PM 2.5 Filter (Particulate Matter 2.5) – What they are & How they Work!

Recently, New Delhi was in the news for all the wrong reasons. The pollution levels in the NCR and the adjoining areas were alarming.

It set a record of sorts when a cricket match (Test Match between India and Sri Lanka) was interrupted due to air pollution for the first time in the annals of cricketing history.

The reason – Alarming levels of PM 2.5 (Particulate Matter 2.5)

What is PM 2.5 and why is it so dangerous?

PM 2.5 consists of very fine dust particles having the size 2.5 microns or less. How much are 2.5 microns? A micron is a unit of measurement on a microscopic scale with one inch equal to 25,000 microns. 

PM 2.5 – The Sources

The primary sources of PM 2.5 are vehicular emission, burning of wood and oil and so on. In the case of New Delhi, the principal culprit was the burning of crops by the farmers in the villages adjoining the NCR.

There are other sources as well. They are the emissions from power plants, motor vehicles, aeroplanes, burning of wood as fuel especially by people living in slum areas, forest fires, agricultural burning, dust storms, and volcanic eruptions.

Some PM 2.5 is direct emission into the air whereas gases and other particles interact with each other to form PM 2.5. You can see such types of pollution from power plant emissions.

The SO2 (Sulphur Di-oxide) emitted by these power plants interact with oxygen and water to form H2SO4 (Sulphuric acid) as a secondary particle.

Why is PM 2.5 dangerous?

As they are small and light, these particles stay in the air for a longer time as compared to the heavier particles. Hence, there is a higher probability of humans and animals inhaling the PM 2.5.

In case you have respiratory problems like asthma or bronchitis, the situation can worsen. Continuous exposure to PM 2.5 can cause plaque deposits in arteries leading to its hardening.

It is the primary cause of strokes and heart attacks. It can also cause irritations in the eyes and nose. Coughing and sneezing are common problems associated with PM 2.5.

Inhaling PM 2.5 can impact the smooth functioning of the lungs.

PM 2.5 Filters – The Utility

PM 2.5 filters are necessary to purify the indoor air that we breathe. You cannot control the pollution levels outdoors as it involves various factors. However, you can install AC units having PM 2.5 filters and improve the quality of the indoor air.

The HEPA filters cannot function on the AC units because they restrict the air flow causing the evaporator coils to freeze. The PM 2.5 filters are the perfect alternative to the HEPA filters in the AC units.

PM 2.5 Filter – Pros & Cons

  • Extremely useful as they remove the minutest of pollutants
  • Inexpensive compared to HEPA filters
  • Is an essential constituent of the modern-day ACs
  • Cannot handle impurities less than 2.5 microns in diameter.

Today, you have reputed Air Conditioner brands like LG, Whirlpool, and Carrier and so on using PM 2.5 filters in their latest models.

LG has gone one step further as they have introduced specialised sensors that sense, monitor, and appraise the user of the PM 1 levels using a dedicated app.

These AC units claim to purify the indoor air thereby reducing the risk of contracting respiratory problems like asthma and bronchitis. Considering the levels of pollution today, it has become imperative for everyone to install ACs or air purifiers with PM 2.5 filters.

Chaithanya Vanjari
Chaithanya Vanjari
I'm Chaithanya Vanjari, the Creator and Editor-in-Chief at KitchenArena. With a decade of experience in evaluating large appliances like air conditioners, washing machines, refrigerators, and various small home devices, I possess the technical expertise needed to thoroughly review and understand the operational complexities of these appliances.


  1. I would like to use a PM 2.5 and Merv 13 in my face mask to help slow down the covid virus but can you clean the filters by using an ultra violet light so they can used again.


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