
Why Does My Air Purifier Smell? (Urgent)
Why Does My Air Purifier Smell Bad?
There are some downsides to an air purifier, but the active smell shouldn’t be one of them. A brand new unit that you recently unboxed, dirty filters, mold infestation, or a damaged component could be one of the many reasons your air purifier smells bad. If you have a sensitive nose, the stench could be mildly nauseating to extremely noxious. In any case, it clearly indicates that something is wrong with the air cleaner, and you will need to look into it promptly. We break down the many causes for your air purifier smells ranging from ignorable to potentially dangerous. Find the one most relatable to you and rectify it at the earliest.
1. Ozone Smell
The main reason your air cleaner gives off a bad smell is likely ozone. The “clean” chlorine smell is ozone byproducts generated from a running air purifier. It is the same experience after a thunderstorm or a chlorinated swimming pool. The causation is either from ionization technology or a broken UV light bulb that leaks out a repulsive ozone smell that you can scent even from afar. Shockingly, many people don’t realize that their air purifiers produce ozone during operation.

Ozone is a highly reactive gas formed of three oxygen atoms. Manufacturers often promote the disinfectant smell as fresh air to mitigate any fear. Because of its unstable chemical composition, exposure to ozone can trigger symptoms such as:
- Coughing
- Dizziness
- Shortness of breath
- Chest pain/ tightness
- Headache
- Wheezing
- Throat irritation
- Nausea
At a high concentration level, ozone can damage our lungs, aggravate asthma, and lead to chronic respiratory diseases such as bronchitis and COPD.
Never purchase or use an ozone generator. It is banned in states like California and is notorious for emitting a high concentration level of dangerous ozone byproducts. What’s more, the ozone smell could last from 30 minutes to 4 hours before it dissipates. While the distinctive smell wouldn’t last forever, stay alert whenever you sense it.
Instead, go with certified Ionizer/ Ionic air purifiers or PCO/ UV air purifiers. The low concentration level of ozone released is harmless under The California Air Resources Board (CARB) guideline. By default, the ozone byproducts released from an undamaged vacuum-LED UV-C light (100-240 nm wavelengths) are too low to cause any harm. The same goes for an ionizer that emits an insignificantly level of ozone, no more than 0.05 ppm, as part of the requirement by the FDA.
Solution: If you are susceptible to ozone, a quick fix is to disable all non-mechanical purification features that don’t involve filters. Experiment and monitor to see if the ozone/ chlorine smell persists; if it does, you could be dealing with an ozone generator instead.

2. Burning Smell
If the air purifier emits an awful burning smell comparable to a fish, urine, or a burning candle, switch it off immediately as you run the risk of a fire hazard. There could be electrical components failure, faulty UV Light, or wiring issue that causes the plastic coating to melt. Most modern air purifiers come with a safety short-circuit trip that protects the circuit from overloading. When the breaker is tripped or the fuse is blown, it may cause sparks and smoke with a sharp burning smell.
Solution: Inspect your air purifier thoroughly when something doesn’t feel right. If the burnt smells are not originated from the air purifier, review the sources and leave the air cleaner on to remove the pungent odor. While it cannot remove all the smoke particles at once (as pointed out by EPA), you will at least be protected from inhaling the toxic fume for the time being.
3. The “New” Plasticky Smell
When a brand-new air purifier produces a strong plastic smell during the initial few days of operation, it is normal, and the scent will dissipate eventually. It is because the freshly molded plastic fume smell remains trapped inside the original box during manufacturing, with no chance of airing it out. When you unbox the air cleaner, the plastic odor residue will finally be released into the air and fade away quickly.
Solution: Let it be, as the plasticky smell shouldn’t last long. You can reduce the smell drastically by letting the air purifier run at high speed for 24 to 48 hours. If the strong plastic smells persist after a couple of days, it could be due to burning plastic internally from the wire short-circuit. Turn off the machine and send it back to the manufacturer for service and repair.

4. Wet Dog/ Damp Smell
When the air purifier emits a musty wet dog smell, it is caused by bacteria, mold spores, yeast, algal slimes, or mildew growing inside the filter/ machine. The foulness is the combination of natural oils and microorganisms’ growth, e.g. bacteria combined with water in the rain/ pond. If it is not dealt with, the air purifier may end up spreading allergens that are harmful to our health.
Solution: The higher the dampness, the stronger the smell. High humidity in the room is often the root cause of the growth of microorganisms. So inspect the filters, air inlet, and outlet for any signs of dirt, grime, or mold infestation. You can use sodium chlorite or chlorine dioxide to remove the bacteria and fungi on the air purifier, thus ending the wet dog smell. Alternatively, opt for filters with an antibacterial coating that inhibits the growth of microorganisms. Lastly, ensure the air purifier is only used in a dry environment to prevent moisture build-up. Get a dehumidifier to remove excess moisture. As always, check with the manufacturer prior to the cleaning.
5. Strange Yet Sweet Smell
When an air purifier releases a sweet smell, it is likely from the air passing through the absorption compounds of the new charcoal/ carbon filter. It is hard to notice this weird smell as it is not obnoxious but not too pleasant either. At times, it will have a hint of sweetness or fruity aroma that some won’t mind breathing in.
Solution: Ignorable. There is nothing to worry about the odor you scent, as the smell poses no harm to our bodies. The strange sweet smell should subside within 1-3 weeks, and if that does not happen, it may be a good sign to check on the activated carbon filter.
6. The Other New/ Dirty Filter Smell
When the air purifier releases a strong hint of dusty, stale odor, it either comes from the glue that holds the PP/ PET material filter (usually happens on a new filter) or the filter is dirty.
Solution: Use the brand new HEPA filter for 2-3 days, and the unpleasant “newness” smell will fade away. It is not dangerous, and you can leave it as it is. If the filter is dirty, you can eradicate the smell by cleaning or replacing the filter regularly. For pre-filter clogged with dust, hair, and other large particles, vacuum the filter gently with a brush attachment. Do it at least once a month. As for the HEPA and activated carbon filters, replace them, as both are non-washable. The unpleasant smell will slowly disappear by maintaining the filters according to the recommended interval. Your air purifier will be odor-free moving forward.
7. Poor Ventilation
Another culprit of an air purifier smell is insufficient ventilation due to confined space or blockage on the air inlet/ outlet. It causes the activated carbon filters to be over-saturated with different odors and quickly wear out. When the carbon filter is worn out, it will produce the same awful smell every time you turn on the air purifier.
Solution: Ensure there is ample ventilation in a room. Next, ensure no foreign objects like the wall, sofa, or cabinet impede the air ventilation. The general guideline is to leave 2-4 feet of space for an air purifier.
How Do I Get The Smell Out Of My Air Purifier?
To recap, below are the common sources of odor associated with an air purifier and how to differentiate between good and bad smells. The odors range from mildly irritating to nauseating and potentially dangerous when inhaled.
Air Purifier Smell | What Causes It | What To Do (Solution) | Urgency |
---|---|---|---|
Burning smell similar to a fish, urine, burning candle. | Electrical components failure or wiring issue. | Send it for repair. Do not attempt to fix it yourself. | High |
Distinct chlorine/ swimming pool smell. | Ozone byproducts. | Disable ionizer/ UV-light, replace UV light bulb. Stop using if it is an Ozone generator. | High |
Heavy plastic smell. | Trapped molded plastic fume in plastic wrap or box. | Unbox and air it out for a couple of days. Run the air purifier at max speed. | Low |
Dusty, stale odor that is not pleasant. | New or dirty/ worn out filter. | Vacuum or wash the pre-filter every 2-3 weeks. Dispose and replace the HEPA and carbon filter periodically. | Medium |
Musty Wet Dog Smell. | Mold spores, mildew, or bacteria inside the machine. | Check the filter, air inlet, air outlet for any mold infestation. Do not run the air purifier in a humid area. | High |
Strange fruity, Sweet Smell. | New activated carbon filter. | Harmless. Let the smell dissipate after a couple of days. | Low |
Which Air Purifier Is Best For Odor?
A staple in most homes, here are some of the finest air purifiers to deal with all types of smoke and odors currently on sale. In no particular order. The models recommended here are considerably reviewed, tested, and compared on their filtration performance and usability. Note that this list will not be updated regularly, do check out our best air purifier for smoke listing here or specifically tailored best air purifier for kitchen use here.
- Rabbit Air MinusA2
- Levoit LV-PUR131
- Winix 5500-2
- IQAir HealthPro Plus
- Austin Air HealthMate
- Dyson Pure Cool TP01
- LEVOIT Core 300
- Medify Air MA-15
- TREDY TD-1500
- Bissell MYair 2780A
- Blueair 605
- Coway Airmega series
Final Thoughts
Everyone has a different tolerance for smells, including good scents from essential oil or cologne. Some models or brands are notorious for emitting byproducts that smell bad. One thing is for sure; everyone would want an air purifier that DOES NOT produce any unpleasant smell. A good air purifier is not supposed to smell. In fact, it can make your house smell better by swiftly removing smoke and odor-causing allergens from mold, cooking (frying/ baking/ leftover), pet (urine/ feces/ dirty water tank/ cage), cigarettes, chemicals (VOCs, CO, DO, radon), diaper, cleaning products, wood-burning, and wildfire. If your air purifier smells weird out of the blue, something has gone wrong, and immediate attention is needed. Do not procrastinate on this matter.