After having very little luck with a digital formaldehyde meter to test indoor air quality I decided it was time to switch to a more proven way to do DIY formaldehyde testing. After some research I decided to try colorimetric gas detector tubes to measure formaldehyde levels which don’t require sending samples off to a lab. The most common way for homeowners to test formaldehyde levels is using a passive sampler which is placed in a room for 24 hours then sealed up and mailed off to a lab for analysis. If you only want one data point then mailing off an air sample to the lab is more cost effective. I wanted quick results from measurements so I could make a change and see the impact without having to wait for a lab so a formaldehyde colorimetric gas detector tube was the logical choice outside of an electronic meter.
To use colorimetric gas detector tubes you need a few things; a gas detector tube for the specific gas you are testing for, an air sampling pump that can accurately meter a specific amount of air through the tube, a thermometer to make corrections to the formaldehyde detector tube’s reading. After stumbling around with a ton of air pumps I found a great resource, Public Lab formaldehyde testing which was a lot of help to find a stable air pump. I wanted to expand upon this article and go into more detail for anyone interested in doing indoor air quality testing using colorimetric gas detector tubes.
The air sampling pump, flow meter, and other miscellaneous parts can be sourced for about $70 which is a one time purchase. The Kitagawa 710 formaldehyde test tubes are about $135 shipped for a box of 20, the GASTEC 91PL tubes are $83 shipped for a box of 10. The cost per test excluding the one time equipment purchase is $6.75 for the Kitagawa 710 tubes (but requires a larger purchase price up front) and $8.30 for the GASTEC 91PL tubes.