Are the filters recyclable?
HEPA filters: Most of them contain glass fibres or dense synthetic fibres. Due to the complexity of the material and the possibility of adsorption of contaminants, they are not recyclable and should be disposed of as ordinary rubbish.
Activated carbon filters: Activated carbon itself is non-toxic, but the adsorbed chemicals such as formaldehyde and VOCs may pollute the environment and are usually not recyclable.
Composite filters (e.g. HEPA + activated carbon combination): due to the difficulty of separating the mixed materials, generally non-recyclable.
Recyclable:
Pure plastic frame or metal support: if the filter can be dismantled.
Do they require special treatment when discarded?
Activated carbon filters:
Sealed disposal: Wrap in a plastic bag and discard to prevent scattering of activated carbon particles or release of adsorbed pollutants.
Sorting suggestion: If there is a local classification of ‘hazardous waste’ (e.g., adsorbed large amount of chemical substances), put it into the hazardous waste bin as a priority; if there is none, treat it as ordinary waste. -HEPA filters
HEPA filter:
If it only adsorbs dust, pollen and other ordinary particles, it can be directly disposed of in the ordinary rubbish.
If used in a medical environment or have adsorbed pathogens, they need to be disposed of according to medical waste specifications (e.g. high temperature incineration).
Other Precautions
Avoid incineration: burning of synthetic fibres or chemical coatings in the filter may release toxic gases.
Do not dismantle: glass fibre filters may release irritating particles when broken and should be handled with gloves.
Eco-friendly alternatives
Choose washable filters: The pre-filters of some air purifiers can be washed and reused to reduce waste. -
Up-cycling: Use discarded filters for DIY projects (e.g. plant pot fillers), but need to ensure no risk of contamination.
