Our tests of two DIY formaldehyde test kits suggest that well-intentioned home testers may face distorted results and potentially unnecessary worry. Learn more about the risks of formaldehyde, the China connection, and the downsides of DIY test kits.
What risks does formaldehyde pose?
Formaldehyde is one of the most common offenders that we encounter in terms of indoor pollutants, due to frequent remodeling and the use of inexpensive particle board furniture. Formaldehyde is a common manufacturing additive and is found in glues, adhesives, carpeting, cigarette smoke, paints, and especially particle board furniture. Exposure to formaldehyde causes eye irritation, respiratory tract tightening, coughing, and headaches. Even at low concentrations, formaldehyde vapors can cause sensitization, resulting in allergic symptoms similar to asthma. The WHO and EPA have both classified formaldehyde as known carcinogens based on evidence linking the chemical to nasal cancer and leukemia.
The China connection
Formaldehyde, while not a unique problem to China, has received a disproportionate amount of Chinese media attention and is blamed for leukemia, birth defects, and just about any ailment. In an office setting, Chinese employees may be far more aware of and concerned about formaldehyde, even though other VOCs may have more serious impacts. The Chinese standards for indoor formaldehyde exposure are actually even more stringent than WHO standards (0.08 vs. 0.10mg/m3.)
DIY formaldehyde test kits
Public concern about formaldehyde has generated a market for sprays and DIY formaldehyde testing kits. We first came across DIY kits while consulting at the recently renovated Shanghai office of a multinational bank. While the air tests indicated clean results, a lack of confidence and rumors led to a widespread belief that the indoor air was unhealthy. One manager we spoke with said that one of his staff had claimed a number of different ailments and had been allowed to work from home. A test of the employee’s workstation found no unusual odors or high levels of TVOCs. However, we spotted a home test kit on the employee’s windowsill and saw that it indicated high formaldehyde levels. Since our own independent testing had shown low levels, we decided to test the DIY kits to determine their accuracy.
PureLiving China test of DIY formaldehyde kits
We purchased two of the most popular brands on Taobao for 20RMB. Both are pretty simple — take off the seal, mix the two liquid vials into a central capsule, expose to air for 15 minutes, and then compare the color to a colormetric chart indicating the level of formaldehyde. But there are a few problems:
(1) Everyone’s eyes are different. The differences between different colors to determine the reading are pretty slight, so it’s a subjective matter of interpretation.
(2) The kits don’t read the same. As you can see from the photo, the kit on the left indicated 0.20mg/m3, while the one on the right indicated 0.60mg/m3 – three times higher!
(3) The kits are not very sensitive. Six of the 8 color bands are above the safe limit, so they are not even very useful as screeners.
(4) They’re wrong. The test kits yielded 0.20mg/m3 and 0.60mg/m3. The actual level of formaldehyde using laboratory test methods? 0.07mg/m3
The dangers of these DIY kits is that they give false positives and can cause a lot of unnecessary worry. Since our noses are sometimes not as sensitive as the standard, the only reliable way to determine exposure levels is to measure the amount of formaldehyde in the air.