Formaldehyde Detectors are Fake: 3 Things to Know About Formaldehyde (Part 1)

Lots of companies will sell you formaldehyde detectors, but a simple test you can do at home will reveal they are fakes. Formaldehyde detectors routinely react to lots of common gases that are not formaldehyde, making the numbers basically impossible to interpret. Given that unfortunate fact, here’s what you can do to test formaldehyde in […]

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35 healthy Shanghai college students used a purifier for 48 hours. Here’s what happened to their bodies

Does air pollution affect the health of young people with no symptoms? Let’s start with three things we know about the science behind air pollution and one really important thing we don’t know.   1. We know that purifiers reduce PM2.5   Loads of tests have found this in labs and in real-world homes. I’ve tested […]

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This Data Explains Why You Should Never Use Your Purifier’s Auto Mode – Supplemental Data

Data and Test Details   Test Methods: These tests were identical to my previously published tests, details of which can befound here, here, and here. Original Data: The original data for all 13 tests is available as an Excel file here   Average Outdoor PM2.5 During Tests It’s important to note the average outdoor PM2.5 during tests because purifiers achieve smaller percentage […]

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