025 we were preparing a DAC CCC grant proposal to distribute funds to the ten ACS regions, for redistribution to local sections for air quality (and water, etc) monitoring, citizen science. However, we were unable to submit, but plan to try in 2026.

I hope this helps. Let me know if you need more information on indoor air quality monitors.

Joe Sabol

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> On 01/16/2026 12:00 AM EST DCHAS-L automatic digest system <listserv**At_Symbol_Here**lists.princeton.edu> wrote:
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> There is 1 message totaling 129 lines in this issue.
>
> Topics of the day:
>
> 1. “Canary in the Coal Mine” Indicators for College Organic Chemistry Labs
>
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> Date: Wed, 14 Jan 2026 18:22:28 -0700
> From: David EldrEdge <Dave.EldrEdge**At_Symbol_Here**NALTIC.COM>
> Subject: “Canary in the Coal Mine” Indicators for College Organic Chemistry Labs
>
> Dear DCHAS-L colleagues,
>
> I’m reaching out to see whether anyone has had success using *VOC sensors
> or other real-time indicators* as a practical “canary in the coal mine” to
> help assess air quality in undergraduate teaching laboratories.
>
> I’m starting a new organic chemistry lab semester, and a student has shared
> that she is actively trying to become pregnant. This has prompted me to
> think more carefully about whether our laboratory air is truly as safe as
> we assume, particularly with respect to *chronic, low-level VOC exposure*,
> even in a space that is generally considered well ventilated.
>
> Our lab has multiple fume hoods and decent overall ventilation, but it is
> not a wind tunnel, and at times VOCs are still noticeable in the room. I’m
> interested in tools that might help move beyond subjective perception and
> provide *actionable data* to inform decisions, conversations with ADA or
> Title IX, and discussions with students’ health care providers.
>
> Specifically, I’m curious whether anyone has experience with:
>
> -
>
> Portable or fixed *VOC sensors* used in teaching labs
> -
>
> CO₂ used as a proxy for ventilation effectiveness, in combination with
> chemical use
> -
>
> Other indicators or monitoring approaches that have proven useful in
> practice
> -
>
> Lessons learned about what *does not* work well in this context
>
> I am not looking for medical guidance, but rather for practical,
> evidence-based approaches that can help faculty better understand and
> communicate the level of risk in real instructional environments.
>
> Any insights, references, or experiences would be greatly appreciated.
>
> Thank you in advance for your time and expertise.
> Warm regards,
>
> David EldrEdge
> Co-Owner
> NALTIC Industrials, LLC
> de**At_Symbol_Here**naltic.com
> www.naltic.com
> 888.891.0077 Main
> 435.503.4972 Cell
> 435.767.7714 Google Voice & Text
> 435.654.2727 Fax
>
>
> ᐧ
>
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> End of DCHAS-L Digest - 14 Jan 2026 to 15 Jan 2026 (#2026-5)
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