9 Reasons Why Your Air Purifier Smells – And How To Fix It

Has your air purifier recently started giving off a new smell? Depending on the smell, it can be normal or mean there’s problem. Either way, it’s important to know what the underlying cause is, and how to fix it.

An air purifier usually smells because of a saturated carbon filter, faulty UV light or mold growths. Ozone production or broken wiring can also create a noticeable smell. New air purifiers or filters will normally produce a smell as the plastic off-gasses.

Each smell comes with its own problem, so this guide explains all the possible causes of a smelly air purifier – and how to fix them.

9 Reasons for a smelly air purifier

Before we get into the list of all the possible smelly reasons, it’s important to know that ALL new air purifiers give off a characteristic smell. If you have a new air purifier or filter, or you’re using one after a long time of it sitting unused, it’s normal for it to give off a plastic-like smell.

This smell will go away with time. You can speed up the off-gassing by turning the purifier fan to high.

Here is a summary that links the type of smell with the reason behind it. Keep reading for more details on each problem (there’s more!) and how to fix it.

An air purifier usually smells because of a saturated carbon filter, faulty UV light or mold growths. Ozone production or broken wiring can also create a noticeable smell. New air purifiers or filters will normally produce a smell as the plastic off-gasses. air purifiers can shave a burnt, smoky, sweet, sour, plastic or bleach-like smell.

If your air purifier is giving off a smell, here are reasons to look for:

1. Burnt Plastic

A burning smell is the most common complaint of a faulty air purifier. It’s a tricky one to solve because there are actually a few reasons why an air purifier can smell like its burning.

Dust and dirt build-up

When dust, debris, or particles accumulate inside the purifier, especially on the circuit board or filters, it can give off a burning smell. These elements become clogged or overheated, and it also has to work harder to push air through.

Ozone byproducts

Some air purifiers use ionizers that makes ozone to clean the air. But if they make too much ozone, it can create a burning smell (it can also smell like chlorine or bleach).

New product smell

The initial “new product” smell can be mistaken for a burning odor. This smell usually goes away after a few hours or days of use.

Broken Parts

Damaged wires or overheating motors can generate a genuine burning smell. Air purifiers with a plastic body (which is most of them), can also start giving off a burning odor when the system overheats.


Check for any damaged or burnt interal components, or burnt wires if you smell burning plastic.

Disassemble the purifier and remove the filter. Clean the filter and filter housing area, making sure to remove any bits of debris or hardened deposits.

If you suspect an ozone smell, then make sure you don’t use the air purifier when there’s someone in the room. You are best to contact customer service for your brand of air purifier and organize either a repair or replacement.

If your purifier feels hot on touch, unplug and allow it to cool down before turning it on again. If the problem persists, call a technician to check for any electrical fault in the system.

2. Faulty UV Light

Some air purifiers use a UV light to kill germs.

A technical fault in a UV light, or a damaged bulb, can create either a chlorine or burning smell, which pollutes the air.

UV lights, on average last up to 5 years. But they are easily damaged, especially when cleaning or moving the purifier around, Any damage to it will stop it working as well as causing the bad smell.


Replace the UV light bulb.

Make sure you only use genuine (branded) parts for your purifier. This limits the chances of more problems down the road.

3. Saturated Carbon Filter

Most air purifiers have an activated carbon filters to remove gasses. If you smell smoke in the room it can be because the filter has become saturated or damaged.

It’s completely normal for a carbon filter to become saturated over time. Once full, the trapped gasses can eventually start leaking out. The purifier also has to work extra hard to push air through the clogged filer. This gives off a mixed smell. Apart from a smoky smell, you might also smell a mix of different foul odors or a sweet smell in the room, depending on the type of gasses trapped in the carbon filter.


To prevent the filter from getting saturated, all you need to do is clean it regularly or replace it, depending on the type of filter.

  1. For a carbon filter, rinse it with lightly running warm water every 3-4 months. Avoid using detergents or soap as they wash away the charcoal and hence hamper effective filtration.
  2. Refer to your manual and locate the filter. Detach it and rinse thoroughly. Let it dry before assembling the system back.
  3. Vacuum the HEPA filter monthly.

4. New Filter

The ‘new-appliance smell’ is not just limited to a brand new air purifier. Instead, a recently replaced HEPA filter can also cause a noticeable plastic-like smell.

This can also happen with pre-filters and carbon filters, but it’s more common with HEPA filters.

This can also happen if you haven’t installed a new filter but are using your purifier after a long time of it sitting unused. You’ll usually experience a plasticky or sweetish scent in this case.

It’s good to know that this smell is normal and goes away on its own.


  1. Run the air purifier on high fan speed (this gets rid of the smell faster)
  2. If the scent is strong, you can use an air freshener to help disguise it.

5. Mold or Bacteria

If the filters in your air purifier are not cleaned or replaced regularly enough, contaminants can accumulate in the filter, this forms a deposit that’s a perfect environment for mold or bacteria to set up shop in.

Mold and bacterial colonies can grow inside the filter and filter housing area, as well as the vents. It creates a musty, sour or wet dog smell.


Cleaning your filters will help get rid of the smell. There are different filters for each type of air purifier, and you’ll need to check your manual for a detailed guide on which ones you can rinse vs vacuum.

The most common filters though are the pre-filter, activated carbon filter and HEPA filter.

Pre-filter and activated carbon filters are usually washable. Both need to be washed every 3-4 months to prevent clogging or the development of mold. Use a dry cotton cloth to clear off the dust, and then rinse them with warm water.

Don’t use any alcohol wipes, bleach, or soaps though.

HEPA filters are generally not washable, but can just be vacuumed or brushed.

However, if after cleaning some mold or bacteria remains on your filter then it must be replaced.

We recommend replacing filters if possible, instead of cleaning them. Mold can have serious effects on us, and their spores are so tiny that we can’t see them. It’s best to replace the filter and know that the problem is permanently gone (as long as you regularly clean your new filters, of course!)

6. Ozone Production

Ozone generators are a type of air cleaner that makes ozone to oxidize contaminants and remove smells. But because ozone is a powerful oxidizing agent, it easily reacts with other contaminants in the air to create its own odor.

When a purifier produces ozone there is usually a chlorine-like or chemical-like smell. This type of smell usually spreads across the room as the ozone is released into the air.

You can also experience an ozone smell, even if you have a model that technically doesn’t make ozone.

Ionizing pins in non-ozone producing air purifiers also produce an tiny amount of ozone as a by-product. If the ozone levels increase to a certain extent due to any fault in the system, it can cause the pungent, chlorine-like (ozone) smell in the room.


Check that you don’t have a model that produces ozone to sanitize the air.

  1. Turn the purifier off, as ozone is a toxic gas and lethal in high concentrations. The ionizing pins may start producing ozone because of a fault in the filtration system.
  2. Call customer service or a technician to fix the problem (there’s no real DIY fix for this).
  3. Replace the air purifier of it can’t be fixed,

7. Broken or Dirty Wires

Broken or dirty air purifier wires are not only a safety hazard but can also cause nasty smells to spread throughout the room. Purifiers come with a number of wires that interconnect the different components of the system. If any of these wires frays, it can cause the coating to burn, giving off a smoke or burning smell.


  1. Unplug and disassemble the purifiier
  2. Carefully clean the wires with a soft, dry cloth.
  3. While cleaning, look for any damaged or broken wires and replace them immediately (or the purifier itself).

8. Electrical Fault or Burnout

If your purifier is new and gives off a burning smell, a wiring fault from the manufacturing process is possible. It’s a rare problem, but it does happen.

If you’ve had your air purifier for awhile (or recently moved it) it’s likely to be an electrical fault caused by something blocking the proper rotation of the fan, fan burnout or a faulty blower or motor.


Disassemble your purifier and make sure your fan is rotating smoothly by gently moving it with your hand. If it doesn’t turn smoothly, look for any debris blocking the fan or for any loose screws.

Gently clean the space around the fan, and tighten any loose screws. Plug the system in, and check if the motor is working fine. Clean or replace it if required.

Also look for any faults in the wiring – if this is the case see if you can get a replacement (hopefully under warranty), otherwise you may need to simply purchase a new air purifier.

If your air purifier is also not working properly, Plentiful Air has more information to help you troubleshoot available here.

9. Off-Gassing Filter

An off-gassing filter is the one that passes volatile organic compounds (VOCs) from the air purifier back into the air. Based on the type and level of volatile compounds or gasses, smells can vary, but you can experience a slightly metallic smell or a strong foul odor.

Some purifiers come with a titanium oxide coating that leads to off-gassing. Usually, this smell goes after a few months of operation. If it doesn’t stop, you may need to replace the filter.


An off-gassing filter is normal for a new appliance. However, if you aren’t comfortable with the smell, consider buying a HEPA-filter vacuum to clean the filter effectively.

How To Get The Smell Out Of Your Air Purifier

To get rid of the smell coming from an air purifier it depends on the root cause. Cleaning and/r replacing the filters, fixing any damaged wires, and placing the purifier in a properly ventilated space will help remove any odors.

The smell of off-gassing plastic will naturally resolve itself over time.

  • Clean all the filters. Maintenance of the appliance is crucial for it to deliver effective performance. Since all the models come with different filters, refer to your user manual and clean or replace the filters as instructed.
  • Inspect for any damage in wiring and replace them if need be.
  • Turn off your air purifier immediately and call a technician if the room smells excessively of ozone (wet, vinegar-like, or bleach-like smell)
  • Certain kinds of smells, like a plasticky new-appliance smell or a sweet carbon filter smell are normal and go away on their own. You may use an air freshener to help with the odor if it feels uncomfortable.

Frequently Asked Questions

Do Air Purifiers Make Your Home Smell Better?

Air purifiers sanitize the air and remove contaminants that can make a room or home smell bad. The removal of odor agents, eventually makes homes smell better. However, air purifiers don’t impart any fragrance to the room.

But they do help by removing the bad odors, by filtering contaminants. Hence, they make the atmosphere in the house smell pleasant.

Is an Air Purifier Supposed to Smell?

It’s normal for new air purifiers to give off a plastic-like smell. A slightly sweet smell is also acceptable and indicates a properly functioning carbon filter. Any other odor from the appliance is not normal and needs to be checked.

Air purifiers are only supposed to give off a plastic-like new appliance smell or a slightly sweet carbon filter smell. Any other odor is indicative of a malfunction. Therefore, you need to diagnose the problem and fix it.

Theresa Orr

Theresa Orr holds a PhD in Earth Science and specializes in determining past climates from rocks using geochemistry. Her passion for clean water, soil and air drives her to provide easy to understand information for everyone to read.

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