If you can smell an odor while you’re wearing an N95 mask, does that mean the mask isn’t fitting well? Many people experience this when they notice they can still smell cigarette smoke, even though they’re wearing a mask. Thus, can we use smells as an indicator of getting a …
Many people wonder about the difference between N95 and KF94 masks. But actually, for the things most people care about, the difference is not small. KF94 is the “Korean filter” standard similar to the US N95 mask rating. Let’s dive into the differences: KF95 vs N95. Note, there is no …
We previously discussed how HEPA filters remove asbestos from the air extremely well. But asbestos causes cancer, so I wouldn’t rely on just a purifier while in the room. I’d want to wear a mask. How Big Are Asbestos Particles? Asbestos particles range from 0.7 to 90 microns. To put this …
Lots of companies will sell you formaldehyde sensors, 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 impossible to interpret. Given that unfortunate fact, here’s what you can do …
My intuition has always been that there is less air pollution at night because there are fewer cars on the road and fewer factories humming at that time of day. Pollution Time of Day Guesses Apparently, I’m not alone: 139 voted for their guess about what time of day has …
Does activated carbon filters remove formaldehyde and VOCs? Earlier tests from Smart Air found that carbon does reduce VOCs from cigarette smoke. But formaldehyde and VOCs in general are particular concern for many people. We put activated carbon filters to the test by ordering formaldehyde straight from the factory and …
The difference between P2 and N95 masks is so small that most users will not notice anything amiss. The P2 rating is the standard in Australia and New Zealand similar to the US N95 mask rating. What is a P2 Mask? A P2 respirator mask is a type of mask …
Should air purifiers have the HEPA filter on the front or the back–is it better to push or pull air? The Smart Air lab in Beijing ran tests of the same fan with the HEPA filter on either side, and the results contradict most people’s intuition. When I made my …
An important question about formaldehyde is how long it takes for formaldehyde to off-gas in new homes and new furniture–how long will it take for levels to get back to normal? The best data I’ve seen suggests formaldehyde takes about two years to off-gas back to normal levels. What is …
