I Tried an Air Purifier Designed to Filter Out Weed and Cigarette Smoke

In the US and globally, April 20 has become an unofficial holiday for weed smokers. While vaping, gummies and edibles are increasingly popular, a fair number of people still light up for a smoke, and that can result in a lingering odor many find unpleasant.

I'm one of those people, and GermGuardian's new FLT420B air purifier filter is designed to remove cannabis smoke more effectively than standard air purifier filters.
"As cannabis use becomes more widely accepted, we recognized a real gap in the market for a filter purpose-built to tackle cannabis smoke odors, not just mask them," said Rukky Ojakovo, senior director of heaters and air quality at Guardian Technologies. "In our two-week in-home test, over 90% of users rated it very effective at reducing cannabis odor."

I've been using the FLT420B filter in my home with a GermGuardian AC4880B air purifier for several weeks now, and I've been impressed with just how effectively it tackles smoke odors. In my case, the odor is more from cigarette smoke than marijuana (I had the misfortune of indoor smokers moving into the unit below me). The FLT420B filter has been effective at tackling the smell.

"While the FLT420B was engineered specifically for cannabis smoke, its advanced odor-control media targets VOCs [volatile organic compounds] broadly, making it effective against other herbal smoke as well," Ojakovo told me over email.

According to GermGuardian, the filter is 300 times more effective than standard HEPA smoke filters and targets odor-causing VOCs at the "molecular" level. The company says it can remove cannabis odor within 90 minutes. Though I'm not a marijuana smoker myself -- I'm very sensitive to bad odors, and I have two asthmatic cats -- I'm planning on testing this soon by using cannabis-scented incense sticks.

In the meantime, to test this, I placed the entire AC4880B air purifier unit, with the smoke filter installed, in a closet in my wife's office and shut the door. Using the UV-C sanitizing light, which can generate a small amount of safe ozone, the entire closet was effectively deodorized in about 24 hours.

I asked Ojakovo what played the largest role in clearing the odor from the closet. The filter was the primary driver. 

"The FLT420B's advanced odor-control media is specifically designed to capture VOCs and lingering odors like cigarette smoke," Ojakovo said. "The UV-C light is great for reducing airborne bacteria, germs, and mold spores, but is less targeted toward chemical-based smoke odors specifically."     

Interestingly, even after I pulled it out of the closet, the air inside has stayed deodorized, though sealing gaps and cracks likely helped.

To further test how well the filter cleared smells, I moved the GermGuardian unit to my galley kitchen and placed it by my trash cans. There's not much ventilation in there, and I have a gas range, so there are plenty of VOCs. I've left it there for over a week now, and since then, I've noticed a distinct reduction in stale cooking smells and a general improvement in air quality, verified by an air quality monitor. 

"Since the FLT420B is designed to tackle VOCs, it can certainly help with cooking-related odors and gases," said Ojakovo, while also pointing out that the company sells filters designed for kitchen use specifically. "For heavier kitchen use near a gas range, we'd recommend exploring our broader lineup of filters, designed for specific use cases." 

Now, if you suffer from allergies, you may want to consider a different air purifier model, but for VOCs, it's been one of the more effective ones I've used. 

Price and availability

The FLT420B will work with GermGuardian's most widely used air purifiers, including the AC4880, AC4825E, AC4300, AC4825, AC4870, AC4820, AC4900, AC4850PT, CDAP4500 and AP2200CA. If you own one of those models, it's simply a matter of purchasing the FLT420B filter from Amazon (currently out of stock) or directly from Guardian Technologies for $40. 

If you're a new customer, you can buy the model with the features you prefer and pair it with a filter that suits your use case. 

Editor's note: While cannabis has been legalized for medical and even recreational use in some states, marijuana and products containing THC are still a Schedule I drug under US federal law. Always exercise caution and judgment when consuming cannabis or any other controlled substance.